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![Peter Zijlstra](/assets/img/avatar_default.png)
sys_perf_event_open() had an imbalance in the number of task refs it took causing memory leakage Cc: Jiri Olsa <jolsa@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: stable@kernel.org # .37+ Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
7443 lines
169 KiB
C
7443 lines
169 KiB
C
/*
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* Performance events core code:
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*
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* Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
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* Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
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* Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
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* Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
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*
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* For licensing details see kernel-base/COPYING
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*/
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/cpu.h>
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#include <linux/smp.h>
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#include <linux/idr.h>
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#include <linux/file.h>
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#include <linux/poll.h>
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#include <linux/slab.h>
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#include <linux/hash.h>
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#include <linux/sysfs.h>
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#include <linux/dcache.h>
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#include <linux/percpu.h>
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#include <linux/ptrace.h>
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#include <linux/reboot.h>
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#include <linux/vmstat.h>
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#include <linux/device.h>
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#include <linux/vmalloc.h>
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#include <linux/hardirq.h>
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#include <linux/rculist.h>
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#include <linux/uaccess.h>
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#include <linux/syscalls.h>
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#include <linux/anon_inodes.h>
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#include <linux/kernel_stat.h>
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#include <linux/perf_event.h>
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#include <linux/ftrace_event.h>
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#include <linux/hw_breakpoint.h>
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#include <asm/irq_regs.h>
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struct remote_function_call {
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struct task_struct *p;
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int (*func)(void *info);
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void *info;
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int ret;
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};
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static void remote_function(void *data)
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{
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struct remote_function_call *tfc = data;
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struct task_struct *p = tfc->p;
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if (p) {
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tfc->ret = -EAGAIN;
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if (task_cpu(p) != smp_processor_id() || !task_curr(p))
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return;
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}
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tfc->ret = tfc->func(tfc->info);
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}
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/**
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* task_function_call - call a function on the cpu on which a task runs
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* @p: the task to evaluate
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* @func: the function to be called
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* @info: the function call argument
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*
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* Calls the function @func when the task is currently running. This might
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* be on the current CPU, which just calls the function directly
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*
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* returns: @func return value, or
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* -ESRCH - when the process isn't running
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* -EAGAIN - when the process moved away
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*/
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static int
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task_function_call(struct task_struct *p, int (*func) (void *info), void *info)
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{
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struct remote_function_call data = {
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.p = p,
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.func = func,
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.info = info,
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.ret = -ESRCH, /* No such (running) process */
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};
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if (task_curr(p))
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smp_call_function_single(task_cpu(p), remote_function, &data, 1);
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return data.ret;
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}
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/**
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* cpu_function_call - call a function on the cpu
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* @func: the function to be called
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* @info: the function call argument
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*
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* Calls the function @func on the remote cpu.
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*
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* returns: @func return value or -ENXIO when the cpu is offline
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*/
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static int cpu_function_call(int cpu, int (*func) (void *info), void *info)
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{
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struct remote_function_call data = {
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.p = NULL,
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.func = func,
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.info = info,
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.ret = -ENXIO, /* No such CPU */
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};
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smp_call_function_single(cpu, remote_function, &data, 1);
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return data.ret;
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}
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#define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
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PERF_FLAG_FD_OUTPUT |\
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PERF_FLAG_PID_CGROUP)
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enum event_type_t {
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EVENT_FLEXIBLE = 0x1,
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EVENT_PINNED = 0x2,
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EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
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};
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/*
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* perf_sched_events : >0 events exist
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* perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
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*/
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atomic_t perf_sched_events __read_mostly;
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static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
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static atomic_t nr_mmap_events __read_mostly;
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static atomic_t nr_comm_events __read_mostly;
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static atomic_t nr_task_events __read_mostly;
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static LIST_HEAD(pmus);
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static DEFINE_MUTEX(pmus_lock);
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static struct srcu_struct pmus_srcu;
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/*
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* perf event paranoia level:
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* -1 - not paranoid at all
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* 0 - disallow raw tracepoint access for unpriv
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* 1 - disallow cpu events for unpriv
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* 2 - disallow kernel profiling for unpriv
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*/
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int sysctl_perf_event_paranoid __read_mostly = 1;
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/* Minimum for 512 kiB + 1 user control page */
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int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */
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/*
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* max perf event sample rate
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*/
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#define DEFAULT_MAX_SAMPLE_RATE 100000
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int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE;
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static int max_samples_per_tick __read_mostly =
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DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ);
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int perf_proc_update_handler(struct ctl_table *table, int write,
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void __user *buffer, size_t *lenp,
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loff_t *ppos)
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{
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int ret = proc_dointvec(table, write, buffer, lenp, ppos);
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if (ret || !write)
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return ret;
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max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ);
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return 0;
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}
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static atomic64_t perf_event_id;
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static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
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enum event_type_t event_type);
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static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
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enum event_type_t event_type,
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struct task_struct *task);
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static void update_context_time(struct perf_event_context *ctx);
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static u64 perf_event_time(struct perf_event *event);
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void __weak perf_event_print_debug(void) { }
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extern __weak const char *perf_pmu_name(void)
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{
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return "pmu";
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}
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static inline u64 perf_clock(void)
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{
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return local_clock();
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}
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static inline struct perf_cpu_context *
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__get_cpu_context(struct perf_event_context *ctx)
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{
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return this_cpu_ptr(ctx->pmu->pmu_cpu_context);
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}
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#ifdef CONFIG_CGROUP_PERF
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/*
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* Must ensure cgroup is pinned (css_get) before calling
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* this function. In other words, we cannot call this function
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* if there is no cgroup event for the current CPU context.
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*/
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static inline struct perf_cgroup *
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perf_cgroup_from_task(struct task_struct *task)
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{
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return container_of(task_subsys_state(task, perf_subsys_id),
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struct perf_cgroup, css);
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}
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static inline bool
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perf_cgroup_match(struct perf_event *event)
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{
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struct perf_event_context *ctx = event->ctx;
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struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
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return !event->cgrp || event->cgrp == cpuctx->cgrp;
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}
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static inline void perf_get_cgroup(struct perf_event *event)
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{
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css_get(&event->cgrp->css);
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}
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static inline void perf_put_cgroup(struct perf_event *event)
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{
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css_put(&event->cgrp->css);
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}
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static inline void perf_detach_cgroup(struct perf_event *event)
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{
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perf_put_cgroup(event);
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event->cgrp = NULL;
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}
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static inline int is_cgroup_event(struct perf_event *event)
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{
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return event->cgrp != NULL;
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}
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static inline u64 perf_cgroup_event_time(struct perf_event *event)
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{
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struct perf_cgroup_info *t;
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t = per_cpu_ptr(event->cgrp->info, event->cpu);
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return t->time;
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}
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static inline void __update_cgrp_time(struct perf_cgroup *cgrp)
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{
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struct perf_cgroup_info *info;
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u64 now;
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now = perf_clock();
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info = this_cpu_ptr(cgrp->info);
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info->time += now - info->timestamp;
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info->timestamp = now;
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}
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static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
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{
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struct perf_cgroup *cgrp_out = cpuctx->cgrp;
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if (cgrp_out)
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__update_cgrp_time(cgrp_out);
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}
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static inline void update_cgrp_time_from_event(struct perf_event *event)
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{
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struct perf_cgroup *cgrp;
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/*
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* ensure we access cgroup data only when needed and
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* when we know the cgroup is pinned (css_get)
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*/
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if (!is_cgroup_event(event))
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return;
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cgrp = perf_cgroup_from_task(current);
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/*
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* Do not update time when cgroup is not active
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*/
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if (cgrp == event->cgrp)
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__update_cgrp_time(event->cgrp);
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}
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static inline void
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perf_cgroup_set_timestamp(struct task_struct *task,
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struct perf_event_context *ctx)
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{
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struct perf_cgroup *cgrp;
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struct perf_cgroup_info *info;
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/*
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* ctx->lock held by caller
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* ensure we do not access cgroup data
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* unless we have the cgroup pinned (css_get)
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*/
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if (!task || !ctx->nr_cgroups)
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return;
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cgrp = perf_cgroup_from_task(task);
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info = this_cpu_ptr(cgrp->info);
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info->timestamp = ctx->timestamp;
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}
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#define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
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#define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
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/*
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* reschedule events based on the cgroup constraint of task.
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*
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* mode SWOUT : schedule out everything
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* mode SWIN : schedule in based on cgroup for next
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*/
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void perf_cgroup_switch(struct task_struct *task, int mode)
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{
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struct perf_cpu_context *cpuctx;
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struct pmu *pmu;
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unsigned long flags;
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/*
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* disable interrupts to avoid geting nr_cgroup
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* changes via __perf_event_disable(). Also
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* avoids preemption.
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*/
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local_irq_save(flags);
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/*
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* we reschedule only in the presence of cgroup
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* constrained events.
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*/
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rcu_read_lock();
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list_for_each_entry_rcu(pmu, &pmus, entry) {
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cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
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perf_pmu_disable(cpuctx->ctx.pmu);
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/*
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* perf_cgroup_events says at least one
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* context on this CPU has cgroup events.
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*
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* ctx->nr_cgroups reports the number of cgroup
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* events for a context.
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*/
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if (cpuctx->ctx.nr_cgroups > 0) {
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if (mode & PERF_CGROUP_SWOUT) {
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cpu_ctx_sched_out(cpuctx, EVENT_ALL);
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/*
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* must not be done before ctxswout due
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* to event_filter_match() in event_sched_out()
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*/
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cpuctx->cgrp = NULL;
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}
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if (mode & PERF_CGROUP_SWIN) {
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/* set cgrp before ctxsw in to
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* allow event_filter_match() to not
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* have to pass task around
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*/
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cpuctx->cgrp = perf_cgroup_from_task(task);
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cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
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}
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}
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perf_pmu_enable(cpuctx->ctx.pmu);
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}
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rcu_read_unlock();
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local_irq_restore(flags);
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}
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static inline void perf_cgroup_sched_out(struct task_struct *task)
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{
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perf_cgroup_switch(task, PERF_CGROUP_SWOUT);
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}
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static inline void perf_cgroup_sched_in(struct task_struct *task)
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{
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perf_cgroup_switch(task, PERF_CGROUP_SWIN);
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}
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static inline int perf_cgroup_connect(int fd, struct perf_event *event,
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struct perf_event_attr *attr,
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struct perf_event *group_leader)
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{
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struct perf_cgroup *cgrp;
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struct cgroup_subsys_state *css;
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struct file *file;
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int ret = 0, fput_needed;
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file = fget_light(fd, &fput_needed);
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if (!file)
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return -EBADF;
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css = cgroup_css_from_dir(file, perf_subsys_id);
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if (IS_ERR(css)) {
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ret = PTR_ERR(css);
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goto out;
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}
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cgrp = container_of(css, struct perf_cgroup, css);
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event->cgrp = cgrp;
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/* must be done before we fput() the file */
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perf_get_cgroup(event);
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/*
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* all events in a group must monitor
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* the same cgroup because a task belongs
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* to only one perf cgroup at a time
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*/
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if (group_leader && group_leader->cgrp != cgrp) {
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perf_detach_cgroup(event);
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ret = -EINVAL;
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}
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out:
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fput_light(file, fput_needed);
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return ret;
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}
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static inline void
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perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
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{
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struct perf_cgroup_info *t;
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t = per_cpu_ptr(event->cgrp->info, event->cpu);
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event->shadow_ctx_time = now - t->timestamp;
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}
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static inline void
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perf_cgroup_defer_enabled(struct perf_event *event)
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{
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/*
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* when the current task's perf cgroup does not match
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* the event's, we need to remember to call the
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* perf_mark_enable() function the first time a task with
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* a matching perf cgroup is scheduled in.
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*/
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if (is_cgroup_event(event) && !perf_cgroup_match(event))
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event->cgrp_defer_enabled = 1;
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}
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static inline void
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perf_cgroup_mark_enabled(struct perf_event *event,
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struct perf_event_context *ctx)
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{
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struct perf_event *sub;
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u64 tstamp = perf_event_time(event);
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if (!event->cgrp_defer_enabled)
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return;
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event->cgrp_defer_enabled = 0;
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event->tstamp_enabled = tstamp - event->total_time_enabled;
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list_for_each_entry(sub, &event->sibling_list, group_entry) {
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if (sub->state >= PERF_EVENT_STATE_INACTIVE) {
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sub->tstamp_enabled = tstamp - sub->total_time_enabled;
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sub->cgrp_defer_enabled = 0;
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}
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}
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}
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#else /* !CONFIG_CGROUP_PERF */
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static inline bool
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perf_cgroup_match(struct perf_event *event)
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{
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return true;
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}
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|
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static inline void perf_detach_cgroup(struct perf_event *event)
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{}
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static inline int is_cgroup_event(struct perf_event *event)
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{
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return 0;
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}
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|
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static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event)
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{
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return 0;
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}
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static inline void update_cgrp_time_from_event(struct perf_event *event)
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{
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}
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static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
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{
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}
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|
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static inline void perf_cgroup_sched_out(struct task_struct *task)
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{
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}
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|
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static inline void perf_cgroup_sched_in(struct task_struct *task)
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{
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}
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|
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static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event,
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struct perf_event_attr *attr,
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struct perf_event *group_leader)
|
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{
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return -EINVAL;
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}
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|
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static inline void
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perf_cgroup_set_timestamp(struct task_struct *task,
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struct perf_event_context *ctx)
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{
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}
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|
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void
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perf_cgroup_switch(struct task_struct *task, struct task_struct *next)
|
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{
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}
|
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|
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static inline void
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perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
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{
|
|
}
|
|
|
|
static inline u64 perf_cgroup_event_time(struct perf_event *event)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void
|
|
perf_cgroup_defer_enabled(struct perf_event *event)
|
|
{
|
|
}
|
|
|
|
static inline void
|
|
perf_cgroup_mark_enabled(struct perf_event *event,
|
|
struct perf_event_context *ctx)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
void perf_pmu_disable(struct pmu *pmu)
|
|
{
|
|
int *count = this_cpu_ptr(pmu->pmu_disable_count);
|
|
if (!(*count)++)
|
|
pmu->pmu_disable(pmu);
|
|
}
|
|
|
|
void perf_pmu_enable(struct pmu *pmu)
|
|
{
|
|
int *count = this_cpu_ptr(pmu->pmu_disable_count);
|
|
if (!--(*count))
|
|
pmu->pmu_enable(pmu);
|
|
}
|
|
|
|
static DEFINE_PER_CPU(struct list_head, rotation_list);
|
|
|
|
/*
|
|
* perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
|
|
* because they're strictly cpu affine and rotate_start is called with IRQs
|
|
* disabled, while rotate_context is called from IRQ context.
|
|
*/
|
|
static void perf_pmu_rotate_start(struct pmu *pmu)
|
|
{
|
|
struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
|
|
struct list_head *head = &__get_cpu_var(rotation_list);
|
|
|
|
WARN_ON(!irqs_disabled());
|
|
|
|
if (list_empty(&cpuctx->rotation_list))
|
|
list_add(&cpuctx->rotation_list, head);
|
|
}
|
|
|
|
static void get_ctx(struct perf_event_context *ctx)
|
|
{
|
|
WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
|
|
}
|
|
|
|
static void free_ctx(struct rcu_head *head)
|
|
{
|
|
struct perf_event_context *ctx;
|
|
|
|
ctx = container_of(head, struct perf_event_context, rcu_head);
|
|
kfree(ctx);
|
|
}
|
|
|
|
static void put_ctx(struct perf_event_context *ctx)
|
|
{
|
|
if (atomic_dec_and_test(&ctx->refcount)) {
|
|
if (ctx->parent_ctx)
|
|
put_ctx(ctx->parent_ctx);
|
|
if (ctx->task)
|
|
put_task_struct(ctx->task);
|
|
call_rcu(&ctx->rcu_head, free_ctx);
|
|
}
|
|
}
|
|
|
|
static void unclone_ctx(struct perf_event_context *ctx)
|
|
{
|
|
if (ctx->parent_ctx) {
|
|
put_ctx(ctx->parent_ctx);
|
|
ctx->parent_ctx = NULL;
|
|
}
|
|
}
|
|
|
|
static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
|
|
{
|
|
/*
|
|
* only top level events have the pid namespace they were created in
|
|
*/
|
|
if (event->parent)
|
|
event = event->parent;
|
|
|
|
return task_tgid_nr_ns(p, event->ns);
|
|
}
|
|
|
|
static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
|
|
{
|
|
/*
|
|
* only top level events have the pid namespace they were created in
|
|
*/
|
|
if (event->parent)
|
|
event = event->parent;
|
|
|
|
return task_pid_nr_ns(p, event->ns);
|
|
}
|
|
|
|
/*
|
|
* If we inherit events we want to return the parent event id
|
|
* to userspace.
|
|
*/
|
|
static u64 primary_event_id(struct perf_event *event)
|
|
{
|
|
u64 id = event->id;
|
|
|
|
if (event->parent)
|
|
id = event->parent->id;
|
|
|
|
return id;
|
|
}
|
|
|
|
/*
|
|
* Get the perf_event_context for a task and lock it.
|
|
* This has to cope with with the fact that until it is locked,
|
|
* the context could get moved to another task.
|
|
*/
|
|
static struct perf_event_context *
|
|
perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
|
|
{
|
|
struct perf_event_context *ctx;
|
|
|
|
rcu_read_lock();
|
|
retry:
|
|
ctx = rcu_dereference(task->perf_event_ctxp[ctxn]);
|
|
if (ctx) {
|
|
/*
|
|
* If this context is a clone of another, it might
|
|
* get swapped for another underneath us by
|
|
* perf_event_task_sched_out, though the
|
|
* rcu_read_lock() protects us from any context
|
|
* getting freed. Lock the context and check if it
|
|
* got swapped before we could get the lock, and retry
|
|
* if so. If we locked the right context, then it
|
|
* can't get swapped on us any more.
|
|
*/
|
|
raw_spin_lock_irqsave(&ctx->lock, *flags);
|
|
if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) {
|
|
raw_spin_unlock_irqrestore(&ctx->lock, *flags);
|
|
goto retry;
|
|
}
|
|
|
|
if (!atomic_inc_not_zero(&ctx->refcount)) {
|
|
raw_spin_unlock_irqrestore(&ctx->lock, *flags);
|
|
ctx = NULL;
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
return ctx;
|
|
}
|
|
|
|
/*
|
|
* Get the context for a task and increment its pin_count so it
|
|
* can't get swapped to another task. This also increments its
|
|
* reference count so that the context can't get freed.
|
|
*/
|
|
static struct perf_event_context *
|
|
perf_pin_task_context(struct task_struct *task, int ctxn)
|
|
{
|
|
struct perf_event_context *ctx;
|
|
unsigned long flags;
|
|
|
|
ctx = perf_lock_task_context(task, ctxn, &flags);
|
|
if (ctx) {
|
|
++ctx->pin_count;
|
|
raw_spin_unlock_irqrestore(&ctx->lock, flags);
|
|
}
|
|
return ctx;
|
|
}
|
|
|
|
static void perf_unpin_context(struct perf_event_context *ctx)
|
|
{
|
|
unsigned long flags;
|
|
|
|
raw_spin_lock_irqsave(&ctx->lock, flags);
|
|
--ctx->pin_count;
|
|
raw_spin_unlock_irqrestore(&ctx->lock, flags);
|
|
}
|
|
|
|
/*
|
|
* Update the record of the current time in a context.
|
|
*/
|
|
static void update_context_time(struct perf_event_context *ctx)
|
|
{
|
|
u64 now = perf_clock();
|
|
|
|
ctx->time += now - ctx->timestamp;
|
|
ctx->timestamp = now;
|
|
}
|
|
|
|
static u64 perf_event_time(struct perf_event *event)
|
|
{
|
|
struct perf_event_context *ctx = event->ctx;
|
|
|
|
if (is_cgroup_event(event))
|
|
return perf_cgroup_event_time(event);
|
|
|
|
return ctx ? ctx->time : 0;
|
|
}
|
|
|
|
/*
|
|
* Update the total_time_enabled and total_time_running fields for a event.
|
|
*/
|
|
static void update_event_times(struct perf_event *event)
|
|
{
|
|
struct perf_event_context *ctx = event->ctx;
|
|
u64 run_end;
|
|
|
|
if (event->state < PERF_EVENT_STATE_INACTIVE ||
|
|
event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
|
|
return;
|
|
/*
|
|
* in cgroup mode, time_enabled represents
|
|
* the time the event was enabled AND active
|
|
* tasks were in the monitored cgroup. This is
|
|
* independent of the activity of the context as
|
|
* there may be a mix of cgroup and non-cgroup events.
|
|
*
|
|
* That is why we treat cgroup events differently
|
|
* here.
|
|
*/
|
|
if (is_cgroup_event(event))
|
|
run_end = perf_event_time(event);
|
|
else if (ctx->is_active)
|
|
run_end = ctx->time;
|
|
else
|
|
run_end = event->tstamp_stopped;
|
|
|
|
event->total_time_enabled = run_end - event->tstamp_enabled;
|
|
|
|
if (event->state == PERF_EVENT_STATE_INACTIVE)
|
|
run_end = event->tstamp_stopped;
|
|
else
|
|
run_end = perf_event_time(event);
|
|
|
|
event->total_time_running = run_end - event->tstamp_running;
|
|
|
|
}
|
|
|
|
/*
|
|
* Update total_time_enabled and total_time_running for all events in a group.
|
|
*/
|
|
static void update_group_times(struct perf_event *leader)
|
|
{
|
|
struct perf_event *event;
|
|
|
|
update_event_times(leader);
|
|
list_for_each_entry(event, &leader->sibling_list, group_entry)
|
|
update_event_times(event);
|
|
}
|
|
|
|
static struct list_head *
|
|
ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
|
|
{
|
|
if (event->attr.pinned)
|
|
return &ctx->pinned_groups;
|
|
else
|
|
return &ctx->flexible_groups;
|
|
}
|
|
|
|
/*
|
|
* Add a event from the lists for its context.
|
|
* Must be called with ctx->mutex and ctx->lock held.
|
|
*/
|
|
static void
|
|
list_add_event(struct perf_event *event, struct perf_event_context *ctx)
|
|
{
|
|
WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
|
|
event->attach_state |= PERF_ATTACH_CONTEXT;
|
|
|
|
/*
|
|
* If we're a stand alone event or group leader, we go to the context
|
|
* list, group events are kept attached to the group so that
|
|
* perf_group_detach can, at all times, locate all siblings.
|
|
*/
|
|
if (event->group_leader == event) {
|
|
struct list_head *list;
|
|
|
|
if (is_software_event(event))
|
|
event->group_flags |= PERF_GROUP_SOFTWARE;
|
|
|
|
list = ctx_group_list(event, ctx);
|
|
list_add_tail(&event->group_entry, list);
|
|
}
|
|
|
|
if (is_cgroup_event(event))
|
|
ctx->nr_cgroups++;
|
|
|
|
list_add_rcu(&event->event_entry, &ctx->event_list);
|
|
if (!ctx->nr_events)
|
|
perf_pmu_rotate_start(ctx->pmu);
|
|
ctx->nr_events++;
|
|
if (event->attr.inherit_stat)
|
|
ctx->nr_stat++;
|
|
}
|
|
|
|
/*
|
|
* Called at perf_event creation and when events are attached/detached from a
|
|
* group.
|
|
*/
|
|
static void perf_event__read_size(struct perf_event *event)
|
|
{
|
|
int entry = sizeof(u64); /* value */
|
|
int size = 0;
|
|
int nr = 1;
|
|
|
|
if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
|
|
size += sizeof(u64);
|
|
|
|
if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
|
|
size += sizeof(u64);
|
|
|
|
if (event->attr.read_format & PERF_FORMAT_ID)
|
|
entry += sizeof(u64);
|
|
|
|
if (event->attr.read_format & PERF_FORMAT_GROUP) {
|
|
nr += event->group_leader->nr_siblings;
|
|
size += sizeof(u64);
|
|
}
|
|
|
|
size += entry * nr;
|
|
event->read_size = size;
|
|
}
|
|
|
|
static void perf_event__header_size(struct perf_event *event)
|
|
{
|
|
struct perf_sample_data *data;
|
|
u64 sample_type = event->attr.sample_type;
|
|
u16 size = 0;
|
|
|
|
perf_event__read_size(event);
|
|
|
|
if (sample_type & PERF_SAMPLE_IP)
|
|
size += sizeof(data->ip);
|
|
|
|
if (sample_type & PERF_SAMPLE_ADDR)
|
|
size += sizeof(data->addr);
|
|
|
|
if (sample_type & PERF_SAMPLE_PERIOD)
|
|
size += sizeof(data->period);
|
|
|
|
if (sample_type & PERF_SAMPLE_READ)
|
|
size += event->read_size;
|
|
|
|
event->header_size = size;
|
|
}
|
|
|
|
static void perf_event__id_header_size(struct perf_event *event)
|
|
{
|
|
struct perf_sample_data *data;
|
|
u64 sample_type = event->attr.sample_type;
|
|
u16 size = 0;
|
|
|
|
if (sample_type & PERF_SAMPLE_TID)
|
|
size += sizeof(data->tid_entry);
|
|
|
|
if (sample_type & PERF_SAMPLE_TIME)
|
|
size += sizeof(data->time);
|
|
|
|
if (sample_type & PERF_SAMPLE_ID)
|
|
size += sizeof(data->id);
|
|
|
|
if (sample_type & PERF_SAMPLE_STREAM_ID)
|
|
size += sizeof(data->stream_id);
|
|
|
|
if (sample_type & PERF_SAMPLE_CPU)
|
|
size += sizeof(data->cpu_entry);
|
|
|
|
event->id_header_size = size;
|
|
}
|
|
|
|
static void perf_group_attach(struct perf_event *event)
|
|
{
|
|
struct perf_event *group_leader = event->group_leader, *pos;
|
|
|
|
/*
|
|
* We can have double attach due to group movement in perf_event_open.
|
|
*/
|
|
if (event->attach_state & PERF_ATTACH_GROUP)
|
|
return;
|
|
|
|
event->attach_state |= PERF_ATTACH_GROUP;
|
|
|
|
if (group_leader == event)
|
|
return;
|
|
|
|
if (group_leader->group_flags & PERF_GROUP_SOFTWARE &&
|
|
!is_software_event(event))
|
|
group_leader->group_flags &= ~PERF_GROUP_SOFTWARE;
|
|
|
|
list_add_tail(&event->group_entry, &group_leader->sibling_list);
|
|
group_leader->nr_siblings++;
|
|
|
|
perf_event__header_size(group_leader);
|
|
|
|
list_for_each_entry(pos, &group_leader->sibling_list, group_entry)
|
|
perf_event__header_size(pos);
|
|
}
|
|
|
|
/*
|
|
* Remove a event from the lists for its context.
|
|
* Must be called with ctx->mutex and ctx->lock held.
|
|
*/
|
|
static void
|
|
list_del_event(struct perf_event *event, struct perf_event_context *ctx)
|
|
{
|
|
struct perf_cpu_context *cpuctx;
|
|
/*
|
|
* We can have double detach due to exit/hot-unplug + close.
|
|
*/
|
|
if (!(event->attach_state & PERF_ATTACH_CONTEXT))
|
|
return;
|
|
|
|
event->attach_state &= ~PERF_ATTACH_CONTEXT;
|
|
|
|
if (is_cgroup_event(event)) {
|
|
ctx->nr_cgroups--;
|
|
cpuctx = __get_cpu_context(ctx);
|
|
/*
|
|
* if there are no more cgroup events
|
|
* then cler cgrp to avoid stale pointer
|
|
* in update_cgrp_time_from_cpuctx()
|
|
*/
|
|
if (!ctx->nr_cgroups)
|
|
cpuctx->cgrp = NULL;
|
|
}
|
|
|
|
ctx->nr_events--;
|
|
if (event->attr.inherit_stat)
|
|
ctx->nr_stat--;
|
|
|
|
list_del_rcu(&event->event_entry);
|
|
|
|
if (event->group_leader == event)
|
|
list_del_init(&event->group_entry);
|
|
|
|
update_group_times(event);
|
|
|
|
/*
|
|
* If event was in error state, then keep it
|
|
* that way, otherwise bogus counts will be
|
|
* returned on read(). The only way to get out
|
|
* of error state is by explicit re-enabling
|
|
* of the event
|
|
*/
|
|
if (event->state > PERF_EVENT_STATE_OFF)
|
|
event->state = PERF_EVENT_STATE_OFF;
|
|
}
|
|
|
|
static void perf_group_detach(struct perf_event *event)
|
|
{
|
|
struct perf_event *sibling, *tmp;
|
|
struct list_head *list = NULL;
|
|
|
|
/*
|
|
* We can have double detach due to exit/hot-unplug + close.
|
|
*/
|
|
if (!(event->attach_state & PERF_ATTACH_GROUP))
|
|
return;
|
|
|
|
event->attach_state &= ~PERF_ATTACH_GROUP;
|
|
|
|
/*
|
|
* If this is a sibling, remove it from its group.
|
|
*/
|
|
if (event->group_leader != event) {
|
|
list_del_init(&event->group_entry);
|
|
event->group_leader->nr_siblings--;
|
|
goto out;
|
|
}
|
|
|
|
if (!list_empty(&event->group_entry))
|
|
list = &event->group_entry;
|
|
|
|
/*
|
|
* If this was a group event with sibling events then
|
|
* upgrade the siblings to singleton events by adding them
|
|
* to whatever list we are on.
|
|
*/
|
|
list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
|
|
if (list)
|
|
list_move_tail(&sibling->group_entry, list);
|
|
sibling->group_leader = sibling;
|
|
|
|
/* Inherit group flags from the previous leader */
|
|
sibling->group_flags = event->group_flags;
|
|
}
|
|
|
|
out:
|
|
perf_event__header_size(event->group_leader);
|
|
|
|
list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry)
|
|
perf_event__header_size(tmp);
|
|
}
|
|
|
|
static inline int
|
|
event_filter_match(struct perf_event *event)
|
|
{
|
|
return (event->cpu == -1 || event->cpu == smp_processor_id())
|
|
&& perf_cgroup_match(event);
|
|
}
|
|
|
|
static void
|
|
event_sched_out(struct perf_event *event,
|
|
struct perf_cpu_context *cpuctx,
|
|
struct perf_event_context *ctx)
|
|
{
|
|
u64 tstamp = perf_event_time(event);
|
|
u64 delta;
|
|
/*
|
|
* An event which could not be activated because of
|
|
* filter mismatch still needs to have its timings
|
|
* maintained, otherwise bogus information is return
|
|
* via read() for time_enabled, time_running:
|
|
*/
|
|
if (event->state == PERF_EVENT_STATE_INACTIVE
|
|
&& !event_filter_match(event)) {
|
|
delta = tstamp - event->tstamp_stopped;
|
|
event->tstamp_running += delta;
|
|
event->tstamp_stopped = tstamp;
|
|
}
|
|
|
|
if (event->state != PERF_EVENT_STATE_ACTIVE)
|
|
return;
|
|
|
|
event->state = PERF_EVENT_STATE_INACTIVE;
|
|
if (event->pending_disable) {
|
|
event->pending_disable = 0;
|
|
event->state = PERF_EVENT_STATE_OFF;
|
|
}
|
|
event->tstamp_stopped = tstamp;
|
|
event->pmu->del(event, 0);
|
|
event->oncpu = -1;
|
|
|
|
if (!is_software_event(event))
|
|
cpuctx->active_oncpu--;
|
|
ctx->nr_active--;
|
|
if (event->attr.exclusive || !cpuctx->active_oncpu)
|
|
cpuctx->exclusive = 0;
|
|
}
|
|
|
|
static void
|
|
group_sched_out(struct perf_event *group_event,
|
|
struct perf_cpu_context *cpuctx,
|
|
struct perf_event_context *ctx)
|
|
{
|
|
struct perf_event *event;
|
|
int state = group_event->state;
|
|
|
|
event_sched_out(group_event, cpuctx, ctx);
|
|
|
|
/*
|
|
* Schedule out siblings (if any):
|
|
*/
|
|
list_for_each_entry(event, &group_event->sibling_list, group_entry)
|
|
event_sched_out(event, cpuctx, ctx);
|
|
|
|
if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive)
|
|
cpuctx->exclusive = 0;
|
|
}
|
|
|
|
/*
|
|
* Cross CPU call to remove a performance event
|
|
*
|
|
* We disable the event on the hardware level first. After that we
|
|
* remove it from the context list.
|
|
*/
|
|
static int __perf_remove_from_context(void *info)
|
|
{
|
|
struct perf_event *event = info;
|
|
struct perf_event_context *ctx = event->ctx;
|
|
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
|
|
|
|
raw_spin_lock(&ctx->lock);
|
|
event_sched_out(event, cpuctx, ctx);
|
|
list_del_event(event, ctx);
|
|
raw_spin_unlock(&ctx->lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* Remove the event from a task's (or a CPU's) list of events.
|
|
*
|
|
* CPU events are removed with a smp call. For task events we only
|
|
* call when the task is on a CPU.
|
|
*
|
|
* If event->ctx is a cloned context, callers must make sure that
|
|
* every task struct that event->ctx->task could possibly point to
|
|
* remains valid. This is OK when called from perf_release since
|
|
* that only calls us on the top-level context, which can't be a clone.
|
|
* When called from perf_event_exit_task, it's OK because the
|
|
* context has been detached from its task.
|
|
*/
|
|
static void perf_remove_from_context(struct perf_event *event)
|
|
{
|
|
struct perf_event_context *ctx = event->ctx;
|
|
struct task_struct *task = ctx->task;
|
|
|
|
lockdep_assert_held(&ctx->mutex);
|
|
|
|
if (!task) {
|
|
/*
|
|
* Per cpu events are removed via an smp call and
|
|
* the removal is always successful.
|
|
*/
|
|
cpu_function_call(event->cpu, __perf_remove_from_context, event);
|
|
return;
|
|
}
|
|
|
|
retry:
|
|
if (!task_function_call(task, __perf_remove_from_context, event))
|
|
return;
|
|
|
|
raw_spin_lock_irq(&ctx->lock);
|
|
/*
|
|
* If we failed to find a running task, but find the context active now
|
|
* that we've acquired the ctx->lock, retry.
|
|
*/
|
|
if (ctx->is_active) {
|
|
raw_spin_unlock_irq(&ctx->lock);
|
|
goto retry;
|
|
}
|
|
|
|
/*
|
|
* Since the task isn't running, its safe to remove the event, us
|
|
* holding the ctx->lock ensures the task won't get scheduled in.
|
|
*/
|
|
list_del_event(event, ctx);
|
|
raw_spin_unlock_irq(&ctx->lock);
|
|
}
|
|
|
|
/*
|
|
* Cross CPU call to disable a performance event
|
|
*/
|
|
static int __perf_event_disable(void *info)
|
|
{
|
|
struct perf_event *event = info;
|
|
struct perf_event_context *ctx = event->ctx;
|
|
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
|
|
|
|
/*
|
|
* If this is a per-task event, need to check whether this
|
|
* event's task is the current task on this cpu.
|
|
*
|
|
* Can trigger due to concurrent perf_event_context_sched_out()
|
|
* flipping contexts around.
|
|
*/
|
|
if (ctx->task && cpuctx->task_ctx != ctx)
|
|
return -EINVAL;
|
|
|
|
raw_spin_lock(&ctx->lock);
|
|
|
|
/*
|
|
* If the event is on, turn it off.
|
|
* If it is in error state, leave it in error state.
|
|
*/
|
|
if (event->state >= PERF_EVENT_STATE_INACTIVE) {
|
|
update_context_time(ctx);
|
|
update_cgrp_time_from_event(event);
|
|
update_group_times(event);
|
|
if (event == event->group_leader)
|
|
group_sched_out(event, cpuctx, ctx);
|
|
else
|
|
event_sched_out(event, cpuctx, ctx);
|
|
event->state = PERF_EVENT_STATE_OFF;
|
|
}
|
|
|
|
raw_spin_unlock(&ctx->lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Disable a event.
|
|
*
|
|
* If event->ctx is a cloned context, callers must make sure that
|
|
* every task struct that event->ctx->task could possibly point to
|
|
* remains valid. This condition is satisifed when called through
|
|
* perf_event_for_each_child or perf_event_for_each because they
|
|
* hold the top-level event's child_mutex, so any descendant that
|
|
* goes to exit will block in sync_child_event.
|
|
* When called from perf_pending_event it's OK because event->ctx
|
|
* is the current context on this CPU and preemption is disabled,
|
|
* hence we can't get into perf_event_task_sched_out for this context.
|
|
*/
|
|
void perf_event_disable(struct perf_event *event)
|
|
{
|
|
struct perf_event_context *ctx = event->ctx;
|
|
struct task_struct *task = ctx->task;
|
|
|
|
if (!task) {
|
|
/*
|
|
* Disable the event on the cpu that it's on
|
|
*/
|
|
cpu_function_call(event->cpu, __perf_event_disable, event);
|
|
return;
|
|
}
|
|
|
|
retry:
|
|
if (!task_function_call(task, __perf_event_disable, event))
|
|
return;
|
|
|
|
raw_spin_lock_irq(&ctx->lock);
|
|
/*
|
|
* If the event is still active, we need to retry the cross-call.
|
|
*/
|
|
if (event->state == PERF_EVENT_STATE_ACTIVE) {
|
|
raw_spin_unlock_irq(&ctx->lock);
|
|
/*
|
|
* Reload the task pointer, it might have been changed by
|
|
* a concurrent perf_event_context_sched_out().
|
|
*/
|
|
task = ctx->task;
|
|
goto retry;
|
|
}
|
|
|
|
/*
|
|
* Since we have the lock this context can't be scheduled
|
|
* in, so we can change the state safely.
|
|
*/
|
|
if (event->state == PERF_EVENT_STATE_INACTIVE) {
|
|
update_group_times(event);
|
|
event->state = PERF_EVENT_STATE_OFF;
|
|
}
|
|
raw_spin_unlock_irq(&ctx->lock);
|
|
}
|
|
|
|
static void perf_set_shadow_time(struct perf_event *event,
|
|
struct perf_event_context *ctx,
|
|
u64 tstamp)
|
|
{
|
|
/*
|
|
* use the correct time source for the time snapshot
|
|
*
|
|
* We could get by without this by leveraging the
|
|
* fact that to get to this function, the caller
|
|
* has most likely already called update_context_time()
|
|
* and update_cgrp_time_xx() and thus both timestamp
|
|
* are identical (or very close). Given that tstamp is,
|
|
* already adjusted for cgroup, we could say that:
|
|
* tstamp - ctx->timestamp
|
|
* is equivalent to
|
|
* tstamp - cgrp->timestamp.
|
|
*
|
|
* Then, in perf_output_read(), the calculation would
|
|
* work with no changes because:
|
|
* - event is guaranteed scheduled in
|
|
* - no scheduled out in between
|
|
* - thus the timestamp would be the same
|
|
*
|
|
* But this is a bit hairy.
|
|
*
|
|
* So instead, we have an explicit cgroup call to remain
|
|
* within the time time source all along. We believe it
|
|
* is cleaner and simpler to understand.
|
|
*/
|
|
if (is_cgroup_event(event))
|
|
perf_cgroup_set_shadow_time(event, tstamp);
|
|
else
|
|
event->shadow_ctx_time = tstamp - ctx->timestamp;
|
|
}
|
|
|
|
#define MAX_INTERRUPTS (~0ULL)
|
|
|
|
static void perf_log_throttle(struct perf_event *event, int enable);
|
|
|
|
static int
|
|
event_sched_in(struct perf_event *event,
|
|
struct perf_cpu_context *cpuctx,
|
|
struct perf_event_context *ctx)
|
|
{
|
|
u64 tstamp = perf_event_time(event);
|
|
|
|
if (event->state <= PERF_EVENT_STATE_OFF)
|
|
return 0;
|
|
|
|
event->state = PERF_EVENT_STATE_ACTIVE;
|
|
event->oncpu = smp_processor_id();
|
|
|
|
/*
|
|
* Unthrottle events, since we scheduled we might have missed several
|
|
* ticks already, also for a heavily scheduling task there is little
|
|
* guarantee it'll get a tick in a timely manner.
|
|
*/
|
|
if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
|
|
perf_log_throttle(event, 1);
|
|
event->hw.interrupts = 0;
|
|
}
|
|
|
|
/*
|
|
* The new state must be visible before we turn it on in the hardware:
|
|
*/
|
|
smp_wmb();
|
|
|
|
if (event->pmu->add(event, PERF_EF_START)) {
|
|
event->state = PERF_EVENT_STATE_INACTIVE;
|
|
event->oncpu = -1;
|
|
return -EAGAIN;
|
|
}
|
|
|
|
event->tstamp_running += tstamp - event->tstamp_stopped;
|
|
|
|
perf_set_shadow_time(event, ctx, tstamp);
|
|
|
|
if (!is_software_event(event))
|
|
cpuctx->active_oncpu++;
|
|
ctx->nr_active++;
|
|
|
|
if (event->attr.exclusive)
|
|
cpuctx->exclusive = 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
group_sched_in(struct perf_event *group_event,
|
|
struct perf_cpu_context *cpuctx,
|
|
struct perf_event_context *ctx)
|
|
{
|
|
struct perf_event *event, *partial_group = NULL;
|
|
struct pmu *pmu = group_event->pmu;
|
|
u64 now = ctx->time;
|
|
bool simulate = false;
|
|
|
|
if (group_event->state == PERF_EVENT_STATE_OFF)
|
|
return 0;
|
|
|
|
pmu->start_txn(pmu);
|
|
|
|
if (event_sched_in(group_event, cpuctx, ctx)) {
|
|
pmu->cancel_txn(pmu);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
/*
|
|
* Schedule in siblings as one group (if any):
|
|
*/
|
|
list_for_each_entry(event, &group_event->sibling_list, group_entry) {
|
|
if (event_sched_in(event, cpuctx, ctx)) {
|
|
partial_group = event;
|
|
goto group_error;
|
|
}
|
|
}
|
|
|
|
if (!pmu->commit_txn(pmu))
|
|
return 0;
|
|
|
|
group_error:
|
|
/*
|
|
* Groups can be scheduled in as one unit only, so undo any
|
|
* partial group before returning:
|
|
* The events up to the failed event are scheduled out normally,
|
|
* tstamp_stopped will be updated.
|
|
*
|
|
* The failed events and the remaining siblings need to have
|
|
* their timings updated as if they had gone thru event_sched_in()
|
|
* and event_sched_out(). This is required to get consistent timings
|
|
* across the group. This also takes care of the case where the group
|
|
* could never be scheduled by ensuring tstamp_stopped is set to mark
|
|
* the time the event was actually stopped, such that time delta
|
|
* calculation in update_event_times() is correct.
|
|
*/
|
|
list_for_each_entry(event, &group_event->sibling_list, group_entry) {
|
|
if (event == partial_group)
|
|
simulate = true;
|
|
|
|
if (simulate) {
|
|
event->tstamp_running += now - event->tstamp_stopped;
|
|
event->tstamp_stopped = now;
|
|
} else {
|
|
event_sched_out(event, cpuctx, ctx);
|
|
}
|
|
}
|
|
event_sched_out(group_event, cpuctx, ctx);
|
|
|
|
pmu->cancel_txn(pmu);
|
|
|
|
return -EAGAIN;
|
|
}
|
|
|
|
/*
|
|
* Work out whether we can put this event group on the CPU now.
|
|
*/
|
|
static int group_can_go_on(struct perf_event *event,
|
|
struct perf_cpu_context *cpuctx,
|
|
int can_add_hw)
|
|
{
|
|
/*
|
|
* Groups consisting entirely of software events can always go on.
|
|
*/
|
|
if (event->group_flags & PERF_GROUP_SOFTWARE)
|
|
return 1;
|
|
/*
|
|
* If an exclusive group is already on, no other hardware
|
|
* events can go on.
|
|
*/
|
|
if (cpuctx->exclusive)
|
|
return 0;
|
|
/*
|
|
* If this group is exclusive and there are already
|
|
* events on the CPU, it can't go on.
|
|
*/
|
|
if (event->attr.exclusive && cpuctx->active_oncpu)
|
|
return 0;
|
|
/*
|
|
* Otherwise, try to add it if all previous groups were able
|
|
* to go on.
|
|
*/
|
|
return can_add_hw;
|
|
}
|
|
|
|
static void add_event_to_ctx(struct perf_event *event,
|
|
struct perf_event_context *ctx)
|
|
{
|
|
u64 tstamp = perf_event_time(event);
|
|
|
|
list_add_event(event, ctx);
|
|
perf_group_attach(event);
|
|
event->tstamp_enabled = tstamp;
|
|
event->tstamp_running = tstamp;
|
|
event->tstamp_stopped = tstamp;
|
|
}
|
|
|
|
static void perf_event_context_sched_in(struct perf_event_context *ctx,
|
|
struct task_struct *tsk);
|
|
|
|
/*
|
|
* Cross CPU call to install and enable a performance event
|
|
*
|
|
* Must be called with ctx->mutex held
|
|
*/
|
|
static int __perf_install_in_context(void *info)
|
|
{
|
|
struct perf_event *event = info;
|
|
struct perf_event_context *ctx = event->ctx;
|
|
struct perf_event *leader = event->group_leader;
|
|
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
|
|
int err;
|
|
|
|
/*
|
|
* In case we're installing a new context to an already running task,
|
|
* could also happen before perf_event_task_sched_in() on architectures
|
|
* which do context switches with IRQs enabled.
|
|
*/
|
|
if (ctx->task && !cpuctx->task_ctx)
|
|
perf_event_context_sched_in(ctx, ctx->task);
|
|
|
|
raw_spin_lock(&ctx->lock);
|
|
ctx->is_active = 1;
|
|
update_context_time(ctx);
|
|
/*
|
|
* update cgrp time only if current cgrp
|
|
* matches event->cgrp. Must be done before
|
|
* calling add_event_to_ctx()
|
|
*/
|
|
update_cgrp_time_from_event(event);
|
|
|
|
add_event_to_ctx(event, ctx);
|
|
|
|
if (!event_filter_match(event))
|
|
goto unlock;
|
|
|
|
/*
|
|
* Don't put the event on if it is disabled or if
|
|
* it is in a group and the group isn't on.
|
|
*/
|
|
if (event->state != PERF_EVENT_STATE_INACTIVE ||
|
|
(leader != event && leader->state != PERF_EVENT_STATE_ACTIVE))
|
|
goto unlock;
|
|
|
|
/*
|
|
* An exclusive event can't go on if there are already active
|
|
* hardware events, and no hardware event can go on if there
|
|
* is already an exclusive event on.
|
|
*/
|
|
if (!group_can_go_on(event, cpuctx, 1))
|
|
err = -EEXIST;
|
|
else
|
|
err = event_sched_in(event, cpuctx, ctx);
|
|
|
|
if (err) {
|
|
/*
|
|
* This event couldn't go on. If it is in a group
|
|
* then we have to pull the whole group off.
|
|
* If the event group is pinned then put it in error state.
|
|
*/
|
|
if (leader != event)
|
|
group_sched_out(leader, cpuctx, ctx);
|
|
if (leader->attr.pinned) {
|
|
update_group_times(leader);
|
|
leader->state = PERF_EVENT_STATE_ERROR;
|
|
}
|
|
}
|
|
|
|
unlock:
|
|
raw_spin_unlock(&ctx->lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Attach a performance event to a context
|
|
*
|
|
* First we add the event to the list with the hardware enable bit
|
|
* in event->hw_config cleared.
|
|
*
|
|
* If the event is attached to a task which is on a CPU we use a smp
|
|
* call to enable it in the task context. The task might have been
|
|
* scheduled away, but we check this in the smp call again.
|
|
*/
|
|
static void
|
|
perf_install_in_context(struct perf_event_context *ctx,
|
|
struct perf_event *event,
|
|
int cpu)
|
|
{
|
|
struct task_struct *task = ctx->task;
|
|
|
|
lockdep_assert_held(&ctx->mutex);
|
|
|
|
event->ctx = ctx;
|
|
|
|
if (!task) {
|
|
/*
|
|
* Per cpu events are installed via an smp call and
|
|
* the install is always successful.
|
|
*/
|
|
cpu_function_call(cpu, __perf_install_in_context, event);
|
|
return;
|
|
}
|
|
|
|
retry:
|
|
if (!task_function_call(task, __perf_install_in_context, event))
|
|
return;
|
|
|
|
raw_spin_lock_irq(&ctx->lock);
|
|
/*
|
|
* If we failed to find a running task, but find the context active now
|
|
* that we've acquired the ctx->lock, retry.
|
|
*/
|
|
if (ctx->is_active) {
|
|
raw_spin_unlock_irq(&ctx->lock);
|
|
goto retry;
|
|
}
|
|
|
|
/*
|
|
* Since the task isn't running, its safe to add the event, us holding
|
|
* the ctx->lock ensures the task won't get scheduled in.
|
|
*/
|
|
add_event_to_ctx(event, ctx);
|
|
raw_spin_unlock_irq(&ctx->lock);
|
|
}
|
|
|
|
/*
|
|
* Put a event into inactive state and update time fields.
|
|
* Enabling the leader of a group effectively enables all
|
|
* the group members that aren't explicitly disabled, so we
|
|
* have to update their ->tstamp_enabled also.
|
|
* Note: this works for group members as well as group leaders
|
|
* since the non-leader members' sibling_lists will be empty.
|
|
*/
|
|
static void __perf_event_mark_enabled(struct perf_event *event,
|
|
struct perf_event_context *ctx)
|
|
{
|
|
struct perf_event *sub;
|
|
u64 tstamp = perf_event_time(event);
|
|
|
|
event->state = PERF_EVENT_STATE_INACTIVE;
|
|
event->tstamp_enabled = tstamp - event->total_time_enabled;
|
|
list_for_each_entry(sub, &event->sibling_list, group_entry) {
|
|
if (sub->state >= PERF_EVENT_STATE_INACTIVE)
|
|
sub->tstamp_enabled = tstamp - sub->total_time_enabled;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Cross CPU call to enable a performance event
|
|
*/
|
|
static int __perf_event_enable(void *info)
|
|
{
|
|
struct perf_event *event = info;
|
|
struct perf_event_context *ctx = event->ctx;
|
|
struct perf_event *leader = event->group_leader;
|
|
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
|
|
int err;
|
|
|
|
if (WARN_ON_ONCE(!ctx->is_active))
|
|
return -EINVAL;
|
|
|
|
raw_spin_lock(&ctx->lock);
|
|
update_context_time(ctx);
|
|
|
|
if (event->state >= PERF_EVENT_STATE_INACTIVE)
|
|
goto unlock;
|
|
|
|
/*
|
|
* set current task's cgroup time reference point
|
|
*/
|
|
perf_cgroup_set_timestamp(current, ctx);
|
|
|
|
__perf_event_mark_enabled(event, ctx);
|
|
|
|
if (!event_filter_match(event)) {
|
|
if (is_cgroup_event(event))
|
|
perf_cgroup_defer_enabled(event);
|
|
goto unlock;
|
|
}
|
|
|
|
/*
|
|
* If the event is in a group and isn't the group leader,
|
|
* then don't put it on unless the group is on.
|
|
*/
|
|
if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
|
|
goto unlock;
|
|
|
|
if (!group_can_go_on(event, cpuctx, 1)) {
|
|
err = -EEXIST;
|
|
} else {
|
|
if (event == leader)
|
|
err = group_sched_in(event, cpuctx, ctx);
|
|
else
|
|
err = event_sched_in(event, cpuctx, ctx);
|
|
}
|
|
|
|
if (err) {
|
|
/*
|
|
* If this event can't go on and it's part of a
|
|
* group, then the whole group has to come off.
|
|
*/
|
|
if (leader != event)
|
|
group_sched_out(leader, cpuctx, ctx);
|
|
if (leader->attr.pinned) {
|
|
update_group_times(leader);
|
|
leader->state = PERF_EVENT_STATE_ERROR;
|
|
}
|
|
}
|
|
|
|
unlock:
|
|
raw_spin_unlock(&ctx->lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Enable a event.
|
|
*
|
|
* If event->ctx is a cloned context, callers must make sure that
|
|
* every task struct that event->ctx->task could possibly point to
|
|
* remains valid. This condition is satisfied when called through
|
|
* perf_event_for_each_child or perf_event_for_each as described
|
|
* for perf_event_disable.
|
|
*/
|
|
void perf_event_enable(struct perf_event *event)
|
|
{
|
|
struct perf_event_context *ctx = event->ctx;
|
|
struct task_struct *task = ctx->task;
|
|
|
|
if (!task) {
|
|
/*
|
|
* Enable the event on the cpu that it's on
|
|
*/
|
|
cpu_function_call(event->cpu, __perf_event_enable, event);
|
|
return;
|
|
}
|
|
|
|
raw_spin_lock_irq(&ctx->lock);
|
|
if (event->state >= PERF_EVENT_STATE_INACTIVE)
|
|
goto out;
|
|
|
|
/*
|
|
* If the event is in error state, clear that first.
|
|
* That way, if we see the event in error state below, we
|
|
* know that it has gone back into error state, as distinct
|
|
* from the task having been scheduled away before the
|
|
* cross-call arrived.
|
|
*/
|
|
if (event->state == PERF_EVENT_STATE_ERROR)
|
|
event->state = PERF_EVENT_STATE_OFF;
|
|
|
|
retry:
|
|
if (!ctx->is_active) {
|
|
__perf_event_mark_enabled(event, ctx);
|
|
goto out;
|
|
}
|
|
|
|
raw_spin_unlock_irq(&ctx->lock);
|
|
|
|
if (!task_function_call(task, __perf_event_enable, event))
|
|
return;
|
|
|
|
raw_spin_lock_irq(&ctx->lock);
|
|
|
|
/*
|
|
* If the context is active and the event is still off,
|
|
* we need to retry the cross-call.
|
|
*/
|
|
if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF) {
|
|
/*
|
|
* task could have been flipped by a concurrent
|
|
* perf_event_context_sched_out()
|
|
*/
|
|
task = ctx->task;
|
|
goto retry;
|
|
}
|
|
|
|
out:
|
|
raw_spin_unlock_irq(&ctx->lock);
|
|
}
|
|
|
|
static int perf_event_refresh(struct perf_event *event, int refresh)
|
|
{
|
|
/*
|
|
* not supported on inherited events
|
|
*/
|
|
if (event->attr.inherit || !is_sampling_event(event))
|
|
return -EINVAL;
|
|
|
|
atomic_add(refresh, &event->event_limit);
|
|
perf_event_enable(event);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ctx_sched_out(struct perf_event_context *ctx,
|
|
struct perf_cpu_context *cpuctx,
|
|
enum event_type_t event_type)
|
|
{
|
|
struct perf_event *event;
|
|
|
|
raw_spin_lock(&ctx->lock);
|
|
perf_pmu_disable(ctx->pmu);
|
|
ctx->is_active = 0;
|
|
if (likely(!ctx->nr_events))
|
|
goto out;
|
|
update_context_time(ctx);
|
|
update_cgrp_time_from_cpuctx(cpuctx);
|
|
|
|
if (!ctx->nr_active)
|
|
goto out;
|
|
|
|
if (event_type & EVENT_PINNED) {
|
|
list_for_each_entry(event, &ctx->pinned_groups, group_entry)
|
|
group_sched_out(event, cpuctx, ctx);
|
|
}
|
|
|
|
if (event_type & EVENT_FLEXIBLE) {
|
|
list_for_each_entry(event, &ctx->flexible_groups, group_entry)
|
|
group_sched_out(event, cpuctx, ctx);
|
|
}
|
|
out:
|
|
perf_pmu_enable(ctx->pmu);
|
|
raw_spin_unlock(&ctx->lock);
|
|
}
|
|
|
|
/*
|
|
* Test whether two contexts are equivalent, i.e. whether they
|
|
* have both been cloned from the same version of the same context
|
|
* and they both have the same number of enabled events.
|
|
* If the number of enabled events is the same, then the set
|
|
* of enabled events should be the same, because these are both
|
|
* inherited contexts, therefore we can't access individual events
|
|
* in them directly with an fd; we can only enable/disable all
|
|
* events via prctl, or enable/disable all events in a family
|
|
* via ioctl, which will have the same effect on both contexts.
|
|
*/
|
|
static int context_equiv(struct perf_event_context *ctx1,
|
|
struct perf_event_context *ctx2)
|
|
{
|
|
return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx
|
|
&& ctx1->parent_gen == ctx2->parent_gen
|
|
&& !ctx1->pin_count && !ctx2->pin_count;
|
|
}
|
|
|
|
static void __perf_event_sync_stat(struct perf_event *event,
|
|
struct perf_event *next_event)
|
|
{
|
|
u64 value;
|
|
|
|
if (!event->attr.inherit_stat)
|
|
return;
|
|
|
|
/*
|
|
* Update the event value, we cannot use perf_event_read()
|
|
* because we're in the middle of a context switch and have IRQs
|
|
* disabled, which upsets smp_call_function_single(), however
|
|
* we know the event must be on the current CPU, therefore we
|
|
* don't need to use it.
|
|
*/
|
|
switch (event->state) {
|
|
case PERF_EVENT_STATE_ACTIVE:
|
|
event->pmu->read(event);
|
|
/* fall-through */
|
|
|
|
case PERF_EVENT_STATE_INACTIVE:
|
|
update_event_times(event);
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* In order to keep per-task stats reliable we need to flip the event
|
|
* values when we flip the contexts.
|
|
*/
|
|
value = local64_read(&next_event->count);
|
|
value = local64_xchg(&event->count, value);
|
|
local64_set(&next_event->count, value);
|
|
|
|
swap(event->total_time_enabled, next_event->total_time_enabled);
|
|
swap(event->total_time_running, next_event->total_time_running);
|
|
|
|
/*
|
|
* Since we swizzled the values, update the user visible data too.
|
|
*/
|
|
perf_event_update_userpage(event);
|
|
perf_event_update_userpage(next_event);
|
|
}
|
|
|
|
#define list_next_entry(pos, member) \
|
|
list_entry(pos->member.next, typeof(*pos), member)
|
|
|
|
static void perf_event_sync_stat(struct perf_event_context *ctx,
|
|
struct perf_event_context *next_ctx)
|
|
{
|
|
struct perf_event *event, *next_event;
|
|
|
|
if (!ctx->nr_stat)
|
|
return;
|
|
|
|
update_context_time(ctx);
|
|
|
|
event = list_first_entry(&ctx->event_list,
|
|
struct perf_event, event_entry);
|
|
|
|
next_event = list_first_entry(&next_ctx->event_list,
|
|
struct perf_event, event_entry);
|
|
|
|
while (&event->event_entry != &ctx->event_list &&
|
|
&next_event->event_entry != &next_ctx->event_list) {
|
|
|
|
__perf_event_sync_stat(event, next_event);
|
|
|
|
event = list_next_entry(event, event_entry);
|
|
next_event = list_next_entry(next_event, event_entry);
|
|
}
|
|
}
|
|
|
|
static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
|
|
struct task_struct *next)
|
|
{
|
|
struct perf_event_context *ctx = task->perf_event_ctxp[ctxn];
|
|
struct perf_event_context *next_ctx;
|
|
struct perf_event_context *parent;
|
|
struct perf_cpu_context *cpuctx;
|
|
int do_switch = 1;
|
|
|
|
if (likely(!ctx))
|
|
return;
|
|
|
|
cpuctx = __get_cpu_context(ctx);
|
|
if (!cpuctx->task_ctx)
|
|
return;
|
|
|
|
rcu_read_lock();
|
|
parent = rcu_dereference(ctx->parent_ctx);
|
|
next_ctx = next->perf_event_ctxp[ctxn];
|
|
if (parent && next_ctx &&
|
|
rcu_dereference(next_ctx->parent_ctx) == parent) {
|
|
/*
|
|
* Looks like the two contexts are clones, so we might be
|
|
* able to optimize the context switch. We lock both
|
|
* contexts and check that they are clones under the
|
|
* lock (including re-checking that neither has been
|
|
* uncloned in the meantime). It doesn't matter which
|
|
* order we take the locks because no other cpu could
|
|
* be trying to lock both of these tasks.
|
|
*/
|
|
raw_spin_lock(&ctx->lock);
|
|
raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
|
|
if (context_equiv(ctx, next_ctx)) {
|
|
/*
|
|
* XXX do we need a memory barrier of sorts
|
|
* wrt to rcu_dereference() of perf_event_ctxp
|
|
*/
|
|
task->perf_event_ctxp[ctxn] = next_ctx;
|
|
next->perf_event_ctxp[ctxn] = ctx;
|
|
ctx->task = next;
|
|
next_ctx->task = task;
|
|
do_switch = 0;
|
|
|
|
perf_event_sync_stat(ctx, next_ctx);
|
|
}
|
|
raw_spin_unlock(&next_ctx->lock);
|
|
raw_spin_unlock(&ctx->lock);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
if (do_switch) {
|
|
ctx_sched_out(ctx, cpuctx, EVENT_ALL);
|
|
cpuctx->task_ctx = NULL;
|
|
}
|
|
}
|
|
|
|
#define for_each_task_context_nr(ctxn) \
|
|
for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
|
|
|
|
/*
|
|
* Called from scheduler to remove the events of the current task,
|
|
* with interrupts disabled.
|
|
*
|
|
* We stop each event and update the event value in event->count.
|
|
*
|
|
* This does not protect us against NMI, but disable()
|
|
* sets the disabled bit in the control field of event _before_
|
|
* accessing the event control register. If a NMI hits, then it will
|
|
* not restart the event.
|
|
*/
|
|
void __perf_event_task_sched_out(struct task_struct *task,
|
|
struct task_struct *next)
|
|
{
|
|
int ctxn;
|
|
|
|
for_each_task_context_nr(ctxn)
|
|
perf_event_context_sched_out(task, ctxn, next);
|
|
|
|
/*
|
|
* if cgroup events exist on this CPU, then we need
|
|
* to check if we have to switch out PMU state.
|
|
* cgroup event are system-wide mode only
|
|
*/
|
|
if (atomic_read(&__get_cpu_var(perf_cgroup_events)))
|
|
perf_cgroup_sched_out(task);
|
|
}
|
|
|
|
static void task_ctx_sched_out(struct perf_event_context *ctx,
|
|
enum event_type_t event_type)
|
|
{
|
|
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
|
|
|
|
if (!cpuctx->task_ctx)
|
|
return;
|
|
|
|
if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
|
|
return;
|
|
|
|
ctx_sched_out(ctx, cpuctx, event_type);
|
|
cpuctx->task_ctx = NULL;
|
|
}
|
|
|
|
/*
|
|
* Called with IRQs disabled
|
|
*/
|
|
static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
|
|
enum event_type_t event_type)
|
|
{
|
|
ctx_sched_out(&cpuctx->ctx, cpuctx, event_type);
|
|
}
|
|
|
|
static void
|
|
ctx_pinned_sched_in(struct perf_event_context *ctx,
|
|
struct perf_cpu_context *cpuctx)
|
|
{
|
|
struct perf_event *event;
|
|
|
|
list_for_each_entry(event, &ctx->pinned_groups, group_entry) {
|
|
if (event->state <= PERF_EVENT_STATE_OFF)
|
|
continue;
|
|
if (!event_filter_match(event))
|
|
continue;
|
|
|
|
/* may need to reset tstamp_enabled */
|
|
if (is_cgroup_event(event))
|
|
perf_cgroup_mark_enabled(event, ctx);
|
|
|
|
if (group_can_go_on(event, cpuctx, 1))
|
|
group_sched_in(event, cpuctx, ctx);
|
|
|
|
/*
|
|
* If this pinned group hasn't been scheduled,
|
|
* put it in error state.
|
|
*/
|
|
if (event->state == PERF_EVENT_STATE_INACTIVE) {
|
|
update_group_times(event);
|
|
event->state = PERF_EVENT_STATE_ERROR;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
ctx_flexible_sched_in(struct perf_event_context *ctx,
|
|
struct perf_cpu_context *cpuctx)
|
|
{
|
|
struct perf_event *event;
|
|
int can_add_hw = 1;
|
|
|
|
list_for_each_entry(event, &ctx->flexible_groups, group_entry) {
|
|
/* Ignore events in OFF or ERROR state */
|
|
if (event->state <= PERF_EVENT_STATE_OFF)
|
|
continue;
|
|
/*
|
|
* Listen to the 'cpu' scheduling filter constraint
|
|
* of events:
|
|
*/
|
|
if (!event_filter_match(event))
|
|
continue;
|
|
|
|
/* may need to reset tstamp_enabled */
|
|
if (is_cgroup_event(event))
|
|
perf_cgroup_mark_enabled(event, ctx);
|
|
|
|
if (group_can_go_on(event, cpuctx, can_add_hw)) {
|
|
if (group_sched_in(event, cpuctx, ctx))
|
|
can_add_hw = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
ctx_sched_in(struct perf_event_context *ctx,
|
|
struct perf_cpu_context *cpuctx,
|
|
enum event_type_t event_type,
|
|
struct task_struct *task)
|
|
{
|
|
u64 now;
|
|
|
|
raw_spin_lock(&ctx->lock);
|
|
ctx->is_active = 1;
|
|
if (likely(!ctx->nr_events))
|
|
goto out;
|
|
|
|
now = perf_clock();
|
|
ctx->timestamp = now;
|
|
perf_cgroup_set_timestamp(task, ctx);
|
|
/*
|
|
* First go through the list and put on any pinned groups
|
|
* in order to give them the best chance of going on.
|
|
*/
|
|
if (event_type & EVENT_PINNED)
|
|
ctx_pinned_sched_in(ctx, cpuctx);
|
|
|
|
/* Then walk through the lower prio flexible groups */
|
|
if (event_type & EVENT_FLEXIBLE)
|
|
ctx_flexible_sched_in(ctx, cpuctx);
|
|
|
|
out:
|
|
raw_spin_unlock(&ctx->lock);
|
|
}
|
|
|
|
static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
|
|
enum event_type_t event_type,
|
|
struct task_struct *task)
|
|
{
|
|
struct perf_event_context *ctx = &cpuctx->ctx;
|
|
|
|
ctx_sched_in(ctx, cpuctx, event_type, task);
|
|
}
|
|
|
|
static void task_ctx_sched_in(struct perf_event_context *ctx,
|
|
enum event_type_t event_type)
|
|
{
|
|
struct perf_cpu_context *cpuctx;
|
|
|
|
cpuctx = __get_cpu_context(ctx);
|
|
if (cpuctx->task_ctx == ctx)
|
|
return;
|
|
|
|
ctx_sched_in(ctx, cpuctx, event_type, NULL);
|
|
cpuctx->task_ctx = ctx;
|
|
}
|
|
|
|
static void perf_event_context_sched_in(struct perf_event_context *ctx,
|
|
struct task_struct *task)
|
|
{
|
|
struct perf_cpu_context *cpuctx;
|
|
|
|
cpuctx = __get_cpu_context(ctx);
|
|
if (cpuctx->task_ctx == ctx)
|
|
return;
|
|
|
|
perf_pmu_disable(ctx->pmu);
|
|
/*
|
|
* We want to keep the following priority order:
|
|
* cpu pinned (that don't need to move), task pinned,
|
|
* cpu flexible, task flexible.
|
|
*/
|
|
cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
|
|
|
|
ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task);
|
|
cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task);
|
|
ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
|
|
|
|
cpuctx->task_ctx = ctx;
|
|
|
|
/*
|
|
* Since these rotations are per-cpu, we need to ensure the
|
|
* cpu-context we got scheduled on is actually rotating.
|
|
*/
|
|
perf_pmu_rotate_start(ctx->pmu);
|
|
perf_pmu_enable(ctx->pmu);
|
|
}
|
|
|
|
/*
|
|
* Called from scheduler to add the events of the current task
|
|
* with interrupts disabled.
|
|
*
|
|
* We restore the event value and then enable it.
|
|
*
|
|
* This does not protect us against NMI, but enable()
|
|
* sets the enabled bit in the control field of event _before_
|
|
* accessing the event control register. If a NMI hits, then it will
|
|
* keep the event running.
|
|
*/
|
|
void __perf_event_task_sched_in(struct task_struct *task)
|
|
{
|
|
struct perf_event_context *ctx;
|
|
int ctxn;
|
|
|
|
for_each_task_context_nr(ctxn) {
|
|
ctx = task->perf_event_ctxp[ctxn];
|
|
if (likely(!ctx))
|
|
continue;
|
|
|
|
perf_event_context_sched_in(ctx, task);
|
|
}
|
|
/*
|
|
* if cgroup events exist on this CPU, then we need
|
|
* to check if we have to switch in PMU state.
|
|
* cgroup event are system-wide mode only
|
|
*/
|
|
if (atomic_read(&__get_cpu_var(perf_cgroup_events)))
|
|
perf_cgroup_sched_in(task);
|
|
}
|
|
|
|
static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
|
|
{
|
|
u64 frequency = event->attr.sample_freq;
|
|
u64 sec = NSEC_PER_SEC;
|
|
u64 divisor, dividend;
|
|
|
|
int count_fls, nsec_fls, frequency_fls, sec_fls;
|
|
|
|
count_fls = fls64(count);
|
|
nsec_fls = fls64(nsec);
|
|
frequency_fls = fls64(frequency);
|
|
sec_fls = 30;
|
|
|
|
/*
|
|
* We got @count in @nsec, with a target of sample_freq HZ
|
|
* the target period becomes:
|
|
*
|
|
* @count * 10^9
|
|
* period = -------------------
|
|
* @nsec * sample_freq
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* Reduce accuracy by one bit such that @a and @b converge
|
|
* to a similar magnitude.
|
|
*/
|
|
#define REDUCE_FLS(a, b) \
|
|
do { \
|
|
if (a##_fls > b##_fls) { \
|
|
a >>= 1; \
|
|
a##_fls--; \
|
|
} else { \
|
|
b >>= 1; \
|
|
b##_fls--; \
|
|
} \
|
|
} while (0)
|
|
|
|
/*
|
|
* Reduce accuracy until either term fits in a u64, then proceed with
|
|
* the other, so that finally we can do a u64/u64 division.
|
|
*/
|
|
while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) {
|
|
REDUCE_FLS(nsec, frequency);
|
|
REDUCE_FLS(sec, count);
|
|
}
|
|
|
|
if (count_fls + sec_fls > 64) {
|
|
divisor = nsec * frequency;
|
|
|
|
while (count_fls + sec_fls > 64) {
|
|
REDUCE_FLS(count, sec);
|
|
divisor >>= 1;
|
|
}
|
|
|
|
dividend = count * sec;
|
|
} else {
|
|
dividend = count * sec;
|
|
|
|
while (nsec_fls + frequency_fls > 64) {
|
|
REDUCE_FLS(nsec, frequency);
|
|
dividend >>= 1;
|
|
}
|
|
|
|
divisor = nsec * frequency;
|
|
}
|
|
|
|
if (!divisor)
|
|
return dividend;
|
|
|
|
return div64_u64(dividend, divisor);
|
|
}
|
|
|
|
static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count)
|
|
{
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
s64 period, sample_period;
|
|
s64 delta;
|
|
|
|
period = perf_calculate_period(event, nsec, count);
|
|
|
|
delta = (s64)(period - hwc->sample_period);
|
|
delta = (delta + 7) / 8; /* low pass filter */
|
|
|
|
sample_period = hwc->sample_period + delta;
|
|
|
|
if (!sample_period)
|
|
sample_period = 1;
|
|
|
|
hwc->sample_period = sample_period;
|
|
|
|
if (local64_read(&hwc->period_left) > 8*sample_period) {
|
|
event->pmu->stop(event, PERF_EF_UPDATE);
|
|
local64_set(&hwc->period_left, 0);
|
|
event->pmu->start(event, PERF_EF_RELOAD);
|
|
}
|
|
}
|
|
|
|
static void perf_ctx_adjust_freq(struct perf_event_context *ctx, u64 period)
|
|
{
|
|
struct perf_event *event;
|
|
struct hw_perf_event *hwc;
|
|
u64 interrupts, now;
|
|
s64 delta;
|
|
|
|
raw_spin_lock(&ctx->lock);
|
|
list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
|
|
if (event->state != PERF_EVENT_STATE_ACTIVE)
|
|
continue;
|
|
|
|
if (!event_filter_match(event))
|
|
continue;
|
|
|
|
hwc = &event->hw;
|
|
|
|
interrupts = hwc->interrupts;
|
|
hwc->interrupts = 0;
|
|
|
|
/*
|
|
* unthrottle events on the tick
|
|
*/
|
|
if (interrupts == MAX_INTERRUPTS) {
|
|
perf_log_throttle(event, 1);
|
|
event->pmu->start(event, 0);
|
|
}
|
|
|
|
if (!event->attr.freq || !event->attr.sample_freq)
|
|
continue;
|
|
|
|
event->pmu->read(event);
|
|
now = local64_read(&event->count);
|
|
delta = now - hwc->freq_count_stamp;
|
|
hwc->freq_count_stamp = now;
|
|
|
|
if (delta > 0)
|
|
perf_adjust_period(event, period, delta);
|
|
}
|
|
raw_spin_unlock(&ctx->lock);
|
|
}
|
|
|
|
/*
|
|
* Round-robin a context's events:
|
|
*/
|
|
static void rotate_ctx(struct perf_event_context *ctx)
|
|
{
|
|
raw_spin_lock(&ctx->lock);
|
|
|
|
/*
|
|
* Rotate the first entry last of non-pinned groups. Rotation might be
|
|
* disabled by the inheritance code.
|
|
*/
|
|
if (!ctx->rotate_disable)
|
|
list_rotate_left(&ctx->flexible_groups);
|
|
|
|
raw_spin_unlock(&ctx->lock);
|
|
}
|
|
|
|
/*
|
|
* perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
|
|
* because they're strictly cpu affine and rotate_start is called with IRQs
|
|
* disabled, while rotate_context is called from IRQ context.
|
|
*/
|
|
static void perf_rotate_context(struct perf_cpu_context *cpuctx)
|
|
{
|
|
u64 interval = (u64)cpuctx->jiffies_interval * TICK_NSEC;
|
|
struct perf_event_context *ctx = NULL;
|
|
int rotate = 0, remove = 1;
|
|
|
|
if (cpuctx->ctx.nr_events) {
|
|
remove = 0;
|
|
if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
|
|
rotate = 1;
|
|
}
|
|
|
|
ctx = cpuctx->task_ctx;
|
|
if (ctx && ctx->nr_events) {
|
|
remove = 0;
|
|
if (ctx->nr_events != ctx->nr_active)
|
|
rotate = 1;
|
|
}
|
|
|
|
perf_pmu_disable(cpuctx->ctx.pmu);
|
|
perf_ctx_adjust_freq(&cpuctx->ctx, interval);
|
|
if (ctx)
|
|
perf_ctx_adjust_freq(ctx, interval);
|
|
|
|
if (!rotate)
|
|
goto done;
|
|
|
|
cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
|
|
if (ctx)
|
|
task_ctx_sched_out(ctx, EVENT_FLEXIBLE);
|
|
|
|
rotate_ctx(&cpuctx->ctx);
|
|
if (ctx)
|
|
rotate_ctx(ctx);
|
|
|
|
cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, current);
|
|
if (ctx)
|
|
task_ctx_sched_in(ctx, EVENT_FLEXIBLE);
|
|
|
|
done:
|
|
if (remove)
|
|
list_del_init(&cpuctx->rotation_list);
|
|
|
|
perf_pmu_enable(cpuctx->ctx.pmu);
|
|
}
|
|
|
|
void perf_event_task_tick(void)
|
|
{
|
|
struct list_head *head = &__get_cpu_var(rotation_list);
|
|
struct perf_cpu_context *cpuctx, *tmp;
|
|
|
|
WARN_ON(!irqs_disabled());
|
|
|
|
list_for_each_entry_safe(cpuctx, tmp, head, rotation_list) {
|
|
if (cpuctx->jiffies_interval == 1 ||
|
|
!(jiffies % cpuctx->jiffies_interval))
|
|
perf_rotate_context(cpuctx);
|
|
}
|
|
}
|
|
|
|
static int event_enable_on_exec(struct perf_event *event,
|
|
struct perf_event_context *ctx)
|
|
{
|
|
if (!event->attr.enable_on_exec)
|
|
return 0;
|
|
|
|
event->attr.enable_on_exec = 0;
|
|
if (event->state >= PERF_EVENT_STATE_INACTIVE)
|
|
return 0;
|
|
|
|
__perf_event_mark_enabled(event, ctx);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Enable all of a task's events that have been marked enable-on-exec.
|
|
* This expects task == current.
|
|
*/
|
|
static void perf_event_enable_on_exec(struct perf_event_context *ctx)
|
|
{
|
|
struct perf_event *event;
|
|
unsigned long flags;
|
|
int enabled = 0;
|
|
int ret;
|
|
|
|
local_irq_save(flags);
|
|
if (!ctx || !ctx->nr_events)
|
|
goto out;
|
|
|
|
task_ctx_sched_out(ctx, EVENT_ALL);
|
|
|
|
raw_spin_lock(&ctx->lock);
|
|
|
|
list_for_each_entry(event, &ctx->pinned_groups, group_entry) {
|
|
ret = event_enable_on_exec(event, ctx);
|
|
if (ret)
|
|
enabled = 1;
|
|
}
|
|
|
|
list_for_each_entry(event, &ctx->flexible_groups, group_entry) {
|
|
ret = event_enable_on_exec(event, ctx);
|
|
if (ret)
|
|
enabled = 1;
|
|
}
|
|
|
|
/*
|
|
* Unclone this context if we enabled any event.
|
|
*/
|
|
if (enabled)
|
|
unclone_ctx(ctx);
|
|
|
|
raw_spin_unlock(&ctx->lock);
|
|
|
|
perf_event_context_sched_in(ctx, ctx->task);
|
|
out:
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/*
|
|
* Cross CPU call to read the hardware event
|
|
*/
|
|
static void __perf_event_read(void *info)
|
|
{
|
|
struct perf_event *event = info;
|
|
struct perf_event_context *ctx = event->ctx;
|
|
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
|
|
|
|
/*
|
|
* If this is a task context, we need to check whether it is
|
|
* the current task context of this cpu. If not it has been
|
|
* scheduled out before the smp call arrived. In that case
|
|
* event->count would have been updated to a recent sample
|
|
* when the event was scheduled out.
|
|
*/
|
|
if (ctx->task && cpuctx->task_ctx != ctx)
|
|
return;
|
|
|
|
raw_spin_lock(&ctx->lock);
|
|
if (ctx->is_active) {
|
|
update_context_time(ctx);
|
|
update_cgrp_time_from_event(event);
|
|
}
|
|
update_event_times(event);
|
|
if (event->state == PERF_EVENT_STATE_ACTIVE)
|
|
event->pmu->read(event);
|
|
raw_spin_unlock(&ctx->lock);
|
|
}
|
|
|
|
static inline u64 perf_event_count(struct perf_event *event)
|
|
{
|
|
return local64_read(&event->count) + atomic64_read(&event->child_count);
|
|
}
|
|
|
|
static u64 perf_event_read(struct perf_event *event)
|
|
{
|
|
/*
|
|
* If event is enabled and currently active on a CPU, update the
|
|
* value in the event structure:
|
|
*/
|
|
if (event->state == PERF_EVENT_STATE_ACTIVE) {
|
|
smp_call_function_single(event->oncpu,
|
|
__perf_event_read, event, 1);
|
|
} else if (event->state == PERF_EVENT_STATE_INACTIVE) {
|
|
struct perf_event_context *ctx = event->ctx;
|
|
unsigned long flags;
|
|
|
|
raw_spin_lock_irqsave(&ctx->lock, flags);
|
|
/*
|
|
* may read while context is not active
|
|
* (e.g., thread is blocked), in that case
|
|
* we cannot update context time
|
|
*/
|
|
if (ctx->is_active) {
|
|
update_context_time(ctx);
|
|
update_cgrp_time_from_event(event);
|
|
}
|
|
update_event_times(event);
|
|
raw_spin_unlock_irqrestore(&ctx->lock, flags);
|
|
}
|
|
|
|
return perf_event_count(event);
|
|
}
|
|
|
|
/*
|
|
* Callchain support
|
|
*/
|
|
|
|
struct callchain_cpus_entries {
|
|
struct rcu_head rcu_head;
|
|
struct perf_callchain_entry *cpu_entries[0];
|
|
};
|
|
|
|
static DEFINE_PER_CPU(int, callchain_recursion[PERF_NR_CONTEXTS]);
|
|
static atomic_t nr_callchain_events;
|
|
static DEFINE_MUTEX(callchain_mutex);
|
|
struct callchain_cpus_entries *callchain_cpus_entries;
|
|
|
|
|
|
__weak void perf_callchain_kernel(struct perf_callchain_entry *entry,
|
|
struct pt_regs *regs)
|
|
{
|
|
}
|
|
|
|
__weak void perf_callchain_user(struct perf_callchain_entry *entry,
|
|
struct pt_regs *regs)
|
|
{
|
|
}
|
|
|
|
static void release_callchain_buffers_rcu(struct rcu_head *head)
|
|
{
|
|
struct callchain_cpus_entries *entries;
|
|
int cpu;
|
|
|
|
entries = container_of(head, struct callchain_cpus_entries, rcu_head);
|
|
|
|
for_each_possible_cpu(cpu)
|
|
kfree(entries->cpu_entries[cpu]);
|
|
|
|
kfree(entries);
|
|
}
|
|
|
|
static void release_callchain_buffers(void)
|
|
{
|
|
struct callchain_cpus_entries *entries;
|
|
|
|
entries = callchain_cpus_entries;
|
|
rcu_assign_pointer(callchain_cpus_entries, NULL);
|
|
call_rcu(&entries->rcu_head, release_callchain_buffers_rcu);
|
|
}
|
|
|
|
static int alloc_callchain_buffers(void)
|
|
{
|
|
int cpu;
|
|
int size;
|
|
struct callchain_cpus_entries *entries;
|
|
|
|
/*
|
|
* We can't use the percpu allocation API for data that can be
|
|
* accessed from NMI. Use a temporary manual per cpu allocation
|
|
* until that gets sorted out.
|
|
*/
|
|
size = offsetof(struct callchain_cpus_entries, cpu_entries[nr_cpu_ids]);
|
|
|
|
entries = kzalloc(size, GFP_KERNEL);
|
|
if (!entries)
|
|
return -ENOMEM;
|
|
|
|
size = sizeof(struct perf_callchain_entry) * PERF_NR_CONTEXTS;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
entries->cpu_entries[cpu] = kmalloc_node(size, GFP_KERNEL,
|
|
cpu_to_node(cpu));
|
|
if (!entries->cpu_entries[cpu])
|
|
goto fail;
|
|
}
|
|
|
|
rcu_assign_pointer(callchain_cpus_entries, entries);
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
for_each_possible_cpu(cpu)
|
|
kfree(entries->cpu_entries[cpu]);
|
|
kfree(entries);
|
|
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int get_callchain_buffers(void)
|
|
{
|
|
int err = 0;
|
|
int count;
|
|
|
|
mutex_lock(&callchain_mutex);
|
|
|
|
count = atomic_inc_return(&nr_callchain_events);
|
|
if (WARN_ON_ONCE(count < 1)) {
|
|
err = -EINVAL;
|
|
goto exit;
|
|
}
|
|
|
|
if (count > 1) {
|
|
/* If the allocation failed, give up */
|
|
if (!callchain_cpus_entries)
|
|
err = -ENOMEM;
|
|
goto exit;
|
|
}
|
|
|
|
err = alloc_callchain_buffers();
|
|
if (err)
|
|
release_callchain_buffers();
|
|
exit:
|
|
mutex_unlock(&callchain_mutex);
|
|
|
|
return err;
|
|
}
|
|
|
|
static void put_callchain_buffers(void)
|
|
{
|
|
if (atomic_dec_and_mutex_lock(&nr_callchain_events, &callchain_mutex)) {
|
|
release_callchain_buffers();
|
|
mutex_unlock(&callchain_mutex);
|
|
}
|
|
}
|
|
|
|
static int get_recursion_context(int *recursion)
|
|
{
|
|
int rctx;
|
|
|
|
if (in_nmi())
|
|
rctx = 3;
|
|
else if (in_irq())
|
|
rctx = 2;
|
|
else if (in_softirq())
|
|
rctx = 1;
|
|
else
|
|
rctx = 0;
|
|
|
|
if (recursion[rctx])
|
|
return -1;
|
|
|
|
recursion[rctx]++;
|
|
barrier();
|
|
|
|
return rctx;
|
|
}
|
|
|
|
static inline void put_recursion_context(int *recursion, int rctx)
|
|
{
|
|
barrier();
|
|
recursion[rctx]--;
|
|
}
|
|
|
|
static struct perf_callchain_entry *get_callchain_entry(int *rctx)
|
|
{
|
|
int cpu;
|
|
struct callchain_cpus_entries *entries;
|
|
|
|
*rctx = get_recursion_context(__get_cpu_var(callchain_recursion));
|
|
if (*rctx == -1)
|
|
return NULL;
|
|
|
|
entries = rcu_dereference(callchain_cpus_entries);
|
|
if (!entries)
|
|
return NULL;
|
|
|
|
cpu = smp_processor_id();
|
|
|
|
return &entries->cpu_entries[cpu][*rctx];
|
|
}
|
|
|
|
static void
|
|
put_callchain_entry(int rctx)
|
|
{
|
|
put_recursion_context(__get_cpu_var(callchain_recursion), rctx);
|
|
}
|
|
|
|
static struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
|
|
{
|
|
int rctx;
|
|
struct perf_callchain_entry *entry;
|
|
|
|
|
|
entry = get_callchain_entry(&rctx);
|
|
if (rctx == -1)
|
|
return NULL;
|
|
|
|
if (!entry)
|
|
goto exit_put;
|
|
|
|
entry->nr = 0;
|
|
|
|
if (!user_mode(regs)) {
|
|
perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
|
|
perf_callchain_kernel(entry, regs);
|
|
if (current->mm)
|
|
regs = task_pt_regs(current);
|
|
else
|
|
regs = NULL;
|
|
}
|
|
|
|
if (regs) {
|
|
perf_callchain_store(entry, PERF_CONTEXT_USER);
|
|
perf_callchain_user(entry, regs);
|
|
}
|
|
|
|
exit_put:
|
|
put_callchain_entry(rctx);
|
|
|
|
return entry;
|
|
}
|
|
|
|
/*
|
|
* Initialize the perf_event context in a task_struct:
|
|
*/
|
|
static void __perf_event_init_context(struct perf_event_context *ctx)
|
|
{
|
|
raw_spin_lock_init(&ctx->lock);
|
|
mutex_init(&ctx->mutex);
|
|
INIT_LIST_HEAD(&ctx->pinned_groups);
|
|
INIT_LIST_HEAD(&ctx->flexible_groups);
|
|
INIT_LIST_HEAD(&ctx->event_list);
|
|
atomic_set(&ctx->refcount, 1);
|
|
}
|
|
|
|
static struct perf_event_context *
|
|
alloc_perf_context(struct pmu *pmu, struct task_struct *task)
|
|
{
|
|
struct perf_event_context *ctx;
|
|
|
|
ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
|
|
if (!ctx)
|
|
return NULL;
|
|
|
|
__perf_event_init_context(ctx);
|
|
if (task) {
|
|
ctx->task = task;
|
|
get_task_struct(task);
|
|
}
|
|
ctx->pmu = pmu;
|
|
|
|
return ctx;
|
|
}
|
|
|
|
static struct task_struct *
|
|
find_lively_task_by_vpid(pid_t vpid)
|
|
{
|
|
struct task_struct *task;
|
|
int err;
|
|
|
|
rcu_read_lock();
|
|
if (!vpid)
|
|
task = current;
|
|
else
|
|
task = find_task_by_vpid(vpid);
|
|
if (task)
|
|
get_task_struct(task);
|
|
rcu_read_unlock();
|
|
|
|
if (!task)
|
|
return ERR_PTR(-ESRCH);
|
|
|
|
/* Reuse ptrace permission checks for now. */
|
|
err = -EACCES;
|
|
if (!ptrace_may_access(task, PTRACE_MODE_READ))
|
|
goto errout;
|
|
|
|
return task;
|
|
errout:
|
|
put_task_struct(task);
|
|
return ERR_PTR(err);
|
|
|
|
}
|
|
|
|
/*
|
|
* Returns a matching context with refcount and pincount.
|
|
*/
|
|
static struct perf_event_context *
|
|
find_get_context(struct pmu *pmu, struct task_struct *task, int cpu)
|
|
{
|
|
struct perf_event_context *ctx;
|
|
struct perf_cpu_context *cpuctx;
|
|
unsigned long flags;
|
|
int ctxn, err;
|
|
|
|
if (!task) {
|
|
/* Must be root to operate on a CPU event: */
|
|
if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
|
|
return ERR_PTR(-EACCES);
|
|
|
|
/*
|
|
* We could be clever and allow to attach a event to an
|
|
* offline CPU and activate it when the CPU comes up, but
|
|
* that's for later.
|
|
*/
|
|
if (!cpu_online(cpu))
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
|
|
ctx = &cpuctx->ctx;
|
|
get_ctx(ctx);
|
|
++ctx->pin_count;
|
|
|
|
return ctx;
|
|
}
|
|
|
|
err = -EINVAL;
|
|
ctxn = pmu->task_ctx_nr;
|
|
if (ctxn < 0)
|
|
goto errout;
|
|
|
|
retry:
|
|
ctx = perf_lock_task_context(task, ctxn, &flags);
|
|
if (ctx) {
|
|
unclone_ctx(ctx);
|
|
++ctx->pin_count;
|
|
raw_spin_unlock_irqrestore(&ctx->lock, flags);
|
|
}
|
|
|
|
if (!ctx) {
|
|
ctx = alloc_perf_context(pmu, task);
|
|
err = -ENOMEM;
|
|
if (!ctx)
|
|
goto errout;
|
|
|
|
get_ctx(ctx);
|
|
|
|
err = 0;
|
|
mutex_lock(&task->perf_event_mutex);
|
|
/*
|
|
* If it has already passed perf_event_exit_task().
|
|
* we must see PF_EXITING, it takes this mutex too.
|
|
*/
|
|
if (task->flags & PF_EXITING)
|
|
err = -ESRCH;
|
|
else if (task->perf_event_ctxp[ctxn])
|
|
err = -EAGAIN;
|
|
else {
|
|
++ctx->pin_count;
|
|
rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
|
|
}
|
|
mutex_unlock(&task->perf_event_mutex);
|
|
|
|
if (unlikely(err)) {
|
|
put_task_struct(task);
|
|
kfree(ctx);
|
|
|
|
if (err == -EAGAIN)
|
|
goto retry;
|
|
goto errout;
|
|
}
|
|
}
|
|
|
|
return ctx;
|
|
|
|
errout:
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static void perf_event_free_filter(struct perf_event *event);
|
|
|
|
static void free_event_rcu(struct rcu_head *head)
|
|
{
|
|
struct perf_event *event;
|
|
|
|
event = container_of(head, struct perf_event, rcu_head);
|
|
if (event->ns)
|
|
put_pid_ns(event->ns);
|
|
perf_event_free_filter(event);
|
|
kfree(event);
|
|
}
|
|
|
|
static void perf_buffer_put(struct perf_buffer *buffer);
|
|
|
|
static void free_event(struct perf_event *event)
|
|
{
|
|
irq_work_sync(&event->pending);
|
|
|
|
if (!event->parent) {
|
|
if (event->attach_state & PERF_ATTACH_TASK)
|
|
jump_label_dec(&perf_sched_events);
|
|
if (event->attr.mmap || event->attr.mmap_data)
|
|
atomic_dec(&nr_mmap_events);
|
|
if (event->attr.comm)
|
|
atomic_dec(&nr_comm_events);
|
|
if (event->attr.task)
|
|
atomic_dec(&nr_task_events);
|
|
if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
|
|
put_callchain_buffers();
|
|
if (is_cgroup_event(event)) {
|
|
atomic_dec(&per_cpu(perf_cgroup_events, event->cpu));
|
|
jump_label_dec(&perf_sched_events);
|
|
}
|
|
}
|
|
|
|
if (event->buffer) {
|
|
perf_buffer_put(event->buffer);
|
|
event->buffer = NULL;
|
|
}
|
|
|
|
if (is_cgroup_event(event))
|
|
perf_detach_cgroup(event);
|
|
|
|
if (event->destroy)
|
|
event->destroy(event);
|
|
|
|
if (event->ctx)
|
|
put_ctx(event->ctx);
|
|
|
|
call_rcu(&event->rcu_head, free_event_rcu);
|
|
}
|
|
|
|
int perf_event_release_kernel(struct perf_event *event)
|
|
{
|
|
struct perf_event_context *ctx = event->ctx;
|
|
|
|
/*
|
|
* Remove from the PMU, can't get re-enabled since we got
|
|
* here because the last ref went.
|
|
*/
|
|
perf_event_disable(event);
|
|
|
|
WARN_ON_ONCE(ctx->parent_ctx);
|
|
/*
|
|
* There are two ways this annotation is useful:
|
|
*
|
|
* 1) there is a lock recursion from perf_event_exit_task
|
|
* see the comment there.
|
|
*
|
|
* 2) there is a lock-inversion with mmap_sem through
|
|
* perf_event_read_group(), which takes faults while
|
|
* holding ctx->mutex, however this is called after
|
|
* the last filedesc died, so there is no possibility
|
|
* to trigger the AB-BA case.
|
|
*/
|
|
mutex_lock_nested(&ctx->mutex, SINGLE_DEPTH_NESTING);
|
|
raw_spin_lock_irq(&ctx->lock);
|
|
perf_group_detach(event);
|
|
list_del_event(event, ctx);
|
|
raw_spin_unlock_irq(&ctx->lock);
|
|
mutex_unlock(&ctx->mutex);
|
|
|
|
free_event(event);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(perf_event_release_kernel);
|
|
|
|
/*
|
|
* Called when the last reference to the file is gone.
|
|
*/
|
|
static int perf_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct perf_event *event = file->private_data;
|
|
struct task_struct *owner;
|
|
|
|
file->private_data = NULL;
|
|
|
|
rcu_read_lock();
|
|
owner = ACCESS_ONCE(event->owner);
|
|
/*
|
|
* Matches the smp_wmb() in perf_event_exit_task(). If we observe
|
|
* !owner it means the list deletion is complete and we can indeed
|
|
* free this event, otherwise we need to serialize on
|
|
* owner->perf_event_mutex.
|
|
*/
|
|
smp_read_barrier_depends();
|
|
if (owner) {
|
|
/*
|
|
* Since delayed_put_task_struct() also drops the last
|
|
* task reference we can safely take a new reference
|
|
* while holding the rcu_read_lock().
|
|
*/
|
|
get_task_struct(owner);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
if (owner) {
|
|
mutex_lock(&owner->perf_event_mutex);
|
|
/*
|
|
* We have to re-check the event->owner field, if it is cleared
|
|
* we raced with perf_event_exit_task(), acquiring the mutex
|
|
* ensured they're done, and we can proceed with freeing the
|
|
* event.
|
|
*/
|
|
if (event->owner)
|
|
list_del_init(&event->owner_entry);
|
|
mutex_unlock(&owner->perf_event_mutex);
|
|
put_task_struct(owner);
|
|
}
|
|
|
|
return perf_event_release_kernel(event);
|
|
}
|
|
|
|
u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
|
|
{
|
|
struct perf_event *child;
|
|
u64 total = 0;
|
|
|
|
*enabled = 0;
|
|
*running = 0;
|
|
|
|
mutex_lock(&event->child_mutex);
|
|
total += perf_event_read(event);
|
|
*enabled += event->total_time_enabled +
|
|
atomic64_read(&event->child_total_time_enabled);
|
|
*running += event->total_time_running +
|
|
atomic64_read(&event->child_total_time_running);
|
|
|
|
list_for_each_entry(child, &event->child_list, child_list) {
|
|
total += perf_event_read(child);
|
|
*enabled += child->total_time_enabled;
|
|
*running += child->total_time_running;
|
|
}
|
|
mutex_unlock(&event->child_mutex);
|
|
|
|
return total;
|
|
}
|
|
EXPORT_SYMBOL_GPL(perf_event_read_value);
|
|
|
|
static int perf_event_read_group(struct perf_event *event,
|
|
u64 read_format, char __user *buf)
|
|
{
|
|
struct perf_event *leader = event->group_leader, *sub;
|
|
int n = 0, size = 0, ret = -EFAULT;
|
|
struct perf_event_context *ctx = leader->ctx;
|
|
u64 values[5];
|
|
u64 count, enabled, running;
|
|
|
|
mutex_lock(&ctx->mutex);
|
|
count = perf_event_read_value(leader, &enabled, &running);
|
|
|
|
values[n++] = 1 + leader->nr_siblings;
|
|
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
|
|
values[n++] = enabled;
|
|
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
|
|
values[n++] = running;
|
|
values[n++] = count;
|
|
if (read_format & PERF_FORMAT_ID)
|
|
values[n++] = primary_event_id(leader);
|
|
|
|
size = n * sizeof(u64);
|
|
|
|
if (copy_to_user(buf, values, size))
|
|
goto unlock;
|
|
|
|
ret = size;
|
|
|
|
list_for_each_entry(sub, &leader->sibling_list, group_entry) {
|
|
n = 0;
|
|
|
|
values[n++] = perf_event_read_value(sub, &enabled, &running);
|
|
if (read_format & PERF_FORMAT_ID)
|
|
values[n++] = primary_event_id(sub);
|
|
|
|
size = n * sizeof(u64);
|
|
|
|
if (copy_to_user(buf + ret, values, size)) {
|
|
ret = -EFAULT;
|
|
goto unlock;
|
|
}
|
|
|
|
ret += size;
|
|
}
|
|
unlock:
|
|
mutex_unlock(&ctx->mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int perf_event_read_one(struct perf_event *event,
|
|
u64 read_format, char __user *buf)
|
|
{
|
|
u64 enabled, running;
|
|
u64 values[4];
|
|
int n = 0;
|
|
|
|
values[n++] = perf_event_read_value(event, &enabled, &running);
|
|
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
|
|
values[n++] = enabled;
|
|
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
|
|
values[n++] = running;
|
|
if (read_format & PERF_FORMAT_ID)
|
|
values[n++] = primary_event_id(event);
|
|
|
|
if (copy_to_user(buf, values, n * sizeof(u64)))
|
|
return -EFAULT;
|
|
|
|
return n * sizeof(u64);
|
|
}
|
|
|
|
/*
|
|
* Read the performance event - simple non blocking version for now
|
|
*/
|
|
static ssize_t
|
|
perf_read_hw(struct perf_event *event, char __user *buf, size_t count)
|
|
{
|
|
u64 read_format = event->attr.read_format;
|
|
int ret;
|
|
|
|
/*
|
|
* Return end-of-file for a read on a event that is in
|
|
* error state (i.e. because it was pinned but it couldn't be
|
|
* scheduled on to the CPU at some point).
|
|
*/
|
|
if (event->state == PERF_EVENT_STATE_ERROR)
|
|
return 0;
|
|
|
|
if (count < event->read_size)
|
|
return -ENOSPC;
|
|
|
|
WARN_ON_ONCE(event->ctx->parent_ctx);
|
|
if (read_format & PERF_FORMAT_GROUP)
|
|
ret = perf_event_read_group(event, read_format, buf);
|
|
else
|
|
ret = perf_event_read_one(event, read_format, buf);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
|
|
{
|
|
struct perf_event *event = file->private_data;
|
|
|
|
return perf_read_hw(event, buf, count);
|
|
}
|
|
|
|
static unsigned int perf_poll(struct file *file, poll_table *wait)
|
|
{
|
|
struct perf_event *event = file->private_data;
|
|
struct perf_buffer *buffer;
|
|
unsigned int events = POLL_HUP;
|
|
|
|
rcu_read_lock();
|
|
buffer = rcu_dereference(event->buffer);
|
|
if (buffer)
|
|
events = atomic_xchg(&buffer->poll, 0);
|
|
rcu_read_unlock();
|
|
|
|
poll_wait(file, &event->waitq, wait);
|
|
|
|
return events;
|
|
}
|
|
|
|
static void perf_event_reset(struct perf_event *event)
|
|
{
|
|
(void)perf_event_read(event);
|
|
local64_set(&event->count, 0);
|
|
perf_event_update_userpage(event);
|
|
}
|
|
|
|
/*
|
|
* Holding the top-level event's child_mutex means that any
|
|
* descendant process that has inherited this event will block
|
|
* in sync_child_event if it goes to exit, thus satisfying the
|
|
* task existence requirements of perf_event_enable/disable.
|
|
*/
|
|
static void perf_event_for_each_child(struct perf_event *event,
|
|
void (*func)(struct perf_event *))
|
|
{
|
|
struct perf_event *child;
|
|
|
|
WARN_ON_ONCE(event->ctx->parent_ctx);
|
|
mutex_lock(&event->child_mutex);
|
|
func(event);
|
|
list_for_each_entry(child, &event->child_list, child_list)
|
|
func(child);
|
|
mutex_unlock(&event->child_mutex);
|
|
}
|
|
|
|
static void perf_event_for_each(struct perf_event *event,
|
|
void (*func)(struct perf_event *))
|
|
{
|
|
struct perf_event_context *ctx = event->ctx;
|
|
struct perf_event *sibling;
|
|
|
|
WARN_ON_ONCE(ctx->parent_ctx);
|
|
mutex_lock(&ctx->mutex);
|
|
event = event->group_leader;
|
|
|
|
perf_event_for_each_child(event, func);
|
|
func(event);
|
|
list_for_each_entry(sibling, &event->sibling_list, group_entry)
|
|
perf_event_for_each_child(event, func);
|
|
mutex_unlock(&ctx->mutex);
|
|
}
|
|
|
|
static int perf_event_period(struct perf_event *event, u64 __user *arg)
|
|
{
|
|
struct perf_event_context *ctx = event->ctx;
|
|
int ret = 0;
|
|
u64 value;
|
|
|
|
if (!is_sampling_event(event))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&value, arg, sizeof(value)))
|
|
return -EFAULT;
|
|
|
|
if (!value)
|
|
return -EINVAL;
|
|
|
|
raw_spin_lock_irq(&ctx->lock);
|
|
if (event->attr.freq) {
|
|
if (value > sysctl_perf_event_sample_rate) {
|
|
ret = -EINVAL;
|
|
goto unlock;
|
|
}
|
|
|
|
event->attr.sample_freq = value;
|
|
} else {
|
|
event->attr.sample_period = value;
|
|
event->hw.sample_period = value;
|
|
}
|
|
unlock:
|
|
raw_spin_unlock_irq(&ctx->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations perf_fops;
|
|
|
|
static struct perf_event *perf_fget_light(int fd, int *fput_needed)
|
|
{
|
|
struct file *file;
|
|
|
|
file = fget_light(fd, fput_needed);
|
|
if (!file)
|
|
return ERR_PTR(-EBADF);
|
|
|
|
if (file->f_op != &perf_fops) {
|
|
fput_light(file, *fput_needed);
|
|
*fput_needed = 0;
|
|
return ERR_PTR(-EBADF);
|
|
}
|
|
|
|
return file->private_data;
|
|
}
|
|
|
|
static int perf_event_set_output(struct perf_event *event,
|
|
struct perf_event *output_event);
|
|
static int perf_event_set_filter(struct perf_event *event, void __user *arg);
|
|
|
|
static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct perf_event *event = file->private_data;
|
|
void (*func)(struct perf_event *);
|
|
u32 flags = arg;
|
|
|
|
switch (cmd) {
|
|
case PERF_EVENT_IOC_ENABLE:
|
|
func = perf_event_enable;
|
|
break;
|
|
case PERF_EVENT_IOC_DISABLE:
|
|
func = perf_event_disable;
|
|
break;
|
|
case PERF_EVENT_IOC_RESET:
|
|
func = perf_event_reset;
|
|
break;
|
|
|
|
case PERF_EVENT_IOC_REFRESH:
|
|
return perf_event_refresh(event, arg);
|
|
|
|
case PERF_EVENT_IOC_PERIOD:
|
|
return perf_event_period(event, (u64 __user *)arg);
|
|
|
|
case PERF_EVENT_IOC_SET_OUTPUT:
|
|
{
|
|
struct perf_event *output_event = NULL;
|
|
int fput_needed = 0;
|
|
int ret;
|
|
|
|
if (arg != -1) {
|
|
output_event = perf_fget_light(arg, &fput_needed);
|
|
if (IS_ERR(output_event))
|
|
return PTR_ERR(output_event);
|
|
}
|
|
|
|
ret = perf_event_set_output(event, output_event);
|
|
if (output_event)
|
|
fput_light(output_event->filp, fput_needed);
|
|
|
|
return ret;
|
|
}
|
|
|
|
case PERF_EVENT_IOC_SET_FILTER:
|
|
return perf_event_set_filter(event, (void __user *)arg);
|
|
|
|
default:
|
|
return -ENOTTY;
|
|
}
|
|
|
|
if (flags & PERF_IOC_FLAG_GROUP)
|
|
perf_event_for_each(event, func);
|
|
else
|
|
perf_event_for_each_child(event, func);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int perf_event_task_enable(void)
|
|
{
|
|
struct perf_event *event;
|
|
|
|
mutex_lock(¤t->perf_event_mutex);
|
|
list_for_each_entry(event, ¤t->perf_event_list, owner_entry)
|
|
perf_event_for_each_child(event, perf_event_enable);
|
|
mutex_unlock(¤t->perf_event_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int perf_event_task_disable(void)
|
|
{
|
|
struct perf_event *event;
|
|
|
|
mutex_lock(¤t->perf_event_mutex);
|
|
list_for_each_entry(event, ¤t->perf_event_list, owner_entry)
|
|
perf_event_for_each_child(event, perf_event_disable);
|
|
mutex_unlock(¤t->perf_event_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifndef PERF_EVENT_INDEX_OFFSET
|
|
# define PERF_EVENT_INDEX_OFFSET 0
|
|
#endif
|
|
|
|
static int perf_event_index(struct perf_event *event)
|
|
{
|
|
if (event->hw.state & PERF_HES_STOPPED)
|
|
return 0;
|
|
|
|
if (event->state != PERF_EVENT_STATE_ACTIVE)
|
|
return 0;
|
|
|
|
return event->hw.idx + 1 - PERF_EVENT_INDEX_OFFSET;
|
|
}
|
|
|
|
/*
|
|
* Callers need to ensure there can be no nesting of this function, otherwise
|
|
* the seqlock logic goes bad. We can not serialize this because the arch
|
|
* code calls this from NMI context.
|
|
*/
|
|
void perf_event_update_userpage(struct perf_event *event)
|
|
{
|
|
struct perf_event_mmap_page *userpg;
|
|
struct perf_buffer *buffer;
|
|
|
|
rcu_read_lock();
|
|
buffer = rcu_dereference(event->buffer);
|
|
if (!buffer)
|
|
goto unlock;
|
|
|
|
userpg = buffer->user_page;
|
|
|
|
/*
|
|
* Disable preemption so as to not let the corresponding user-space
|
|
* spin too long if we get preempted.
|
|
*/
|
|
preempt_disable();
|
|
++userpg->lock;
|
|
barrier();
|
|
userpg->index = perf_event_index(event);
|
|
userpg->offset = perf_event_count(event);
|
|
if (event->state == PERF_EVENT_STATE_ACTIVE)
|
|
userpg->offset -= local64_read(&event->hw.prev_count);
|
|
|
|
userpg->time_enabled = event->total_time_enabled +
|
|
atomic64_read(&event->child_total_time_enabled);
|
|
|
|
userpg->time_running = event->total_time_running +
|
|
atomic64_read(&event->child_total_time_running);
|
|
|
|
barrier();
|
|
++userpg->lock;
|
|
preempt_enable();
|
|
unlock:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static unsigned long perf_data_size(struct perf_buffer *buffer);
|
|
|
|
static void
|
|
perf_buffer_init(struct perf_buffer *buffer, long watermark, int flags)
|
|
{
|
|
long max_size = perf_data_size(buffer);
|
|
|
|
if (watermark)
|
|
buffer->watermark = min(max_size, watermark);
|
|
|
|
if (!buffer->watermark)
|
|
buffer->watermark = max_size / 2;
|
|
|
|
if (flags & PERF_BUFFER_WRITABLE)
|
|
buffer->writable = 1;
|
|
|
|
atomic_set(&buffer->refcount, 1);
|
|
}
|
|
|
|
#ifndef CONFIG_PERF_USE_VMALLOC
|
|
|
|
/*
|
|
* Back perf_mmap() with regular GFP_KERNEL-0 pages.
|
|
*/
|
|
|
|
static struct page *
|
|
perf_mmap_to_page(struct perf_buffer *buffer, unsigned long pgoff)
|
|
{
|
|
if (pgoff > buffer->nr_pages)
|
|
return NULL;
|
|
|
|
if (pgoff == 0)
|
|
return virt_to_page(buffer->user_page);
|
|
|
|
return virt_to_page(buffer->data_pages[pgoff - 1]);
|
|
}
|
|
|
|
static void *perf_mmap_alloc_page(int cpu)
|
|
{
|
|
struct page *page;
|
|
int node;
|
|
|
|
node = (cpu == -1) ? cpu : cpu_to_node(cpu);
|
|
page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
|
|
if (!page)
|
|
return NULL;
|
|
|
|
return page_address(page);
|
|
}
|
|
|
|
static struct perf_buffer *
|
|
perf_buffer_alloc(int nr_pages, long watermark, int cpu, int flags)
|
|
{
|
|
struct perf_buffer *buffer;
|
|
unsigned long size;
|
|
int i;
|
|
|
|
size = sizeof(struct perf_buffer);
|
|
size += nr_pages * sizeof(void *);
|
|
|
|
buffer = kzalloc(size, GFP_KERNEL);
|
|
if (!buffer)
|
|
goto fail;
|
|
|
|
buffer->user_page = perf_mmap_alloc_page(cpu);
|
|
if (!buffer->user_page)
|
|
goto fail_user_page;
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
buffer->data_pages[i] = perf_mmap_alloc_page(cpu);
|
|
if (!buffer->data_pages[i])
|
|
goto fail_data_pages;
|
|
}
|
|
|
|
buffer->nr_pages = nr_pages;
|
|
|
|
perf_buffer_init(buffer, watermark, flags);
|
|
|
|
return buffer;
|
|
|
|
fail_data_pages:
|
|
for (i--; i >= 0; i--)
|
|
free_page((unsigned long)buffer->data_pages[i]);
|
|
|
|
free_page((unsigned long)buffer->user_page);
|
|
|
|
fail_user_page:
|
|
kfree(buffer);
|
|
|
|
fail:
|
|
return NULL;
|
|
}
|
|
|
|
static void perf_mmap_free_page(unsigned long addr)
|
|
{
|
|
struct page *page = virt_to_page((void *)addr);
|
|
|
|
page->mapping = NULL;
|
|
__free_page(page);
|
|
}
|
|
|
|
static void perf_buffer_free(struct perf_buffer *buffer)
|
|
{
|
|
int i;
|
|
|
|
perf_mmap_free_page((unsigned long)buffer->user_page);
|
|
for (i = 0; i < buffer->nr_pages; i++)
|
|
perf_mmap_free_page((unsigned long)buffer->data_pages[i]);
|
|
kfree(buffer);
|
|
}
|
|
|
|
static inline int page_order(struct perf_buffer *buffer)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#else
|
|
|
|
/*
|
|
* Back perf_mmap() with vmalloc memory.
|
|
*
|
|
* Required for architectures that have d-cache aliasing issues.
|
|
*/
|
|
|
|
static inline int page_order(struct perf_buffer *buffer)
|
|
{
|
|
return buffer->page_order;
|
|
}
|
|
|
|
static struct page *
|
|
perf_mmap_to_page(struct perf_buffer *buffer, unsigned long pgoff)
|
|
{
|
|
if (pgoff > (1UL << page_order(buffer)))
|
|
return NULL;
|
|
|
|
return vmalloc_to_page((void *)buffer->user_page + pgoff * PAGE_SIZE);
|
|
}
|
|
|
|
static void perf_mmap_unmark_page(void *addr)
|
|
{
|
|
struct page *page = vmalloc_to_page(addr);
|
|
|
|
page->mapping = NULL;
|
|
}
|
|
|
|
static void perf_buffer_free_work(struct work_struct *work)
|
|
{
|
|
struct perf_buffer *buffer;
|
|
void *base;
|
|
int i, nr;
|
|
|
|
buffer = container_of(work, struct perf_buffer, work);
|
|
nr = 1 << page_order(buffer);
|
|
|
|
base = buffer->user_page;
|
|
for (i = 0; i < nr + 1; i++)
|
|
perf_mmap_unmark_page(base + (i * PAGE_SIZE));
|
|
|
|
vfree(base);
|
|
kfree(buffer);
|
|
}
|
|
|
|
static void perf_buffer_free(struct perf_buffer *buffer)
|
|
{
|
|
schedule_work(&buffer->work);
|
|
}
|
|
|
|
static struct perf_buffer *
|
|
perf_buffer_alloc(int nr_pages, long watermark, int cpu, int flags)
|
|
{
|
|
struct perf_buffer *buffer;
|
|
unsigned long size;
|
|
void *all_buf;
|
|
|
|
size = sizeof(struct perf_buffer);
|
|
size += sizeof(void *);
|
|
|
|
buffer = kzalloc(size, GFP_KERNEL);
|
|
if (!buffer)
|
|
goto fail;
|
|
|
|
INIT_WORK(&buffer->work, perf_buffer_free_work);
|
|
|
|
all_buf = vmalloc_user((nr_pages + 1) * PAGE_SIZE);
|
|
if (!all_buf)
|
|
goto fail_all_buf;
|
|
|
|
buffer->user_page = all_buf;
|
|
buffer->data_pages[0] = all_buf + PAGE_SIZE;
|
|
buffer->page_order = ilog2(nr_pages);
|
|
buffer->nr_pages = 1;
|
|
|
|
perf_buffer_init(buffer, watermark, flags);
|
|
|
|
return buffer;
|
|
|
|
fail_all_buf:
|
|
kfree(buffer);
|
|
|
|
fail:
|
|
return NULL;
|
|
}
|
|
|
|
#endif
|
|
|
|
static unsigned long perf_data_size(struct perf_buffer *buffer)
|
|
{
|
|
return buffer->nr_pages << (PAGE_SHIFT + page_order(buffer));
|
|
}
|
|
|
|
static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
|
|
{
|
|
struct perf_event *event = vma->vm_file->private_data;
|
|
struct perf_buffer *buffer;
|
|
int ret = VM_FAULT_SIGBUS;
|
|
|
|
if (vmf->flags & FAULT_FLAG_MKWRITE) {
|
|
if (vmf->pgoff == 0)
|
|
ret = 0;
|
|
return ret;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
buffer = rcu_dereference(event->buffer);
|
|
if (!buffer)
|
|
goto unlock;
|
|
|
|
if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
|
|
goto unlock;
|
|
|
|
vmf->page = perf_mmap_to_page(buffer, vmf->pgoff);
|
|
if (!vmf->page)
|
|
goto unlock;
|
|
|
|
get_page(vmf->page);
|
|
vmf->page->mapping = vma->vm_file->f_mapping;
|
|
vmf->page->index = vmf->pgoff;
|
|
|
|
ret = 0;
|
|
unlock:
|
|
rcu_read_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void perf_buffer_free_rcu(struct rcu_head *rcu_head)
|
|
{
|
|
struct perf_buffer *buffer;
|
|
|
|
buffer = container_of(rcu_head, struct perf_buffer, rcu_head);
|
|
perf_buffer_free(buffer);
|
|
}
|
|
|
|
static struct perf_buffer *perf_buffer_get(struct perf_event *event)
|
|
{
|
|
struct perf_buffer *buffer;
|
|
|
|
rcu_read_lock();
|
|
buffer = rcu_dereference(event->buffer);
|
|
if (buffer) {
|
|
if (!atomic_inc_not_zero(&buffer->refcount))
|
|
buffer = NULL;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return buffer;
|
|
}
|
|
|
|
static void perf_buffer_put(struct perf_buffer *buffer)
|
|
{
|
|
if (!atomic_dec_and_test(&buffer->refcount))
|
|
return;
|
|
|
|
call_rcu(&buffer->rcu_head, perf_buffer_free_rcu);
|
|
}
|
|
|
|
static void perf_mmap_open(struct vm_area_struct *vma)
|
|
{
|
|
struct perf_event *event = vma->vm_file->private_data;
|
|
|
|
atomic_inc(&event->mmap_count);
|
|
}
|
|
|
|
static void perf_mmap_close(struct vm_area_struct *vma)
|
|
{
|
|
struct perf_event *event = vma->vm_file->private_data;
|
|
|
|
if (atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) {
|
|
unsigned long size = perf_data_size(event->buffer);
|
|
struct user_struct *user = event->mmap_user;
|
|
struct perf_buffer *buffer = event->buffer;
|
|
|
|
atomic_long_sub((size >> PAGE_SHIFT) + 1, &user->locked_vm);
|
|
vma->vm_mm->locked_vm -= event->mmap_locked;
|
|
rcu_assign_pointer(event->buffer, NULL);
|
|
mutex_unlock(&event->mmap_mutex);
|
|
|
|
perf_buffer_put(buffer);
|
|
free_uid(user);
|
|
}
|
|
}
|
|
|
|
static const struct vm_operations_struct perf_mmap_vmops = {
|
|
.open = perf_mmap_open,
|
|
.close = perf_mmap_close,
|
|
.fault = perf_mmap_fault,
|
|
.page_mkwrite = perf_mmap_fault,
|
|
};
|
|
|
|
static int perf_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
struct perf_event *event = file->private_data;
|
|
unsigned long user_locked, user_lock_limit;
|
|
struct user_struct *user = current_user();
|
|
unsigned long locked, lock_limit;
|
|
struct perf_buffer *buffer;
|
|
unsigned long vma_size;
|
|
unsigned long nr_pages;
|
|
long user_extra, extra;
|
|
int ret = 0, flags = 0;
|
|
|
|
/*
|
|
* Don't allow mmap() of inherited per-task counters. This would
|
|
* create a performance issue due to all children writing to the
|
|
* same buffer.
|
|
*/
|
|
if (event->cpu == -1 && event->attr.inherit)
|
|
return -EINVAL;
|
|
|
|
if (!(vma->vm_flags & VM_SHARED))
|
|
return -EINVAL;
|
|
|
|
vma_size = vma->vm_end - vma->vm_start;
|
|
nr_pages = (vma_size / PAGE_SIZE) - 1;
|
|
|
|
/*
|
|
* If we have buffer pages ensure they're a power-of-two number, so we
|
|
* can do bitmasks instead of modulo.
|
|
*/
|
|
if (nr_pages != 0 && !is_power_of_2(nr_pages))
|
|
return -EINVAL;
|
|
|
|
if (vma_size != PAGE_SIZE * (1 + nr_pages))
|
|
return -EINVAL;
|
|
|
|
if (vma->vm_pgoff != 0)
|
|
return -EINVAL;
|
|
|
|
WARN_ON_ONCE(event->ctx->parent_ctx);
|
|
mutex_lock(&event->mmap_mutex);
|
|
if (event->buffer) {
|
|
if (event->buffer->nr_pages == nr_pages)
|
|
atomic_inc(&event->buffer->refcount);
|
|
else
|
|
ret = -EINVAL;
|
|
goto unlock;
|
|
}
|
|
|
|
user_extra = nr_pages + 1;
|
|
user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
|
|
|
|
/*
|
|
* Increase the limit linearly with more CPUs:
|
|
*/
|
|
user_lock_limit *= num_online_cpus();
|
|
|
|
user_locked = atomic_long_read(&user->locked_vm) + user_extra;
|
|
|
|
extra = 0;
|
|
if (user_locked > user_lock_limit)
|
|
extra = user_locked - user_lock_limit;
|
|
|
|
lock_limit = rlimit(RLIMIT_MEMLOCK);
|
|
lock_limit >>= PAGE_SHIFT;
|
|
locked = vma->vm_mm->locked_vm + extra;
|
|
|
|
if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
|
|
!capable(CAP_IPC_LOCK)) {
|
|
ret = -EPERM;
|
|
goto unlock;
|
|
}
|
|
|
|
WARN_ON(event->buffer);
|
|
|
|
if (vma->vm_flags & VM_WRITE)
|
|
flags |= PERF_BUFFER_WRITABLE;
|
|
|
|
buffer = perf_buffer_alloc(nr_pages, event->attr.wakeup_watermark,
|
|
event->cpu, flags);
|
|
if (!buffer) {
|
|
ret = -ENOMEM;
|
|
goto unlock;
|
|
}
|
|
rcu_assign_pointer(event->buffer, buffer);
|
|
|
|
atomic_long_add(user_extra, &user->locked_vm);
|
|
event->mmap_locked = extra;
|
|
event->mmap_user = get_current_user();
|
|
vma->vm_mm->locked_vm += event->mmap_locked;
|
|
|
|
unlock:
|
|
if (!ret)
|
|
atomic_inc(&event->mmap_count);
|
|
mutex_unlock(&event->mmap_mutex);
|
|
|
|
vma->vm_flags |= VM_RESERVED;
|
|
vma->vm_ops = &perf_mmap_vmops;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int perf_fasync(int fd, struct file *filp, int on)
|
|
{
|
|
struct inode *inode = filp->f_path.dentry->d_inode;
|
|
struct perf_event *event = filp->private_data;
|
|
int retval;
|
|
|
|
mutex_lock(&inode->i_mutex);
|
|
retval = fasync_helper(fd, filp, on, &event->fasync);
|
|
mutex_unlock(&inode->i_mutex);
|
|
|
|
if (retval < 0)
|
|
return retval;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations perf_fops = {
|
|
.llseek = no_llseek,
|
|
.release = perf_release,
|
|
.read = perf_read,
|
|
.poll = perf_poll,
|
|
.unlocked_ioctl = perf_ioctl,
|
|
.compat_ioctl = perf_ioctl,
|
|
.mmap = perf_mmap,
|
|
.fasync = perf_fasync,
|
|
};
|
|
|
|
/*
|
|
* Perf event wakeup
|
|
*
|
|
* If there's data, ensure we set the poll() state and publish everything
|
|
* to user-space before waking everybody up.
|
|
*/
|
|
|
|
void perf_event_wakeup(struct perf_event *event)
|
|
{
|
|
wake_up_all(&event->waitq);
|
|
|
|
if (event->pending_kill) {
|
|
kill_fasync(&event->fasync, SIGIO, event->pending_kill);
|
|
event->pending_kill = 0;
|
|
}
|
|
}
|
|
|
|
static void perf_pending_event(struct irq_work *entry)
|
|
{
|
|
struct perf_event *event = container_of(entry,
|
|
struct perf_event, pending);
|
|
|
|
if (event->pending_disable) {
|
|
event->pending_disable = 0;
|
|
__perf_event_disable(event);
|
|
}
|
|
|
|
if (event->pending_wakeup) {
|
|
event->pending_wakeup = 0;
|
|
perf_event_wakeup(event);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We assume there is only KVM supporting the callbacks.
|
|
* Later on, we might change it to a list if there is
|
|
* another virtualization implementation supporting the callbacks.
|
|
*/
|
|
struct perf_guest_info_callbacks *perf_guest_cbs;
|
|
|
|
int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
|
|
{
|
|
perf_guest_cbs = cbs;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
|
|
|
|
int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
|
|
{
|
|
perf_guest_cbs = NULL;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
|
|
|
|
/*
|
|
* Output
|
|
*/
|
|
static bool perf_output_space(struct perf_buffer *buffer, unsigned long tail,
|
|
unsigned long offset, unsigned long head)
|
|
{
|
|
unsigned long mask;
|
|
|
|
if (!buffer->writable)
|
|
return true;
|
|
|
|
mask = perf_data_size(buffer) - 1;
|
|
|
|
offset = (offset - tail) & mask;
|
|
head = (head - tail) & mask;
|
|
|
|
if ((int)(head - offset) < 0)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static void perf_output_wakeup(struct perf_output_handle *handle)
|
|
{
|
|
atomic_set(&handle->buffer->poll, POLL_IN);
|
|
|
|
if (handle->nmi) {
|
|
handle->event->pending_wakeup = 1;
|
|
irq_work_queue(&handle->event->pending);
|
|
} else
|
|
perf_event_wakeup(handle->event);
|
|
}
|
|
|
|
/*
|
|
* We need to ensure a later event_id doesn't publish a head when a former
|
|
* event isn't done writing. However since we need to deal with NMIs we
|
|
* cannot fully serialize things.
|
|
*
|
|
* We only publish the head (and generate a wakeup) when the outer-most
|
|
* event completes.
|
|
*/
|
|
static void perf_output_get_handle(struct perf_output_handle *handle)
|
|
{
|
|
struct perf_buffer *buffer = handle->buffer;
|
|
|
|
preempt_disable();
|
|
local_inc(&buffer->nest);
|
|
handle->wakeup = local_read(&buffer->wakeup);
|
|
}
|
|
|
|
static void perf_output_put_handle(struct perf_output_handle *handle)
|
|
{
|
|
struct perf_buffer *buffer = handle->buffer;
|
|
unsigned long head;
|
|
|
|
again:
|
|
head = local_read(&buffer->head);
|
|
|
|
/*
|
|
* IRQ/NMI can happen here, which means we can miss a head update.
|
|
*/
|
|
|
|
if (!local_dec_and_test(&buffer->nest))
|
|
goto out;
|
|
|
|
/*
|
|
* Publish the known good head. Rely on the full barrier implied
|
|
* by atomic_dec_and_test() order the buffer->head read and this
|
|
* write.
|
|
*/
|
|
buffer->user_page->data_head = head;
|
|
|
|
/*
|
|
* Now check if we missed an update, rely on the (compiler)
|
|
* barrier in atomic_dec_and_test() to re-read buffer->head.
|
|
*/
|
|
if (unlikely(head != local_read(&buffer->head))) {
|
|
local_inc(&buffer->nest);
|
|
goto again;
|
|
}
|
|
|
|
if (handle->wakeup != local_read(&buffer->wakeup))
|
|
perf_output_wakeup(handle);
|
|
|
|
out:
|
|
preempt_enable();
|
|
}
|
|
|
|
__always_inline void perf_output_copy(struct perf_output_handle *handle,
|
|
const void *buf, unsigned int len)
|
|
{
|
|
do {
|
|
unsigned long size = min_t(unsigned long, handle->size, len);
|
|
|
|
memcpy(handle->addr, buf, size);
|
|
|
|
len -= size;
|
|
handle->addr += size;
|
|
buf += size;
|
|
handle->size -= size;
|
|
if (!handle->size) {
|
|
struct perf_buffer *buffer = handle->buffer;
|
|
|
|
handle->page++;
|
|
handle->page &= buffer->nr_pages - 1;
|
|
handle->addr = buffer->data_pages[handle->page];
|
|
handle->size = PAGE_SIZE << page_order(buffer);
|
|
}
|
|
} while (len);
|
|
}
|
|
|
|
static void __perf_event_header__init_id(struct perf_event_header *header,
|
|
struct perf_sample_data *data,
|
|
struct perf_event *event)
|
|
{
|
|
u64 sample_type = event->attr.sample_type;
|
|
|
|
data->type = sample_type;
|
|
header->size += event->id_header_size;
|
|
|
|
if (sample_type & PERF_SAMPLE_TID) {
|
|
/* namespace issues */
|
|
data->tid_entry.pid = perf_event_pid(event, current);
|
|
data->tid_entry.tid = perf_event_tid(event, current);
|
|
}
|
|
|
|
if (sample_type & PERF_SAMPLE_TIME)
|
|
data->time = perf_clock();
|
|
|
|
if (sample_type & PERF_SAMPLE_ID)
|
|
data->id = primary_event_id(event);
|
|
|
|
if (sample_type & PERF_SAMPLE_STREAM_ID)
|
|
data->stream_id = event->id;
|
|
|
|
if (sample_type & PERF_SAMPLE_CPU) {
|
|
data->cpu_entry.cpu = raw_smp_processor_id();
|
|
data->cpu_entry.reserved = 0;
|
|
}
|
|
}
|
|
|
|
static void perf_event_header__init_id(struct perf_event_header *header,
|
|
struct perf_sample_data *data,
|
|
struct perf_event *event)
|
|
{
|
|
if (event->attr.sample_id_all)
|
|
__perf_event_header__init_id(header, data, event);
|
|
}
|
|
|
|
static void __perf_event__output_id_sample(struct perf_output_handle *handle,
|
|
struct perf_sample_data *data)
|
|
{
|
|
u64 sample_type = data->type;
|
|
|
|
if (sample_type & PERF_SAMPLE_TID)
|
|
perf_output_put(handle, data->tid_entry);
|
|
|
|
if (sample_type & PERF_SAMPLE_TIME)
|
|
perf_output_put(handle, data->time);
|
|
|
|
if (sample_type & PERF_SAMPLE_ID)
|
|
perf_output_put(handle, data->id);
|
|
|
|
if (sample_type & PERF_SAMPLE_STREAM_ID)
|
|
perf_output_put(handle, data->stream_id);
|
|
|
|
if (sample_type & PERF_SAMPLE_CPU)
|
|
perf_output_put(handle, data->cpu_entry);
|
|
}
|
|
|
|
static void perf_event__output_id_sample(struct perf_event *event,
|
|
struct perf_output_handle *handle,
|
|
struct perf_sample_data *sample)
|
|
{
|
|
if (event->attr.sample_id_all)
|
|
__perf_event__output_id_sample(handle, sample);
|
|
}
|
|
|
|
int perf_output_begin(struct perf_output_handle *handle,
|
|
struct perf_event *event, unsigned int size,
|
|
int nmi, int sample)
|
|
{
|
|
struct perf_buffer *buffer;
|
|
unsigned long tail, offset, head;
|
|
int have_lost;
|
|
struct perf_sample_data sample_data;
|
|
struct {
|
|
struct perf_event_header header;
|
|
u64 id;
|
|
u64 lost;
|
|
} lost_event;
|
|
|
|
rcu_read_lock();
|
|
/*
|
|
* For inherited events we send all the output towards the parent.
|
|
*/
|
|
if (event->parent)
|
|
event = event->parent;
|
|
|
|
buffer = rcu_dereference(event->buffer);
|
|
if (!buffer)
|
|
goto out;
|
|
|
|
handle->buffer = buffer;
|
|
handle->event = event;
|
|
handle->nmi = nmi;
|
|
handle->sample = sample;
|
|
|
|
if (!buffer->nr_pages)
|
|
goto out;
|
|
|
|
have_lost = local_read(&buffer->lost);
|
|
if (have_lost) {
|
|
lost_event.header.size = sizeof(lost_event);
|
|
perf_event_header__init_id(&lost_event.header, &sample_data,
|
|
event);
|
|
size += lost_event.header.size;
|
|
}
|
|
|
|
perf_output_get_handle(handle);
|
|
|
|
do {
|
|
/*
|
|
* Userspace could choose to issue a mb() before updating the
|
|
* tail pointer. So that all reads will be completed before the
|
|
* write is issued.
|
|
*/
|
|
tail = ACCESS_ONCE(buffer->user_page->data_tail);
|
|
smp_rmb();
|
|
offset = head = local_read(&buffer->head);
|
|
head += size;
|
|
if (unlikely(!perf_output_space(buffer, tail, offset, head)))
|
|
goto fail;
|
|
} while (local_cmpxchg(&buffer->head, offset, head) != offset);
|
|
|
|
if (head - local_read(&buffer->wakeup) > buffer->watermark)
|
|
local_add(buffer->watermark, &buffer->wakeup);
|
|
|
|
handle->page = offset >> (PAGE_SHIFT + page_order(buffer));
|
|
handle->page &= buffer->nr_pages - 1;
|
|
handle->size = offset & ((PAGE_SIZE << page_order(buffer)) - 1);
|
|
handle->addr = buffer->data_pages[handle->page];
|
|
handle->addr += handle->size;
|
|
handle->size = (PAGE_SIZE << page_order(buffer)) - handle->size;
|
|
|
|
if (have_lost) {
|
|
lost_event.header.type = PERF_RECORD_LOST;
|
|
lost_event.header.misc = 0;
|
|
lost_event.id = event->id;
|
|
lost_event.lost = local_xchg(&buffer->lost, 0);
|
|
|
|
perf_output_put(handle, lost_event);
|
|
perf_event__output_id_sample(event, handle, &sample_data);
|
|
}
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
local_inc(&buffer->lost);
|
|
perf_output_put_handle(handle);
|
|
out:
|
|
rcu_read_unlock();
|
|
|
|
return -ENOSPC;
|
|
}
|
|
|
|
void perf_output_end(struct perf_output_handle *handle)
|
|
{
|
|
struct perf_event *event = handle->event;
|
|
struct perf_buffer *buffer = handle->buffer;
|
|
|
|
int wakeup_events = event->attr.wakeup_events;
|
|
|
|
if (handle->sample && wakeup_events) {
|
|
int events = local_inc_return(&buffer->events);
|
|
if (events >= wakeup_events) {
|
|
local_sub(wakeup_events, &buffer->events);
|
|
local_inc(&buffer->wakeup);
|
|
}
|
|
}
|
|
|
|
perf_output_put_handle(handle);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void perf_output_read_one(struct perf_output_handle *handle,
|
|
struct perf_event *event,
|
|
u64 enabled, u64 running)
|
|
{
|
|
u64 read_format = event->attr.read_format;
|
|
u64 values[4];
|
|
int n = 0;
|
|
|
|
values[n++] = perf_event_count(event);
|
|
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
|
|
values[n++] = enabled +
|
|
atomic64_read(&event->child_total_time_enabled);
|
|
}
|
|
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
|
|
values[n++] = running +
|
|
atomic64_read(&event->child_total_time_running);
|
|
}
|
|
if (read_format & PERF_FORMAT_ID)
|
|
values[n++] = primary_event_id(event);
|
|
|
|
perf_output_copy(handle, values, n * sizeof(u64));
|
|
}
|
|
|
|
/*
|
|
* XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
|
|
*/
|
|
static void perf_output_read_group(struct perf_output_handle *handle,
|
|
struct perf_event *event,
|
|
u64 enabled, u64 running)
|
|
{
|
|
struct perf_event *leader = event->group_leader, *sub;
|
|
u64 read_format = event->attr.read_format;
|
|
u64 values[5];
|
|
int n = 0;
|
|
|
|
values[n++] = 1 + leader->nr_siblings;
|
|
|
|
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
|
|
values[n++] = enabled;
|
|
|
|
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
|
|
values[n++] = running;
|
|
|
|
if (leader != event)
|
|
leader->pmu->read(leader);
|
|
|
|
values[n++] = perf_event_count(leader);
|
|
if (read_format & PERF_FORMAT_ID)
|
|
values[n++] = primary_event_id(leader);
|
|
|
|
perf_output_copy(handle, values, n * sizeof(u64));
|
|
|
|
list_for_each_entry(sub, &leader->sibling_list, group_entry) {
|
|
n = 0;
|
|
|
|
if (sub != event)
|
|
sub->pmu->read(sub);
|
|
|
|
values[n++] = perf_event_count(sub);
|
|
if (read_format & PERF_FORMAT_ID)
|
|
values[n++] = primary_event_id(sub);
|
|
|
|
perf_output_copy(handle, values, n * sizeof(u64));
|
|
}
|
|
}
|
|
|
|
#define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
|
|
PERF_FORMAT_TOTAL_TIME_RUNNING)
|
|
|
|
static void perf_output_read(struct perf_output_handle *handle,
|
|
struct perf_event *event)
|
|
{
|
|
u64 enabled = 0, running = 0, now, ctx_time;
|
|
u64 read_format = event->attr.read_format;
|
|
|
|
/*
|
|
* compute total_time_enabled, total_time_running
|
|
* based on snapshot values taken when the event
|
|
* was last scheduled in.
|
|
*
|
|
* we cannot simply called update_context_time()
|
|
* because of locking issue as we are called in
|
|
* NMI context
|
|
*/
|
|
if (read_format & PERF_FORMAT_TOTAL_TIMES) {
|
|
now = perf_clock();
|
|
ctx_time = event->shadow_ctx_time + now;
|
|
enabled = ctx_time - event->tstamp_enabled;
|
|
running = ctx_time - event->tstamp_running;
|
|
}
|
|
|
|
if (event->attr.read_format & PERF_FORMAT_GROUP)
|
|
perf_output_read_group(handle, event, enabled, running);
|
|
else
|
|
perf_output_read_one(handle, event, enabled, running);
|
|
}
|
|
|
|
void perf_output_sample(struct perf_output_handle *handle,
|
|
struct perf_event_header *header,
|
|
struct perf_sample_data *data,
|
|
struct perf_event *event)
|
|
{
|
|
u64 sample_type = data->type;
|
|
|
|
perf_output_put(handle, *header);
|
|
|
|
if (sample_type & PERF_SAMPLE_IP)
|
|
perf_output_put(handle, data->ip);
|
|
|
|
if (sample_type & PERF_SAMPLE_TID)
|
|
perf_output_put(handle, data->tid_entry);
|
|
|
|
if (sample_type & PERF_SAMPLE_TIME)
|
|
perf_output_put(handle, data->time);
|
|
|
|
if (sample_type & PERF_SAMPLE_ADDR)
|
|
perf_output_put(handle, data->addr);
|
|
|
|
if (sample_type & PERF_SAMPLE_ID)
|
|
perf_output_put(handle, data->id);
|
|
|
|
if (sample_type & PERF_SAMPLE_STREAM_ID)
|
|
perf_output_put(handle, data->stream_id);
|
|
|
|
if (sample_type & PERF_SAMPLE_CPU)
|
|
perf_output_put(handle, data->cpu_entry);
|
|
|
|
if (sample_type & PERF_SAMPLE_PERIOD)
|
|
perf_output_put(handle, data->period);
|
|
|
|
if (sample_type & PERF_SAMPLE_READ)
|
|
perf_output_read(handle, event);
|
|
|
|
if (sample_type & PERF_SAMPLE_CALLCHAIN) {
|
|
if (data->callchain) {
|
|
int size = 1;
|
|
|
|
if (data->callchain)
|
|
size += data->callchain->nr;
|
|
|
|
size *= sizeof(u64);
|
|
|
|
perf_output_copy(handle, data->callchain, size);
|
|
} else {
|
|
u64 nr = 0;
|
|
perf_output_put(handle, nr);
|
|
}
|
|
}
|
|
|
|
if (sample_type & PERF_SAMPLE_RAW) {
|
|
if (data->raw) {
|
|
perf_output_put(handle, data->raw->size);
|
|
perf_output_copy(handle, data->raw->data,
|
|
data->raw->size);
|
|
} else {
|
|
struct {
|
|
u32 size;
|
|
u32 data;
|
|
} raw = {
|
|
.size = sizeof(u32),
|
|
.data = 0,
|
|
};
|
|
perf_output_put(handle, raw);
|
|
}
|
|
}
|
|
}
|
|
|
|
void perf_prepare_sample(struct perf_event_header *header,
|
|
struct perf_sample_data *data,
|
|
struct perf_event *event,
|
|
struct pt_regs *regs)
|
|
{
|
|
u64 sample_type = event->attr.sample_type;
|
|
|
|
header->type = PERF_RECORD_SAMPLE;
|
|
header->size = sizeof(*header) + event->header_size;
|
|
|
|
header->misc = 0;
|
|
header->misc |= perf_misc_flags(regs);
|
|
|
|
__perf_event_header__init_id(header, data, event);
|
|
|
|
if (sample_type & PERF_SAMPLE_IP)
|
|
data->ip = perf_instruction_pointer(regs);
|
|
|
|
if (sample_type & PERF_SAMPLE_CALLCHAIN) {
|
|
int size = 1;
|
|
|
|
data->callchain = perf_callchain(regs);
|
|
|
|
if (data->callchain)
|
|
size += data->callchain->nr;
|
|
|
|
header->size += size * sizeof(u64);
|
|
}
|
|
|
|
if (sample_type & PERF_SAMPLE_RAW) {
|
|
int size = sizeof(u32);
|
|
|
|
if (data->raw)
|
|
size += data->raw->size;
|
|
else
|
|
size += sizeof(u32);
|
|
|
|
WARN_ON_ONCE(size & (sizeof(u64)-1));
|
|
header->size += size;
|
|
}
|
|
}
|
|
|
|
static void perf_event_output(struct perf_event *event, int nmi,
|
|
struct perf_sample_data *data,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct perf_output_handle handle;
|
|
struct perf_event_header header;
|
|
|
|
/* protect the callchain buffers */
|
|
rcu_read_lock();
|
|
|
|
perf_prepare_sample(&header, data, event, regs);
|
|
|
|
if (perf_output_begin(&handle, event, header.size, nmi, 1))
|
|
goto exit;
|
|
|
|
perf_output_sample(&handle, &header, data, event);
|
|
|
|
perf_output_end(&handle);
|
|
|
|
exit:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/*
|
|
* read event_id
|
|
*/
|
|
|
|
struct perf_read_event {
|
|
struct perf_event_header header;
|
|
|
|
u32 pid;
|
|
u32 tid;
|
|
};
|
|
|
|
static void
|
|
perf_event_read_event(struct perf_event *event,
|
|
struct task_struct *task)
|
|
{
|
|
struct perf_output_handle handle;
|
|
struct perf_sample_data sample;
|
|
struct perf_read_event read_event = {
|
|
.header = {
|
|
.type = PERF_RECORD_READ,
|
|
.misc = 0,
|
|
.size = sizeof(read_event) + event->read_size,
|
|
},
|
|
.pid = perf_event_pid(event, task),
|
|
.tid = perf_event_tid(event, task),
|
|
};
|
|
int ret;
|
|
|
|
perf_event_header__init_id(&read_event.header, &sample, event);
|
|
ret = perf_output_begin(&handle, event, read_event.header.size, 0, 0);
|
|
if (ret)
|
|
return;
|
|
|
|
perf_output_put(&handle, read_event);
|
|
perf_output_read(&handle, event);
|
|
perf_event__output_id_sample(event, &handle, &sample);
|
|
|
|
perf_output_end(&handle);
|
|
}
|
|
|
|
/*
|
|
* task tracking -- fork/exit
|
|
*
|
|
* enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
|
|
*/
|
|
|
|
struct perf_task_event {
|
|
struct task_struct *task;
|
|
struct perf_event_context *task_ctx;
|
|
|
|
struct {
|
|
struct perf_event_header header;
|
|
|
|
u32 pid;
|
|
u32 ppid;
|
|
u32 tid;
|
|
u32 ptid;
|
|
u64 time;
|
|
} event_id;
|
|
};
|
|
|
|
static void perf_event_task_output(struct perf_event *event,
|
|
struct perf_task_event *task_event)
|
|
{
|
|
struct perf_output_handle handle;
|
|
struct perf_sample_data sample;
|
|
struct task_struct *task = task_event->task;
|
|
int ret, size = task_event->event_id.header.size;
|
|
|
|
perf_event_header__init_id(&task_event->event_id.header, &sample, event);
|
|
|
|
ret = perf_output_begin(&handle, event,
|
|
task_event->event_id.header.size, 0, 0);
|
|
if (ret)
|
|
goto out;
|
|
|
|
task_event->event_id.pid = perf_event_pid(event, task);
|
|
task_event->event_id.ppid = perf_event_pid(event, current);
|
|
|
|
task_event->event_id.tid = perf_event_tid(event, task);
|
|
task_event->event_id.ptid = perf_event_tid(event, current);
|
|
|
|
perf_output_put(&handle, task_event->event_id);
|
|
|
|
perf_event__output_id_sample(event, &handle, &sample);
|
|
|
|
perf_output_end(&handle);
|
|
out:
|
|
task_event->event_id.header.size = size;
|
|
}
|
|
|
|
static int perf_event_task_match(struct perf_event *event)
|
|
{
|
|
if (event->state < PERF_EVENT_STATE_INACTIVE)
|
|
return 0;
|
|
|
|
if (!event_filter_match(event))
|
|
return 0;
|
|
|
|
if (event->attr.comm || event->attr.mmap ||
|
|
event->attr.mmap_data || event->attr.task)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void perf_event_task_ctx(struct perf_event_context *ctx,
|
|
struct perf_task_event *task_event)
|
|
{
|
|
struct perf_event *event;
|
|
|
|
list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
|
|
if (perf_event_task_match(event))
|
|
perf_event_task_output(event, task_event);
|
|
}
|
|
}
|
|
|
|
static void perf_event_task_event(struct perf_task_event *task_event)
|
|
{
|
|
struct perf_cpu_context *cpuctx;
|
|
struct perf_event_context *ctx;
|
|
struct pmu *pmu;
|
|
int ctxn;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(pmu, &pmus, entry) {
|
|
cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
|
|
if (cpuctx->active_pmu != pmu)
|
|
goto next;
|
|
perf_event_task_ctx(&cpuctx->ctx, task_event);
|
|
|
|
ctx = task_event->task_ctx;
|
|
if (!ctx) {
|
|
ctxn = pmu->task_ctx_nr;
|
|
if (ctxn < 0)
|
|
goto next;
|
|
ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
|
|
}
|
|
if (ctx)
|
|
perf_event_task_ctx(ctx, task_event);
|
|
next:
|
|
put_cpu_ptr(pmu->pmu_cpu_context);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void perf_event_task(struct task_struct *task,
|
|
struct perf_event_context *task_ctx,
|
|
int new)
|
|
{
|
|
struct perf_task_event task_event;
|
|
|
|
if (!atomic_read(&nr_comm_events) &&
|
|
!atomic_read(&nr_mmap_events) &&
|
|
!atomic_read(&nr_task_events))
|
|
return;
|
|
|
|
task_event = (struct perf_task_event){
|
|
.task = task,
|
|
.task_ctx = task_ctx,
|
|
.event_id = {
|
|
.header = {
|
|
.type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
|
|
.misc = 0,
|
|
.size = sizeof(task_event.event_id),
|
|
},
|
|
/* .pid */
|
|
/* .ppid */
|
|
/* .tid */
|
|
/* .ptid */
|
|
.time = perf_clock(),
|
|
},
|
|
};
|
|
|
|
perf_event_task_event(&task_event);
|
|
}
|
|
|
|
void perf_event_fork(struct task_struct *task)
|
|
{
|
|
perf_event_task(task, NULL, 1);
|
|
}
|
|
|
|
/*
|
|
* comm tracking
|
|
*/
|
|
|
|
struct perf_comm_event {
|
|
struct task_struct *task;
|
|
char *comm;
|
|
int comm_size;
|
|
|
|
struct {
|
|
struct perf_event_header header;
|
|
|
|
u32 pid;
|
|
u32 tid;
|
|
} event_id;
|
|
};
|
|
|
|
static void perf_event_comm_output(struct perf_event *event,
|
|
struct perf_comm_event *comm_event)
|
|
{
|
|
struct perf_output_handle handle;
|
|
struct perf_sample_data sample;
|
|
int size = comm_event->event_id.header.size;
|
|
int ret;
|
|
|
|
perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
|
|
ret = perf_output_begin(&handle, event,
|
|
comm_event->event_id.header.size, 0, 0);
|
|
|
|
if (ret)
|
|
goto out;
|
|
|
|
comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
|
|
comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
|
|
|
|
perf_output_put(&handle, comm_event->event_id);
|
|
perf_output_copy(&handle, comm_event->comm,
|
|
comm_event->comm_size);
|
|
|
|
perf_event__output_id_sample(event, &handle, &sample);
|
|
|
|
perf_output_end(&handle);
|
|
out:
|
|
comm_event->event_id.header.size = size;
|
|
}
|
|
|
|
static int perf_event_comm_match(struct perf_event *event)
|
|
{
|
|
if (event->state < PERF_EVENT_STATE_INACTIVE)
|
|
return 0;
|
|
|
|
if (!event_filter_match(event))
|
|
return 0;
|
|
|
|
if (event->attr.comm)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void perf_event_comm_ctx(struct perf_event_context *ctx,
|
|
struct perf_comm_event *comm_event)
|
|
{
|
|
struct perf_event *event;
|
|
|
|
list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
|
|
if (perf_event_comm_match(event))
|
|
perf_event_comm_output(event, comm_event);
|
|
}
|
|
}
|
|
|
|
static void perf_event_comm_event(struct perf_comm_event *comm_event)
|
|
{
|
|
struct perf_cpu_context *cpuctx;
|
|
struct perf_event_context *ctx;
|
|
char comm[TASK_COMM_LEN];
|
|
unsigned int size;
|
|
struct pmu *pmu;
|
|
int ctxn;
|
|
|
|
memset(comm, 0, sizeof(comm));
|
|
strlcpy(comm, comm_event->task->comm, sizeof(comm));
|
|
size = ALIGN(strlen(comm)+1, sizeof(u64));
|
|
|
|
comm_event->comm = comm;
|
|
comm_event->comm_size = size;
|
|
|
|
comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(pmu, &pmus, entry) {
|
|
cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
|
|
if (cpuctx->active_pmu != pmu)
|
|
goto next;
|
|
perf_event_comm_ctx(&cpuctx->ctx, comm_event);
|
|
|
|
ctxn = pmu->task_ctx_nr;
|
|
if (ctxn < 0)
|
|
goto next;
|
|
|
|
ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
|
|
if (ctx)
|
|
perf_event_comm_ctx(ctx, comm_event);
|
|
next:
|
|
put_cpu_ptr(pmu->pmu_cpu_context);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
void perf_event_comm(struct task_struct *task)
|
|
{
|
|
struct perf_comm_event comm_event;
|
|
struct perf_event_context *ctx;
|
|
int ctxn;
|
|
|
|
for_each_task_context_nr(ctxn) {
|
|
ctx = task->perf_event_ctxp[ctxn];
|
|
if (!ctx)
|
|
continue;
|
|
|
|
perf_event_enable_on_exec(ctx);
|
|
}
|
|
|
|
if (!atomic_read(&nr_comm_events))
|
|
return;
|
|
|
|
comm_event = (struct perf_comm_event){
|
|
.task = task,
|
|
/* .comm */
|
|
/* .comm_size */
|
|
.event_id = {
|
|
.header = {
|
|
.type = PERF_RECORD_COMM,
|
|
.misc = 0,
|
|
/* .size */
|
|
},
|
|
/* .pid */
|
|
/* .tid */
|
|
},
|
|
};
|
|
|
|
perf_event_comm_event(&comm_event);
|
|
}
|
|
|
|
/*
|
|
* mmap tracking
|
|
*/
|
|
|
|
struct perf_mmap_event {
|
|
struct vm_area_struct *vma;
|
|
|
|
const char *file_name;
|
|
int file_size;
|
|
|
|
struct {
|
|
struct perf_event_header header;
|
|
|
|
u32 pid;
|
|
u32 tid;
|
|
u64 start;
|
|
u64 len;
|
|
u64 pgoff;
|
|
} event_id;
|
|
};
|
|
|
|
static void perf_event_mmap_output(struct perf_event *event,
|
|
struct perf_mmap_event *mmap_event)
|
|
{
|
|
struct perf_output_handle handle;
|
|
struct perf_sample_data sample;
|
|
int size = mmap_event->event_id.header.size;
|
|
int ret;
|
|
|
|
perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
|
|
ret = perf_output_begin(&handle, event,
|
|
mmap_event->event_id.header.size, 0, 0);
|
|
if (ret)
|
|
goto out;
|
|
|
|
mmap_event->event_id.pid = perf_event_pid(event, current);
|
|
mmap_event->event_id.tid = perf_event_tid(event, current);
|
|
|
|
perf_output_put(&handle, mmap_event->event_id);
|
|
perf_output_copy(&handle, mmap_event->file_name,
|
|
mmap_event->file_size);
|
|
|
|
perf_event__output_id_sample(event, &handle, &sample);
|
|
|
|
perf_output_end(&handle);
|
|
out:
|
|
mmap_event->event_id.header.size = size;
|
|
}
|
|
|
|
static int perf_event_mmap_match(struct perf_event *event,
|
|
struct perf_mmap_event *mmap_event,
|
|
int executable)
|
|
{
|
|
if (event->state < PERF_EVENT_STATE_INACTIVE)
|
|
return 0;
|
|
|
|
if (!event_filter_match(event))
|
|
return 0;
|
|
|
|
if ((!executable && event->attr.mmap_data) ||
|
|
(executable && event->attr.mmap))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void perf_event_mmap_ctx(struct perf_event_context *ctx,
|
|
struct perf_mmap_event *mmap_event,
|
|
int executable)
|
|
{
|
|
struct perf_event *event;
|
|
|
|
list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
|
|
if (perf_event_mmap_match(event, mmap_event, executable))
|
|
perf_event_mmap_output(event, mmap_event);
|
|
}
|
|
}
|
|
|
|
static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
|
|
{
|
|
struct perf_cpu_context *cpuctx;
|
|
struct perf_event_context *ctx;
|
|
struct vm_area_struct *vma = mmap_event->vma;
|
|
struct file *file = vma->vm_file;
|
|
unsigned int size;
|
|
char tmp[16];
|
|
char *buf = NULL;
|
|
const char *name;
|
|
struct pmu *pmu;
|
|
int ctxn;
|
|
|
|
memset(tmp, 0, sizeof(tmp));
|
|
|
|
if (file) {
|
|
/*
|
|
* d_path works from the end of the buffer backwards, so we
|
|
* need to add enough zero bytes after the string to handle
|
|
* the 64bit alignment we do later.
|
|
*/
|
|
buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL);
|
|
if (!buf) {
|
|
name = strncpy(tmp, "//enomem", sizeof(tmp));
|
|
goto got_name;
|
|
}
|
|
name = d_path(&file->f_path, buf, PATH_MAX);
|
|
if (IS_ERR(name)) {
|
|
name = strncpy(tmp, "//toolong", sizeof(tmp));
|
|
goto got_name;
|
|
}
|
|
} else {
|
|
if (arch_vma_name(mmap_event->vma)) {
|
|
name = strncpy(tmp, arch_vma_name(mmap_event->vma),
|
|
sizeof(tmp));
|
|
goto got_name;
|
|
}
|
|
|
|
if (!vma->vm_mm) {
|
|
name = strncpy(tmp, "[vdso]", sizeof(tmp));
|
|
goto got_name;
|
|
} else if (vma->vm_start <= vma->vm_mm->start_brk &&
|
|
vma->vm_end >= vma->vm_mm->brk) {
|
|
name = strncpy(tmp, "[heap]", sizeof(tmp));
|
|
goto got_name;
|
|
} else if (vma->vm_start <= vma->vm_mm->start_stack &&
|
|
vma->vm_end >= vma->vm_mm->start_stack) {
|
|
name = strncpy(tmp, "[stack]", sizeof(tmp));
|
|
goto got_name;
|
|
}
|
|
|
|
name = strncpy(tmp, "//anon", sizeof(tmp));
|
|
goto got_name;
|
|
}
|
|
|
|
got_name:
|
|
size = ALIGN(strlen(name)+1, sizeof(u64));
|
|
|
|
mmap_event->file_name = name;
|
|
mmap_event->file_size = size;
|
|
|
|
mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(pmu, &pmus, entry) {
|
|
cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
|
|
if (cpuctx->active_pmu != pmu)
|
|
goto next;
|
|
perf_event_mmap_ctx(&cpuctx->ctx, mmap_event,
|
|
vma->vm_flags & VM_EXEC);
|
|
|
|
ctxn = pmu->task_ctx_nr;
|
|
if (ctxn < 0)
|
|
goto next;
|
|
|
|
ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
|
|
if (ctx) {
|
|
perf_event_mmap_ctx(ctx, mmap_event,
|
|
vma->vm_flags & VM_EXEC);
|
|
}
|
|
next:
|
|
put_cpu_ptr(pmu->pmu_cpu_context);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
kfree(buf);
|
|
}
|
|
|
|
void perf_event_mmap(struct vm_area_struct *vma)
|
|
{
|
|
struct perf_mmap_event mmap_event;
|
|
|
|
if (!atomic_read(&nr_mmap_events))
|
|
return;
|
|
|
|
mmap_event = (struct perf_mmap_event){
|
|
.vma = vma,
|
|
/* .file_name */
|
|
/* .file_size */
|
|
.event_id = {
|
|
.header = {
|
|
.type = PERF_RECORD_MMAP,
|
|
.misc = PERF_RECORD_MISC_USER,
|
|
/* .size */
|
|
},
|
|
/* .pid */
|
|
/* .tid */
|
|
.start = vma->vm_start,
|
|
.len = vma->vm_end - vma->vm_start,
|
|
.pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT,
|
|
},
|
|
};
|
|
|
|
perf_event_mmap_event(&mmap_event);
|
|
}
|
|
|
|
/*
|
|
* IRQ throttle logging
|
|
*/
|
|
|
|
static void perf_log_throttle(struct perf_event *event, int enable)
|
|
{
|
|
struct perf_output_handle handle;
|
|
struct perf_sample_data sample;
|
|
int ret;
|
|
|
|
struct {
|
|
struct perf_event_header header;
|
|
u64 time;
|
|
u64 id;
|
|
u64 stream_id;
|
|
} throttle_event = {
|
|
.header = {
|
|
.type = PERF_RECORD_THROTTLE,
|
|
.misc = 0,
|
|
.size = sizeof(throttle_event),
|
|
},
|
|
.time = perf_clock(),
|
|
.id = primary_event_id(event),
|
|
.stream_id = event->id,
|
|
};
|
|
|
|
if (enable)
|
|
throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
|
|
|
|
perf_event_header__init_id(&throttle_event.header, &sample, event);
|
|
|
|
ret = perf_output_begin(&handle, event,
|
|
throttle_event.header.size, 1, 0);
|
|
if (ret)
|
|
return;
|
|
|
|
perf_output_put(&handle, throttle_event);
|
|
perf_event__output_id_sample(event, &handle, &sample);
|
|
perf_output_end(&handle);
|
|
}
|
|
|
|
/*
|
|
* Generic event overflow handling, sampling.
|
|
*/
|
|
|
|
static int __perf_event_overflow(struct perf_event *event, int nmi,
|
|
int throttle, struct perf_sample_data *data,
|
|
struct pt_regs *regs)
|
|
{
|
|
int events = atomic_read(&event->event_limit);
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
int ret = 0;
|
|
|
|
/*
|
|
* Non-sampling counters might still use the PMI to fold short
|
|
* hardware counters, ignore those.
|
|
*/
|
|
if (unlikely(!is_sampling_event(event)))
|
|
return 0;
|
|
|
|
if (unlikely(hwc->interrupts >= max_samples_per_tick)) {
|
|
if (throttle) {
|
|
hwc->interrupts = MAX_INTERRUPTS;
|
|
perf_log_throttle(event, 0);
|
|
ret = 1;
|
|
}
|
|
} else
|
|
hwc->interrupts++;
|
|
|
|
if (event->attr.freq) {
|
|
u64 now = perf_clock();
|
|
s64 delta = now - hwc->freq_time_stamp;
|
|
|
|
hwc->freq_time_stamp = now;
|
|
|
|
if (delta > 0 && delta < 2*TICK_NSEC)
|
|
perf_adjust_period(event, delta, hwc->last_period);
|
|
}
|
|
|
|
/*
|
|
* XXX event_limit might not quite work as expected on inherited
|
|
* events
|
|
*/
|
|
|
|
event->pending_kill = POLL_IN;
|
|
if (events && atomic_dec_and_test(&event->event_limit)) {
|
|
ret = 1;
|
|
event->pending_kill = POLL_HUP;
|
|
if (nmi) {
|
|
event->pending_disable = 1;
|
|
irq_work_queue(&event->pending);
|
|
} else
|
|
perf_event_disable(event);
|
|
}
|
|
|
|
if (event->overflow_handler)
|
|
event->overflow_handler(event, nmi, data, regs);
|
|
else
|
|
perf_event_output(event, nmi, data, regs);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int perf_event_overflow(struct perf_event *event, int nmi,
|
|
struct perf_sample_data *data,
|
|
struct pt_regs *regs)
|
|
{
|
|
return __perf_event_overflow(event, nmi, 1, data, regs);
|
|
}
|
|
|
|
/*
|
|
* Generic software event infrastructure
|
|
*/
|
|
|
|
struct swevent_htable {
|
|
struct swevent_hlist *swevent_hlist;
|
|
struct mutex hlist_mutex;
|
|
int hlist_refcount;
|
|
|
|
/* Recursion avoidance in each contexts */
|
|
int recursion[PERF_NR_CONTEXTS];
|
|
};
|
|
|
|
static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
|
|
|
|
/*
|
|
* We directly increment event->count and keep a second value in
|
|
* event->hw.period_left to count intervals. This period event
|
|
* is kept in the range [-sample_period, 0] so that we can use the
|
|
* sign as trigger.
|
|
*/
|
|
|
|
static u64 perf_swevent_set_period(struct perf_event *event)
|
|
{
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
u64 period = hwc->last_period;
|
|
u64 nr, offset;
|
|
s64 old, val;
|
|
|
|
hwc->last_period = hwc->sample_period;
|
|
|
|
again:
|
|
old = val = local64_read(&hwc->period_left);
|
|
if (val < 0)
|
|
return 0;
|
|
|
|
nr = div64_u64(period + val, period);
|
|
offset = nr * period;
|
|
val -= offset;
|
|
if (local64_cmpxchg(&hwc->period_left, old, val) != old)
|
|
goto again;
|
|
|
|
return nr;
|
|
}
|
|
|
|
static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
|
|
int nmi, struct perf_sample_data *data,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
int throttle = 0;
|
|
|
|
data->period = event->hw.last_period;
|
|
if (!overflow)
|
|
overflow = perf_swevent_set_period(event);
|
|
|
|
if (hwc->interrupts == MAX_INTERRUPTS)
|
|
return;
|
|
|
|
for (; overflow; overflow--) {
|
|
if (__perf_event_overflow(event, nmi, throttle,
|
|
data, regs)) {
|
|
/*
|
|
* We inhibit the overflow from happening when
|
|
* hwc->interrupts == MAX_INTERRUPTS.
|
|
*/
|
|
break;
|
|
}
|
|
throttle = 1;
|
|
}
|
|
}
|
|
|
|
static void perf_swevent_event(struct perf_event *event, u64 nr,
|
|
int nmi, struct perf_sample_data *data,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
|
|
local64_add(nr, &event->count);
|
|
|
|
if (!regs)
|
|
return;
|
|
|
|
if (!is_sampling_event(event))
|
|
return;
|
|
|
|
if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
|
|
return perf_swevent_overflow(event, 1, nmi, data, regs);
|
|
|
|
if (local64_add_negative(nr, &hwc->period_left))
|
|
return;
|
|
|
|
perf_swevent_overflow(event, 0, nmi, data, regs);
|
|
}
|
|
|
|
static int perf_exclude_event(struct perf_event *event,
|
|
struct pt_regs *regs)
|
|
{
|
|
if (event->hw.state & PERF_HES_STOPPED)
|
|
return 1;
|
|
|
|
if (regs) {
|
|
if (event->attr.exclude_user && user_mode(regs))
|
|
return 1;
|
|
|
|
if (event->attr.exclude_kernel && !user_mode(regs))
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int perf_swevent_match(struct perf_event *event,
|
|
enum perf_type_id type,
|
|
u32 event_id,
|
|
struct perf_sample_data *data,
|
|
struct pt_regs *regs)
|
|
{
|
|
if (event->attr.type != type)
|
|
return 0;
|
|
|
|
if (event->attr.config != event_id)
|
|
return 0;
|
|
|
|
if (perf_exclude_event(event, regs))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static inline u64 swevent_hash(u64 type, u32 event_id)
|
|
{
|
|
u64 val = event_id | (type << 32);
|
|
|
|
return hash_64(val, SWEVENT_HLIST_BITS);
|
|
}
|
|
|
|
static inline struct hlist_head *
|
|
__find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id)
|
|
{
|
|
u64 hash = swevent_hash(type, event_id);
|
|
|
|
return &hlist->heads[hash];
|
|
}
|
|
|
|
/* For the read side: events when they trigger */
|
|
static inline struct hlist_head *
|
|
find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id)
|
|
{
|
|
struct swevent_hlist *hlist;
|
|
|
|
hlist = rcu_dereference(swhash->swevent_hlist);
|
|
if (!hlist)
|
|
return NULL;
|
|
|
|
return __find_swevent_head(hlist, type, event_id);
|
|
}
|
|
|
|
/* For the event head insertion and removal in the hlist */
|
|
static inline struct hlist_head *
|
|
find_swevent_head(struct swevent_htable *swhash, struct perf_event *event)
|
|
{
|
|
struct swevent_hlist *hlist;
|
|
u32 event_id = event->attr.config;
|
|
u64 type = event->attr.type;
|
|
|
|
/*
|
|
* Event scheduling is always serialized against hlist allocation
|
|
* and release. Which makes the protected version suitable here.
|
|
* The context lock guarantees that.
|
|
*/
|
|
hlist = rcu_dereference_protected(swhash->swevent_hlist,
|
|
lockdep_is_held(&event->ctx->lock));
|
|
if (!hlist)
|
|
return NULL;
|
|
|
|
return __find_swevent_head(hlist, type, event_id);
|
|
}
|
|
|
|
static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
|
|
u64 nr, int nmi,
|
|
struct perf_sample_data *data,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
|
|
struct perf_event *event;
|
|
struct hlist_node *node;
|
|
struct hlist_head *head;
|
|
|
|
rcu_read_lock();
|
|
head = find_swevent_head_rcu(swhash, type, event_id);
|
|
if (!head)
|
|
goto end;
|
|
|
|
hlist_for_each_entry_rcu(event, node, head, hlist_entry) {
|
|
if (perf_swevent_match(event, type, event_id, data, regs))
|
|
perf_swevent_event(event, nr, nmi, data, regs);
|
|
}
|
|
end:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
int perf_swevent_get_recursion_context(void)
|
|
{
|
|
struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
|
|
|
|
return get_recursion_context(swhash->recursion);
|
|
}
|
|
EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
|
|
|
|
inline void perf_swevent_put_recursion_context(int rctx)
|
|
{
|
|
struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
|
|
|
|
put_recursion_context(swhash->recursion, rctx);
|
|
}
|
|
|
|
void __perf_sw_event(u32 event_id, u64 nr, int nmi,
|
|
struct pt_regs *regs, u64 addr)
|
|
{
|
|
struct perf_sample_data data;
|
|
int rctx;
|
|
|
|
preempt_disable_notrace();
|
|
rctx = perf_swevent_get_recursion_context();
|
|
if (rctx < 0)
|
|
return;
|
|
|
|
perf_sample_data_init(&data, addr);
|
|
|
|
do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, &data, regs);
|
|
|
|
perf_swevent_put_recursion_context(rctx);
|
|
preempt_enable_notrace();
|
|
}
|
|
|
|
static void perf_swevent_read(struct perf_event *event)
|
|
{
|
|
}
|
|
|
|
static int perf_swevent_add(struct perf_event *event, int flags)
|
|
{
|
|
struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
struct hlist_head *head;
|
|
|
|
if (is_sampling_event(event)) {
|
|
hwc->last_period = hwc->sample_period;
|
|
perf_swevent_set_period(event);
|
|
}
|
|
|
|
hwc->state = !(flags & PERF_EF_START);
|
|
|
|
head = find_swevent_head(swhash, event);
|
|
if (WARN_ON_ONCE(!head))
|
|
return -EINVAL;
|
|
|
|
hlist_add_head_rcu(&event->hlist_entry, head);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void perf_swevent_del(struct perf_event *event, int flags)
|
|
{
|
|
hlist_del_rcu(&event->hlist_entry);
|
|
}
|
|
|
|
static void perf_swevent_start(struct perf_event *event, int flags)
|
|
{
|
|
event->hw.state = 0;
|
|
}
|
|
|
|
static void perf_swevent_stop(struct perf_event *event, int flags)
|
|
{
|
|
event->hw.state = PERF_HES_STOPPED;
|
|
}
|
|
|
|
/* Deref the hlist from the update side */
|
|
static inline struct swevent_hlist *
|
|
swevent_hlist_deref(struct swevent_htable *swhash)
|
|
{
|
|
return rcu_dereference_protected(swhash->swevent_hlist,
|
|
lockdep_is_held(&swhash->hlist_mutex));
|
|
}
|
|
|
|
static void swevent_hlist_release_rcu(struct rcu_head *rcu_head)
|
|
{
|
|
struct swevent_hlist *hlist;
|
|
|
|
hlist = container_of(rcu_head, struct swevent_hlist, rcu_head);
|
|
kfree(hlist);
|
|
}
|
|
|
|
static void swevent_hlist_release(struct swevent_htable *swhash)
|
|
{
|
|
struct swevent_hlist *hlist = swevent_hlist_deref(swhash);
|
|
|
|
if (!hlist)
|
|
return;
|
|
|
|
rcu_assign_pointer(swhash->swevent_hlist, NULL);
|
|
call_rcu(&hlist->rcu_head, swevent_hlist_release_rcu);
|
|
}
|
|
|
|
static void swevent_hlist_put_cpu(struct perf_event *event, int cpu)
|
|
{
|
|
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
|
|
|
|
mutex_lock(&swhash->hlist_mutex);
|
|
|
|
if (!--swhash->hlist_refcount)
|
|
swevent_hlist_release(swhash);
|
|
|
|
mutex_unlock(&swhash->hlist_mutex);
|
|
}
|
|
|
|
static void swevent_hlist_put(struct perf_event *event)
|
|
{
|
|
int cpu;
|
|
|
|
if (event->cpu != -1) {
|
|
swevent_hlist_put_cpu(event, event->cpu);
|
|
return;
|
|
}
|
|
|
|
for_each_possible_cpu(cpu)
|
|
swevent_hlist_put_cpu(event, cpu);
|
|
}
|
|
|
|
static int swevent_hlist_get_cpu(struct perf_event *event, int cpu)
|
|
{
|
|
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
|
|
int err = 0;
|
|
|
|
mutex_lock(&swhash->hlist_mutex);
|
|
|
|
if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) {
|
|
struct swevent_hlist *hlist;
|
|
|
|
hlist = kzalloc(sizeof(*hlist), GFP_KERNEL);
|
|
if (!hlist) {
|
|
err = -ENOMEM;
|
|
goto exit;
|
|
}
|
|
rcu_assign_pointer(swhash->swevent_hlist, hlist);
|
|
}
|
|
swhash->hlist_refcount++;
|
|
exit:
|
|
mutex_unlock(&swhash->hlist_mutex);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int swevent_hlist_get(struct perf_event *event)
|
|
{
|
|
int err;
|
|
int cpu, failed_cpu;
|
|
|
|
if (event->cpu != -1)
|
|
return swevent_hlist_get_cpu(event, event->cpu);
|
|
|
|
get_online_cpus();
|
|
for_each_possible_cpu(cpu) {
|
|
err = swevent_hlist_get_cpu(event, cpu);
|
|
if (err) {
|
|
failed_cpu = cpu;
|
|
goto fail;
|
|
}
|
|
}
|
|
put_online_cpus();
|
|
|
|
return 0;
|
|
fail:
|
|
for_each_possible_cpu(cpu) {
|
|
if (cpu == failed_cpu)
|
|
break;
|
|
swevent_hlist_put_cpu(event, cpu);
|
|
}
|
|
|
|
put_online_cpus();
|
|
return err;
|
|
}
|
|
|
|
atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX];
|
|
|
|
static void sw_perf_event_destroy(struct perf_event *event)
|
|
{
|
|
u64 event_id = event->attr.config;
|
|
|
|
WARN_ON(event->parent);
|
|
|
|
jump_label_dec(&perf_swevent_enabled[event_id]);
|
|
swevent_hlist_put(event);
|
|
}
|
|
|
|
static int perf_swevent_init(struct perf_event *event)
|
|
{
|
|
int event_id = event->attr.config;
|
|
|
|
if (event->attr.type != PERF_TYPE_SOFTWARE)
|
|
return -ENOENT;
|
|
|
|
switch (event_id) {
|
|
case PERF_COUNT_SW_CPU_CLOCK:
|
|
case PERF_COUNT_SW_TASK_CLOCK:
|
|
return -ENOENT;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (event_id >= PERF_COUNT_SW_MAX)
|
|
return -ENOENT;
|
|
|
|
if (!event->parent) {
|
|
int err;
|
|
|
|
err = swevent_hlist_get(event);
|
|
if (err)
|
|
return err;
|
|
|
|
jump_label_inc(&perf_swevent_enabled[event_id]);
|
|
event->destroy = sw_perf_event_destroy;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct pmu perf_swevent = {
|
|
.task_ctx_nr = perf_sw_context,
|
|
|
|
.event_init = perf_swevent_init,
|
|
.add = perf_swevent_add,
|
|
.del = perf_swevent_del,
|
|
.start = perf_swevent_start,
|
|
.stop = perf_swevent_stop,
|
|
.read = perf_swevent_read,
|
|
};
|
|
|
|
#ifdef CONFIG_EVENT_TRACING
|
|
|
|
static int perf_tp_filter_match(struct perf_event *event,
|
|
struct perf_sample_data *data)
|
|
{
|
|
void *record = data->raw->data;
|
|
|
|
if (likely(!event->filter) || filter_match_preds(event->filter, record))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static int perf_tp_event_match(struct perf_event *event,
|
|
struct perf_sample_data *data,
|
|
struct pt_regs *regs)
|
|
{
|
|
if (event->hw.state & PERF_HES_STOPPED)
|
|
return 0;
|
|
/*
|
|
* All tracepoints are from kernel-space.
|
|
*/
|
|
if (event->attr.exclude_kernel)
|
|
return 0;
|
|
|
|
if (!perf_tp_filter_match(event, data))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
|
|
struct pt_regs *regs, struct hlist_head *head, int rctx)
|
|
{
|
|
struct perf_sample_data data;
|
|
struct perf_event *event;
|
|
struct hlist_node *node;
|
|
|
|
struct perf_raw_record raw = {
|
|
.size = entry_size,
|
|
.data = record,
|
|
};
|
|
|
|
perf_sample_data_init(&data, addr);
|
|
data.raw = &raw;
|
|
|
|
hlist_for_each_entry_rcu(event, node, head, hlist_entry) {
|
|
if (perf_tp_event_match(event, &data, regs))
|
|
perf_swevent_event(event, count, 1, &data, regs);
|
|
}
|
|
|
|
perf_swevent_put_recursion_context(rctx);
|
|
}
|
|
EXPORT_SYMBOL_GPL(perf_tp_event);
|
|
|
|
static void tp_perf_event_destroy(struct perf_event *event)
|
|
{
|
|
perf_trace_destroy(event);
|
|
}
|
|
|
|
static int perf_tp_event_init(struct perf_event *event)
|
|
{
|
|
int err;
|
|
|
|
if (event->attr.type != PERF_TYPE_TRACEPOINT)
|
|
return -ENOENT;
|
|
|
|
err = perf_trace_init(event);
|
|
if (err)
|
|
return err;
|
|
|
|
event->destroy = tp_perf_event_destroy;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct pmu perf_tracepoint = {
|
|
.task_ctx_nr = perf_sw_context,
|
|
|
|
.event_init = perf_tp_event_init,
|
|
.add = perf_trace_add,
|
|
.del = perf_trace_del,
|
|
.start = perf_swevent_start,
|
|
.stop = perf_swevent_stop,
|
|
.read = perf_swevent_read,
|
|
};
|
|
|
|
static inline void perf_tp_register(void)
|
|
{
|
|
perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
|
|
}
|
|
|
|
static int perf_event_set_filter(struct perf_event *event, void __user *arg)
|
|
{
|
|
char *filter_str;
|
|
int ret;
|
|
|
|
if (event->attr.type != PERF_TYPE_TRACEPOINT)
|
|
return -EINVAL;
|
|
|
|
filter_str = strndup_user(arg, PAGE_SIZE);
|
|
if (IS_ERR(filter_str))
|
|
return PTR_ERR(filter_str);
|
|
|
|
ret = ftrace_profile_set_filter(event, event->attr.config, filter_str);
|
|
|
|
kfree(filter_str);
|
|
return ret;
|
|
}
|
|
|
|
static void perf_event_free_filter(struct perf_event *event)
|
|
{
|
|
ftrace_profile_free_filter(event);
|
|
}
|
|
|
|
#else
|
|
|
|
static inline void perf_tp_register(void)
|
|
{
|
|
}
|
|
|
|
static int perf_event_set_filter(struct perf_event *event, void __user *arg)
|
|
{
|
|
return -ENOENT;
|
|
}
|
|
|
|
static void perf_event_free_filter(struct perf_event *event)
|
|
{
|
|
}
|
|
|
|
#endif /* CONFIG_EVENT_TRACING */
|
|
|
|
#ifdef CONFIG_HAVE_HW_BREAKPOINT
|
|
void perf_bp_event(struct perf_event *bp, void *data)
|
|
{
|
|
struct perf_sample_data sample;
|
|
struct pt_regs *regs = data;
|
|
|
|
perf_sample_data_init(&sample, bp->attr.bp_addr);
|
|
|
|
if (!bp->hw.state && !perf_exclude_event(bp, regs))
|
|
perf_swevent_event(bp, 1, 1, &sample, regs);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* hrtimer based swevent callback
|
|
*/
|
|
|
|
static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
|
|
{
|
|
enum hrtimer_restart ret = HRTIMER_RESTART;
|
|
struct perf_sample_data data;
|
|
struct pt_regs *regs;
|
|
struct perf_event *event;
|
|
u64 period;
|
|
|
|
event = container_of(hrtimer, struct perf_event, hw.hrtimer);
|
|
|
|
if (event->state != PERF_EVENT_STATE_ACTIVE)
|
|
return HRTIMER_NORESTART;
|
|
|
|
event->pmu->read(event);
|
|
|
|
perf_sample_data_init(&data, 0);
|
|
data.period = event->hw.last_period;
|
|
regs = get_irq_regs();
|
|
|
|
if (regs && !perf_exclude_event(event, regs)) {
|
|
if (!(event->attr.exclude_idle && current->pid == 0))
|
|
if (perf_event_overflow(event, 0, &data, regs))
|
|
ret = HRTIMER_NORESTART;
|
|
}
|
|
|
|
period = max_t(u64, 10000, event->hw.sample_period);
|
|
hrtimer_forward_now(hrtimer, ns_to_ktime(period));
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void perf_swevent_start_hrtimer(struct perf_event *event)
|
|
{
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
s64 period;
|
|
|
|
if (!is_sampling_event(event))
|
|
return;
|
|
|
|
period = local64_read(&hwc->period_left);
|
|
if (period) {
|
|
if (period < 0)
|
|
period = 10000;
|
|
|
|
local64_set(&hwc->period_left, 0);
|
|
} else {
|
|
period = max_t(u64, 10000, hwc->sample_period);
|
|
}
|
|
__hrtimer_start_range_ns(&hwc->hrtimer,
|
|
ns_to_ktime(period), 0,
|
|
HRTIMER_MODE_REL_PINNED, 0);
|
|
}
|
|
|
|
static void perf_swevent_cancel_hrtimer(struct perf_event *event)
|
|
{
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
|
|
if (is_sampling_event(event)) {
|
|
ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
|
|
local64_set(&hwc->period_left, ktime_to_ns(remaining));
|
|
|
|
hrtimer_cancel(&hwc->hrtimer);
|
|
}
|
|
}
|
|
|
|
static void perf_swevent_init_hrtimer(struct perf_event *event)
|
|
{
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
|
|
if (!is_sampling_event(event))
|
|
return;
|
|
|
|
hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
|
|
hwc->hrtimer.function = perf_swevent_hrtimer;
|
|
|
|
/*
|
|
* Since hrtimers have a fixed rate, we can do a static freq->period
|
|
* mapping and avoid the whole period adjust feedback stuff.
|
|
*/
|
|
if (event->attr.freq) {
|
|
long freq = event->attr.sample_freq;
|
|
|
|
event->attr.sample_period = NSEC_PER_SEC / freq;
|
|
hwc->sample_period = event->attr.sample_period;
|
|
local64_set(&hwc->period_left, hwc->sample_period);
|
|
event->attr.freq = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Software event: cpu wall time clock
|
|
*/
|
|
|
|
static void cpu_clock_event_update(struct perf_event *event)
|
|
{
|
|
s64 prev;
|
|
u64 now;
|
|
|
|
now = local_clock();
|
|
prev = local64_xchg(&event->hw.prev_count, now);
|
|
local64_add(now - prev, &event->count);
|
|
}
|
|
|
|
static void cpu_clock_event_start(struct perf_event *event, int flags)
|
|
{
|
|
local64_set(&event->hw.prev_count, local_clock());
|
|
perf_swevent_start_hrtimer(event);
|
|
}
|
|
|
|
static void cpu_clock_event_stop(struct perf_event *event, int flags)
|
|
{
|
|
perf_swevent_cancel_hrtimer(event);
|
|
cpu_clock_event_update(event);
|
|
}
|
|
|
|
static int cpu_clock_event_add(struct perf_event *event, int flags)
|
|
{
|
|
if (flags & PERF_EF_START)
|
|
cpu_clock_event_start(event, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cpu_clock_event_del(struct perf_event *event, int flags)
|
|
{
|
|
cpu_clock_event_stop(event, flags);
|
|
}
|
|
|
|
static void cpu_clock_event_read(struct perf_event *event)
|
|
{
|
|
cpu_clock_event_update(event);
|
|
}
|
|
|
|
static int cpu_clock_event_init(struct perf_event *event)
|
|
{
|
|
if (event->attr.type != PERF_TYPE_SOFTWARE)
|
|
return -ENOENT;
|
|
|
|
if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
|
|
return -ENOENT;
|
|
|
|
perf_swevent_init_hrtimer(event);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct pmu perf_cpu_clock = {
|
|
.task_ctx_nr = perf_sw_context,
|
|
|
|
.event_init = cpu_clock_event_init,
|
|
.add = cpu_clock_event_add,
|
|
.del = cpu_clock_event_del,
|
|
.start = cpu_clock_event_start,
|
|
.stop = cpu_clock_event_stop,
|
|
.read = cpu_clock_event_read,
|
|
};
|
|
|
|
/*
|
|
* Software event: task time clock
|
|
*/
|
|
|
|
static void task_clock_event_update(struct perf_event *event, u64 now)
|
|
{
|
|
u64 prev;
|
|
s64 delta;
|
|
|
|
prev = local64_xchg(&event->hw.prev_count, now);
|
|
delta = now - prev;
|
|
local64_add(delta, &event->count);
|
|
}
|
|
|
|
static void task_clock_event_start(struct perf_event *event, int flags)
|
|
{
|
|
local64_set(&event->hw.prev_count, event->ctx->time);
|
|
perf_swevent_start_hrtimer(event);
|
|
}
|
|
|
|
static void task_clock_event_stop(struct perf_event *event, int flags)
|
|
{
|
|
perf_swevent_cancel_hrtimer(event);
|
|
task_clock_event_update(event, event->ctx->time);
|
|
}
|
|
|
|
static int task_clock_event_add(struct perf_event *event, int flags)
|
|
{
|
|
if (flags & PERF_EF_START)
|
|
task_clock_event_start(event, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void task_clock_event_del(struct perf_event *event, int flags)
|
|
{
|
|
task_clock_event_stop(event, PERF_EF_UPDATE);
|
|
}
|
|
|
|
static void task_clock_event_read(struct perf_event *event)
|
|
{
|
|
u64 now = perf_clock();
|
|
u64 delta = now - event->ctx->timestamp;
|
|
u64 time = event->ctx->time + delta;
|
|
|
|
task_clock_event_update(event, time);
|
|
}
|
|
|
|
static int task_clock_event_init(struct perf_event *event)
|
|
{
|
|
if (event->attr.type != PERF_TYPE_SOFTWARE)
|
|
return -ENOENT;
|
|
|
|
if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
|
|
return -ENOENT;
|
|
|
|
perf_swevent_init_hrtimer(event);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct pmu perf_task_clock = {
|
|
.task_ctx_nr = perf_sw_context,
|
|
|
|
.event_init = task_clock_event_init,
|
|
.add = task_clock_event_add,
|
|
.del = task_clock_event_del,
|
|
.start = task_clock_event_start,
|
|
.stop = task_clock_event_stop,
|
|
.read = task_clock_event_read,
|
|
};
|
|
|
|
static void perf_pmu_nop_void(struct pmu *pmu)
|
|
{
|
|
}
|
|
|
|
static int perf_pmu_nop_int(struct pmu *pmu)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void perf_pmu_start_txn(struct pmu *pmu)
|
|
{
|
|
perf_pmu_disable(pmu);
|
|
}
|
|
|
|
static int perf_pmu_commit_txn(struct pmu *pmu)
|
|
{
|
|
perf_pmu_enable(pmu);
|
|
return 0;
|
|
}
|
|
|
|
static void perf_pmu_cancel_txn(struct pmu *pmu)
|
|
{
|
|
perf_pmu_enable(pmu);
|
|
}
|
|
|
|
/*
|
|
* Ensures all contexts with the same task_ctx_nr have the same
|
|
* pmu_cpu_context too.
|
|
*/
|
|
static void *find_pmu_context(int ctxn)
|
|
{
|
|
struct pmu *pmu;
|
|
|
|
if (ctxn < 0)
|
|
return NULL;
|
|
|
|
list_for_each_entry(pmu, &pmus, entry) {
|
|
if (pmu->task_ctx_nr == ctxn)
|
|
return pmu->pmu_cpu_context;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct perf_cpu_context *cpuctx;
|
|
|
|
cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
|
|
|
|
if (cpuctx->active_pmu == old_pmu)
|
|
cpuctx->active_pmu = pmu;
|
|
}
|
|
}
|
|
|
|
static void free_pmu_context(struct pmu *pmu)
|
|
{
|
|
struct pmu *i;
|
|
|
|
mutex_lock(&pmus_lock);
|
|
/*
|
|
* Like a real lame refcount.
|
|
*/
|
|
list_for_each_entry(i, &pmus, entry) {
|
|
if (i->pmu_cpu_context == pmu->pmu_cpu_context) {
|
|
update_pmu_context(i, pmu);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
free_percpu(pmu->pmu_cpu_context);
|
|
out:
|
|
mutex_unlock(&pmus_lock);
|
|
}
|
|
static struct idr pmu_idr;
|
|
|
|
static ssize_t
|
|
type_show(struct device *dev, struct device_attribute *attr, char *page)
|
|
{
|
|
struct pmu *pmu = dev_get_drvdata(dev);
|
|
|
|
return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type);
|
|
}
|
|
|
|
static struct device_attribute pmu_dev_attrs[] = {
|
|
__ATTR_RO(type),
|
|
__ATTR_NULL,
|
|
};
|
|
|
|
static int pmu_bus_running;
|
|
static struct bus_type pmu_bus = {
|
|
.name = "event_source",
|
|
.dev_attrs = pmu_dev_attrs,
|
|
};
|
|
|
|
static void pmu_dev_release(struct device *dev)
|
|
{
|
|
kfree(dev);
|
|
}
|
|
|
|
static int pmu_dev_alloc(struct pmu *pmu)
|
|
{
|
|
int ret = -ENOMEM;
|
|
|
|
pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
|
|
if (!pmu->dev)
|
|
goto out;
|
|
|
|
device_initialize(pmu->dev);
|
|
ret = dev_set_name(pmu->dev, "%s", pmu->name);
|
|
if (ret)
|
|
goto free_dev;
|
|
|
|
dev_set_drvdata(pmu->dev, pmu);
|
|
pmu->dev->bus = &pmu_bus;
|
|
pmu->dev->release = pmu_dev_release;
|
|
ret = device_add(pmu->dev);
|
|
if (ret)
|
|
goto free_dev;
|
|
|
|
out:
|
|
return ret;
|
|
|
|
free_dev:
|
|
put_device(pmu->dev);
|
|
goto out;
|
|
}
|
|
|
|
static struct lock_class_key cpuctx_mutex;
|
|
|
|
int perf_pmu_register(struct pmu *pmu, char *name, int type)
|
|
{
|
|
int cpu, ret;
|
|
|
|
mutex_lock(&pmus_lock);
|
|
ret = -ENOMEM;
|
|
pmu->pmu_disable_count = alloc_percpu(int);
|
|
if (!pmu->pmu_disable_count)
|
|
goto unlock;
|
|
|
|
pmu->type = -1;
|
|
if (!name)
|
|
goto skip_type;
|
|
pmu->name = name;
|
|
|
|
if (type < 0) {
|
|
int err = idr_pre_get(&pmu_idr, GFP_KERNEL);
|
|
if (!err)
|
|
goto free_pdc;
|
|
|
|
err = idr_get_new_above(&pmu_idr, pmu, PERF_TYPE_MAX, &type);
|
|
if (err) {
|
|
ret = err;
|
|
goto free_pdc;
|
|
}
|
|
}
|
|
pmu->type = type;
|
|
|
|
if (pmu_bus_running) {
|
|
ret = pmu_dev_alloc(pmu);
|
|
if (ret)
|
|
goto free_idr;
|
|
}
|
|
|
|
skip_type:
|
|
pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr);
|
|
if (pmu->pmu_cpu_context)
|
|
goto got_cpu_context;
|
|
|
|
pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context);
|
|
if (!pmu->pmu_cpu_context)
|
|
goto free_dev;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct perf_cpu_context *cpuctx;
|
|
|
|
cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
|
|
__perf_event_init_context(&cpuctx->ctx);
|
|
lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
|
|
cpuctx->ctx.type = cpu_context;
|
|
cpuctx->ctx.pmu = pmu;
|
|
cpuctx->jiffies_interval = 1;
|
|
INIT_LIST_HEAD(&cpuctx->rotation_list);
|
|
cpuctx->active_pmu = pmu;
|
|
}
|
|
|
|
got_cpu_context:
|
|
if (!pmu->start_txn) {
|
|
if (pmu->pmu_enable) {
|
|
/*
|
|
* If we have pmu_enable/pmu_disable calls, install
|
|
* transaction stubs that use that to try and batch
|
|
* hardware accesses.
|
|
*/
|
|
pmu->start_txn = perf_pmu_start_txn;
|
|
pmu->commit_txn = perf_pmu_commit_txn;
|
|
pmu->cancel_txn = perf_pmu_cancel_txn;
|
|
} else {
|
|
pmu->start_txn = perf_pmu_nop_void;
|
|
pmu->commit_txn = perf_pmu_nop_int;
|
|
pmu->cancel_txn = perf_pmu_nop_void;
|
|
}
|
|
}
|
|
|
|
if (!pmu->pmu_enable) {
|
|
pmu->pmu_enable = perf_pmu_nop_void;
|
|
pmu->pmu_disable = perf_pmu_nop_void;
|
|
}
|
|
|
|
list_add_rcu(&pmu->entry, &pmus);
|
|
ret = 0;
|
|
unlock:
|
|
mutex_unlock(&pmus_lock);
|
|
|
|
return ret;
|
|
|
|
free_dev:
|
|
device_del(pmu->dev);
|
|
put_device(pmu->dev);
|
|
|
|
free_idr:
|
|
if (pmu->type >= PERF_TYPE_MAX)
|
|
idr_remove(&pmu_idr, pmu->type);
|
|
|
|
free_pdc:
|
|
free_percpu(pmu->pmu_disable_count);
|
|
goto unlock;
|
|
}
|
|
|
|
void perf_pmu_unregister(struct pmu *pmu)
|
|
{
|
|
mutex_lock(&pmus_lock);
|
|
list_del_rcu(&pmu->entry);
|
|
mutex_unlock(&pmus_lock);
|
|
|
|
/*
|
|
* We dereference the pmu list under both SRCU and regular RCU, so
|
|
* synchronize against both of those.
|
|
*/
|
|
synchronize_srcu(&pmus_srcu);
|
|
synchronize_rcu();
|
|
|
|
free_percpu(pmu->pmu_disable_count);
|
|
if (pmu->type >= PERF_TYPE_MAX)
|
|
idr_remove(&pmu_idr, pmu->type);
|
|
device_del(pmu->dev);
|
|
put_device(pmu->dev);
|
|
free_pmu_context(pmu);
|
|
}
|
|
|
|
struct pmu *perf_init_event(struct perf_event *event)
|
|
{
|
|
struct pmu *pmu = NULL;
|
|
int idx;
|
|
int ret;
|
|
|
|
idx = srcu_read_lock(&pmus_srcu);
|
|
|
|
rcu_read_lock();
|
|
pmu = idr_find(&pmu_idr, event->attr.type);
|
|
rcu_read_unlock();
|
|
if (pmu) {
|
|
ret = pmu->event_init(event);
|
|
if (ret)
|
|
pmu = ERR_PTR(ret);
|
|
goto unlock;
|
|
}
|
|
|
|
list_for_each_entry_rcu(pmu, &pmus, entry) {
|
|
ret = pmu->event_init(event);
|
|
if (!ret)
|
|
goto unlock;
|
|
|
|
if (ret != -ENOENT) {
|
|
pmu = ERR_PTR(ret);
|
|
goto unlock;
|
|
}
|
|
}
|
|
pmu = ERR_PTR(-ENOENT);
|
|
unlock:
|
|
srcu_read_unlock(&pmus_srcu, idx);
|
|
|
|
return pmu;
|
|
}
|
|
|
|
/*
|
|
* Allocate and initialize a event structure
|
|
*/
|
|
static struct perf_event *
|
|
perf_event_alloc(struct perf_event_attr *attr, int cpu,
|
|
struct task_struct *task,
|
|
struct perf_event *group_leader,
|
|
struct perf_event *parent_event,
|
|
perf_overflow_handler_t overflow_handler)
|
|
{
|
|
struct pmu *pmu;
|
|
struct perf_event *event;
|
|
struct hw_perf_event *hwc;
|
|
long err;
|
|
|
|
if ((unsigned)cpu >= nr_cpu_ids) {
|
|
if (!task || cpu != -1)
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
event = kzalloc(sizeof(*event), GFP_KERNEL);
|
|
if (!event)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/*
|
|
* Single events are their own group leaders, with an
|
|
* empty sibling list:
|
|
*/
|
|
if (!group_leader)
|
|
group_leader = event;
|
|
|
|
mutex_init(&event->child_mutex);
|
|
INIT_LIST_HEAD(&event->child_list);
|
|
|
|
INIT_LIST_HEAD(&event->group_entry);
|
|
INIT_LIST_HEAD(&event->event_entry);
|
|
INIT_LIST_HEAD(&event->sibling_list);
|
|
init_waitqueue_head(&event->waitq);
|
|
init_irq_work(&event->pending, perf_pending_event);
|
|
|
|
mutex_init(&event->mmap_mutex);
|
|
|
|
event->cpu = cpu;
|
|
event->attr = *attr;
|
|
event->group_leader = group_leader;
|
|
event->pmu = NULL;
|
|
event->oncpu = -1;
|
|
|
|
event->parent = parent_event;
|
|
|
|
event->ns = get_pid_ns(current->nsproxy->pid_ns);
|
|
event->id = atomic64_inc_return(&perf_event_id);
|
|
|
|
event->state = PERF_EVENT_STATE_INACTIVE;
|
|
|
|
if (task) {
|
|
event->attach_state = PERF_ATTACH_TASK;
|
|
#ifdef CONFIG_HAVE_HW_BREAKPOINT
|
|
/*
|
|
* hw_breakpoint is a bit difficult here..
|
|
*/
|
|
if (attr->type == PERF_TYPE_BREAKPOINT)
|
|
event->hw.bp_target = task;
|
|
#endif
|
|
}
|
|
|
|
if (!overflow_handler && parent_event)
|
|
overflow_handler = parent_event->overflow_handler;
|
|
|
|
event->overflow_handler = overflow_handler;
|
|
|
|
if (attr->disabled)
|
|
event->state = PERF_EVENT_STATE_OFF;
|
|
|
|
pmu = NULL;
|
|
|
|
hwc = &event->hw;
|
|
hwc->sample_period = attr->sample_period;
|
|
if (attr->freq && attr->sample_freq)
|
|
hwc->sample_period = 1;
|
|
hwc->last_period = hwc->sample_period;
|
|
|
|
local64_set(&hwc->period_left, hwc->sample_period);
|
|
|
|
/*
|
|
* we currently do not support PERF_FORMAT_GROUP on inherited events
|
|
*/
|
|
if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
|
|
goto done;
|
|
|
|
pmu = perf_init_event(event);
|
|
|
|
done:
|
|
err = 0;
|
|
if (!pmu)
|
|
err = -EINVAL;
|
|
else if (IS_ERR(pmu))
|
|
err = PTR_ERR(pmu);
|
|
|
|
if (err) {
|
|
if (event->ns)
|
|
put_pid_ns(event->ns);
|
|
kfree(event);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
event->pmu = pmu;
|
|
|
|
if (!event->parent) {
|
|
if (event->attach_state & PERF_ATTACH_TASK)
|
|
jump_label_inc(&perf_sched_events);
|
|
if (event->attr.mmap || event->attr.mmap_data)
|
|
atomic_inc(&nr_mmap_events);
|
|
if (event->attr.comm)
|
|
atomic_inc(&nr_comm_events);
|
|
if (event->attr.task)
|
|
atomic_inc(&nr_task_events);
|
|
if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
|
|
err = get_callchain_buffers();
|
|
if (err) {
|
|
free_event(event);
|
|
return ERR_PTR(err);
|
|
}
|
|
}
|
|
}
|
|
|
|
return event;
|
|
}
|
|
|
|
static int perf_copy_attr(struct perf_event_attr __user *uattr,
|
|
struct perf_event_attr *attr)
|
|
{
|
|
u32 size;
|
|
int ret;
|
|
|
|
if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
|
|
return -EFAULT;
|
|
|
|
/*
|
|
* zero the full structure, so that a short copy will be nice.
|
|
*/
|
|
memset(attr, 0, sizeof(*attr));
|
|
|
|
ret = get_user(size, &uattr->size);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (size > PAGE_SIZE) /* silly large */
|
|
goto err_size;
|
|
|
|
if (!size) /* abi compat */
|
|
size = PERF_ATTR_SIZE_VER0;
|
|
|
|
if (size < PERF_ATTR_SIZE_VER0)
|
|
goto err_size;
|
|
|
|
/*
|
|
* If we're handed a bigger struct than we know of,
|
|
* ensure all the unknown bits are 0 - i.e. new
|
|
* user-space does not rely on any kernel feature
|
|
* extensions we dont know about yet.
|
|
*/
|
|
if (size > sizeof(*attr)) {
|
|
unsigned char __user *addr;
|
|
unsigned char __user *end;
|
|
unsigned char val;
|
|
|
|
addr = (void __user *)uattr + sizeof(*attr);
|
|
end = (void __user *)uattr + size;
|
|
|
|
for (; addr < end; addr++) {
|
|
ret = get_user(val, addr);
|
|
if (ret)
|
|
return ret;
|
|
if (val)
|
|
goto err_size;
|
|
}
|
|
size = sizeof(*attr);
|
|
}
|
|
|
|
ret = copy_from_user(attr, uattr, size);
|
|
if (ret)
|
|
return -EFAULT;
|
|
|
|
/*
|
|
* If the type exists, the corresponding creation will verify
|
|
* the attr->config.
|
|
*/
|
|
if (attr->type >= PERF_TYPE_MAX)
|
|
return -EINVAL;
|
|
|
|
if (attr->__reserved_1)
|
|
return -EINVAL;
|
|
|
|
if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
|
|
return -EINVAL;
|
|
|
|
if (attr->read_format & ~(PERF_FORMAT_MAX-1))
|
|
return -EINVAL;
|
|
|
|
out:
|
|
return ret;
|
|
|
|
err_size:
|
|
put_user(sizeof(*attr), &uattr->size);
|
|
ret = -E2BIG;
|
|
goto out;
|
|
}
|
|
|
|
static int
|
|
perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
|
|
{
|
|
struct perf_buffer *buffer = NULL, *old_buffer = NULL;
|
|
int ret = -EINVAL;
|
|
|
|
if (!output_event)
|
|
goto set;
|
|
|
|
/* don't allow circular references */
|
|
if (event == output_event)
|
|
goto out;
|
|
|
|
/*
|
|
* Don't allow cross-cpu buffers
|
|
*/
|
|
if (output_event->cpu != event->cpu)
|
|
goto out;
|
|
|
|
/*
|
|
* If its not a per-cpu buffer, it must be the same task.
|
|
*/
|
|
if (output_event->cpu == -1 && output_event->ctx != event->ctx)
|
|
goto out;
|
|
|
|
set:
|
|
mutex_lock(&event->mmap_mutex);
|
|
/* Can't redirect output if we've got an active mmap() */
|
|
if (atomic_read(&event->mmap_count))
|
|
goto unlock;
|
|
|
|
if (output_event) {
|
|
/* get the buffer we want to redirect to */
|
|
buffer = perf_buffer_get(output_event);
|
|
if (!buffer)
|
|
goto unlock;
|
|
}
|
|
|
|
old_buffer = event->buffer;
|
|
rcu_assign_pointer(event->buffer, buffer);
|
|
ret = 0;
|
|
unlock:
|
|
mutex_unlock(&event->mmap_mutex);
|
|
|
|
if (old_buffer)
|
|
perf_buffer_put(old_buffer);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* sys_perf_event_open - open a performance event, associate it to a task/cpu
|
|
*
|
|
* @attr_uptr: event_id type attributes for monitoring/sampling
|
|
* @pid: target pid
|
|
* @cpu: target cpu
|
|
* @group_fd: group leader event fd
|
|
*/
|
|
SYSCALL_DEFINE5(perf_event_open,
|
|
struct perf_event_attr __user *, attr_uptr,
|
|
pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
|
|
{
|
|
struct perf_event *group_leader = NULL, *output_event = NULL;
|
|
struct perf_event *event, *sibling;
|
|
struct perf_event_attr attr;
|
|
struct perf_event_context *ctx;
|
|
struct file *event_file = NULL;
|
|
struct file *group_file = NULL;
|
|
struct task_struct *task = NULL;
|
|
struct pmu *pmu;
|
|
int event_fd;
|
|
int move_group = 0;
|
|
int fput_needed = 0;
|
|
int err;
|
|
|
|
/* for future expandability... */
|
|
if (flags & ~PERF_FLAG_ALL)
|
|
return -EINVAL;
|
|
|
|
err = perf_copy_attr(attr_uptr, &attr);
|
|
if (err)
|
|
return err;
|
|
|
|
if (!attr.exclude_kernel) {
|
|
if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
|
|
return -EACCES;
|
|
}
|
|
|
|
if (attr.freq) {
|
|
if (attr.sample_freq > sysctl_perf_event_sample_rate)
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* In cgroup mode, the pid argument is used to pass the fd
|
|
* opened to the cgroup directory in cgroupfs. The cpu argument
|
|
* designates the cpu on which to monitor threads from that
|
|
* cgroup.
|
|
*/
|
|
if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
|
|
return -EINVAL;
|
|
|
|
event_fd = get_unused_fd_flags(O_RDWR);
|
|
if (event_fd < 0)
|
|
return event_fd;
|
|
|
|
if (group_fd != -1) {
|
|
group_leader = perf_fget_light(group_fd, &fput_needed);
|
|
if (IS_ERR(group_leader)) {
|
|
err = PTR_ERR(group_leader);
|
|
goto err_fd;
|
|
}
|
|
group_file = group_leader->filp;
|
|
if (flags & PERF_FLAG_FD_OUTPUT)
|
|
output_event = group_leader;
|
|
if (flags & PERF_FLAG_FD_NO_GROUP)
|
|
group_leader = NULL;
|
|
}
|
|
|
|
if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) {
|
|
task = find_lively_task_by_vpid(pid);
|
|
if (IS_ERR(task)) {
|
|
err = PTR_ERR(task);
|
|
goto err_group_fd;
|
|
}
|
|
}
|
|
|
|
event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, NULL);
|
|
if (IS_ERR(event)) {
|
|
err = PTR_ERR(event);
|
|
goto err_task;
|
|
}
|
|
|
|
if (flags & PERF_FLAG_PID_CGROUP) {
|
|
err = perf_cgroup_connect(pid, event, &attr, group_leader);
|
|
if (err)
|
|
goto err_alloc;
|
|
/*
|
|
* one more event:
|
|
* - that has cgroup constraint on event->cpu
|
|
* - that may need work on context switch
|
|
*/
|
|
atomic_inc(&per_cpu(perf_cgroup_events, event->cpu));
|
|
jump_label_inc(&perf_sched_events);
|
|
}
|
|
|
|
/*
|
|
* Special case software events and allow them to be part of
|
|
* any hardware group.
|
|
*/
|
|
pmu = event->pmu;
|
|
|
|
if (group_leader &&
|
|
(is_software_event(event) != is_software_event(group_leader))) {
|
|
if (is_software_event(event)) {
|
|
/*
|
|
* If event and group_leader are not both a software
|
|
* event, and event is, then group leader is not.
|
|
*
|
|
* Allow the addition of software events to !software
|
|
* groups, this is safe because software events never
|
|
* fail to schedule.
|
|
*/
|
|
pmu = group_leader->pmu;
|
|
} else if (is_software_event(group_leader) &&
|
|
(group_leader->group_flags & PERF_GROUP_SOFTWARE)) {
|
|
/*
|
|
* In case the group is a pure software group, and we
|
|
* try to add a hardware event, move the whole group to
|
|
* the hardware context.
|
|
*/
|
|
move_group = 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Get the target context (task or percpu):
|
|
*/
|
|
ctx = find_get_context(pmu, task, cpu);
|
|
if (IS_ERR(ctx)) {
|
|
err = PTR_ERR(ctx);
|
|
goto err_alloc;
|
|
}
|
|
|
|
if (task) {
|
|
put_task_struct(task);
|
|
task = NULL;
|
|
}
|
|
|
|
/*
|
|
* Look up the group leader (we will attach this event to it):
|
|
*/
|
|
if (group_leader) {
|
|
err = -EINVAL;
|
|
|
|
/*
|
|
* Do not allow a recursive hierarchy (this new sibling
|
|
* becoming part of another group-sibling):
|
|
*/
|
|
if (group_leader->group_leader != group_leader)
|
|
goto err_context;
|
|
/*
|
|
* Do not allow to attach to a group in a different
|
|
* task or CPU context:
|
|
*/
|
|
if (move_group) {
|
|
if (group_leader->ctx->type != ctx->type)
|
|
goto err_context;
|
|
} else {
|
|
if (group_leader->ctx != ctx)
|
|
goto err_context;
|
|
}
|
|
|
|
/*
|
|
* Only a group leader can be exclusive or pinned
|
|
*/
|
|
if (attr.exclusive || attr.pinned)
|
|
goto err_context;
|
|
}
|
|
|
|
if (output_event) {
|
|
err = perf_event_set_output(event, output_event);
|
|
if (err)
|
|
goto err_context;
|
|
}
|
|
|
|
event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, O_RDWR);
|
|
if (IS_ERR(event_file)) {
|
|
err = PTR_ERR(event_file);
|
|
goto err_context;
|
|
}
|
|
|
|
if (move_group) {
|
|
struct perf_event_context *gctx = group_leader->ctx;
|
|
|
|
mutex_lock(&gctx->mutex);
|
|
perf_remove_from_context(group_leader);
|
|
list_for_each_entry(sibling, &group_leader->sibling_list,
|
|
group_entry) {
|
|
perf_remove_from_context(sibling);
|
|
put_ctx(gctx);
|
|
}
|
|
mutex_unlock(&gctx->mutex);
|
|
put_ctx(gctx);
|
|
}
|
|
|
|
event->filp = event_file;
|
|
WARN_ON_ONCE(ctx->parent_ctx);
|
|
mutex_lock(&ctx->mutex);
|
|
|
|
if (move_group) {
|
|
perf_install_in_context(ctx, group_leader, cpu);
|
|
get_ctx(ctx);
|
|
list_for_each_entry(sibling, &group_leader->sibling_list,
|
|
group_entry) {
|
|
perf_install_in_context(ctx, sibling, cpu);
|
|
get_ctx(ctx);
|
|
}
|
|
}
|
|
|
|
perf_install_in_context(ctx, event, cpu);
|
|
++ctx->generation;
|
|
perf_unpin_context(ctx);
|
|
mutex_unlock(&ctx->mutex);
|
|
|
|
event->owner = current;
|
|
|
|
mutex_lock(¤t->perf_event_mutex);
|
|
list_add_tail(&event->owner_entry, ¤t->perf_event_list);
|
|
mutex_unlock(¤t->perf_event_mutex);
|
|
|
|
/*
|
|
* Precalculate sample_data sizes
|
|
*/
|
|
perf_event__header_size(event);
|
|
perf_event__id_header_size(event);
|
|
|
|
/*
|
|
* Drop the reference on the group_event after placing the
|
|
* new event on the sibling_list. This ensures destruction
|
|
* of the group leader will find the pointer to itself in
|
|
* perf_group_detach().
|
|
*/
|
|
fput_light(group_file, fput_needed);
|
|
fd_install(event_fd, event_file);
|
|
return event_fd;
|
|
|
|
err_context:
|
|
perf_unpin_context(ctx);
|
|
put_ctx(ctx);
|
|
err_alloc:
|
|
free_event(event);
|
|
err_task:
|
|
if (task)
|
|
put_task_struct(task);
|
|
err_group_fd:
|
|
fput_light(group_file, fput_needed);
|
|
err_fd:
|
|
put_unused_fd(event_fd);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* perf_event_create_kernel_counter
|
|
*
|
|
* @attr: attributes of the counter to create
|
|
* @cpu: cpu in which the counter is bound
|
|
* @task: task to profile (NULL for percpu)
|
|
*/
|
|
struct perf_event *
|
|
perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
|
|
struct task_struct *task,
|
|
perf_overflow_handler_t overflow_handler)
|
|
{
|
|
struct perf_event_context *ctx;
|
|
struct perf_event *event;
|
|
int err;
|
|
|
|
/*
|
|
* Get the target context (task or percpu):
|
|
*/
|
|
|
|
event = perf_event_alloc(attr, cpu, task, NULL, NULL, overflow_handler);
|
|
if (IS_ERR(event)) {
|
|
err = PTR_ERR(event);
|
|
goto err;
|
|
}
|
|
|
|
ctx = find_get_context(event->pmu, task, cpu);
|
|
if (IS_ERR(ctx)) {
|
|
err = PTR_ERR(ctx);
|
|
goto err_free;
|
|
}
|
|
|
|
event->filp = NULL;
|
|
WARN_ON_ONCE(ctx->parent_ctx);
|
|
mutex_lock(&ctx->mutex);
|
|
perf_install_in_context(ctx, event, cpu);
|
|
++ctx->generation;
|
|
perf_unpin_context(ctx);
|
|
mutex_unlock(&ctx->mutex);
|
|
|
|
return event;
|
|
|
|
err_free:
|
|
free_event(event);
|
|
err:
|
|
return ERR_PTR(err);
|
|
}
|
|
EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
|
|
|
|
static void sync_child_event(struct perf_event *child_event,
|
|
struct task_struct *child)
|
|
{
|
|
struct perf_event *parent_event = child_event->parent;
|
|
u64 child_val;
|
|
|
|
if (child_event->attr.inherit_stat)
|
|
perf_event_read_event(child_event, child);
|
|
|
|
child_val = perf_event_count(child_event);
|
|
|
|
/*
|
|
* Add back the child's count to the parent's count:
|
|
*/
|
|
atomic64_add(child_val, &parent_event->child_count);
|
|
atomic64_add(child_event->total_time_enabled,
|
|
&parent_event->child_total_time_enabled);
|
|
atomic64_add(child_event->total_time_running,
|
|
&parent_event->child_total_time_running);
|
|
|
|
/*
|
|
* Remove this event from the parent's list
|
|
*/
|
|
WARN_ON_ONCE(parent_event->ctx->parent_ctx);
|
|
mutex_lock(&parent_event->child_mutex);
|
|
list_del_init(&child_event->child_list);
|
|
mutex_unlock(&parent_event->child_mutex);
|
|
|
|
/*
|
|
* Release the parent event, if this was the last
|
|
* reference to it.
|
|
*/
|
|
fput(parent_event->filp);
|
|
}
|
|
|
|
static void
|
|
__perf_event_exit_task(struct perf_event *child_event,
|
|
struct perf_event_context *child_ctx,
|
|
struct task_struct *child)
|
|
{
|
|
if (child_event->parent) {
|
|
raw_spin_lock_irq(&child_ctx->lock);
|
|
perf_group_detach(child_event);
|
|
raw_spin_unlock_irq(&child_ctx->lock);
|
|
}
|
|
|
|
perf_remove_from_context(child_event);
|
|
|
|
/*
|
|
* It can happen that the parent exits first, and has events
|
|
* that are still around due to the child reference. These
|
|
* events need to be zapped.
|
|
*/
|
|
if (child_event->parent) {
|
|
sync_child_event(child_event, child);
|
|
free_event(child_event);
|
|
}
|
|
}
|
|
|
|
static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
|
|
{
|
|
struct perf_event *child_event, *tmp;
|
|
struct perf_event_context *child_ctx;
|
|
unsigned long flags;
|
|
|
|
if (likely(!child->perf_event_ctxp[ctxn])) {
|
|
perf_event_task(child, NULL, 0);
|
|
return;
|
|
}
|
|
|
|
local_irq_save(flags);
|
|
/*
|
|
* We can't reschedule here because interrupts are disabled,
|
|
* and either child is current or it is a task that can't be
|
|
* scheduled, so we are now safe from rescheduling changing
|
|
* our context.
|
|
*/
|
|
child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]);
|
|
task_ctx_sched_out(child_ctx, EVENT_ALL);
|
|
|
|
/*
|
|
* Take the context lock here so that if find_get_context is
|
|
* reading child->perf_event_ctxp, we wait until it has
|
|
* incremented the context's refcount before we do put_ctx below.
|
|
*/
|
|
raw_spin_lock(&child_ctx->lock);
|
|
child->perf_event_ctxp[ctxn] = NULL;
|
|
/*
|
|
* If this context is a clone; unclone it so it can't get
|
|
* swapped to another process while we're removing all
|
|
* the events from it.
|
|
*/
|
|
unclone_ctx(child_ctx);
|
|
update_context_time(child_ctx);
|
|
raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
|
|
|
|
/*
|
|
* Report the task dead after unscheduling the events so that we
|
|
* won't get any samples after PERF_RECORD_EXIT. We can however still
|
|
* get a few PERF_RECORD_READ events.
|
|
*/
|
|
perf_event_task(child, child_ctx, 0);
|
|
|
|
/*
|
|
* We can recurse on the same lock type through:
|
|
*
|
|
* __perf_event_exit_task()
|
|
* sync_child_event()
|
|
* fput(parent_event->filp)
|
|
* perf_release()
|
|
* mutex_lock(&ctx->mutex)
|
|
*
|
|
* But since its the parent context it won't be the same instance.
|
|
*/
|
|
mutex_lock(&child_ctx->mutex);
|
|
|
|
again:
|
|
list_for_each_entry_safe(child_event, tmp, &child_ctx->pinned_groups,
|
|
group_entry)
|
|
__perf_event_exit_task(child_event, child_ctx, child);
|
|
|
|
list_for_each_entry_safe(child_event, tmp, &child_ctx->flexible_groups,
|
|
group_entry)
|
|
__perf_event_exit_task(child_event, child_ctx, child);
|
|
|
|
/*
|
|
* If the last event was a group event, it will have appended all
|
|
* its siblings to the list, but we obtained 'tmp' before that which
|
|
* will still point to the list head terminating the iteration.
|
|
*/
|
|
if (!list_empty(&child_ctx->pinned_groups) ||
|
|
!list_empty(&child_ctx->flexible_groups))
|
|
goto again;
|
|
|
|
mutex_unlock(&child_ctx->mutex);
|
|
|
|
put_ctx(child_ctx);
|
|
}
|
|
|
|
/*
|
|
* When a child task exits, feed back event values to parent events.
|
|
*/
|
|
void perf_event_exit_task(struct task_struct *child)
|
|
{
|
|
struct perf_event *event, *tmp;
|
|
int ctxn;
|
|
|
|
mutex_lock(&child->perf_event_mutex);
|
|
list_for_each_entry_safe(event, tmp, &child->perf_event_list,
|
|
owner_entry) {
|
|
list_del_init(&event->owner_entry);
|
|
|
|
/*
|
|
* Ensure the list deletion is visible before we clear
|
|
* the owner, closes a race against perf_release() where
|
|
* we need to serialize on the owner->perf_event_mutex.
|
|
*/
|
|
smp_wmb();
|
|
event->owner = NULL;
|
|
}
|
|
mutex_unlock(&child->perf_event_mutex);
|
|
|
|
for_each_task_context_nr(ctxn)
|
|
perf_event_exit_task_context(child, ctxn);
|
|
}
|
|
|
|
static void perf_free_event(struct perf_event *event,
|
|
struct perf_event_context *ctx)
|
|
{
|
|
struct perf_event *parent = event->parent;
|
|
|
|
if (WARN_ON_ONCE(!parent))
|
|
return;
|
|
|
|
mutex_lock(&parent->child_mutex);
|
|
list_del_init(&event->child_list);
|
|
mutex_unlock(&parent->child_mutex);
|
|
|
|
fput(parent->filp);
|
|
|
|
perf_group_detach(event);
|
|
list_del_event(event, ctx);
|
|
free_event(event);
|
|
}
|
|
|
|
/*
|
|
* free an unexposed, unused context as created by inheritance by
|
|
* perf_event_init_task below, used by fork() in case of fail.
|
|
*/
|
|
void perf_event_free_task(struct task_struct *task)
|
|
{
|
|
struct perf_event_context *ctx;
|
|
struct perf_event *event, *tmp;
|
|
int ctxn;
|
|
|
|
for_each_task_context_nr(ctxn) {
|
|
ctx = task->perf_event_ctxp[ctxn];
|
|
if (!ctx)
|
|
continue;
|
|
|
|
mutex_lock(&ctx->mutex);
|
|
again:
|
|
list_for_each_entry_safe(event, tmp, &ctx->pinned_groups,
|
|
group_entry)
|
|
perf_free_event(event, ctx);
|
|
|
|
list_for_each_entry_safe(event, tmp, &ctx->flexible_groups,
|
|
group_entry)
|
|
perf_free_event(event, ctx);
|
|
|
|
if (!list_empty(&ctx->pinned_groups) ||
|
|
!list_empty(&ctx->flexible_groups))
|
|
goto again;
|
|
|
|
mutex_unlock(&ctx->mutex);
|
|
|
|
put_ctx(ctx);
|
|
}
|
|
}
|
|
|
|
void perf_event_delayed_put(struct task_struct *task)
|
|
{
|
|
int ctxn;
|
|
|
|
for_each_task_context_nr(ctxn)
|
|
WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
|
|
}
|
|
|
|
/*
|
|
* inherit a event from parent task to child task:
|
|
*/
|
|
static struct perf_event *
|
|
inherit_event(struct perf_event *parent_event,
|
|
struct task_struct *parent,
|
|
struct perf_event_context *parent_ctx,
|
|
struct task_struct *child,
|
|
struct perf_event *group_leader,
|
|
struct perf_event_context *child_ctx)
|
|
{
|
|
struct perf_event *child_event;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* Instead of creating recursive hierarchies of events,
|
|
* we link inherited events back to the original parent,
|
|
* which has a filp for sure, which we use as the reference
|
|
* count:
|
|
*/
|
|
if (parent_event->parent)
|
|
parent_event = parent_event->parent;
|
|
|
|
child_event = perf_event_alloc(&parent_event->attr,
|
|
parent_event->cpu,
|
|
child,
|
|
group_leader, parent_event,
|
|
NULL);
|
|
if (IS_ERR(child_event))
|
|
return child_event;
|
|
get_ctx(child_ctx);
|
|
|
|
/*
|
|
* Make the child state follow the state of the parent event,
|
|
* not its attr.disabled bit. We hold the parent's mutex,
|
|
* so we won't race with perf_event_{en, dis}able_family.
|
|
*/
|
|
if (parent_event->state >= PERF_EVENT_STATE_INACTIVE)
|
|
child_event->state = PERF_EVENT_STATE_INACTIVE;
|
|
else
|
|
child_event->state = PERF_EVENT_STATE_OFF;
|
|
|
|
if (parent_event->attr.freq) {
|
|
u64 sample_period = parent_event->hw.sample_period;
|
|
struct hw_perf_event *hwc = &child_event->hw;
|
|
|
|
hwc->sample_period = sample_period;
|
|
hwc->last_period = sample_period;
|
|
|
|
local64_set(&hwc->period_left, sample_period);
|
|
}
|
|
|
|
child_event->ctx = child_ctx;
|
|
child_event->overflow_handler = parent_event->overflow_handler;
|
|
|
|
/*
|
|
* Precalculate sample_data sizes
|
|
*/
|
|
perf_event__header_size(child_event);
|
|
perf_event__id_header_size(child_event);
|
|
|
|
/*
|
|
* Link it up in the child's context:
|
|
*/
|
|
raw_spin_lock_irqsave(&child_ctx->lock, flags);
|
|
add_event_to_ctx(child_event, child_ctx);
|
|
raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
|
|
|
|
/*
|
|
* Get a reference to the parent filp - we will fput it
|
|
* when the child event exits. This is safe to do because
|
|
* we are in the parent and we know that the filp still
|
|
* exists and has a nonzero count:
|
|
*/
|
|
atomic_long_inc(&parent_event->filp->f_count);
|
|
|
|
/*
|
|
* Link this into the parent event's child list
|
|
*/
|
|
WARN_ON_ONCE(parent_event->ctx->parent_ctx);
|
|
mutex_lock(&parent_event->child_mutex);
|
|
list_add_tail(&child_event->child_list, &parent_event->child_list);
|
|
mutex_unlock(&parent_event->child_mutex);
|
|
|
|
return child_event;
|
|
}
|
|
|
|
static int inherit_group(struct perf_event *parent_event,
|
|
struct task_struct *parent,
|
|
struct perf_event_context *parent_ctx,
|
|
struct task_struct *child,
|
|
struct perf_event_context *child_ctx)
|
|
{
|
|
struct perf_event *leader;
|
|
struct perf_event *sub;
|
|
struct perf_event *child_ctr;
|
|
|
|
leader = inherit_event(parent_event, parent, parent_ctx,
|
|
child, NULL, child_ctx);
|
|
if (IS_ERR(leader))
|
|
return PTR_ERR(leader);
|
|
list_for_each_entry(sub, &parent_event->sibling_list, group_entry) {
|
|
child_ctr = inherit_event(sub, parent, parent_ctx,
|
|
child, leader, child_ctx);
|
|
if (IS_ERR(child_ctr))
|
|
return PTR_ERR(child_ctr);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
inherit_task_group(struct perf_event *event, struct task_struct *parent,
|
|
struct perf_event_context *parent_ctx,
|
|
struct task_struct *child, int ctxn,
|
|
int *inherited_all)
|
|
{
|
|
int ret;
|
|
struct perf_event_context *child_ctx;
|
|
|
|
if (!event->attr.inherit) {
|
|
*inherited_all = 0;
|
|
return 0;
|
|
}
|
|
|
|
child_ctx = child->perf_event_ctxp[ctxn];
|
|
if (!child_ctx) {
|
|
/*
|
|
* This is executed from the parent task context, so
|
|
* inherit events that have been marked for cloning.
|
|
* First allocate and initialize a context for the
|
|
* child.
|
|
*/
|
|
|
|
child_ctx = alloc_perf_context(event->pmu, child);
|
|
if (!child_ctx)
|
|
return -ENOMEM;
|
|
|
|
child->perf_event_ctxp[ctxn] = child_ctx;
|
|
}
|
|
|
|
ret = inherit_group(event, parent, parent_ctx,
|
|
child, child_ctx);
|
|
|
|
if (ret)
|
|
*inherited_all = 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Initialize the perf_event context in task_struct
|
|
*/
|
|
int perf_event_init_context(struct task_struct *child, int ctxn)
|
|
{
|
|
struct perf_event_context *child_ctx, *parent_ctx;
|
|
struct perf_event_context *cloned_ctx;
|
|
struct perf_event *event;
|
|
struct task_struct *parent = current;
|
|
int inherited_all = 1;
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
|
|
if (likely(!parent->perf_event_ctxp[ctxn]))
|
|
return 0;
|
|
|
|
/*
|
|
* If the parent's context is a clone, pin it so it won't get
|
|
* swapped under us.
|
|
*/
|
|
parent_ctx = perf_pin_task_context(parent, ctxn);
|
|
|
|
/*
|
|
* No need to check if parent_ctx != NULL here; since we saw
|
|
* it non-NULL earlier, the only reason for it to become NULL
|
|
* is if we exit, and since we're currently in the middle of
|
|
* a fork we can't be exiting at the same time.
|
|
*/
|
|
|
|
/*
|
|
* Lock the parent list. No need to lock the child - not PID
|
|
* hashed yet and not running, so nobody can access it.
|
|
*/
|
|
mutex_lock(&parent_ctx->mutex);
|
|
|
|
/*
|
|
* We dont have to disable NMIs - we are only looking at
|
|
* the list, not manipulating it:
|
|
*/
|
|
list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) {
|
|
ret = inherit_task_group(event, parent, parent_ctx,
|
|
child, ctxn, &inherited_all);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* We can't hold ctx->lock when iterating the ->flexible_group list due
|
|
* to allocations, but we need to prevent rotation because
|
|
* rotate_ctx() will change the list from interrupt context.
|
|
*/
|
|
raw_spin_lock_irqsave(&parent_ctx->lock, flags);
|
|
parent_ctx->rotate_disable = 1;
|
|
raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
|
|
|
|
list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) {
|
|
ret = inherit_task_group(event, parent, parent_ctx,
|
|
child, ctxn, &inherited_all);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
raw_spin_lock_irqsave(&parent_ctx->lock, flags);
|
|
parent_ctx->rotate_disable = 0;
|
|
|
|
child_ctx = child->perf_event_ctxp[ctxn];
|
|
|
|
if (child_ctx && inherited_all) {
|
|
/*
|
|
* Mark the child context as a clone of the parent
|
|
* context, or of whatever the parent is a clone of.
|
|
*
|
|
* Note that if the parent is a clone, the holding of
|
|
* parent_ctx->lock avoids it from being uncloned.
|
|
*/
|
|
cloned_ctx = parent_ctx->parent_ctx;
|
|
if (cloned_ctx) {
|
|
child_ctx->parent_ctx = cloned_ctx;
|
|
child_ctx->parent_gen = parent_ctx->parent_gen;
|
|
} else {
|
|
child_ctx->parent_ctx = parent_ctx;
|
|
child_ctx->parent_gen = parent_ctx->generation;
|
|
}
|
|
get_ctx(child_ctx->parent_ctx);
|
|
}
|
|
|
|
raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
|
|
mutex_unlock(&parent_ctx->mutex);
|
|
|
|
perf_unpin_context(parent_ctx);
|
|
put_ctx(parent_ctx);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Initialize the perf_event context in task_struct
|
|
*/
|
|
int perf_event_init_task(struct task_struct *child)
|
|
{
|
|
int ctxn, ret;
|
|
|
|
memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
|
|
mutex_init(&child->perf_event_mutex);
|
|
INIT_LIST_HEAD(&child->perf_event_list);
|
|
|
|
for_each_task_context_nr(ctxn) {
|
|
ret = perf_event_init_context(child, ctxn);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __init perf_event_init_all_cpus(void)
|
|
{
|
|
struct swevent_htable *swhash;
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
swhash = &per_cpu(swevent_htable, cpu);
|
|
mutex_init(&swhash->hlist_mutex);
|
|
INIT_LIST_HEAD(&per_cpu(rotation_list, cpu));
|
|
}
|
|
}
|
|
|
|
static void __cpuinit perf_event_init_cpu(int cpu)
|
|
{
|
|
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
|
|
|
|
mutex_lock(&swhash->hlist_mutex);
|
|
if (swhash->hlist_refcount > 0) {
|
|
struct swevent_hlist *hlist;
|
|
|
|
hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
|
|
WARN_ON(!hlist);
|
|
rcu_assign_pointer(swhash->swevent_hlist, hlist);
|
|
}
|
|
mutex_unlock(&swhash->hlist_mutex);
|
|
}
|
|
|
|
#if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
|
|
static void perf_pmu_rotate_stop(struct pmu *pmu)
|
|
{
|
|
struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
|
|
|
|
WARN_ON(!irqs_disabled());
|
|
|
|
list_del_init(&cpuctx->rotation_list);
|
|
}
|
|
|
|
static void __perf_event_exit_context(void *__info)
|
|
{
|
|
struct perf_event_context *ctx = __info;
|
|
struct perf_event *event, *tmp;
|
|
|
|
perf_pmu_rotate_stop(ctx->pmu);
|
|
|
|
list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, group_entry)
|
|
__perf_remove_from_context(event);
|
|
list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, group_entry)
|
|
__perf_remove_from_context(event);
|
|
}
|
|
|
|
static void perf_event_exit_cpu_context(int cpu)
|
|
{
|
|
struct perf_event_context *ctx;
|
|
struct pmu *pmu;
|
|
int idx;
|
|
|
|
idx = srcu_read_lock(&pmus_srcu);
|
|
list_for_each_entry_rcu(pmu, &pmus, entry) {
|
|
ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx;
|
|
|
|
mutex_lock(&ctx->mutex);
|
|
smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
|
|
mutex_unlock(&ctx->mutex);
|
|
}
|
|
srcu_read_unlock(&pmus_srcu, idx);
|
|
}
|
|
|
|
static void perf_event_exit_cpu(int cpu)
|
|
{
|
|
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
|
|
|
|
mutex_lock(&swhash->hlist_mutex);
|
|
swevent_hlist_release(swhash);
|
|
mutex_unlock(&swhash->hlist_mutex);
|
|
|
|
perf_event_exit_cpu_context(cpu);
|
|
}
|
|
#else
|
|
static inline void perf_event_exit_cpu(int cpu) { }
|
|
#endif
|
|
|
|
static int
|
|
perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_online_cpu(cpu)
|
|
perf_event_exit_cpu(cpu);
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
/*
|
|
* Run the perf reboot notifier at the very last possible moment so that
|
|
* the generic watchdog code runs as long as possible.
|
|
*/
|
|
static struct notifier_block perf_reboot_notifier = {
|
|
.notifier_call = perf_reboot,
|
|
.priority = INT_MIN,
|
|
};
|
|
|
|
static int __cpuinit
|
|
perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
|
|
{
|
|
unsigned int cpu = (long)hcpu;
|
|
|
|
switch (action & ~CPU_TASKS_FROZEN) {
|
|
|
|
case CPU_UP_PREPARE:
|
|
case CPU_DOWN_FAILED:
|
|
perf_event_init_cpu(cpu);
|
|
break;
|
|
|
|
case CPU_UP_CANCELED:
|
|
case CPU_DOWN_PREPARE:
|
|
perf_event_exit_cpu(cpu);
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
void __init perf_event_init(void)
|
|
{
|
|
int ret;
|
|
|
|
idr_init(&pmu_idr);
|
|
|
|
perf_event_init_all_cpus();
|
|
init_srcu_struct(&pmus_srcu);
|
|
perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
|
|
perf_pmu_register(&perf_cpu_clock, NULL, -1);
|
|
perf_pmu_register(&perf_task_clock, NULL, -1);
|
|
perf_tp_register();
|
|
perf_cpu_notifier(perf_cpu_notify);
|
|
register_reboot_notifier(&perf_reboot_notifier);
|
|
|
|
ret = init_hw_breakpoint();
|
|
WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
|
|
}
|
|
|
|
static int __init perf_event_sysfs_init(void)
|
|
{
|
|
struct pmu *pmu;
|
|
int ret;
|
|
|
|
mutex_lock(&pmus_lock);
|
|
|
|
ret = bus_register(&pmu_bus);
|
|
if (ret)
|
|
goto unlock;
|
|
|
|
list_for_each_entry(pmu, &pmus, entry) {
|
|
if (!pmu->name || pmu->type < 0)
|
|
continue;
|
|
|
|
ret = pmu_dev_alloc(pmu);
|
|
WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret);
|
|
}
|
|
pmu_bus_running = 1;
|
|
ret = 0;
|
|
|
|
unlock:
|
|
mutex_unlock(&pmus_lock);
|
|
|
|
return ret;
|
|
}
|
|
device_initcall(perf_event_sysfs_init);
|
|
|
|
#ifdef CONFIG_CGROUP_PERF
|
|
static struct cgroup_subsys_state *perf_cgroup_create(
|
|
struct cgroup_subsys *ss, struct cgroup *cont)
|
|
{
|
|
struct perf_cgroup *jc;
|
|
|
|
jc = kzalloc(sizeof(*jc), GFP_KERNEL);
|
|
if (!jc)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
jc->info = alloc_percpu(struct perf_cgroup_info);
|
|
if (!jc->info) {
|
|
kfree(jc);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
return &jc->css;
|
|
}
|
|
|
|
static void perf_cgroup_destroy(struct cgroup_subsys *ss,
|
|
struct cgroup *cont)
|
|
{
|
|
struct perf_cgroup *jc;
|
|
jc = container_of(cgroup_subsys_state(cont, perf_subsys_id),
|
|
struct perf_cgroup, css);
|
|
free_percpu(jc->info);
|
|
kfree(jc);
|
|
}
|
|
|
|
static int __perf_cgroup_move(void *info)
|
|
{
|
|
struct task_struct *task = info;
|
|
perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN);
|
|
return 0;
|
|
}
|
|
|
|
static void perf_cgroup_move(struct task_struct *task)
|
|
{
|
|
task_function_call(task, __perf_cgroup_move, task);
|
|
}
|
|
|
|
static void perf_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
|
|
struct cgroup *old_cgrp, struct task_struct *task,
|
|
bool threadgroup)
|
|
{
|
|
perf_cgroup_move(task);
|
|
if (threadgroup) {
|
|
struct task_struct *c;
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(c, &task->thread_group, thread_group) {
|
|
perf_cgroup_move(c);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
}
|
|
|
|
static void perf_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp,
|
|
struct cgroup *old_cgrp, struct task_struct *task)
|
|
{
|
|
/*
|
|
* cgroup_exit() is called in the copy_process() failure path.
|
|
* Ignore this case since the task hasn't ran yet, this avoids
|
|
* trying to poke a half freed task state from generic code.
|
|
*/
|
|
if (!(task->flags & PF_EXITING))
|
|
return;
|
|
|
|
perf_cgroup_move(task);
|
|
}
|
|
|
|
struct cgroup_subsys perf_subsys = {
|
|
.name = "perf_event",
|
|
.subsys_id = perf_subsys_id,
|
|
.create = perf_cgroup_create,
|
|
.destroy = perf_cgroup_destroy,
|
|
.exit = perf_cgroup_exit,
|
|
.attach = perf_cgroup_attach,
|
|
};
|
|
#endif /* CONFIG_CGROUP_PERF */
|