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![Ingo Molnar](/assets/img/avatar_default.png)
Merge reason: tracing/core was on a .30-rc1 base and was missing out on on a handful of tracing fixes present in .30-rc5-almost. Signed-off-by: Ingo Molnar <mingo@elte.hu>
390 lines
8.6 KiB
C
390 lines
8.6 KiB
C
/*
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* unlikely profiler
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*
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* Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
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*/
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#include <linux/kallsyms.h>
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#include <linux/seq_file.h>
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#include <linux/spinlock.h>
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#include <linux/irqflags.h>
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#include <linux/debugfs.h>
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#include <linux/uaccess.h>
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#include <linux/module.h>
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#include <linux/ftrace.h>
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#include <linux/hash.h>
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#include <linux/fs.h>
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#include <asm/local.h>
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#include "trace.h"
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#include "trace_stat.h"
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#include "trace_output.h"
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#ifdef CONFIG_BRANCH_TRACER
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static struct tracer branch_trace;
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static int branch_tracing_enabled __read_mostly;
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static DEFINE_MUTEX(branch_tracing_mutex);
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static struct trace_array *branch_tracer;
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static void
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probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
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{
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struct ftrace_event_call *call = &event_branch;
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struct trace_array *tr = branch_tracer;
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struct ring_buffer_event *event;
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struct trace_branch *entry;
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unsigned long flags;
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int cpu, pc;
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const char *p;
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/*
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* I would love to save just the ftrace_likely_data pointer, but
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* this code can also be used by modules. Ugly things can happen
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* if the module is unloaded, and then we go and read the
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* pointer. This is slower, but much safer.
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*/
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if (unlikely(!tr))
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return;
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local_irq_save(flags);
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cpu = raw_smp_processor_id();
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if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
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goto out;
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pc = preempt_count();
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event = trace_buffer_lock_reserve(tr, TRACE_BRANCH,
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sizeof(*entry), flags, pc);
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if (!event)
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goto out;
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entry = ring_buffer_event_data(event);
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/* Strip off the path, only save the file */
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p = f->file + strlen(f->file);
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while (p >= f->file && *p != '/')
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p--;
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p++;
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strncpy(entry->func, f->func, TRACE_FUNC_SIZE);
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strncpy(entry->file, p, TRACE_FILE_SIZE);
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entry->func[TRACE_FUNC_SIZE] = 0;
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entry->file[TRACE_FILE_SIZE] = 0;
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entry->line = f->line;
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entry->correct = val == expect;
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if (!filter_check_discard(call, entry, tr->buffer, event))
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ring_buffer_unlock_commit(tr->buffer, event);
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out:
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atomic_dec(&tr->data[cpu]->disabled);
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local_irq_restore(flags);
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}
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static inline
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void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
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{
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if (!branch_tracing_enabled)
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return;
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probe_likely_condition(f, val, expect);
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}
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int enable_branch_tracing(struct trace_array *tr)
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{
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mutex_lock(&branch_tracing_mutex);
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branch_tracer = tr;
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/*
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* Must be seen before enabling. The reader is a condition
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* where we do not need a matching rmb()
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*/
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smp_wmb();
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branch_tracing_enabled++;
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mutex_unlock(&branch_tracing_mutex);
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return 0;
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}
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void disable_branch_tracing(void)
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{
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mutex_lock(&branch_tracing_mutex);
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if (!branch_tracing_enabled)
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goto out_unlock;
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branch_tracing_enabled--;
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out_unlock:
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mutex_unlock(&branch_tracing_mutex);
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}
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static void start_branch_trace(struct trace_array *tr)
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{
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enable_branch_tracing(tr);
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}
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static void stop_branch_trace(struct trace_array *tr)
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{
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disable_branch_tracing();
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}
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static int branch_trace_init(struct trace_array *tr)
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{
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start_branch_trace(tr);
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return 0;
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}
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static void branch_trace_reset(struct trace_array *tr)
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{
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stop_branch_trace(tr);
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}
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static enum print_line_t trace_branch_print(struct trace_iterator *iter,
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int flags)
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{
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struct trace_branch *field;
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trace_assign_type(field, iter->ent);
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if (trace_seq_printf(&iter->seq, "[%s] %s:%s:%d\n",
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field->correct ? " ok " : " MISS ",
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field->func,
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field->file,
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field->line))
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return TRACE_TYPE_PARTIAL_LINE;
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return TRACE_TYPE_HANDLED;
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}
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static void branch_print_header(struct seq_file *s)
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{
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seq_puts(s, "# TASK-PID CPU# TIMESTAMP CORRECT"
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" FUNC:FILE:LINE\n");
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seq_puts(s, "# | | | | | "
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" |\n");
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}
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static struct trace_event trace_branch_event = {
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.type = TRACE_BRANCH,
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.trace = trace_branch_print,
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};
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static struct tracer branch_trace __read_mostly =
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{
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.name = "branch",
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.init = branch_trace_init,
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.reset = branch_trace_reset,
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#ifdef CONFIG_FTRACE_SELFTEST
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.selftest = trace_selftest_startup_branch,
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#endif /* CONFIG_FTRACE_SELFTEST */
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.print_header = branch_print_header,
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};
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__init static int init_branch_tracer(void)
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{
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int ret;
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ret = register_ftrace_event(&trace_branch_event);
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if (!ret) {
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printk(KERN_WARNING "Warning: could not register "
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"branch events\n");
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return 1;
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}
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return register_tracer(&branch_trace);
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}
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device_initcall(init_branch_tracer);
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#else
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static inline
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void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
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{
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}
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#endif /* CONFIG_BRANCH_TRACER */
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void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect)
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{
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/*
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* I would love to have a trace point here instead, but the
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* trace point code is so inundated with unlikely and likely
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* conditions that the recursive nightmare that exists is too
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* much to try to get working. At least for now.
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*/
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trace_likely_condition(f, val, expect);
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/* FIXME: Make this atomic! */
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if (val == expect)
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f->correct++;
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else
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f->incorrect++;
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}
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EXPORT_SYMBOL(ftrace_likely_update);
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extern unsigned long __start_annotated_branch_profile[];
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extern unsigned long __stop_annotated_branch_profile[];
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static int annotated_branch_stat_headers(struct seq_file *m)
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{
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seq_printf(m, " correct incorrect %% ");
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seq_printf(m, " Function "
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" File Line\n"
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" ------- --------- - "
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" -------- "
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" ---- ----\n");
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return 0;
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}
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static inline long get_incorrect_percent(struct ftrace_branch_data *p)
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{
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long percent;
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if (p->correct) {
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percent = p->incorrect * 100;
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percent /= p->correct + p->incorrect;
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} else
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percent = p->incorrect ? 100 : -1;
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return percent;
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}
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static int branch_stat_show(struct seq_file *m, void *v)
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{
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struct ftrace_branch_data *p = v;
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const char *f;
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long percent;
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/* Only print the file, not the path */
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f = p->file + strlen(p->file);
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while (f >= p->file && *f != '/')
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f--;
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f++;
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/*
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* The miss is overlayed on correct, and hit on incorrect.
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*/
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percent = get_incorrect_percent(p);
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seq_printf(m, "%8lu %8lu ", p->correct, p->incorrect);
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if (percent < 0)
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seq_printf(m, " X ");
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else
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seq_printf(m, "%3ld ", percent);
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seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line);
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return 0;
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}
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static void *annotated_branch_stat_start(struct tracer_stat *trace)
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{
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return __start_annotated_branch_profile;
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}
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static void *
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annotated_branch_stat_next(void *v, int idx)
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{
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struct ftrace_branch_data *p = v;
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++p;
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if ((void *)p >= (void *)__stop_annotated_branch_profile)
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return NULL;
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return p;
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}
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static int annotated_branch_stat_cmp(void *p1, void *p2)
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{
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struct ftrace_branch_data *a = p1;
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struct ftrace_branch_data *b = p2;
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long percent_a, percent_b;
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percent_a = get_incorrect_percent(a);
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percent_b = get_incorrect_percent(b);
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if (percent_a < percent_b)
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return -1;
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if (percent_a > percent_b)
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return 1;
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else
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return 0;
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}
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static struct tracer_stat annotated_branch_stats = {
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.name = "branch_annotated",
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.stat_start = annotated_branch_stat_start,
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.stat_next = annotated_branch_stat_next,
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.stat_cmp = annotated_branch_stat_cmp,
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.stat_headers = annotated_branch_stat_headers,
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.stat_show = branch_stat_show
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};
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__init static int init_annotated_branch_stats(void)
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{
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int ret;
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ret = register_stat_tracer(&annotated_branch_stats);
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if (!ret) {
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printk(KERN_WARNING "Warning: could not register "
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"annotated branches stats\n");
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return 1;
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}
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return 0;
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}
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fs_initcall(init_annotated_branch_stats);
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#ifdef CONFIG_PROFILE_ALL_BRANCHES
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extern unsigned long __start_branch_profile[];
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extern unsigned long __stop_branch_profile[];
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static int all_branch_stat_headers(struct seq_file *m)
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{
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seq_printf(m, " miss hit %% ");
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seq_printf(m, " Function "
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" File Line\n"
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" ------- --------- - "
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" -------- "
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" ---- ----\n");
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return 0;
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}
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static void *all_branch_stat_start(struct tracer_stat *trace)
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{
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return __start_branch_profile;
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}
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static void *
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all_branch_stat_next(void *v, int idx)
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{
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struct ftrace_branch_data *p = v;
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++p;
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if ((void *)p >= (void *)__stop_branch_profile)
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return NULL;
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return p;
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}
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static struct tracer_stat all_branch_stats = {
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.name = "branch_all",
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.stat_start = all_branch_stat_start,
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.stat_next = all_branch_stat_next,
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.stat_headers = all_branch_stat_headers,
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.stat_show = branch_stat_show
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};
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__init static int all_annotated_branch_stats(void)
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{
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int ret;
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ret = register_stat_tracer(&all_branch_stats);
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if (!ret) {
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printk(KERN_WARNING "Warning: could not register "
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"all branches stats\n");
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return 1;
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}
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return 0;
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}
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fs_initcall(all_annotated_branch_stats);
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#endif /* CONFIG_PROFILE_ALL_BRANCHES */
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