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![Yang Jihong](/assets/img/avatar_default.png)
If no target is specified for 'latency' subcommand, the execution fails
because - 1 (invalid value) is written to set_ftrace_pid tracefs file.
Make system wide the default target, which is the same as the default
behavior of 'trace' subcommand.
Before the fix:
# perf ftrace latency -T schedule
failed to set ftrace pid
After the fix:
# perf ftrace latency -T schedule
^C# DURATION | COUNT | GRAPH |
0 - 1 us | 0 | |
1 - 2 us | 0 | |
2 - 4 us | 0 | |
4 - 8 us | 2828 | #### |
8 - 16 us | 23953 | ######################################## |
16 - 32 us | 408 | |
32 - 64 us | 318 | |
64 - 128 us | 4 | |
128 - 256 us | 3 | |
256 - 512 us | 0 | |
512 - 1024 us | 1 | |
1 - 2 ms | 4 | |
2 - 4 ms | 0 | |
4 - 8 ms | 0 | |
8 - 16 ms | 0 | |
16 - 32 ms | 0 | |
32 - 64 ms | 0 | |
64 - 128 ms | 0 | |
128 - 256 ms | 4 | |
256 - 512 ms | 2 | |
512 - 1024 ms | 0 | |
1 - ... s | 0 | |
Fixes: 53be502822
("perf ftrace: Add 'latency' subcommand")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230324032702.109964-1-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
1294 lines
29 KiB
C
1294 lines
29 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* builtin-ftrace.c
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*
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* Copyright (c) 2013 LG Electronics, Namhyung Kim <namhyung@kernel.org>
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* Copyright (c) 2020 Changbin Du <changbin.du@gmail.com>, significant enhancement.
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*/
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#include "builtin.h"
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#include <errno.h>
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#include <unistd.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <fcntl.h>
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#include <math.h>
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#include <poll.h>
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#include <ctype.h>
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#include <linux/capability.h>
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#include <linux/string.h>
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#include "debug.h"
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#include <subcmd/pager.h>
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#include <subcmd/parse-options.h>
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#include <api/fs/tracing_path.h>
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#include "evlist.h"
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#include "target.h"
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#include "cpumap.h"
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#include "thread_map.h"
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#include "strfilter.h"
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#include "util/cap.h"
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#include "util/config.h"
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#include "util/ftrace.h"
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#include "util/units.h"
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#include "util/parse-sublevel-options.h"
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#define DEFAULT_TRACER "function_graph"
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static volatile sig_atomic_t workload_exec_errno;
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static volatile sig_atomic_t done;
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static void sig_handler(int sig __maybe_unused)
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{
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done = true;
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}
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/*
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* evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
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* we asked by setting its exec_error to the function below,
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* ftrace__workload_exec_failed_signal.
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*
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* XXX We need to handle this more appropriately, emitting an error, etc.
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*/
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static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
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siginfo_t *info __maybe_unused,
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void *ucontext __maybe_unused)
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{
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workload_exec_errno = info->si_value.sival_int;
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done = true;
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}
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static int __write_tracing_file(const char *name, const char *val, bool append)
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{
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char *file;
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int fd, ret = -1;
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ssize_t size = strlen(val);
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int flags = O_WRONLY;
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char errbuf[512];
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char *val_copy;
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file = get_tracing_file(name);
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if (!file) {
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pr_debug("cannot get tracing file: %s\n", name);
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return -1;
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}
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if (append)
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flags |= O_APPEND;
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else
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flags |= O_TRUNC;
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fd = open(file, flags);
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if (fd < 0) {
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pr_debug("cannot open tracing file: %s: %s\n",
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name, str_error_r(errno, errbuf, sizeof(errbuf)));
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goto out;
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}
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/*
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* Copy the original value and append a '\n'. Without this,
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* the kernel can hide possible errors.
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*/
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val_copy = strdup(val);
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if (!val_copy)
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goto out_close;
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val_copy[size] = '\n';
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if (write(fd, val_copy, size + 1) == size + 1)
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ret = 0;
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else
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pr_debug("write '%s' to tracing/%s failed: %s\n",
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val, name, str_error_r(errno, errbuf, sizeof(errbuf)));
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free(val_copy);
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out_close:
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close(fd);
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out:
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put_tracing_file(file);
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return ret;
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}
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static int write_tracing_file(const char *name, const char *val)
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{
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return __write_tracing_file(name, val, false);
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}
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static int append_tracing_file(const char *name, const char *val)
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{
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return __write_tracing_file(name, val, true);
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}
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static int read_tracing_file_to_stdout(const char *name)
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{
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char buf[4096];
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char *file;
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int fd;
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int ret = -1;
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file = get_tracing_file(name);
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if (!file) {
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pr_debug("cannot get tracing file: %s\n", name);
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return -1;
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}
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fd = open(file, O_RDONLY);
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if (fd < 0) {
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pr_debug("cannot open tracing file: %s: %s\n",
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name, str_error_r(errno, buf, sizeof(buf)));
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goto out;
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}
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/* read contents to stdout */
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while (true) {
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int n = read(fd, buf, sizeof(buf));
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if (n == 0)
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break;
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else if (n < 0)
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goto out_close;
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if (fwrite(buf, n, 1, stdout) != 1)
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goto out_close;
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}
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ret = 0;
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out_close:
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close(fd);
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out:
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put_tracing_file(file);
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return ret;
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}
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static int read_tracing_file_by_line(const char *name,
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void (*cb)(char *str, void *arg),
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void *cb_arg)
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{
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char *line = NULL;
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size_t len = 0;
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char *file;
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FILE *fp;
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file = get_tracing_file(name);
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if (!file) {
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pr_debug("cannot get tracing file: %s\n", name);
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return -1;
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}
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fp = fopen(file, "r");
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if (fp == NULL) {
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pr_debug("cannot open tracing file: %s\n", name);
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put_tracing_file(file);
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return -1;
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}
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while (getline(&line, &len, fp) != -1) {
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cb(line, cb_arg);
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}
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if (line)
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free(line);
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fclose(fp);
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put_tracing_file(file);
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return 0;
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}
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static int write_tracing_file_int(const char *name, int value)
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{
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char buf[16];
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snprintf(buf, sizeof(buf), "%d", value);
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if (write_tracing_file(name, buf) < 0)
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return -1;
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return 0;
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}
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static int write_tracing_option_file(const char *name, const char *val)
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{
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char *file;
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int ret;
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if (asprintf(&file, "options/%s", name) < 0)
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return -1;
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ret = __write_tracing_file(file, val, false);
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free(file);
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return ret;
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}
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static int reset_tracing_cpu(void);
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static void reset_tracing_filters(void);
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static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
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{
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write_tracing_option_file("function-fork", "0");
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write_tracing_option_file("func_stack_trace", "0");
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write_tracing_option_file("sleep-time", "1");
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write_tracing_option_file("funcgraph-irqs", "1");
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write_tracing_option_file("funcgraph-proc", "0");
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write_tracing_option_file("funcgraph-abstime", "0");
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write_tracing_option_file("latency-format", "0");
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write_tracing_option_file("irq-info", "0");
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}
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static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
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{
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if (write_tracing_file("tracing_on", "0") < 0)
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return -1;
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if (write_tracing_file("current_tracer", "nop") < 0)
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return -1;
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if (write_tracing_file("set_ftrace_pid", " ") < 0)
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return -1;
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if (reset_tracing_cpu() < 0)
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return -1;
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if (write_tracing_file("max_graph_depth", "0") < 0)
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return -1;
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if (write_tracing_file("tracing_thresh", "0") < 0)
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return -1;
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reset_tracing_filters();
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reset_tracing_options(ftrace);
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return 0;
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}
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static int set_tracing_pid(struct perf_ftrace *ftrace)
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{
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int i;
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char buf[16];
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if (target__has_cpu(&ftrace->target))
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return 0;
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for (i = 0; i < perf_thread_map__nr(ftrace->evlist->core.threads); i++) {
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scnprintf(buf, sizeof(buf), "%d",
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perf_thread_map__pid(ftrace->evlist->core.threads, i));
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if (append_tracing_file("set_ftrace_pid", buf) < 0)
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return -1;
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}
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return 0;
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}
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static int set_tracing_cpumask(struct perf_cpu_map *cpumap)
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{
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char *cpumask;
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size_t mask_size;
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int ret;
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int last_cpu;
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last_cpu = perf_cpu_map__cpu(cpumap, perf_cpu_map__nr(cpumap) - 1).cpu;
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mask_size = last_cpu / 4 + 2; /* one more byte for EOS */
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mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
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cpumask = malloc(mask_size);
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if (cpumask == NULL) {
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pr_debug("failed to allocate cpu mask\n");
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return -1;
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}
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cpu_map__snprint_mask(cpumap, cpumask, mask_size);
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ret = write_tracing_file("tracing_cpumask", cpumask);
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free(cpumask);
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return ret;
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}
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static int set_tracing_cpu(struct perf_ftrace *ftrace)
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{
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struct perf_cpu_map *cpumap = ftrace->evlist->core.user_requested_cpus;
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if (!target__has_cpu(&ftrace->target))
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return 0;
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return set_tracing_cpumask(cpumap);
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}
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static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
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{
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if (!ftrace->func_stack_trace)
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return 0;
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if (write_tracing_option_file("func_stack_trace", "1") < 0)
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return -1;
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return 0;
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}
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static int set_tracing_func_irqinfo(struct perf_ftrace *ftrace)
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{
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if (!ftrace->func_irq_info)
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return 0;
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if (write_tracing_option_file("irq-info", "1") < 0)
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return -1;
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return 0;
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}
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static int reset_tracing_cpu(void)
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{
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struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL);
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int ret;
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ret = set_tracing_cpumask(cpumap);
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perf_cpu_map__put(cpumap);
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return ret;
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}
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static int __set_tracing_filter(const char *filter_file, struct list_head *funcs)
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{
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struct filter_entry *pos;
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list_for_each_entry(pos, funcs, list) {
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if (append_tracing_file(filter_file, pos->name) < 0)
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return -1;
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}
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return 0;
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}
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static int set_tracing_filters(struct perf_ftrace *ftrace)
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{
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int ret;
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ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
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if (ret < 0)
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return ret;
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ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
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if (ret < 0)
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return ret;
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ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
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if (ret < 0)
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return ret;
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/* old kernels do not have this filter */
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__set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);
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return ret;
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}
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static void reset_tracing_filters(void)
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{
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write_tracing_file("set_ftrace_filter", " ");
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write_tracing_file("set_ftrace_notrace", " ");
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write_tracing_file("set_graph_function", " ");
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write_tracing_file("set_graph_notrace", " ");
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}
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static int set_tracing_depth(struct perf_ftrace *ftrace)
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{
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if (ftrace->graph_depth == 0)
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return 0;
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if (ftrace->graph_depth < 0) {
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pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
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return -1;
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}
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if (write_tracing_file_int("max_graph_depth", ftrace->graph_depth) < 0)
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return -1;
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return 0;
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}
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static int set_tracing_percpu_buffer_size(struct perf_ftrace *ftrace)
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{
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int ret;
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if (ftrace->percpu_buffer_size == 0)
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return 0;
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ret = write_tracing_file_int("buffer_size_kb",
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ftrace->percpu_buffer_size / 1024);
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if (ret < 0)
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return ret;
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return 0;
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}
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static int set_tracing_trace_inherit(struct perf_ftrace *ftrace)
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{
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if (!ftrace->inherit)
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return 0;
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if (write_tracing_option_file("function-fork", "1") < 0)
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return -1;
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return 0;
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}
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static int set_tracing_sleep_time(struct perf_ftrace *ftrace)
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{
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if (!ftrace->graph_nosleep_time)
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return 0;
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if (write_tracing_option_file("sleep-time", "0") < 0)
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return -1;
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return 0;
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}
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static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace)
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{
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if (!ftrace->graph_noirqs)
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return 0;
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if (write_tracing_option_file("funcgraph-irqs", "0") < 0)
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return -1;
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return 0;
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}
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static int set_tracing_funcgraph_verbose(struct perf_ftrace *ftrace)
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{
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if (!ftrace->graph_verbose)
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return 0;
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if (write_tracing_option_file("funcgraph-proc", "1") < 0)
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return -1;
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if (write_tracing_option_file("funcgraph-abstime", "1") < 0)
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return -1;
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if (write_tracing_option_file("latency-format", "1") < 0)
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return -1;
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return 0;
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}
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static int set_tracing_thresh(struct perf_ftrace *ftrace)
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{
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int ret;
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if (ftrace->graph_thresh == 0)
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return 0;
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ret = write_tracing_file_int("tracing_thresh", ftrace->graph_thresh);
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if (ret < 0)
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return ret;
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return 0;
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}
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static int set_tracing_options(struct perf_ftrace *ftrace)
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{
|
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if (set_tracing_pid(ftrace) < 0) {
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pr_err("failed to set ftrace pid\n");
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return -1;
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}
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|
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if (set_tracing_cpu(ftrace) < 0) {
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pr_err("failed to set tracing cpumask\n");
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return -1;
|
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}
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|
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if (set_tracing_func_stack_trace(ftrace) < 0) {
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pr_err("failed to set tracing option func_stack_trace\n");
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return -1;
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}
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|
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if (set_tracing_func_irqinfo(ftrace) < 0) {
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pr_err("failed to set tracing option irq-info\n");
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return -1;
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}
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|
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if (set_tracing_filters(ftrace) < 0) {
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pr_err("failed to set tracing filters\n");
|
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return -1;
|
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}
|
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|
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if (set_tracing_depth(ftrace) < 0) {
|
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pr_err("failed to set graph depth\n");
|
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return -1;
|
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}
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|
|
if (set_tracing_percpu_buffer_size(ftrace) < 0) {
|
|
pr_err("failed to set tracing per-cpu buffer size\n");
|
|
return -1;
|
|
}
|
|
|
|
if (set_tracing_trace_inherit(ftrace) < 0) {
|
|
pr_err("failed to set tracing option function-fork\n");
|
|
return -1;
|
|
}
|
|
|
|
if (set_tracing_sleep_time(ftrace) < 0) {
|
|
pr_err("failed to set tracing option sleep-time\n");
|
|
return -1;
|
|
}
|
|
|
|
if (set_tracing_funcgraph_irqs(ftrace) < 0) {
|
|
pr_err("failed to set tracing option funcgraph-irqs\n");
|
|
return -1;
|
|
}
|
|
|
|
if (set_tracing_funcgraph_verbose(ftrace) < 0) {
|
|
pr_err("failed to set tracing option funcgraph-proc/funcgraph-abstime\n");
|
|
return -1;
|
|
}
|
|
|
|
if (set_tracing_thresh(ftrace) < 0) {
|
|
pr_err("failed to set tracing thresh\n");
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void select_tracer(struct perf_ftrace *ftrace)
|
|
{
|
|
bool graph = !list_empty(&ftrace->graph_funcs) ||
|
|
!list_empty(&ftrace->nograph_funcs);
|
|
bool func = !list_empty(&ftrace->filters) ||
|
|
!list_empty(&ftrace->notrace);
|
|
|
|
/* The function_graph has priority over function tracer. */
|
|
if (graph)
|
|
ftrace->tracer = "function_graph";
|
|
else if (func)
|
|
ftrace->tracer = "function";
|
|
/* Otherwise, the default tracer is used. */
|
|
|
|
pr_debug("%s tracer is used\n", ftrace->tracer);
|
|
}
|
|
|
|
static int __cmd_ftrace(struct perf_ftrace *ftrace)
|
|
{
|
|
char *trace_file;
|
|
int trace_fd;
|
|
char buf[4096];
|
|
struct pollfd pollfd = {
|
|
.events = POLLIN,
|
|
};
|
|
|
|
if (!(perf_cap__capable(CAP_PERFMON) ||
|
|
perf_cap__capable(CAP_SYS_ADMIN))) {
|
|
pr_err("ftrace only works for %s!\n",
|
|
#ifdef HAVE_LIBCAP_SUPPORT
|
|
"users with the CAP_PERFMON or CAP_SYS_ADMIN capability"
|
|
#else
|
|
"root"
|
|
#endif
|
|
);
|
|
return -1;
|
|
}
|
|
|
|
select_tracer(ftrace);
|
|
|
|
if (reset_tracing_files(ftrace) < 0) {
|
|
pr_err("failed to reset ftrace\n");
|
|
goto out;
|
|
}
|
|
|
|
/* reset ftrace buffer */
|
|
if (write_tracing_file("trace", "0") < 0)
|
|
goto out;
|
|
|
|
if (set_tracing_options(ftrace) < 0)
|
|
goto out_reset;
|
|
|
|
if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
|
|
pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
|
|
goto out_reset;
|
|
}
|
|
|
|
setup_pager();
|
|
|
|
trace_file = get_tracing_file("trace_pipe");
|
|
if (!trace_file) {
|
|
pr_err("failed to open trace_pipe\n");
|
|
goto out_reset;
|
|
}
|
|
|
|
trace_fd = open(trace_file, O_RDONLY);
|
|
|
|
put_tracing_file(trace_file);
|
|
|
|
if (trace_fd < 0) {
|
|
pr_err("failed to open trace_pipe\n");
|
|
goto out_reset;
|
|
}
|
|
|
|
fcntl(trace_fd, F_SETFL, O_NONBLOCK);
|
|
pollfd.fd = trace_fd;
|
|
|
|
/* display column headers */
|
|
read_tracing_file_to_stdout("trace");
|
|
|
|
if (!ftrace->target.initial_delay) {
|
|
if (write_tracing_file("tracing_on", "1") < 0) {
|
|
pr_err("can't enable tracing\n");
|
|
goto out_close_fd;
|
|
}
|
|
}
|
|
|
|
evlist__start_workload(ftrace->evlist);
|
|
|
|
if (ftrace->target.initial_delay > 0) {
|
|
usleep(ftrace->target.initial_delay * 1000);
|
|
if (write_tracing_file("tracing_on", "1") < 0) {
|
|
pr_err("can't enable tracing\n");
|
|
goto out_close_fd;
|
|
}
|
|
}
|
|
|
|
while (!done) {
|
|
if (poll(&pollfd, 1, -1) < 0)
|
|
break;
|
|
|
|
if (pollfd.revents & POLLIN) {
|
|
int n = read(trace_fd, buf, sizeof(buf));
|
|
if (n < 0)
|
|
break;
|
|
if (fwrite(buf, n, 1, stdout) != 1)
|
|
break;
|
|
}
|
|
}
|
|
|
|
write_tracing_file("tracing_on", "0");
|
|
|
|
if (workload_exec_errno) {
|
|
const char *emsg = str_error_r(workload_exec_errno, buf, sizeof(buf));
|
|
/* flush stdout first so below error msg appears at the end. */
|
|
fflush(stdout);
|
|
pr_err("workload failed: %s\n", emsg);
|
|
goto out_close_fd;
|
|
}
|
|
|
|
/* read remaining buffer contents */
|
|
while (true) {
|
|
int n = read(trace_fd, buf, sizeof(buf));
|
|
if (n <= 0)
|
|
break;
|
|
if (fwrite(buf, n, 1, stdout) != 1)
|
|
break;
|
|
}
|
|
|
|
out_close_fd:
|
|
close(trace_fd);
|
|
out_reset:
|
|
reset_tracing_files(ftrace);
|
|
out:
|
|
return (done && !workload_exec_errno) ? 0 : -1;
|
|
}
|
|
|
|
static void make_histogram(int buckets[], char *buf, size_t len, char *linebuf,
|
|
bool use_nsec)
|
|
{
|
|
char *p, *q;
|
|
char *unit;
|
|
double num;
|
|
int i;
|
|
|
|
/* ensure NUL termination */
|
|
buf[len] = '\0';
|
|
|
|
/* handle data line by line */
|
|
for (p = buf; (q = strchr(p, '\n')) != NULL; p = q + 1) {
|
|
*q = '\0';
|
|
/* move it to the line buffer */
|
|
strcat(linebuf, p);
|
|
|
|
/*
|
|
* parse trace output to get function duration like in
|
|
*
|
|
* # tracer: function_graph
|
|
* #
|
|
* # CPU DURATION FUNCTION CALLS
|
|
* # | | | | | | |
|
|
* 1) + 10.291 us | do_filp_open();
|
|
* 1) 4.889 us | do_filp_open();
|
|
* 1) 6.086 us | do_filp_open();
|
|
*
|
|
*/
|
|
if (linebuf[0] == '#')
|
|
goto next;
|
|
|
|
/* ignore CPU */
|
|
p = strchr(linebuf, ')');
|
|
if (p == NULL)
|
|
p = linebuf;
|
|
|
|
while (*p && !isdigit(*p) && (*p != '|'))
|
|
p++;
|
|
|
|
/* no duration */
|
|
if (*p == '\0' || *p == '|')
|
|
goto next;
|
|
|
|
num = strtod(p, &unit);
|
|
if (!unit || strncmp(unit, " us", 3))
|
|
goto next;
|
|
|
|
if (use_nsec)
|
|
num *= 1000;
|
|
|
|
i = log2(num);
|
|
if (i < 0)
|
|
i = 0;
|
|
if (i >= NUM_BUCKET)
|
|
i = NUM_BUCKET - 1;
|
|
|
|
buckets[i]++;
|
|
|
|
next:
|
|
/* empty the line buffer for the next output */
|
|
linebuf[0] = '\0';
|
|
}
|
|
|
|
/* preserve any remaining output (before newline) */
|
|
strcat(linebuf, p);
|
|
}
|
|
|
|
static void display_histogram(int buckets[], bool use_nsec)
|
|
{
|
|
int i;
|
|
int total = 0;
|
|
int bar_total = 46; /* to fit in 80 column */
|
|
char bar[] = "###############################################";
|
|
int bar_len;
|
|
|
|
for (i = 0; i < NUM_BUCKET; i++)
|
|
total += buckets[i];
|
|
|
|
if (total == 0) {
|
|
printf("No data found\n");
|
|
return;
|
|
}
|
|
|
|
printf("# %14s | %10s | %-*s |\n",
|
|
" DURATION ", "COUNT", bar_total, "GRAPH");
|
|
|
|
bar_len = buckets[0] * bar_total / total;
|
|
printf(" %4d - %-4d %s | %10d | %.*s%*s |\n",
|
|
0, 1, "us", buckets[0], bar_len, bar, bar_total - bar_len, "");
|
|
|
|
for (i = 1; i < NUM_BUCKET - 1; i++) {
|
|
int start = (1 << (i - 1));
|
|
int stop = 1 << i;
|
|
const char *unit = use_nsec ? "ns" : "us";
|
|
|
|
if (start >= 1024) {
|
|
start >>= 10;
|
|
stop >>= 10;
|
|
unit = use_nsec ? "us" : "ms";
|
|
}
|
|
bar_len = buckets[i] * bar_total / total;
|
|
printf(" %4d - %-4d %s | %10d | %.*s%*s |\n",
|
|
start, stop, unit, buckets[i], bar_len, bar,
|
|
bar_total - bar_len, "");
|
|
}
|
|
|
|
bar_len = buckets[NUM_BUCKET - 1] * bar_total / total;
|
|
printf(" %4d - %-4s %s | %10d | %.*s%*s |\n",
|
|
1, "...", use_nsec ? "ms" : " s", buckets[NUM_BUCKET - 1],
|
|
bar_len, bar, bar_total - bar_len, "");
|
|
|
|
}
|
|
|
|
static int prepare_func_latency(struct perf_ftrace *ftrace)
|
|
{
|
|
char *trace_file;
|
|
int fd;
|
|
|
|
if (ftrace->target.use_bpf)
|
|
return perf_ftrace__latency_prepare_bpf(ftrace);
|
|
|
|
if (reset_tracing_files(ftrace) < 0) {
|
|
pr_err("failed to reset ftrace\n");
|
|
return -1;
|
|
}
|
|
|
|
/* reset ftrace buffer */
|
|
if (write_tracing_file("trace", "0") < 0)
|
|
return -1;
|
|
|
|
if (set_tracing_options(ftrace) < 0)
|
|
return -1;
|
|
|
|
/* force to use the function_graph tracer to track duration */
|
|
if (write_tracing_file("current_tracer", "function_graph") < 0) {
|
|
pr_err("failed to set current_tracer to function_graph\n");
|
|
return -1;
|
|
}
|
|
|
|
trace_file = get_tracing_file("trace_pipe");
|
|
if (!trace_file) {
|
|
pr_err("failed to open trace_pipe\n");
|
|
return -1;
|
|
}
|
|
|
|
fd = open(trace_file, O_RDONLY);
|
|
if (fd < 0)
|
|
pr_err("failed to open trace_pipe\n");
|
|
|
|
put_tracing_file(trace_file);
|
|
return fd;
|
|
}
|
|
|
|
static int start_func_latency(struct perf_ftrace *ftrace)
|
|
{
|
|
if (ftrace->target.use_bpf)
|
|
return perf_ftrace__latency_start_bpf(ftrace);
|
|
|
|
if (write_tracing_file("tracing_on", "1") < 0) {
|
|
pr_err("can't enable tracing\n");
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stop_func_latency(struct perf_ftrace *ftrace)
|
|
{
|
|
if (ftrace->target.use_bpf)
|
|
return perf_ftrace__latency_stop_bpf(ftrace);
|
|
|
|
write_tracing_file("tracing_on", "0");
|
|
return 0;
|
|
}
|
|
|
|
static int read_func_latency(struct perf_ftrace *ftrace, int buckets[])
|
|
{
|
|
if (ftrace->target.use_bpf)
|
|
return perf_ftrace__latency_read_bpf(ftrace, buckets);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cleanup_func_latency(struct perf_ftrace *ftrace)
|
|
{
|
|
if (ftrace->target.use_bpf)
|
|
return perf_ftrace__latency_cleanup_bpf(ftrace);
|
|
|
|
reset_tracing_files(ftrace);
|
|
return 0;
|
|
}
|
|
|
|
static int __cmd_latency(struct perf_ftrace *ftrace)
|
|
{
|
|
int trace_fd;
|
|
char buf[4096];
|
|
char line[256];
|
|
struct pollfd pollfd = {
|
|
.events = POLLIN,
|
|
};
|
|
int buckets[NUM_BUCKET] = { };
|
|
|
|
if (!(perf_cap__capable(CAP_PERFMON) ||
|
|
perf_cap__capable(CAP_SYS_ADMIN))) {
|
|
pr_err("ftrace only works for %s!\n",
|
|
#ifdef HAVE_LIBCAP_SUPPORT
|
|
"users with the CAP_PERFMON or CAP_SYS_ADMIN capability"
|
|
#else
|
|
"root"
|
|
#endif
|
|
);
|
|
return -1;
|
|
}
|
|
|
|
trace_fd = prepare_func_latency(ftrace);
|
|
if (trace_fd < 0)
|
|
goto out;
|
|
|
|
fcntl(trace_fd, F_SETFL, O_NONBLOCK);
|
|
pollfd.fd = trace_fd;
|
|
|
|
if (start_func_latency(ftrace) < 0)
|
|
goto out;
|
|
|
|
evlist__start_workload(ftrace->evlist);
|
|
|
|
line[0] = '\0';
|
|
while (!done) {
|
|
if (poll(&pollfd, 1, -1) < 0)
|
|
break;
|
|
|
|
if (pollfd.revents & POLLIN) {
|
|
int n = read(trace_fd, buf, sizeof(buf) - 1);
|
|
if (n < 0)
|
|
break;
|
|
|
|
make_histogram(buckets, buf, n, line, ftrace->use_nsec);
|
|
}
|
|
}
|
|
|
|
stop_func_latency(ftrace);
|
|
|
|
if (workload_exec_errno) {
|
|
const char *emsg = str_error_r(workload_exec_errno, buf, sizeof(buf));
|
|
pr_err("workload failed: %s\n", emsg);
|
|
goto out;
|
|
}
|
|
|
|
/* read remaining buffer contents */
|
|
while (!ftrace->target.use_bpf) {
|
|
int n = read(trace_fd, buf, sizeof(buf) - 1);
|
|
if (n <= 0)
|
|
break;
|
|
make_histogram(buckets, buf, n, line, ftrace->use_nsec);
|
|
}
|
|
|
|
read_func_latency(ftrace, buckets);
|
|
|
|
display_histogram(buckets, ftrace->use_nsec);
|
|
|
|
out:
|
|
close(trace_fd);
|
|
cleanup_func_latency(ftrace);
|
|
|
|
return (done && !workload_exec_errno) ? 0 : -1;
|
|
}
|
|
|
|
static int perf_ftrace_config(const char *var, const char *value, void *cb)
|
|
{
|
|
struct perf_ftrace *ftrace = cb;
|
|
|
|
if (!strstarts(var, "ftrace."))
|
|
return 0;
|
|
|
|
if (strcmp(var, "ftrace.tracer"))
|
|
return -1;
|
|
|
|
if (!strcmp(value, "function_graph") ||
|
|
!strcmp(value, "function")) {
|
|
ftrace->tracer = value;
|
|
return 0;
|
|
}
|
|
|
|
pr_err("Please select \"function_graph\" (default) or \"function\"\n");
|
|
return -1;
|
|
}
|
|
|
|
static void list_function_cb(char *str, void *arg)
|
|
{
|
|
struct strfilter *filter = (struct strfilter *)arg;
|
|
|
|
if (strfilter__compare(filter, str))
|
|
printf("%s", str);
|
|
}
|
|
|
|
static int opt_list_avail_functions(const struct option *opt __maybe_unused,
|
|
const char *str, int unset)
|
|
{
|
|
struct strfilter *filter;
|
|
const char *err = NULL;
|
|
int ret;
|
|
|
|
if (unset || !str)
|
|
return -1;
|
|
|
|
filter = strfilter__new(str, &err);
|
|
if (!filter)
|
|
return err ? -EINVAL : -ENOMEM;
|
|
|
|
ret = strfilter__or(filter, str, &err);
|
|
if (ret == -EINVAL) {
|
|
pr_err("Filter parse error at %td.\n", err - str + 1);
|
|
pr_err("Source: \"%s\"\n", str);
|
|
pr_err(" %*c\n", (int)(err - str + 1), '^');
|
|
strfilter__delete(filter);
|
|
return ret;
|
|
}
|
|
|
|
ret = read_tracing_file_by_line("available_filter_functions",
|
|
list_function_cb, filter);
|
|
strfilter__delete(filter);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
exit(0);
|
|
}
|
|
|
|
static int parse_filter_func(const struct option *opt, const char *str,
|
|
int unset __maybe_unused)
|
|
{
|
|
struct list_head *head = opt->value;
|
|
struct filter_entry *entry;
|
|
|
|
entry = malloc(sizeof(*entry) + strlen(str) + 1);
|
|
if (entry == NULL)
|
|
return -ENOMEM;
|
|
|
|
strcpy(entry->name, str);
|
|
list_add_tail(&entry->list, head);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void delete_filter_func(struct list_head *head)
|
|
{
|
|
struct filter_entry *pos, *tmp;
|
|
|
|
list_for_each_entry_safe(pos, tmp, head, list) {
|
|
list_del_init(&pos->list);
|
|
free(pos);
|
|
}
|
|
}
|
|
|
|
static int parse_buffer_size(const struct option *opt,
|
|
const char *str, int unset)
|
|
{
|
|
unsigned long *s = (unsigned long *)opt->value;
|
|
static struct parse_tag tags_size[] = {
|
|
{ .tag = 'B', .mult = 1 },
|
|
{ .tag = 'K', .mult = 1 << 10 },
|
|
{ .tag = 'M', .mult = 1 << 20 },
|
|
{ .tag = 'G', .mult = 1 << 30 },
|
|
{ .tag = 0 },
|
|
};
|
|
unsigned long val;
|
|
|
|
if (unset) {
|
|
*s = 0;
|
|
return 0;
|
|
}
|
|
|
|
val = parse_tag_value(str, tags_size);
|
|
if (val != (unsigned long) -1) {
|
|
if (val < 1024) {
|
|
pr_err("buffer size too small, must larger than 1KB.");
|
|
return -1;
|
|
}
|
|
*s = val;
|
|
return 0;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
static int parse_func_tracer_opts(const struct option *opt,
|
|
const char *str, int unset)
|
|
{
|
|
int ret;
|
|
struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
|
|
struct sublevel_option func_tracer_opts[] = {
|
|
{ .name = "call-graph", .value_ptr = &ftrace->func_stack_trace },
|
|
{ .name = "irq-info", .value_ptr = &ftrace->func_irq_info },
|
|
{ .name = NULL, }
|
|
};
|
|
|
|
if (unset)
|
|
return 0;
|
|
|
|
ret = perf_parse_sublevel_options(str, func_tracer_opts);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int parse_graph_tracer_opts(const struct option *opt,
|
|
const char *str, int unset)
|
|
{
|
|
int ret;
|
|
struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
|
|
struct sublevel_option graph_tracer_opts[] = {
|
|
{ .name = "nosleep-time", .value_ptr = &ftrace->graph_nosleep_time },
|
|
{ .name = "noirqs", .value_ptr = &ftrace->graph_noirqs },
|
|
{ .name = "verbose", .value_ptr = &ftrace->graph_verbose },
|
|
{ .name = "thresh", .value_ptr = &ftrace->graph_thresh },
|
|
{ .name = "depth", .value_ptr = &ftrace->graph_depth },
|
|
{ .name = NULL, }
|
|
};
|
|
|
|
if (unset)
|
|
return 0;
|
|
|
|
ret = perf_parse_sublevel_options(str, graph_tracer_opts);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
enum perf_ftrace_subcommand {
|
|
PERF_FTRACE_NONE,
|
|
PERF_FTRACE_TRACE,
|
|
PERF_FTRACE_LATENCY,
|
|
};
|
|
|
|
int cmd_ftrace(int argc, const char **argv)
|
|
{
|
|
int ret;
|
|
int (*cmd_func)(struct perf_ftrace *) = NULL;
|
|
struct perf_ftrace ftrace = {
|
|
.tracer = DEFAULT_TRACER,
|
|
.target = { .uid = UINT_MAX, },
|
|
};
|
|
const struct option common_options[] = {
|
|
OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
|
|
"Trace on existing process id"),
|
|
/* TODO: Add short option -t after -t/--tracer can be removed. */
|
|
OPT_STRING(0, "tid", &ftrace.target.tid, "tid",
|
|
"Trace on existing thread id (exclusive to --pid)"),
|
|
OPT_INCR('v', "verbose", &verbose,
|
|
"Be more verbose"),
|
|
OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
|
|
"System-wide collection from all CPUs"),
|
|
OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
|
|
"List of cpus to monitor"),
|
|
OPT_END()
|
|
};
|
|
const struct option ftrace_options[] = {
|
|
OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
|
|
"Tracer to use: function_graph(default) or function"),
|
|
OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
|
|
"Show available functions to filter",
|
|
opt_list_avail_functions, "*"),
|
|
OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
|
|
"Trace given functions using function tracer",
|
|
parse_filter_func),
|
|
OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
|
|
"Do not trace given functions", parse_filter_func),
|
|
OPT_CALLBACK(0, "func-opts", &ftrace, "options",
|
|
"Function tracer options, available options: call-graph,irq-info",
|
|
parse_func_tracer_opts),
|
|
OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
|
|
"Trace given functions using function_graph tracer",
|
|
parse_filter_func),
|
|
OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
|
|
"Set nograph filter on given functions", parse_filter_func),
|
|
OPT_CALLBACK(0, "graph-opts", &ftrace, "options",
|
|
"Graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=<n>,depth=<n>",
|
|
parse_graph_tracer_opts),
|
|
OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
|
|
"Size of per cpu buffer, needs to use a B, K, M or G suffix.", parse_buffer_size),
|
|
OPT_BOOLEAN(0, "inherit", &ftrace.inherit,
|
|
"Trace children processes"),
|
|
OPT_INTEGER('D', "delay", &ftrace.target.initial_delay,
|
|
"Number of milliseconds to wait before starting tracing after program start"),
|
|
OPT_PARENT(common_options),
|
|
};
|
|
const struct option latency_options[] = {
|
|
OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
|
|
"Show latency of given function", parse_filter_func),
|
|
#ifdef HAVE_BPF_SKEL
|
|
OPT_BOOLEAN('b', "use-bpf", &ftrace.target.use_bpf,
|
|
"Use BPF to measure function latency"),
|
|
#endif
|
|
OPT_BOOLEAN('n', "--use-nsec", &ftrace.use_nsec,
|
|
"Use nano-second histogram"),
|
|
OPT_PARENT(common_options),
|
|
};
|
|
const struct option *options = ftrace_options;
|
|
|
|
const char * const ftrace_usage[] = {
|
|
"perf ftrace [<options>] [<command>]",
|
|
"perf ftrace [<options>] -- [<command>] [<options>]",
|
|
"perf ftrace {trace|latency} [<options>] [<command>]",
|
|
"perf ftrace {trace|latency} [<options>] -- [<command>] [<options>]",
|
|
NULL
|
|
};
|
|
enum perf_ftrace_subcommand subcmd = PERF_FTRACE_NONE;
|
|
|
|
INIT_LIST_HEAD(&ftrace.filters);
|
|
INIT_LIST_HEAD(&ftrace.notrace);
|
|
INIT_LIST_HEAD(&ftrace.graph_funcs);
|
|
INIT_LIST_HEAD(&ftrace.nograph_funcs);
|
|
|
|
signal(SIGINT, sig_handler);
|
|
signal(SIGUSR1, sig_handler);
|
|
signal(SIGCHLD, sig_handler);
|
|
signal(SIGPIPE, sig_handler);
|
|
|
|
ret = perf_config(perf_ftrace_config, &ftrace);
|
|
if (ret < 0)
|
|
return -1;
|
|
|
|
if (argc > 1) {
|
|
if (!strcmp(argv[1], "trace")) {
|
|
subcmd = PERF_FTRACE_TRACE;
|
|
} else if (!strcmp(argv[1], "latency")) {
|
|
subcmd = PERF_FTRACE_LATENCY;
|
|
options = latency_options;
|
|
}
|
|
|
|
if (subcmd != PERF_FTRACE_NONE) {
|
|
argc--;
|
|
argv++;
|
|
}
|
|
}
|
|
/* for backward compatibility */
|
|
if (subcmd == PERF_FTRACE_NONE)
|
|
subcmd = PERF_FTRACE_TRACE;
|
|
|
|
argc = parse_options(argc, argv, options, ftrace_usage,
|
|
PARSE_OPT_STOP_AT_NON_OPTION);
|
|
if (argc < 0) {
|
|
ret = -EINVAL;
|
|
goto out_delete_filters;
|
|
}
|
|
|
|
/* Make system wide (-a) the default target. */
|
|
if (!argc && target__none(&ftrace.target))
|
|
ftrace.target.system_wide = true;
|
|
|
|
switch (subcmd) {
|
|
case PERF_FTRACE_TRACE:
|
|
cmd_func = __cmd_ftrace;
|
|
break;
|
|
case PERF_FTRACE_LATENCY:
|
|
if (list_empty(&ftrace.filters)) {
|
|
pr_err("Should provide a function to measure\n");
|
|
parse_options_usage(ftrace_usage, options, "T", 1);
|
|
ret = -EINVAL;
|
|
goto out_delete_filters;
|
|
}
|
|
cmd_func = __cmd_latency;
|
|
break;
|
|
case PERF_FTRACE_NONE:
|
|
default:
|
|
pr_err("Invalid subcommand\n");
|
|
ret = -EINVAL;
|
|
goto out_delete_filters;
|
|
}
|
|
|
|
ret = target__validate(&ftrace.target);
|
|
if (ret) {
|
|
char errbuf[512];
|
|
|
|
target__strerror(&ftrace.target, ret, errbuf, 512);
|
|
pr_err("%s\n", errbuf);
|
|
goto out_delete_filters;
|
|
}
|
|
|
|
ftrace.evlist = evlist__new();
|
|
if (ftrace.evlist == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out_delete_filters;
|
|
}
|
|
|
|
ret = evlist__create_maps(ftrace.evlist, &ftrace.target);
|
|
if (ret < 0)
|
|
goto out_delete_evlist;
|
|
|
|
if (argc) {
|
|
ret = evlist__prepare_workload(ftrace.evlist, &ftrace.target,
|
|
argv, false,
|
|
ftrace__workload_exec_failed_signal);
|
|
if (ret < 0)
|
|
goto out_delete_evlist;
|
|
}
|
|
|
|
ret = cmd_func(&ftrace);
|
|
|
|
out_delete_evlist:
|
|
evlist__delete(ftrace.evlist);
|
|
|
|
out_delete_filters:
|
|
delete_filter_func(&ftrace.filters);
|
|
delete_filter_func(&ftrace.notrace);
|
|
delete_filter_func(&ftrace.graph_funcs);
|
|
delete_filter_func(&ftrace.nograph_funcs);
|
|
|
|
return ret;
|
|
}
|