// SPDX-License-Identifier: GPL-2.0-only
/*
* builtin-ftrace.c
*
* Copyright (c) 2013 LG Electronics, Namhyung Kim <[email protected]>
* Copyright (c) 2020 Changbin Du <[email protected]>, significant enhancement.
*/
#include "builtin.h"
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <fcntl.h>
#include <inttypes.h>
#include <math.h>
#include <poll.h>
#include <ctype.h>
#include <linux/capability.h>
#include <linux/string.h>
#include "debug.h"
#include <subcmd/pager.h>
#include <subcmd/parse-options.h>
#include <api/io.h>
#include <api/fs/tracing_path.h>
#include "evlist.h"
#include "target.h"
#include "cpumap.h"
#include "hashmap.h"
#include "thread_map.h"
#include "strfilter.h"
#include "util/cap.h"
#include "util/config.h"
#include "util/ftrace.h"
#include "util/stat.h"
#include "util/units.h"
#include "util/parse-sublevel-options.h"
#define DEFAULT_TRACER "function_graph"
static volatile sig_atomic_t workload_exec_errno;
static volatile sig_atomic_t done;
static void sig_handler(int sig __maybe_unused)
{
done = true;
}
/*
* evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
* we asked by setting its exec_error to the function below,
* ftrace__workload_exec_failed_signal.
*
* XXX We need to handle this more appropriately, emitting an error, etc.
*/
static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
siginfo_t *info __maybe_unused,
void *ucontext __maybe_unused)
{
workload_exec_errno = info->si_value.sival_int;
done = true;
}
static bool check_ftrace_capable(void)
{
bool used_root;
if (perf_cap__capable(CAP_PERFMON, &used_root))
return true;
if (!used_root && perf_cap__capable(CAP_SYS_ADMIN, &used_root))
return true;
pr_err("ftrace only works for %s!\n",
used_root ? "root"
: "users with the CAP_PERFMON or CAP_SYS_ADMIN capability"
);
return false;
}
static bool is_ftrace_supported(void)
{
char *file;
bool supported = false;
file = get_tracing_file("set_ftrace_pid");
if (!file) {
pr_debug("cannot get tracing file set_ftrace_pid\n");
return false;
}
if (!access(file, F_OK))
supported = true;
put_tracing_file(file);
return supported;
}
static int __write_tracing_file(const char *name, const char *val, bool append)
{
char *file;
int fd, ret = -1;
ssize_t size = strlen(val);
int flags = O_WRONLY;
char errbuf[512];
char *val_copy;
file = get_tracing_file(name);
if (!file) {
pr_debug("cannot get tracing file: %s\n", name);
return -1;
}
if (append)
flags |= O_APPEND;
else
flags |= O_TRUNC;
fd = open(file, flags);
if (fd < 0) {
pr_debug("cannot open tracing file: %s: %s\n",
name, str_error_r(errno, errbuf, sizeof(errbuf)));
goto out;
}
/*
* Copy the original value and append a '\n'. Without this,
* the kernel can hide possible errors.
*/
val_copy = strdup(val);
if (!val_copy)
goto out_close;
val_copy[size] = '\n';
if (write(fd, val_copy, size + 1) == size + 1)
ret = 0;
else
pr_debug("write '%s' to tracing/%s failed: %s\n",
val, name, str_error_r(errno, errbuf, sizeof(errbuf)));
free(val_copy);
out_close:
close(fd);
out:
put_tracing_file(file);
return ret;
}
static int write_tracing_file(const char *name, const char *val)
{
return __write_tracing_file(name, val, false);
}
static int append_tracing_file(const char *name, const char *val)
{
return __write_tracing_file(name, val, true);
}
static int read_tracing_file_to_stdout(const char *name)
{
char buf[4096];
char *file;
int fd;
int ret = -1;
file = get_tracing_file(name);
if (!file) {
pr_debug("cannot get tracing file: %s\n", name);
return -1;
}
fd = open(file, O_RDONLY);
if (fd < 0) {
pr_debug("cannot open tracing file: %s: %s\n",
name, str_error_r(errno, buf, sizeof(buf)));
goto out;
}
/* read contents to stdout */
while (true) {
int n = read(fd, buf, sizeof(buf));
if (n == 0)
break;
else if (n < 0)
goto out_close;
if (fwrite(buf, n, 1, stdout) != 1)
goto out_close;
}
ret = 0;
out_close:
close(fd);
out:
put_tracing_file(file);
return ret;
}
static int read_tracing_file_by_line(const char *name,
void (*cb)(char *str, void *arg),
void *cb_arg)
{
char *line = NULL;
size_t len = 0;
char *file;
FILE *fp;
file = get_tracing_file(name);
if (!file) {
pr_debug("cannot get tracing file: %s\n", name);
return -1;
}
fp = fopen(file, "r");
if (fp == NULL) {
pr_debug("cannot open tracing file: %s\n", name);
put_tracing_file(file);
return -1;
}
while (getline(&line, &len, fp) != -1) {
cb(line, cb_arg);
}
if (line)
free(line);
fclose(fp);
put_tracing_file(file);
return 0;
}
static int write_tracing_file_int(const char *name, int value)
{
char buf[16];
snprintf(buf, sizeof(buf), "%d", value);
if (write_tracing_file(name, buf) < 0)
return -1;
return 0;
}
static int write_tracing_option_file(const char *name, const char *val)
{
char *file;
int ret;
if (asprintf(&file, "options/%s", name) < 0)
return -1;
ret = __write_tracing_file(file, val, false);
free(file);
return ret;
}
static int reset_tracing_cpu(void);
static void reset_tracing_filters(void);
static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
{
write_tracing_option_file("function-fork", "0");
write_tracing_option_file("func_stack_trace", "0");
write_tracing_option_file("sleep-time", "1");
write_tracing_option_file("funcgraph-irqs", "1");
write_tracing_option_file("funcgraph-proc", "0");
write_tracing_option_file("funcgraph-abstime", "0");
write_tracing_option_file("funcgraph-tail", "0");
write_tracing_option_file("latency-format", "0");
write_tracing_option_file("irq-info", "0");
}
static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
{
if (write_tracing_file("tracing_on", "0") < 0)
return -1;
if (write_tracing_file("current_tracer", "nop") < 0)
return -1;
if (write_tracing_file("set_ftrace_pid", " ") < 0)
return -1;
if (reset_tracing_cpu() < 0)
return -1;
if (write_tracing_file("max_graph_depth", "0") < 0)
return -1;
if (write_tracing_file("tracing_thresh", "0") < 0)
return -1;
reset_tracing_filters();
reset_tracing_options(ftrace);
return 0;
}
static int set_tracing_pid(struct perf_ftrace *ftrace)
{
int i;
char buf[16];
if (target__has_cpu(&ftrace->target))
return 0;
for (i = 0; i < perf_thread_map__nr(ftrace->evlist->core.threads); i++) {
scnprintf(buf, sizeof(buf), "%d",
perf_thread_map__pid(ftrace->evlist->core.threads, i));
if (append_tracing_file("set_ftrace_pid", buf) < 0)
return -1;
}
return 0;
}
static int set_tracing_cpumask(struct perf_cpu_map *cpumap)
{
char *cpumask;
size_t mask_size;
int ret;
int last_cpu;
last_cpu = perf_cpu_map__cpu(cpumap, perf_cpu_map__nr(cpumap) - 1).cpu;
mask_size = last_cpu / 4 + 2; /* one more byte for EOS */
mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
cpumask = malloc(mask_size);
if (cpumask == NULL) {
pr_debug("failed to allocate cpu mask\n");
return -1;
}
cpu_map__snprint_mask(cpumap, cpumask, mask_size);
ret = write_tracing_file("tracing_cpumask", cpumask);
free(cpumask);
return ret;
}
static int set_tracing_cpu(struct perf_ftrace *ftrace)
{
struct perf_cpu_map *cpumap = ftrace->evlist->core.user_requested_cpus;
if (!target__has_cpu(&ftrace->target))
return 0;
return set_tracing_cpumask(cpumap);
}
static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
{
if (!ftrace->func_stack_trace)
return 0;
if (write_tracing_option_file("func_stack_trace", "1") < 0)
return -1;
return 0;
}
static int set_tracing_func_irqinfo(struct perf_ftrace *ftrace)
{
if (!ftrace->func_irq_info)
return 0;
if (write_tracing_option_file("irq-info", "1") < 0)
return -1;
return 0;
}
static int reset_tracing_cpu(void)
{
struct perf_cpu_map *cpumap = perf_cpu_map__new_online_cpus();
int ret;
ret = set_tracing_cpumask(cpumap);
perf_cpu_map__put(cpumap);
return ret;
}
static int __set_tracing_filter(const char *filter_file, struct list_head *funcs)
{
struct filter_entry *pos;
list_for_each_entry(pos, funcs, list) {
if (append_tracing_file(filter_file, pos->name) < 0)
return -1;
}
return 0;
}
static int set_tracing_filters(struct perf_ftrace *ftrace)
{
int ret;
ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
if (ret < 0)
return ret;
ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
if (ret < 0)
return ret;
ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
if (ret < 0)
return ret;
/* old kernels do not have this filter */
__set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);
return ret;
}
static void reset_tracing_filters(void)
{
write_tracing_file("set_ftrace_filter", " ");
write_tracing_file("set_ftrace_notrace", " ");
write_tracing_file("set_graph_function", " ");
write_tracing_file("set_graph_notrace", " ");
}
static int set_tracing_depth(struct perf_ftrace *ftrace)
{
if (ftrace->graph_depth == 0)
return 0;
if (ftrace->graph_depth < 0) {
pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
return -1;
}
if (write_tracing_file_int("max_graph_depth", ftrace->graph_depth) < 0)
return -1;
return 0;
}
static int set_tracing_percpu_buffer_size(struct perf_ftrace *ftrace)
{
int ret;
if (ftrace->percpu_buffer_size == 0)
return 0;
ret = write_tracing_file_int("buffer_size_kb",
ftrace->percpu_buffer_size / 1024);
if (ret < 0)
return ret;
return 0;
}
static int set_tracing_trace_inherit(struct perf_ftrace *ftrace)
{
if (!ftrace->inherit)
return 0;
if (write_tracing_option_file("function-fork", "1") < 0)
return -1;
return 0;
}
static int set_tracing_sleep_time(struct perf_ftrace *ftrace)
{
if (!ftrace->graph_nosleep_time)
return 0;
if (write_tracing_option_file("sleep-time", "0") < 0)
return -1;
return 0;
}
static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace)
{
if (!ftrace->graph_noirqs)
return 0;
if (write_tracing_option_file("funcgraph-irqs", "0") < 0)
return -1;
return 0;
}
static int set_tracing_funcgraph_verbose(struct perf_ftrace *ftrace)
{
if (!ftrace->graph_verbose)
return 0;
if (write_tracing_option_file("funcgraph-proc", "1") < 0)
return -1;
if (write_tracing_option_file("funcgraph-abstime", "1") < 0)
return -1;
if (write_tracing_option_file("latency-format", "1") < 0)
return -1;
return 0;
}
static int set_tracing_funcgraph_tail(struct perf_ftrace *ftrace)
{
if (!ftrace->graph_tail)
return 0;
if (write_tracing_option_file("funcgraph-tail", "1") < 0)
return -1;
return 0;
}
static int set_tracing_thresh(struct perf_ftrace *ftrace)
{
int ret;
if (ftrace->graph_thresh == 0)
return 0;
ret = write_tracing_file_int("tracing_thresh", ftrace->graph_thresh);
if (ret < 0)
return ret;
return 0;
}
static int set_tracing_options(struct perf_ftrace *ftrace)
{
if (set_tracing_pid(ftrace) < 0) {
pr_err("failed to set ftrace pid\n");
return -1;
}
if (set_tracing_cpu(ftrace) < 0) {
pr_err("failed to set tracing cpumask\n");
return -1;
}
if (set_tracing_func_stack_trace(ftrace) < 0) {
pr_err("failed to set tracing option func_stack_trace\n");
return -1;
}
if (set_tracing_func_irqinfo(ftrace) < 0) {
pr_err("failed to set tracing option irq-info\n");
return -1;
}
if (set_tracing_filters(ftrace) < 0) {
pr_err("failed to set tracing filters\n");
return -1;
}
if (set_tracing_depth(ftrace) < 0) {
pr_err("failed to set graph depth\n");
return -1;
}
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;
}
if (set_tracing_funcgraph_tail(ftrace) < 0) {
pr_err("failed to set tracing option funcgraph-tail\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,
};
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;
/* flush output since stdout is in full buffering mode due to pager */
fflush(stdout);
}
}
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] = { };
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 size_t profile_hash(long func, void *ctx __maybe_unused)
{
return str_hash((char *)func);
}
static bool profile_equal(long func1, long func2, void *ctx __maybe_unused)
{
return !strcmp((char *)func1, (char *)func2);
}
static int prepare_func_profile(struct perf_ftrace *ftrace)
{
ftrace->tracer = "function_graph";
ftrace->graph_tail = 1;
ftrace->profile_hash = hashmap__new(profile_hash, profile_equal, NULL);
if (ftrace->profile_hash == NULL)
return -ENOMEM;
return 0;
}
/* This is saved in a hashmap keyed by the function name */
struct ftrace_profile_data {
struct stats st;
};
static int add_func_duration(struct perf_ftrace *ftrace, char *func, double time_ns)
{
struct ftrace_profile_data *prof = NULL;
if (!hashmap__find(ftrace->profile_hash, func, &prof)) {
char *key = strdup(func);
if (key == NULL)
return -ENOMEM;
prof = zalloc(sizeof(*prof));
if (prof == NULL) {
free(key);
return -ENOMEM;
}
init_stats(&prof->st);
hashmap__add(ftrace->profile_hash, key, prof);
}
update_stats(&prof->st, time_ns);
return 0;
}
/*
* The ftrace function_graph text output normally looks like below:
*
* CPU DURATION FUNCTION
*
* 0) | syscall_trace_enter.isra.0() {
* 0) | __audit_syscall_entry() {
* 0) | auditd_test_task() {
* 0) 0.271 us | __rcu_read_lock();
* 0) 0.275 us | __rcu_read_unlock();
* 0) 1.254 us | } /\* auditd_test_task *\/
* 0) 0.279 us | ktime_get_coarse_real_ts64();
* 0) 2.227 us | } /\* __audit_syscall_entry *\/
* 0) 2.713 us | } /\* syscall_trace_enter.isra.0 *\/
*
* Parse the line and get the duration and function name.
*/
static int parse_func_duration(struct perf_ftrace *ftrace, char *line, size_t len)
{
char *p;
char *func;
double duration;
/* skip CPU */
p = strchr(line, ')');
if (p == NULL)
return 0;
/* get duration */
p = skip_spaces(p + 1);
/* no duration? */
if (p == NULL || *p == '|')
return 0;
/* skip markers like '*' or '!' for longer than ms */
if (!isdigit(*p))
p++;
duration = strtod(p, &p);
if (strncmp(p, " us", 3)) {
pr_debug("non-usec time found.. ignoring\n");
return 0;
}
/*
* profile stat keeps the max and min values as integer,
* convert to nsec time so that we can have accurate max.
*/
duration *= 1000;
/* skip to the pipe */
while (p < line + len && *p != '|')
p++;
if (*p++ != '|')
return -EINVAL;
/* get function name */
func = skip_spaces(p);
/* skip the closing bracket and the start of comment */
if (*func == '}')
func += 5;
/* remove semi-colon or end of comment at the end */
p = line + len - 1;
while (!isalnum(*p) && *p != ']') {
*p = '\0';
--p;
}
return add_func_duration(ftrace, func, duration);
}
enum perf_ftrace_profile_sort_key {
PFP_SORT_TOTAL = 0,
PFP_SORT_AVG,
PFP_SORT_MAX,
PFP_SORT_COUNT,
PFP_SORT_NAME,
};
static enum perf_ftrace_profile_sort_key profile_sort = PFP_SORT_TOTAL;
static int cmp_profile_data(const void *a, const void *b)
{
const struct hashmap_entry *e1 = *(const struct hashmap_entry **)a;
const struct hashmap_entry *e2 = *(const struct hashmap_entry **)b;
struct ftrace_profile_data *p1 = e1->pvalue;
struct ftrace_profile_data *p2 = e2->pvalue;
double v1, v2;
switch (profile_sort) {
case PFP_SORT_NAME:
return strcmp(e1->pkey, e2->pkey);
case PFP_SORT_AVG:
v1 = p1->st.mean;
v2 = p2->st.mean;
break;
case PFP_SORT_MAX:
v1 = p1->st.max;
v2 = p2->st.max;
break;
case PFP_SORT_COUNT:
v1 = p1->st.n;
v2 = p2->st.n;
break;
case PFP_SORT_TOTAL:
default:
v1 = p1->st.n * p1->st.mean;
v2 = p2->st.n * p2->st.mean;
break;
}
if (v1 > v2)
return -1;
else
return 1;
}
static void print_profile_result(struct perf_ftrace *ftrace)
{
struct hashmap_entry *entry, **profile;
size_t i, nr, bkt;
nr = hashmap__size(ftrace->profile_hash);
if (nr == 0)
return;
profile = calloc(nr, sizeof(*profile));
if (profile == NULL) {
pr_err("failed to allocate memory for the result\n");
return;
}
i = 0;
hashmap__for_each_entry(ftrace->profile_hash, entry, bkt)
profile[i++] = entry;
assert(i == nr);
//cmp_profile_data(profile[0], profile[1]);
qsort(profile, nr, sizeof(*profile), cmp_profile_data);
printf("# %10s %10s %10s %10s %s\n",
"Total (us)", "Avg (us)", "Max (us)", "Count", "Function");
for (i = 0; i < nr; i++) {
const char *name = profile[i]->pkey;
struct ftrace_profile_data *p = profile[i]->pvalue;
printf("%12.3f %10.3f %6"PRIu64".%03"PRIu64" %10.0f %s\n",
p->st.n * p->st.mean / 1000, p->st.mean / 1000,
p->st.max / 1000, p->st.max % 1000, p->st.n, name);
}
free(profile);
hashmap__for_each_entry(ftrace->profile_hash, entry, bkt) {
free((char *)entry->pkey);
free(entry->pvalue);
}
hashmap__free(ftrace->profile_hash);
ftrace->profile_hash = NULL;
}
static int __cmd_profile(struct perf_ftrace *ftrace)
{
char *trace_file;
int trace_fd;
char buf[4096];
struct io io;
char *line = NULL;
size_t line_len = 0;
if (prepare_func_profile(ftrace) < 0) {
pr_err("failed to prepare func profiler\n");
goto out;
}
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)
return -1;
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);
if (write_tracing_file("tracing_on", "1") < 0) {
pr_err("can't enable tracing\n");
goto out_close_fd;
}
evlist__start_workload(ftrace->evlist);
io__init(&io, trace_fd, buf, sizeof(buf));
io.timeout_ms = -1;
while (!done && !io.eof) {
if (io__getline(&io, &line, &line_len) < 0)
break;
if (parse_func_duration(ftrace, line, line_len) < 0)
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_free_line;
}
/* read remaining buffer contents */
io.timeout_ms = 0;
while (!io.eof) {
if (io__getline(&io, &line, &line_len) < 0)
break;
if (parse_func_duration(ftrace, line, line_len) < 0)
break;
}
print_profile_result(ftrace);
out_free_line:
free(line);
out_close_fd:
close(trace_fd);
out_reset:
reset_tracing_files(ftrace);
out:
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 = "tail", .value_ptr = &ftrace->graph_tail },
{ .name = NULL, }
};
if (unset)
return 0;
ret = perf_parse_sublevel_options(str, graph_tracer_opts);
if (ret)
return ret;
return 0;
}
static int parse_sort_key(const struct option *opt, const char *str, int unset)
{
enum perf_ftrace_profile_sort_key *key = (void *)opt->value;
if (unset)
return 0;
if (!strcmp(str, "total"))
*key = PFP_SORT_TOTAL;
else if (!strcmp(str, "avg"))
*key = PFP_SORT_AVG;
else if (!strcmp(str, "max"))
*key = PFP_SORT_MAX;
else if (!strcmp(str, "count"))
*key = PFP_SORT_COUNT;
else if (!strcmp(str, "name"))
*key = PFP_SORT_NAME;
else {
pr_err("Unknown sort key: %s\n", str);
return -1;
}
return 0;
}
enum perf_ftrace_subcommand {
PERF_FTRACE_NONE,
PERF_FTRACE_TRACE,
PERF_FTRACE_LATENCY,
PERF_FTRACE_PROFILE,
};
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 profile_options[] = {
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('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('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_CALLBACK('s', "sort", &profile_sort, "key",
"Sort result by key: total (default), avg, max, count, name.",
parse_sort_key),
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|profile} [<options>] [<command>]",
"perf ftrace {trace|latency|profile} [<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);
if (!check_ftrace_capable())
return -1;
if (!is_ftrace_supported()) {
pr_err("ftrace is not supported on this system\n");
return -ENOTSUP;
}
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;
} else if (!strcmp(argv[1], "profile")) {
subcmd = PERF_FTRACE_PROFILE;
options = profile_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_PROFILE:
cmd_func = __cmd_profile;
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;
}
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