perf evlist: Introduce {prepare,start}_workload refactored from 'perf record'

So that we can easily start a workload in other tools.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-zdsksd4aphu0nltg2lpwsw3x@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0f82ebc4
......@@ -47,11 +47,9 @@ static struct perf_record_opts record_opts = {
static unsigned int page_size;
static unsigned int mmap_pages = UINT_MAX;
static int output;
static int pipe_output = 0;
static const char *output_name = NULL;
static bool group = false;
static int realtime_prio = 0;
static pid_t child_pid = -1;
static enum write_mode_t write_mode = WRITE_FORCE;
static bool no_buildid = false;
static bool no_buildid_cache = false;
......@@ -144,9 +142,9 @@ static void sig_atexit(void)
{
int status;
if (child_pid > 0) {
if (evsel_list->workload.pid > 0) {
if (!child_finished)
kill(child_pid, SIGTERM);
kill(evsel_list->workload.pid, SIGTERM);
wait(&status);
if (WIFSIGNALED(status))
......@@ -304,7 +302,7 @@ static int process_buildids(void)
static void atexit_header(void)
{
if (!pipe_output) {
if (!record_opts.pipe_output) {
session->header.data_size += bytes_written;
if (!no_buildid)
......@@ -377,9 +375,7 @@ static int __cmd_record(int argc, const char **argv)
int flags;
int err;
unsigned long waking = 0;
int child_ready_pipe[2], go_pipe[2];
const bool forks = argc > 0;
char buf;
struct machine *machine;
progname = argv[0];
......@@ -391,20 +387,15 @@ static int __cmd_record(int argc, const char **argv)
signal(SIGINT, sig_handler);
signal(SIGUSR1, sig_handler);
if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
perror("failed to create pipes");
exit(-1);
}
if (!output_name) {
if (!fstat(STDOUT_FILENO, &st) && S_ISFIFO(st.st_mode))
pipe_output = true;
record_opts.pipe_output = true;
else
output_name = "perf.data";
}
if (output_name) {
if (!strcmp(output_name, "-"))
pipe_output = true;
record_opts.pipe_output = true;
else if (!stat(output_name, &st) && st.st_size) {
if (write_mode == WRITE_FORCE) {
char oldname[PATH_MAX];
......@@ -424,7 +415,7 @@ static int __cmd_record(int argc, const char **argv)
else
flags |= O_TRUNC;
if (pipe_output)
if (record_opts.pipe_output)
output = STDOUT_FILENO;
else
output = open(output_name, flags, S_IRUSR | S_IWUSR);
......@@ -470,57 +461,11 @@ static int __cmd_record(int argc, const char **argv)
mmap_pages = (512 * 1024) / page_size;
if (forks) {
child_pid = fork();
if (child_pid < 0) {
perror("failed to fork");
exit(-1);
}
if (!child_pid) {
if (pipe_output)
dup2(2, 1);
close(child_ready_pipe[0]);
close(go_pipe[1]);
fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
/*
* Do a dummy execvp to get the PLT entry resolved,
* so we avoid the resolver overhead on the real
* execvp call.
*/
execvp("", (char **)argv);
/*
* Tell the parent we're ready to go
*/
close(child_ready_pipe[1]);
/*
* Wait until the parent tells us to go.
*/
if (read(go_pipe[0], &buf, 1) == -1)
perror("unable to read pipe");
execvp(argv[0], (char **)argv);
perror(argv[0]);
kill(getppid(), SIGUSR1);
exit(-1);
}
if (!record_opts.system_wide && record_opts.target_tid == -1 && record_opts.target_pid == -1)
evsel_list->threads->map[0] = child_pid;
close(child_ready_pipe[1]);
close(go_pipe[0]);
/*
* wait for child to settle
*/
if (read(child_ready_pipe[0], &buf, 1) == -1) {
perror("unable to read pipe");
exit(-1);
err = perf_evlist__prepare_workload(evsel_list, &record_opts, argv);
if (err < 0) {
pr_err("Couldn't run the workload!\n");
goto out_delete_session;
}
close(child_ready_pipe[0]);
}
open_counters(evsel_list);
......@@ -530,7 +475,7 @@ static int __cmd_record(int argc, const char **argv)
*/
atexit(atexit_header);
if (pipe_output) {
if (record_opts.pipe_output) {
err = perf_header__write_pipe(output);
if (err < 0)
return err;
......@@ -543,7 +488,7 @@ static int __cmd_record(int argc, const char **argv)
post_processing_offset = lseek(output, 0, SEEK_CUR);
if (pipe_output) {
if (record_opts.pipe_output) {
err = perf_session__synthesize_attrs(session,
process_synthesized_event);
if (err < 0) {
......@@ -629,7 +574,7 @@ static int __cmd_record(int argc, const char **argv)
* Let the child rip
*/
if (forks)
close(go_pipe[1]);
perf_evlist__start_workload(evsel_list);
for (;;) {
int hits = samples;
......
......@@ -193,6 +193,7 @@ struct perf_record_opts {
bool no_delay;
bool no_inherit;
bool no_samples;
bool pipe_output;
bool raw_samples;
bool sample_address;
bool sample_time;
......
......@@ -13,6 +13,7 @@
#include "thread_map.h"
#include "evlist.h"
#include "evsel.h"
#include <unistd.h>
#include "parse-events.h"
......@@ -33,6 +34,7 @@ void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
INIT_HLIST_HEAD(&evlist->heads[i]);
INIT_LIST_HEAD(&evlist->entries);
perf_evlist__set_maps(evlist, cpus, threads);
evlist->workload.pid = -1;
}
struct perf_evlist *perf_evlist__new(struct cpu_map *cpus,
......@@ -674,3 +676,97 @@ int perf_evlist__open(struct perf_evlist *evlist, bool group)
return err;
}
int perf_evlist__prepare_workload(struct perf_evlist *evlist,
struct perf_record_opts *opts,
const char *argv[])
{
int child_ready_pipe[2], go_pipe[2];
char bf;
if (pipe(child_ready_pipe) < 0) {
perror("failed to create 'ready' pipe");
return -1;
}
if (pipe(go_pipe) < 0) {
perror("failed to create 'go' pipe");
goto out_close_ready_pipe;
}
evlist->workload.pid = fork();
if (evlist->workload.pid < 0) {
perror("failed to fork");
goto out_close_pipes;
}
if (!evlist->workload.pid) {
if (opts->pipe_output)
dup2(2, 1);
close(child_ready_pipe[0]);
close(go_pipe[1]);
fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
/*
* Do a dummy execvp to get the PLT entry resolved,
* so we avoid the resolver overhead on the real
* execvp call.
*/
execvp("", (char **)argv);
/*
* Tell the parent we're ready to go
*/
close(child_ready_pipe[1]);
/*
* Wait until the parent tells us to go.
*/
if (read(go_pipe[0], &bf, 1) == -1)
perror("unable to read pipe");
execvp(argv[0], (char **)argv);
perror(argv[0]);
kill(getppid(), SIGUSR1);
exit(-1);
}
if (!opts->system_wide && opts->target_tid == -1 && opts->target_pid == -1)
evlist->threads->map[0] = evlist->workload.pid;
close(child_ready_pipe[1]);
close(go_pipe[0]);
/*
* wait for child to settle
*/
if (read(child_ready_pipe[0], &bf, 1) == -1) {
perror("unable to read pipe");
goto out_close_pipes;
}
evlist->workload.cork_fd = go_pipe[1];
close(child_ready_pipe[0]);
return 0;
out_close_pipes:
close(go_pipe[0]);
close(go_pipe[1]);
out_close_ready_pipe:
close(child_ready_pipe[0]);
close(child_ready_pipe[1]);
return -1;
}
int perf_evlist__start_workload(struct perf_evlist *evlist)
{
if (evlist->workload.cork_fd > 0) {
/*
* Remove the cork, let it rip!
*/
return close(evlist->workload.cork_fd);
}
return 0;
}
......@@ -6,6 +6,7 @@
#include "../perf.h"
#include "event.h"
#include "util.h"
#include <unistd.h>
struct pollfd;
struct thread_map;
......@@ -22,6 +23,10 @@ struct perf_evlist {
int nr_fds;
int nr_mmaps;
int mmap_len;
struct {
int cork_fd;
pid_t pid;
} workload;
bool overwrite;
union perf_event event_copy;
struct perf_mmap *mmap;
......@@ -68,6 +73,11 @@ int perf_evlist__open(struct perf_evlist *evlist, bool group);
void perf_evlist__config_attrs(struct perf_evlist *evlist,
struct perf_record_opts *opts);
int perf_evlist__prepare_workload(struct perf_evlist *evlist,
struct perf_record_opts *opts,
const char *argv[]);
int perf_evlist__start_workload(struct perf_evlist *evlist);
int perf_evlist__alloc_mmap(struct perf_evlist *evlist);
int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite);
void perf_evlist__munmap(struct perf_evlist *evlist);
......
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