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Commit 35b9d88e authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

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.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0f82ebc4

tools/perf/builtin-record.c

+13 −68
Original line number Diff line number Diff line
@@ -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;

tools/perf/perf.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

tools/perf/util/evlist.c

+96 −0
Original line number Diff line number Diff line
@@ -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;

}

tools/perf/util/evlist.h

+10 −0
Original line number Diff line number Diff line
@@ -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);