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Commit 363b785f authored by Don Zickus's avatar Don Zickus Committed by Arnaldo Carvalho de Melo
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perf tools: Speed up thread map generation 



When trying to capture perf data on a system running spejbb2013, perf
hung for about 15 minutes.  This is because it took that long to gather
about 10,000 thread maps and process them.

I don't think a user wants to wait that long.

Instead, recognize that thread maps are roughly equivalent to pid maps
and just quickly copy those instead.

To do this, I synthesize 'fork' events, this eventually calls
thread__fork() and copies the maps over.

The overhead goes from 15 minutes down to about a few seconds.

--
V2: based on Jiri's comments, moved malloc up a level
    and made sure the memory was freed

Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Link: http://lkml.kernel.org/r/1394808224-113774-1-git-send-email-dzickus@redhat.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 09a71b97

tools/perf/util/event.c

+51 −8
Original line number Diff line number Diff line
@@ -129,6 +129,28 @@ static pid_t perf_event__synthesize_comm(struct perf_tool *tool, 
	return tgid;

}



static int perf_event__synthesize_fork(struct perf_tool *tool,

				       union perf_event *event, pid_t pid,

				       pid_t tgid, perf_event__handler_t process,

				       struct machine *machine)

{

	memset(&event->fork, 0, sizeof(event->fork) + machine->id_hdr_size);



	/* this is really a clone event but we use fork to synthesize it */

	event->fork.ppid = tgid;

	event->fork.ptid = tgid;

	event->fork.pid  = tgid;

	event->fork.tid  = pid;

	event->fork.header.type = PERF_RECORD_FORK;



	event->fork.header.size = (sizeof(event->fork) + machine->id_hdr_size);



	if (process(tool, event, &synth_sample, machine) != 0)

		return -1;



	return 0;

}



int perf_event__synthesize_mmap_events(struct perf_tool *tool,

				       union perf_event *event,

				       pid_t pid, pid_t tgid,
@@ -278,6 +300,7 @@ int perf_event__synthesize_modules(struct perf_tool *tool, 


static int __event__synthesize_thread(union perf_event *comm_event,

				      union perf_event *mmap_event,

				      union perf_event *fork_event,

				      pid_t pid, int full,

					  perf_event__handler_t process,

				      struct perf_tool *tool,
@@ -326,9 +349,15 @@ static int __event__synthesize_thread(union perf_event *comm_event, 
		if (tgid == -1)

			return -1;



		/* process the thread's maps too */

		rc = perf_event__synthesize_mmap_events(tool, mmap_event, _pid, tgid,

		if (_pid == pid) {

			/* process the parent's maps too */

			rc = perf_event__synthesize_mmap_events(tool, mmap_event, pid, tgid,

						process, machine, mmap_data);

		} else {

			/* only fork the tid's map, to save time */

			rc = perf_event__synthesize_fork(tool, fork_event, _pid, tgid,

						 process, machine);

		}



		if (rc)

			return rc;
@@ -344,7 +373,7 @@ int perf_event__synthesize_thread_map(struct perf_tool *tool, 
				      struct machine *machine,

				      bool mmap_data)

{

	union perf_event *comm_event, *mmap_event;

	union perf_event *comm_event, *mmap_event, *fork_event;

	int err = -1, thread, j;



	comm_event = malloc(sizeof(comm_event->comm) + machine->id_hdr_size);
@@ -355,9 +384,14 @@ int perf_event__synthesize_thread_map(struct perf_tool *tool, 
	if (mmap_event == NULL)

		goto out_free_comm;



	fork_event = malloc(sizeof(fork_event->fork) + machine->id_hdr_size);

	if (fork_event == NULL)

		goto out_free_mmap;



	err = 0;

	for (thread = 0; thread < threads->nr; ++thread) {

		if (__event__synthesize_thread(comm_event, mmap_event,

					       fork_event,

					       threads->map[thread], 0,

					       process, tool, machine,

					       mmap_data)) {
@@ -383,6 +417,7 @@ int perf_event__synthesize_thread_map(struct perf_tool *tool, 
			/* if not, generate events for it */

			if (need_leader &&

			    __event__synthesize_thread(comm_event, mmap_event,

						       fork_event,

						       comm_event->comm.pid, 0,

						       process, tool, machine,

						       mmap_data)) {
@@ -391,6 +426,8 @@ int perf_event__synthesize_thread_map(struct perf_tool *tool, 
			}

		}

	}

	free(fork_event);

out_free_mmap:

	free(mmap_event);

out_free_comm:

	free(comm_event);
@@ -405,7 +442,7 @@ int perf_event__synthesize_threads(struct perf_tool *tool, 
	DIR *proc;

	char proc_path[PATH_MAX];

	struct dirent dirent, *next;

	union perf_event *comm_event, *mmap_event;

	union perf_event *comm_event, *mmap_event, *fork_event;

	int err = -1;



	comm_event = malloc(sizeof(comm_event->comm) + machine->id_hdr_size);
@@ -416,6 +453,10 @@ int perf_event__synthesize_threads(struct perf_tool *tool, 
	if (mmap_event == NULL)

		goto out_free_comm;



	fork_event = malloc(sizeof(fork_event->fork) + machine->id_hdr_size);

	if (fork_event == NULL)

		goto out_free_mmap;



	if (machine__is_default_guest(machine))

		return 0;
@@ -423,7 +464,7 @@ int perf_event__synthesize_threads(struct perf_tool *tool, 
	proc = opendir(proc_path);



	if (proc == NULL)

		goto out_free_mmap;

		goto out_free_fork;



	while (!readdir_r(proc, &dirent, &next) && next) {

		char *end;
@@ -435,12 +476,14 @@ int perf_event__synthesize_threads(struct perf_tool *tool, 
 		 * We may race with exiting thread, so don't stop just because

 		 * one thread couldn't be synthesized.

 		 */

		__event__synthesize_thread(comm_event, mmap_event, pid, 1,

					   process, tool, machine, mmap_data);

		__event__synthesize_thread(comm_event, mmap_event, fork_event, pid,

					   1, process, tool, machine, mmap_data);

	}



	err = 0;

	closedir(proc);

out_free_fork:

	free(fork_event);

out_free_mmap:

	free(mmap_event);

out_free_comm: