[tip:perf/core] perf tools: Speed up thread map generation
From: tip-bot for Don Zickus
Date: Tue Mar 18 2014 - 04:33:02 EST
Commit-ID: 363b785f3805a2632eb09a8b430842461c21a640
Gitweb: http://git.kernel.org/tip/363b785f3805a2632eb09a8b430842461c21a640
Author: Don Zickus <dzickus@xxxxxxxxxx>
AuthorDate: Fri, 14 Mar 2014 10:43:44 -0400
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 14 Mar 2014 18:08:41 -0300
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: Don Zickus <dzickus@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Joe Mario <jmario@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1394808224-113774-1-git-send-email-dzickus@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/event.c | 59 ++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 51 insertions(+), 8 deletions(-)
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 55eebe9..3e580be 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -129,6 +129,28 @@ out:
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,
- process, machine, mmap_data);
+ 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:
--
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