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author | 2014-03-14 10:43:44 -0400 | |
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committer | 2014-03-14 18:08:41 -0300 | |
commit | 363b785f3805a2632eb09a8b430842461c21a640 (patch) | |
tree | 1d6dcd4a3e7c0309c1c19a16ea53c45cd1de5407 /tools/perf/util/event.c | |
parent | perf kvm: introduce --list-cmds for use by scripts (diff) | |
download | linux-363b785f3805a2632eb09a8b430842461c21a640.tar.gz linux-363b785f3805a2632eb09a8b430842461c21a640.tar.bz2 linux-363b785f3805a2632eb09a8b430842461c21a640.zip |
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@redhat.com>
Acked-by: Jiri 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: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/event.c')
-rw-r--r-- | tools/perf/util/event.c | 59 |
1 files changed, 51 insertions, 8 deletions
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index 55eebe936513..3e580be0f6fb 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: |