Messages in this thread | | | Date | Tue, 18 Mar 2014 10:43:24 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH V2] perf: Speed up thread map generation |
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Em Mon, Mar 17, 2014 at 10:45:49AM +0900, Namhyung Kim escreveu: > Hi Don, > > On Fri, 14 Mar 2014 10:43:44 -0400, Don Zickus wrote: > > 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. > > [SNIP] > > @@ -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; > > Not related to this patch, but this will causes a memory leak.. > So I think below patch is needed on top (not sure it's also needed for > perf_event__synthesize_thread_map() too).
Good catch, applying it, please next time send it under separate cover, i.e. not inside another thread.
- Arnaldo
> > >From 3c4b49b4f540c7d49ee78364b02faa0bfce59c67 Mon Sep 17 00:00:00 2001 > From: Namhyung Kim <namhyung@kernel.org> > Date: Mon, 17 Mar 2014 10:23:06 +0900 > Subject: [PATCH] perf tools: Fix a possible memory leak > > Checking default guest machine should be done before allocating event > structures otherwise it'll leak memory. > > Cc: Don Zickus <dzickus@redhat.com> > Cc: Jiri Olsa <jolsa@redhat.com> > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > --- > tools/perf/util/event.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c > index 3e580be0f6fb..eab930d28159 100644 > --- a/tools/perf/util/event.c > +++ b/tools/perf/util/event.c > @@ -445,6 +445,9 @@ int perf_event__synthesize_threads(struct perf_tool *tool, > union perf_event *comm_event, *mmap_event, *fork_event; > int err = -1; > > + if (machine__is_default_guest(machine)) > + return 0; > + > comm_event = malloc(sizeof(comm_event->comm) + machine->id_hdr_size); > if (comm_event == NULL) > goto out; > @@ -457,9 +460,6 @@ int perf_event__synthesize_threads(struct perf_tool *tool, > if (fork_event == NULL) > goto out_free_mmap; > > - if (machine__is_default_guest(machine)) > - return 0; > - > snprintf(proc_path, sizeof(proc_path), "%s/proc", machine->root_dir); > proc = opendir(proc_path); > > -- > 1.7.11.7
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