Re: [PATCH v2 2/2] perf tools: add attr->mmap2 support

[Stephane Eranian]

On Tue, Sep 10, 2013 at 3:00 PM, Arnaldo Carvalho de Melo
<acme@xxxxxxxxxxxxxxxxxx> wrote:
>
>
> Em Mon, Sep 09, 2013 at 04:48:44PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Mon, Sep 09, 2013 at 04:47:45PM -0300, Arnaldo Carvalho de Melo escreveu:
> > > I noticed the kernel part is in, and I'm going to use MMAP2 on that new
> > > tool, so tried merging it, but:
> > >
> > > I fixed it up wrt another patch that makes machine__find_thread receive pid/tid
> > > but then 'perf test' complains about it, see below, trying to fix...
> >
> > Following patch makes it progress a bit, still checking why it is not
> > enough...
>
> Without your patch:
>
> [root@sandy ~]# perf test -v 7
>  7: Validate PERF_RECORD_* events & perf_sample fields     :
> --- start ---
> 61118374953766 0 PERF_RECORD_SAMPLE
> 61118374958840 0 PERF_RECORD_SAMPLE
> 61118374961420 0 PERF_RECORD_SAMPLE
> 61118374964293 0 PERF_RECORD_SAMPLE
> 61118376117716 0 PERF_RECORD_COMM: sleep:5096
> 61118376153724 0 PERF_RECORD_MMAP 5096/5096: [0x400000(0x7000) @ 0]: /usr/bin/sleep
> 61118376190304 0 PERF_RECORD_MMAP 5096/5096: [0x3b7e000000(0x223000) @ 0]: /usr/lib64/ld-2.16.so
> 61118376229562 0 PERF_RECORD_MMAP 5096/5096: [0x7fff2f9ff000(0x1000) @ 0x7fff2f9ff000]: [vdso]
> 61118376526654 0 PERF_RECORD_MMAP 5096/5096: [0x3b7e400000(0x3b8000) @ 0]: /usr/lib64/libc-2.16.so
> 61119377689687 0 PERF_RECORD_EXIT(5096:5096):(5096:5096)
> ---- end ----
> Validate PERF_RECORD_* events & perf_sample fields: Ok
> [root@sandy ~]#
>
> So the tstamp grows monotonically, then, after your patch + the patch at the
> end of this message:
>
> [root@sandy ~]# perf test -v 7
>  7: Validate PERF_RECORD_* events & perf_sample fields     :
> --- start ---
> 61315294449606 0 PERF_RECORD_SAMPLE
> 61315294453161 0 PERF_RECORD_SAMPLE
> 61315294454441 0 PERF_RECORD_SAMPLE
> 61315294455709 0 PERF_RECORD_SAMPLE
> 61315295600899 0 PERF_RECORD_COMM: sleep:6500
> 27917287430500 342521613 PERF_RECORD_MMAP2 6500/6500: [0x400000(0x7000) @ 0 00:1d 311442 9016]: /usr/bin/sleep
> MMAP2 going backwards in time, prev=61315295600899, curr=27917287430500
> MMAP2 with unexpected cpu, expected 0, got 342521613
> MMAP2 with unexpected pid, expected 6500, got 1701606191
> MMAP2 with unexpected tid, expected 6500, got 28773
> 27917287430500 342561333 PERF_RECORD_MMAP2 6500/6500: [0x3b7e000000(0x223000) @ 0 00:1d 309186 9016]: /usr/lib64/ld-2.16.so
> MMAP2 with unexpected cpu, expected 0, got 342561333
> MMAP2 with unexpected pid, expected 6500, got 1932408369
> MMAP2 with unexpected tid, expected 6500, got 111
> 27917287430500 342600095 PERF_RECORD_MMAP2 6500/6500: [0x7fffbd7dc000(0x1000) @ 0x7fffbd7dc000 00:00 0 0]: [vdso]
> MMAP2 with unexpected cpu, expected 0, got 342600095
> MMAP2 with unexpected pid, expected 6500, got 1935963739
> MMAP2 with unexpected tid, expected 6500, got 23919
> 27917287430500 342882834 PERF_RECORD_MMAP2 6500/6500: [0x3b7e400000(0x3b8000) @ 0 00:1d 309187 9016]: /usr/lib64/libc-2.16.so
> MMAP2 with unexpected cpu, expected 0, got 342882834
> MMAP2 with unexpected pid, expected 6500, got 909192754
> MMAP2 with unexpected tid, expected 6500, got 7303982
> 61316297195411 0 PERF_RECORD_EXIT(6500:6500):(6500:6500)
> ---- end ----
> Validate PERF_RECORD_* events & perf_sample fields: FAILED!
> [root@sandy ~]#
>
> So everything that is in perf_sample, i.e. in the variable area, selected via
> sample_type, is invalid for PERF_RECORD_MMAP2.
>
> This is on:
>
> [root@sandy ~]# uname -a
> Linux sandy.ghostprotocols.net.home 3.11.0+ #1 SMP Wed Sep 4 16:47:14 BRT 2013 x86_64 x86_64 x86_64 GNU/Linux
> [root@sandy ~]#
>
> Humm, looking at perf_event_mmap_output it seems this was missed, will rebuild
> a kernel and retest...
>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 2207efc..dd236b6 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -5039,6 +5039,7 @@ static void perf_event_mmap_output(struct perf_event *event,
>                 mmap_event->event_id.header.size += sizeof(mmap_event->maj);
>                 mmap_event->event_id.header.size += sizeof(mmap_event->min);
>                 mmap_event->event_id.header.size += sizeof(mmap_event->ino);
> +               mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation);
>         }
>
>         perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
>
Arg, yes, this is missing.
Do you want to submit the patch?
Thanks for tracking it down.

>
> > - Arnaldo
> >
> > diff --git a/tools/perf/tests/perf-record.c b/tools/perf/tests/perf-record.c
> > index 72d8881..b8a7056 100644
> > --- a/tools/perf/tests/perf-record.c
> > +++ b/tools/perf/tests/perf-record.c
> > @@ -50,7 +50,7 @@ int test__PERF_RECORD(void)
> >       struct perf_sample sample;
> >       const char *cmd = "sleep";
> >       const char *argv[] = { cmd, "1", NULL, };
> > -     char *bname;
> > +     char *bname, *mmap_filename;
> >       u64 prev_time = 0;
> >       bool found_cmd_mmap = false,
> >            found_libc_mmap = false,
> > @@ -212,6 +212,7 @@ int test__PERF_RECORD(void)
> >
> >                               if ((type == PERF_RECORD_COMM ||
> >                                    type == PERF_RECORD_MMAP ||
> > +                                  type == PERF_RECORD_MMAP2 ||
> >                                    type == PERF_RECORD_FORK ||
> >                                    type == PERF_RECORD_EXIT) &&
> >                                    (pid_t)event->comm.pid != evlist->workload.pid) {
> > @@ -220,7 +221,8 @@ int test__PERF_RECORD(void)
> >                               }
> >
> >                               if ((type == PERF_RECORD_COMM ||
> > -                                  type == PERF_RECORD_MMAP) &&
> > +                                  type == PERF_RECORD_MMAP ||
> > +                                  type == PERF_RECORD_MMAP2) &&
> >                                    event->comm.pid != event->comm.tid) {
> >                                       pr_debug("%s with different pid/tid!\n", name);
> >                                       ++errs;
> > @@ -236,7 +238,12 @@ int test__PERF_RECORD(void)
> >                               case PERF_RECORD_EXIT:
> >                                       goto found_exit;
> >                               case PERF_RECORD_MMAP:
> > -                                     bname = strrchr(event->mmap.filename, '/');
> > +                                     mmap_filename = event->mmap.filename;
> > +                                     goto check_bname;
> > +                             case PERF_RECORD_MMAP2:
> > +                                     mmap_filename = event->mmap2.filename;
> > +                             check_bname:
> > +                                     bname = strrchr(mmap_filename, '/');
> >                                       if (bname != NULL) {
> >                                               if (!found_cmd_mmap)
> >                                                       found_cmd_mmap = !strcmp(bname + 1, cmd);
> > @@ -245,7 +252,7 @@ int test__PERF_RECORD(void)
> >                                               if (!found_ld_mmap)
> >                                                       found_ld_mmap = !strncmp(bname + 1, "ld", 2);
> >                                       } else if (!found_vdso_mmap)
> > -                                             found_vdso_mmap = !strcmp(event->mmap.filename, "[vdso]");
> > +                                             found_vdso_mmap = !strcmp(mmap_filename, "[vdso]");
> >                                       break;
> >
> >                               case PERF_RECORD_SAMPLE:
--
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