Messages in this thread | | | Date | Wed, 26 Oct 2011 09:21:54 -0200 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [RFC PATCH 2/2] tools/perf: Make group_fd static and move its place in __perf_evsel__open() |
| |
Em Wed, Oct 26, 2011 at 09:18:28AM -0200, Arnaldo Carvalho de Melo escreveu: > Em Wed, Oct 26, 2011 at 02:26:03PM +0800, Deng-Cheng Zhu escreveu: > > With _only_ your patch applied, I tested with the following commands on > > MIPS 74K (4 counters available in total):
> > perf stat -g -e > > L1-dcache-load-misses,cycles,LLC-load-misses,iTLB-loads,instructions > > find / >/dev/null
> > I tried to group up to 5 events in the hope of seeing NOSPC error. But > > the command didn't fail and output:
> > Performance counter stats for 'find /':
> > 9300823 L1-dcache-load-misses > > <not counted> cycles > > <not counted> LLC-load-misses > > <not counted> iTLB-loads > > <not counted> instructions
> > 8.463207591 seconds time elapsed
> > This is due to the event state check in validate_group() filtering out > > the grouped events in OFF state. They are in OFF state because we are > > running the command with the perf tool as opposed to attaching to an > > existing task:
> > builtin-stat.c:create_perf_stat_counter():
> > if (target_pid == -1 && target_tid == -1) { > > attr->disabled = 1; > > attr->enable_on_exec = 1; > > } > > But they should be in OFF state only till the target program gets > exec'ed, right? > > > I suppose X86 has this issue too -- collect_events() in validate_group() > > won't do real work in the bottom half of the function. > > I'm testing that now.
[root@emilia ~]# perf stat -g -e L1-dcache-load-misses,cycles,LLC-load-misses,iTLB-loads,instructions find / >/dev/null
Performance counter stats for 'find /':
158,807,949 L1-dcache-load-misses <not counted> cycles <not counted> LLC-load-misses <not counted> iTLB-loads <not counted> instructions
100.676645958 seconds time elapsed
[root@emilia ~]#
Yeah, reading more code...
- Arnaldo
| |