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From: Jiri Olsa <jolsa@redhat.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>, David Ahern <dsahern@gmail.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	lkml <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH 4/5] perf tools: Allow to ignore missing pid
Date: Mon, 12 Dec 2016 15:53:12 +0100	[thread overview]
Message-ID: <20161212145312.GA28361@krava> (raw)
In-Reply-To: <20161212143209.GB5650@kernel.org>

On Mon, Dec 12, 2016 at 11:32:09AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Mon, Dec 12, 2016 at 11:35:42AM +0100, Jiri Olsa escreveu:
> > Adding perf_evsel::ignore_missing_cpu_thread bool.
> > 
> > When set true, it allows perf to ignore error of missing
> > pid of perf event syscall.
> > 
> > We remove missing thread id from the thread_map, so the
> > rest of the processing like ioctl and mmap won't get
> > disturbed with -1 fd
> 
> What was the test performed? I tried it here the following while doing
> a 'make -j4 allmodconfig' in the background, i.e. tons of threads coming
> and going, and I sometimes get:
> 
> [root@jouet ~]# perf record -u acme 
> Error:
> The sys_perf_event_open() syscall returned with 3 (No such process) for
> event (cycles:ppp).
> /bin/dmesg may provide additional information.
> No CONFIG_PERF_EVENTS=y kernel support configured?

I dont think it's fast enough (start/stop) to hit the race, I've got best
results with having on background this:

  while :; do /usr/bin/true; done

jirka

  parent reply	other threads:[~2016-12-12 14:53 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-12 10:35 [PATCH 0/5] perf record: Allow to ignore missing pid Jiri Olsa
2016-12-12 10:35 ` [PATCH 1/5] perf mem: Fix --all-user/--all-kernel options Jiri Olsa
2016-12-12 13:43   ` Arnaldo Carvalho de Melo
2016-12-12 13:44     ` Jiri Olsa
2016-12-20 19:23   ` [tip:perf/urgent] " tip-bot for Jiri Olsa
2016-12-12 10:35 ` [PATCH 2/5] perf tools: Use variable instead of repeating lengthy FD macro Jiri Olsa
2016-12-20 19:23   ` [tip:perf/urgent] perf evsel: " tip-bot for Jiri Olsa
2016-12-12 10:35 ` [PATCH 3/5] perf tools: Add thread_map__remove function Jiri Olsa
2016-12-12 20:08   ` Arnaldo Carvalho de Melo
2016-12-12 20:21     ` Arnaldo Carvalho de Melo
2016-12-20 19:24   ` [tip:perf/urgent] perf thread_map: " tip-bot for Jiri Olsa
2016-12-12 10:35 ` [PATCH 4/5] perf tools: Allow to ignore missing pid Jiri Olsa
2016-12-12 14:32   ` Arnaldo Carvalho de Melo
2016-12-12 14:33     ` Arnaldo Carvalho de Melo
2016-12-12 14:53     ` Jiri Olsa [this message]
2016-12-12 15:21       ` Arnaldo Carvalho de Melo
2016-12-12 15:38         ` Jiri Olsa
2016-12-12 19:30           ` Arnaldo Carvalho de Melo
2016-12-12 16:58   ` Namhyung Kim
2016-12-13  7:46     ` [PATCHv2 " Jiri Olsa
2016-12-20 19:24       ` [tip:perf/urgent] perf evsel: " tip-bot for Jiri Olsa
2016-12-12 10:35 ` [PATCH 5/5] perf record: Force ignore_missing_thread for uid option Jiri Olsa
2016-12-20 19:25   ` [tip:perf/urgent] " tip-bot for Jiri Olsa

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