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From: Peter Zijlstra <peterz@infradead.org>
To: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	Stephane Eranian <eranian@google.com>,
	KP Singh <kpsingh@google.com>
Subject: Re: [PATCH] perf/core: fix parent pid/tid in task exit events
Date: Fri, 17 Apr 2020 20:45:36 +0200	[thread overview]
Message-ID: <20200417184536.GK20730@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200417182842.12522-1-irogers@google.com>

On Fri, Apr 17, 2020 at 11:28:42AM -0700, Ian Rogers wrote:
> Current logic yields the child task as the parent.
> 
> Before:
> $ perf record bash -c "perf list > /dev/null"
> $ perf script -D |grep 'FORK\|EXIT'
> 4387036190981094 0x5a70 [0x30]: PERF_RECORD_FORK(10472:10472):(10470:10470)
> 4387036606207580 0xf050 [0x30]: PERF_RECORD_EXIT(10472:10472):(10472:10472)
> 4387036607103839 0x17150 [0x30]: PERF_RECORD_EXIT(10470:10470):(10470:10470)
>                                                    ^
>   Note the repeated values here -------------------/
> 
> After:
> 383281514043 0x9d8 [0x30]: PERF_RECORD_FORK(2268:2268):(2266:2266)
> 383442003996 0x2180 [0x30]: PERF_RECORD_EXIT(2268:2268):(2266:2266)
> 383451297778 0xb70 [0x30]: PERF_RECORD_EXIT(2266:2266):(2265:2265)
> 

Fixes: .... ?

> Reported-by: KP Singh <kpsingh@google.com>
> Signed-off-by: Ian Rogers <irogers@google.com>

  reply	other threads:[~2020-04-17 18:46 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-17 18:28 Ian Rogers
2020-04-17 18:45 ` Peter Zijlstra [this message]
2020-04-17 21:31   ` Ian Rogers
2020-04-22 21:20 ` [tip: perf/urgent] " tip-bot2 for Ian Rogers

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