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From: Mark Rutland <mark.rutland@arm.com>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@redhat.com>, Jiri Olsa <jolsa@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH] perf tools: session: avoid infinite loop
Date: Fri, 18 Sep 2015 14:37:09 +0100	[thread overview]
Message-ID: <20150918133708.GA26468@leverpostej> (raw)
In-Reply-To: <55FBED85.8020603@intel.com>

> > So it looks like I shouldn't have any synthesized events. Have I missed
> > anything?
> 
> Yes, you are right.  But you are not getting the COMM and MMAP events from
> the exec which means you are killing perf before it execs the workload.

Oh, I see.

> Perf writes through a pipe to its forked child to do the exec, so
> to reproduce it you just need to put everything on the same cpu and play around
> with the sleep number
> 
> 	taskset -c 0 tools/perf/perf record -- sleep 1 & sleep 0.005 ; kill -2 $!
> 
> reproduces the problem for me.  Of course, since the workload doesn't get exec'ed
> it doesn't matter if it is bogus i.e.
> 
> 	taskset -c 0 tools/perf/perf record -- sdfgsdgdg & sleep 0.005 ; kill -2 $!
> 
> also reproduces the problem.

Thanks for confirming!

Mark.

  reply	other threads:[~2015-09-18 13:37 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-16 17:18 [PATCH] perf tools: session: avoid infinite loop Mark Rutland
2015-09-16 20:54 ` Arnaldo Carvalho de Melo
2015-09-17 15:41   ` Mark Rutland
2015-09-18  6:09     ` Adrian Hunter
2015-09-18  9:51       ` Mark Rutland
2015-09-18 10:55         ` Adrian Hunter
2015-09-18 13:37           ` Mark Rutland [this message]
2015-09-18 15:00             ` Arnaldo Carvalho de Melo
2015-09-18 15:18               ` Mark Rutland
2015-09-18 15:29                 ` Arnaldo Carvalho de Melo
2015-09-21 12:33                   ` Adrian Hunter
2015-09-23  8:42 ` [tip:perf/core] perf record: Avoid infinite loop at buildid processing with no samples tip-bot for Mark Rutland

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