Re: [PATCH] perf tools: session: avoid infinite loop

From	Mark Rutland <mark.rutland@arm.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] perf tools: session: avoid infinite loop
Date	2015-09-18 15:40 +0200
Message-ID	<qa43p-41T-51@gated-at.bofh.it> (permalink)
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> > 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.
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Thread

[PATCH] perf tools: session: avoid infinite loop Mark Rutland <mark.rutland@arm.com> - 2015-09-16 19:20 +0200
  Re: [PATCH] perf tools: session: avoid infinite loop Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-09-16 23:00 +0200
    Re: [PATCH] perf tools: session: avoid infinite loop Mark Rutland <mark.rutland@arm.com> - 2015-09-17 17:50 +0200
      Re: [PATCH] perf tools: session: avoid infinite loop Adrian Hunter <adrian.hunter@intel.com> - 2015-09-18 08:20 +0200
        Re: [PATCH] perf tools: session: avoid infinite loop Mark Rutland <mark.rutland@arm.com> - 2015-09-18 12:00 +0200
          Re: [PATCH] perf tools: session: avoid infinite loop Adrian Hunter <adrian.hunter@intel.com> - 2015-09-18 13:00 +0200
            Re: [PATCH] perf tools: session: avoid infinite loop Mark Rutland <mark.rutland@arm.com> - 2015-09-18 15:40 +0200
              Re: [PATCH] perf tools: session: avoid infinite loop Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-09-18 17:10 +0200
                Re: [PATCH] perf tools: session: avoid infinite loop Mark Rutland <mark.rutland@arm.com> - 2015-09-18 17:20 +0200
                Re: [PATCH] perf tools: session: avoid infinite loop Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-09-18 17:40 +0200
                Re: [PATCH] perf tools: session: avoid infinite loop Adrian Hunter <adrian.hunter@intel.com> - 2015-09-21 14:40 +0200

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