From: Peter Zijlstra <peterz@infradead.org>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>,
linux-kernel@vger.kernel.org,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Corey Ashford <cjashfor@linux.vnet.ibm.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@kernel.org>, Paul Mackerras <paulus@samba.org>
Subject: Re: [PATCH 1/1] perf: Prevent race in PERF_SAMPLE_READ group format sample output
Date: Mon, 7 Jul 2014 13:43:46 +0200 [thread overview]
Message-ID: <20140707114346.GD19379@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20140707102020.GA22764@krava.redhat.com>
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On Mon, Jul 07, 2014 at 12:20:20PM +0200, Jiri Olsa wrote:
> On Mon, Jul 07, 2014 at 11:04:28AM +0200, Peter Zijlstra wrote:
> > On Wed, Jun 25, 2014 at 08:44:35PM +0200, Jiri Olsa wrote:
> > > From: Jiri Olsa <jolsa@redhat.com>
> > >
> > > While iterating siblings in perf_output_read_group we could
> > > race with addition and removal of sibling in perf_group_attach
> > > and perf_group_detach respective.
> >
> > So why would anybody do this?
>
> the test program from 0/1 email hangs up my server
> but no standard reason AFAICS
>
> I've got soft lockup, sometimes ended up with unkillable perf process
> also few total server hangs
OK, so that's useful information to have in a Changelog ;-)
Not immediately obvious how that can happen though. I can see the output
getting scrambled.
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prev parent reply other threads:[~2014-07-07 11:44 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-25 18:44 [PATCH 0/1] perf: Fix race in sample output Jiri Olsa
2014-06-25 18:44 ` [PATCH 1/1] perf: Prevent race in PERF_SAMPLE_READ group format " Jiri Olsa
2014-07-02 7:56 ` Jiri Olsa
2014-07-07 9:04 ` Peter Zijlstra
2014-07-07 10:20 ` Jiri Olsa
2014-07-07 11:43 ` Peter Zijlstra [this message]
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