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Date: Mon, 18 May 2015 09:30:26 -0300
From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Jiri Olsa <jolsa@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
        David Ahern <dsahern@gmail.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Andi Kleen <andi@firstfloor.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH Not-for-merge 40/40] perf tools: Disable thread refcount
 due to bug
Message-ID: <20150518123026.GC15972@kernel.org>
References: <1431909055-21442-1-git-send-email-namhyung@kernel.org>
 <1431909055-21442-41-git-send-email-namhyung@kernel.org>
 <20150518012336.GB15972@kernel.org>
 <20150518122131.GA7683@danjae.kornet>
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Em Mon, May 18, 2015 at 09:21:31PM +0900, Namhyung Kim escreveu:
> On Sun, May 17, 2015 at 10:23:36PM -0300, Arnaldo Carvalho de Melo wrote:
> > Em Mon, May 18, 2015 at 09:30:55AM +0900, Namhyung Kim escreveu:
> > > This makes thread mg sharing test failed due to not decrement
> > > thread->refcnt on thread__put().

> > I fixed this one already:

> > https://git.kernel.org/cgit/linux/kernel/git/acme/linux.git/commit/?h=perf/core&id=8b00f46951bed1edd9c5cb9d9adb62d28bbe7623

> > No?
 
> I meant that I added this patch not to segfault caused by the thread
> refcount, but as a side-effect it makes thread_mg_sharing test failed
> due to non-decremented refcount.
 
> As of 70923bd26c73 ("perf tools: Make flex/bison calls honour V=1")
> I can reproduce the segfault.

Ok, I'll investigate that report, looks like one more case where
longstanding bugs are exposed by work on multithreading.

- Arnaldo