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Date: Thu, 15 Sep 2016 09:15:00 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Stephane Eranian <eranian@google.com>, Ingo Molnar <mingo@kernel.org>
Subject: Re: perf: perf_fuzzer lockup in perf_cgroup_attach
Message-ID: <20160915071500.GM5008@twins.programming.kicks-ass.net>
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On Wed, Sep 14, 2016 at 10:43:29PM -0400, Vince Weaver wrote:
> 
> so the skylake that was fuzzing finally is mostly locked up.
> 
> Really hard to tell what's going, especially as KASLR made looking up the 
> addresses a big pain.
> 
> The best I can tell things are getting wedged somehow in 
> perf_cgroup_switch() while interrupts are disabled.  Interrupts are never 
> getting re-enabled, causing the RCU and NMI watchdogs to trigger (and more 
> alarming things like the SATA bus resetting).

How do you go about using cgroups? Do you set them up yourself, does the
fuzzer do so?