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Date: Wed, 13 Jul 2016 22:57:12 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>, John Stultz <john.stultz@linaro.org>,
        Ingo Molnar <mingo@redhat.com>, lkml <linux-kernel@vger.kernel.org>,
        Dmitry Shmidt <dimitrysh@google.com>,
        Rom Lemarchand <romlem@google.com>, Colin Cross <ccross@google.com>,
        Todd Kjos <tkjos@google.com>, Oleg Nesterov <oleg@redhat.com>
Subject: Re: Severe performance regression w/ 4.4+ on Android due to cgroup
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On Wed, Jul 13, 2016 at 01:52:11PM -0700, Paul E. McKenney wrote:
> Not a particularly real-time-friendly fix, but certainly a good check
> on our various assumptions.

Not only RT, but also HPC and all the other RDMA userspace polling
freaks ;-)

But yes, it would confirm that this is indeed the issue.