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Date: Wed, 24 Jan 2018 10:46:36 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Lin Xiulei <linxiulei@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>, mingo@redhat.com, acme@kernel.org,
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        Brendan Gregg <brendan.d.gregg@gmail.com>, yang_oliver@hotmail.com,
        jinli.zjl@alibaba-inc.com, "leilei.lin" <leilei.lin@alibaba-inc.com>
Subject: Re: [PATCH v2] perf/core: Fix installing cgroup event into cpu
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On Wed, Jan 24, 2018 at 05:19:34PM +0800, Lin Xiulei wrote:
> Sure, and I consider this "OK" works for "What goes wrong if we leave
> it set?". : )

It would be good if you inspect the code for the case of leaving
cpuctx->cgrp set with no cgroup events left -- AND -- put a blurb about
what you found in your new Changelog.

I suspect it works out and something like perf_cgroup_switch() will fix
things up for us later, but double check and test.