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Sender: Tejun Heo <htejun@gmail.com>
Date:   Mon, 15 Aug 2022 09:50:30 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Johannes Weiner <hannes@cmpxchg.org>
Cc:     Chengming Zhou <zhouchengming@bytedance.com>, corbet@lwn.net,
        surenb@google.com, mingo@redhat.com, peterz@infradead.org,
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        rostedt@goodmis.org, bsegall@google.com, cgroups@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        songmuchun@bytedance.com
Subject: Re: [PATCH v2 09/10] sched/psi: per-cgroup PSI stats
 disable/re-enable interface
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Hello,

On Mon, Aug 15, 2022 at 11:49:55AM -0400, Johannes Weiner wrote:
> I think it should also add/remove the pressure files when enabling and
> disabling the aggregation, since their contents would be stale and
> misleading.
> 
> Take a look at cgroup_add_dfl_cftypes() and cgroup_rm_cftypes()

The problem with adding cftypes dynamically is that it can fail, which isn't
the end of the world here but still kinda sucks. I think what we actually
wanna do is hiding and unhiding while keeping all the data structures in
place which is needed somewhere else anyway.

Thanks.

-- 
tejun