From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCH] memcg: provide reclaim stats via 'memory.reclaim'
Date: Tue, 24 May 2022 07:45:40 -0400
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To: Yosry Ahmed <yosryahmed@google.com>
Cc: Michal Hocko <mhocko@suse.com>, Vaibhav Jain <vaibhav@linux.ibm.com>, Cgroups <cgroups@vger.kernel.org>, linux-doc@vger.kernel.org, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>, Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>, Jonathan Corbet <corbet@lwn.net>, Vladimir Davydov <vdavydov.dev@gmail.com>, Andrew Morton <akpm@linux-foundation.org>, "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>, Shakeel Butt <shakeelb@google.com>

On Mon, May 23, 2022 at 03:50:34PM -0700, Yosry Ahmed wrote:
> I think it might be useful to have a dedicated entry in memory.stat
> for proactively reclaimed memory. A case where this would be useful is
> tuning and evaluating userspace proactive reclaimers. For instance, if
> a userspace agent is asking the kernel to reclaim 100M, but it could
> only reclaim 10M, then most probably the proactive reclaimer is not
> using a good methodology to figure out how much memory do we need to
> reclaim.
> 
> IMO this is more useful, and a superset of just reading the last
> reclaim request status through memory.reclaim (read stat before and
> after).

+1