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From: Ivan Babrou <ivan@cloudflare.com>
Date: Wed, 23 Feb 2022 13:16:21 -0800
Message-ID: <CABWYdi089+3wG-+6a-O8bnOU_U96i+c9AG3ofS+LocA5oXcE0A@mail.gmail.com>
Subject: Re: Regression in workingset_refault latency on 5.15
To: Shakeel Butt <shakeelb@google.com>
Cc: Daniel Dao <dqminh@cloudflare.com>, kernel-team <kernel-team@cloudflare.com>, 
	Linux MM <linux-mm@kvack.org>, Johannes Weiner <hannes@cmpxchg.org>, Roman Gushchin <guro@fb.com>, 
	Feng Tang <feng.tang@intel.com>, Michal Hocko <mhocko@kernel.org>, Hillf Danton <hdanton@sina.com>, 
	=?UTF-8?Q?Michal_Koutn=C3=BD?= <mkoutny@suse.com>, 
	Andrew Morton <akpm@linux-foundation.org>, Linus Torvalds <torvalds@linux-foundation.org>
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> Thanks for the info. Is it possible to test
> https://lore.kernel.org/all/20210929235936.2859271-1-shakeelb@google.com/
> ?
>
> If that patch did not help then we either have to optimize rstat
> flushing or further increase the update buffer which is nr_cpus * 32.

We're working on it and should have some data tomorrow.