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From: Hillf Danton <hdanton@sina.com>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yu Zhao <yuzhao@google.com>,
	Axel Rasmussen <axelrasmussen@google.com>,
	Chris Down <chris@chrisdown.name>,
	cgroups@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-mm@kvack.org
Subject: Re: MGLRU premature memcg OOM on slow writes
Date: Wed, 13 Mar 2024 18:59:53 +0800
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On Tue, 12 Mar 2024 17:08:22 -0400 Johannes Weiner <hannes@cmpxchg.org>
> 
> Back to the broader question though: if reclaim demand outstrips clean
> pages and the only viable candidates are dirty ones (e.g. an
> allocation spike in the presence of dirty/writeback pages), there only
> seem to be 3 options:
> 
> 1) sleep-wait for writeback
> 2) continue scanning, aka busy-wait for writeback + age inversions
> 3) find nothing and declare OOM

  4) make dirty ratio match your writeback bandwidth [1]

[1] Subject: Re: 4.8.8 kernel trigger OOM killer repeatedly when I have lots of RAM that should be free
https://lore.kernel.org/lkml/CA+55aFzNe=3e=cDig+vEzZS5jm2c6apPV4s5NKG4eYL4_jxQjQ@mail.gmail.com/