From: Yosry Ahmed <yosry@kernel.org>
To: Nhat Pham <nphamcs@gmail.com>
Cc: Hao Jia <jiahao.kernel@gmail.com>,
akpm@linux-foundation.org, tj@kernel.org, hannes@cmpxchg.org,
shakeel.butt@linux.dev, mhocko@kernel.org, mkoutny@suse.com,
chengming.zhou@linux.dev, muchun.song@linux.dev,
roman.gushchin@linux.dev, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
Hao Jia <jiahao1@lixiang.com>
Subject: Re: [PATCH 2/2] mm/zswap: Support batch writeback in shrink_memcg()
Date: Fri, 17 Jul 2026 09:55:57 -0700 [thread overview]
Message-ID: <CAO9r8zP8L_4dOSVQT8v6v83uAN1ZG_7vTMxfp5jDME8U2sxEhw@mail.gmail.com> (raw)
In-Reply-To: <CAKEwX=Patm4+gxtxwDYBFXFh+jfaOUSvtKtVZFvp=oQwNmdu1Q@mail.gmail.com>
On Fri, Jul 17, 2026 at 9:50 AM Nhat Pham <nphamcs@gmail.com> wrote:
>
> On Thu, Jul 16, 2026 at 1:35 PM Yosry Ahmed <yosry@kernel.org> wrote:
> >
> >
> > It is a bit alarming that the store rejection rate is still 43% with
> > batching, but we can worry about this later :)
>
> Yeah I think it's unavoidable at the time the global shrinker is
> awaken, unfortunately :( We need to kick off shrinking way ahead of
> time if we want to avoid this, especially since the rate of zswap out
> is going to be faster than the rate of writeback (CPU vs IO).
>
> Sort of why we implement the proactive reclaimers :)
Arguably, reclaim should wait for zswap writeback and retry, similar
to how allocators wakeup kswapd and retry, instead of just skipping
zswap. I was actually thinking about doing this at least for the memcg
limit case, eliminate the sync shrink_memcg(1) call in zswap_store()
and instead wakeup an async flusher and sleep.
A problem for another day I guess :)
prev parent reply other threads:[~2026-07-17 16:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-14 8:15 [PATCH 0/2] mm/zswap: Fixes and improves the zswap global shrinker Hao Jia
2026-07-14 8:15 ` [PATCH 1/2] mm/zswap: Fix global shrinker when memory cgroup is disabled Hao Jia
2026-07-14 16:52 ` Yosry Ahmed
2026-07-15 2:31 ` Andrew Morton
2026-07-15 12:30 ` Hao Jia
2026-07-15 16:13 ` Yosry Ahmed
2026-07-16 2:21 ` Hao Jia
2026-07-16 18:18 ` Nhat Pham
2026-07-17 0:08 ` Yosry Ahmed
2026-07-17 8:46 ` Hao Jia
2026-07-14 8:15 ` [PATCH 2/2] mm/zswap: Support batch writeback in shrink_memcg() Hao Jia
2026-07-14 16:52 ` Yosry Ahmed
2026-07-15 11:28 ` Hao Jia
2026-07-15 16:14 ` Yosry Ahmed
2026-07-16 2:54 ` Hao Jia
2026-07-16 18:04 ` Nhat Pham
2026-07-17 8:29 ` Hao Jia
2026-07-16 20:35 ` Yosry Ahmed
2026-07-17 16:50 ` Nhat Pham
2026-07-17 16:55 ` Yosry Ahmed [this message]
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