From: Nhat Pham <nphamcs@gmail.com>
To: Yosry Ahmed <yosryahmed@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
akpm@linux-foundation.org, shakeelb@google.com,
linux-mm@kvack.org, kernel-team@meta.com,
linux-kernel@vger.kernel.org, flintglass@gmail.com
Subject: Re: [PATCH 1/2] zswap: implement a second chance algorithm for dynamic zswap shrinker
Date: Tue, 30 Jul 2024 14:40:42 -0700 [thread overview]
Message-ID: <CAKEwX=Mzzs0kU4Fmw-hiyMT_6m37N6i=xWaEgZoCN+RAx6McSQ@mail.gmail.com> (raw)
In-Reply-To: <CAJD7tka1tPA=qGFJcf4n1MM20A4WoL0cA28jDcyoc0y+48+0bw@mail.gmail.com>
On Tue, Jul 30, 2024 at 11:46 AM Yosry Ahmed <yosryahmed@google.com> wrote:
>
>
> I still think the nr_deferred handling in the shrinker framework does
> not seem compatible with zswap. Entries could be double counted, and
> previously counted entries could go away during swapins. Unless I am
> missing something, it seems like the scanning can be arbitrary, and
> not truly proportional to the reclaim priority and zswap LRUs size.
We can do some investigation by the side. I did find the trace point
that collects deferred numbers, maybe that can illustrate the problem?
It'd be an orthogonal issue though. I don't think fixing the
nr_deferred part would be enough to handle the various cases Johannes
pointed out.
next prev parent reply other threads:[~2024-07-30 21:40 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-25 23:28 [PATCH 0/2] improving dynamic zswap shrinker protection scheme Nhat Pham
2024-07-25 23:28 ` [PATCH 1/2] zswap: implement a second chance algorithm for dynamic zswap shrinker Nhat Pham
2024-07-26 21:58 ` Yosry Ahmed
2024-07-29 23:07 ` Nhat Pham
2024-07-30 0:07 ` Nhat Pham
2024-07-30 3:39 ` Johannes Weiner
2024-07-30 6:23 ` Nhat Pham
2024-07-30 18:46 ` Yosry Ahmed
2024-07-30 21:40 ` Nhat Pham [this message]
2024-07-30 22:04 ` Nhat Pham
2024-07-25 23:28 ` [PATCH 2/2] zswap: increment swapin count for non-pivot swapped in pages Nhat Pham
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