From: Andrew Morton <akpm@linux-foundation.org>
To: Baoquan He <hebaoquan@kylinos.cn>
Cc: hannes@cmpxchg.org, yosry@kernel.org, nphamcs@gmail.com,
chengming.zhou@linux.dev, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, kasong@tencent.com,
chrisl@kernel.org
Subject: Re: [PATCH] mm: zswap: return -ENOENT when the swap device is gone
Date: Sun, 13 Sep 2026 00:48:31 -0700 [thread overview]
Message-ID: <20260913004831.884d37afd92249d763b7f1da@linux-foundation.org> (raw)
In-Reply-To: <20260913063031.1689420-1-hebaoquan@kylinos.cn>
On Sun, 13 Sep 2026 14:30:31 +0800 Baoquan He <hebaoquan@kylinos.cn> wrote:
> zswap_writeback_entry() returns -EEXIST when get_swap_device() finds no
> device. -EEXIST is the shrinker's "page already in swap cache" signal,
> which makes zswap_shrinker_scan() stop shrinking entirely. A NULL
> get_swap_device() instead means the device is being swapped off, so the
> entry is simply stale.
>
> Return -ENOENT so the shrinker skips the stale entry and keeps scanning.
> Independent of xswap; affects all swap devices.
I'm struggling to understand the userspace-visible runtime effects of this.
I see that reclaim will prematurely abort, but is this a once-off thing
which will resolve on the next reclaim attempt, or will the reclaim
failure persist for a significant period?
next prev parent reply other threads:[~2026-09-13 7:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-13 6:30 Baoquan He
2026-09-13 7:48 ` Andrew Morton [this message]
2026-09-14 6:27 ` Baoquan He
2026-09-13 7:51 ` Andrew Morton
2026-09-14 6:31 ` Baoquan He
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