From: Andrew Morton <akpm@linux-foundation.org>
To: Breno Leitao <leitao@debian.org>
Cc: Chris Li <chrisl@kernel.org>, Kairui Song <kasong@tencent.com>,
Kemeng Shi <shikemeng@huaweicloud.com>,
Nhat Pham <nphamcs@gmail.com>, Baoquan He <baoquan.he@linux.dev>,
Barry Song <baohua@kernel.org>,
Youngjun Park <youngjun.park@lge.com>,
David Hildenbrand <david@kernel.org>,
Miaohe Lin <linmiaohe@huawei.com>,
Oscar Salvador <osalvador@suse.de>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kernel-team@meta.com, stable@vger.kernel.org
Subject: Re: [PATCH] mm, swap: ratelimit bad swap entry reports
Date: Tue, 18 Aug 2026 12:28:44 -0700 [thread overview]
Message-ID: <20260818122844.71988535d6380ba67e8a2b1a@linux-foundation.org> (raw)
In-Reply-To: <20260818-swap_part_one-v1-1-a4fc58119fc0@debian.org>
On Tue, 18 Aug 2026 02:03:40 -0700 Breno Leitao <leitao@debian.org> wrote:
> A corrupt page table hands the same bogus entry to get_swap_device() on
> every access to the mapping, and every rejection is logged. One machine
> logged 6185620 copies of the same line in a few hours.
>
> swap_dup_entry_direct() prints the same message from the fork path, once
> per call: the WARN_ON_ONCE() guarding it warns once, the pr_err() inside
> does not.
>
> Rate limit all three prints.
Sashiko suggests that ratelimiting these might cause pre-existing
problems to become worse:
https://sashiko.dev/#/patchset/20260818-swap_part_one-v1-1-a4fc58119fc0@debian.org
The problem it's identifying does require that unrelated things go
wrong first - get_swap_device() failed, swap_retry_table_alloc() did a
retry. So presumably you wouldn't have hit this in testing.
Sigh, so much to fix.
prev parent reply other threads:[~2026-08-18 19:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-18 9:03 [PATCH] mm, swap: ratelimit bad swap entry reports Breno Leitao
2026-08-18 17:20 ` David Hildenbrand (Arm)
2026-08-18 19:28 ` Andrew Morton [this message]
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