From: Matthew Wilcox <willy@infradead.org>
To: Yafang Shao <laoar.shao@gmail.com>
Cc: akpm@linux-foundation.org, david@kernel.org, ziy@nvidia.com,
matthew.brost@intel.com, joshua.hahnjy@gmail.com,
byungchul@sk.com, gourry@gourry.net,
ying.huang@linux.alibaba.com, apopple@nvidia.com,
linux-mm@kvack.org, "Huang, Ying" <ying.huang@intel.com>
Subject: Re: [PATCH] mm/migrate: snapshot the source nid before the misplaced migration
Date: Fri, 23 Oct 2026 04:28:56 +0100 [thread overview]
Message-ID: <atrUeGPZgoSACpOR@casper.infradead.org> (raw)
In-Reply-To: <20261023023226.29783-1-laoar.shao@gmail.com>
On Fri, Oct 23, 2026 at 10:32:26AM +0800, Yafang Shao wrote:
> A successful migration frees the source folio, so the folio_nid() read
> in the promotion counter update can pick up a reallocated page's nid.
> Snapshot the nid before the migration, next to the memcg snapshot the
> function already takes.
I don't understand how a node ID can change even after the folio has
been freed. I don't think this patch is wrong, but I don't think
there's actually a bug here that's being fixed.
next prev parent reply other threads:[~2026-10-23 3:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-23 2:32 [PATCH] mm/migrate: snapshot the source nid before the misplaced migration Yafang Shao
2026-10-23 3:28 ` Matthew Wilcox [this message]
2026-10-23 3:48 ` Yafang Shao
2026-10-23 14:11 ` Zi Yan
2026-10-25 3:51 ` Yafang Shao
2026-10-25 11:19 ` Matthew Wilcox
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