From: Chris Down <chris@chrisdown.name>
To: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
Cc: "David Hildenbrand" <david@kernel.org>,
"Liam R. Howlett" <liam@infradead.org>,
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stable@vger.kernel.org
Subject: Re: [PATCH v2 08/13] mm/migrate_device: fix ksmd oops on a migrated KSM page
Date: Sat, 14 Nov 2026 11:56:57 -0800 [thread overview]
Message-ID: <20261114115657.f63de4714929f7af@chrisdown.name> (raw)
In-Reply-To: <20261113-mason-migrate-et-al-fixes-v2-8-50a2ed382b61@kernel.org>
Hi Lorenzo,
Lorenzo Stoakes (ARM) writes:
>[ ljs: tweak commit message, comment, also refuse device coherent ]
Alistair's Reviewed-by on v1 came with the argument that KSM pages should
still be able to go to device coherent memory [1], which is the opposite of
what this does now, so it's probably worth checking that he's happy for it
to be carried over. Going by what ksmd does with zone device pages, the
change itself looks right to me.
I've tested the device private case. Without this the process hangs the
next time it touches one of the pages, and with it the migration is
refused and the pages stay merged.
[1] https://lore.kernel.org/r/avTu3LmscsttRVRp@nvdebian.thelocal
Reviewed-by: Chris Down <chris@chrisdown.name>
Tested-by: Chris Down <chris@chrisdown.name>
Chris
next prev parent reply other threads:[~2026-11-14 19:57 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-13 21:45 [PATCH v2 00/13] mm: batch of (urgentish?) fixes in oomk, cachestat, dev-migrate, percpu Lorenzo Stoakes (ARM)
2026-11-13 21:45 ` [PATCH v2 01/13] mm/mmap: free gathered pages before MMF_OOM_SKIP Lorenzo Stoakes (ARM)
2026-11-14 19:56 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 02/13] mm: cachestat: count each page only once Lorenzo Stoakes (ARM)
2026-11-14 19:56 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 03/13] mm: cachestat: restart the walk after each entry Lorenzo Stoakes (ARM)
2026-11-14 18:08 ` Nhat Pham
2026-11-14 19:56 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 04/13] mm/migrate_device: allocate THP deferred split heads Lorenzo Stoakes (ARM)
2026-11-14 19:56 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 05/13] mm/migrate_device: don't collect a range twice Lorenzo Stoakes (ARM)
2026-11-14 5:09 ` Balbir Singh
2026-11-14 6:45 ` Mika Penttilä
2026-11-14 18:34 ` Lorenzo Stoakes (ARM)
2026-11-14 19:56 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 06/13] mm/migrate_device: don't let go of the fault page Lorenzo Stoakes (ARM)
2026-11-13 22:31 ` Balbir Singh
2026-11-14 19:56 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 07/13] mm/migrate_device: look up fault folio after a split Lorenzo Stoakes (ARM)
2026-11-13 22:20 ` Balbir Singh
2026-11-14 19:56 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 08/13] mm/migrate_device: fix ksmd oops on a migrated KSM page Lorenzo Stoakes (ARM)
2026-11-14 19:56 ` Chris Down [this message]
2026-11-13 21:45 ` [PATCH v2 09/13] mm/migrate_device: fix use-after-free of the anon rmap Lorenzo Stoakes (ARM)
2026-11-14 19:57 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 10/13] mm/migrate_device: refuse to migrate shadow stacks Lorenzo Stoakes (ARM)
2026-11-14 19:57 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 11/13] percpu: fix contig hints that are too low Lorenzo Stoakes (ARM)
2026-11-14 19:57 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 12/13] percpu: search the whole reserved chunk Lorenzo Stoakes (ARM)
2026-11-14 19:57 ` Chris Down
2026-11-13 21:45 ` [PATCH v2 13/13] percpu: queue the balance work on an unbound workqueue Lorenzo Stoakes (ARM)
2026-11-14 19:57 ` Chris Down
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