Re: [PATCH 6.12.y] mm/damon/vaddr: drop last same folio access check optimization

[sashiko-bot@kernel.org]

> The optimization can race when multiple kdamonds are running.  Meanwhile,
> the impact of the optimization is quite doubtful.  Just remove it.
> 
> The user impact of the issue should be quite trivial.  After all, the race
> can happen only when the user intentionally setup DAMON in the way.  Even
> if it happens, it would be rare and only degrade the best-effort
> monitoring results.  No critical consequences like kernel panic or memory
> corruption happen.
> 
> The race possibility was discovered [1] by Sashiko.
> 
> Link: https://lore.kernel.org/20260715031002.108504-4-sj@kernel.org
> Link: https://lore.kernel.org/20260621204050.10993-1-sj@kernel.org [1]
> Fixes: 3f49584b262c ("mm/damon: implement primitives for the virtual memory address spaces")
> Signed-off-by: SJ Park <sj@kernel.org>
> Cc: <stable@vger.kernel.org> # 5.15.x
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> (cherry picked from commit 831846078caa14b7d00b2ccca8b8fe522afe3204)
> Signed-off-by: SJ Park <sj@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260909060130.269798-1-sj@kernel.org?part=1