Re: [PATCH v4 0/5] mm/ksm: keep smart scan from losing duplicate pages

From: David Hildenbrand

Date: Mon Nov 09 2026 - 07:50:07 EST


On Sun, 08 Nov 2026 20:22:49 -0500, Qiliang Yuan wrote:
> With smart scan, which is on by default, two identical pages that become
> mergeable some scans apart can stay unmerged for as long as they live:
> each page times its skipped scans on its own, and once both are old they
> may never be looked at in the same scan, which merging through the
> unstable tree requires. This was first noticed as intermittent failures
> of ksm_tests "KSM NUMA merging" in run_vmtests.sh.
>
> [...]

Applied, thanks!

tree: mm/core.git
branch: ksm-7.5.misc

Applied patches will appear soon in mm-next, followed by linux-next.

Please report any outstanding bugs that were missed during review, so we
can either drop the patch series or decide how to fix it up.

It is encouraged to provide Acked-bys, Reviewed-bys, and Tested-bys even
though the patches have already been applied. If possible, patch trailers
will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. Further, this is not a guarantee that the
patches will go upstream. If in doubt, please check the listed branch.

[1/5] mm/ksm: align smart scan skips with the scan number
https://git.kernel.org/mm/core/c/2b86234b
[2/5] docs/mm: ksm: describe how smart scan picks the scans to skip
https://git.kernel.org/mm/core/c/53ee57e0
[3/5] selftests/mm: fail KSM helpers on short reads and writes
https://git.kernel.org/mm/core/c/78509845
[4/5] selftests/mm: move waiting for KSM full scans into a helper
https://git.kernel.org/mm/core/c/579d9b5a
[5/5] selftests/mm: cover merging KSM pages aged by smart scan
https://git.kernel.org/mm/core/c/1c3db177

--
Cheers,

David