[GIT PULL] kthread fix

[GIT PULL] kthread fix

[Frederic Weisbecker]

Hi Linus,

The following changes since commit c03c1a14507dfaf8b856c2608f9ac216021fc222:

  Linux 7.3 (2026-10-18 13:14:58 -1000)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git tags/kthread-fix-for-linus

for you to fetch changes up to 78ff77ded78f2d3d6040705a3ab5a83cc45275e3:

  kthread: Fall back when no preferred housekeeping CPU is online (2026-10-25 19:53:54 +0100)

----------------------------------------------------------------
Fix a bug where dynamic CPU isolation through cpuset isolated partitions
can move a kthread out of the housekeeping range. For example in a
system with 3 CPUs:

_ kthread K has preferred affinity to CPUs 1 et 2 and is affine to them
_ CPU 1 goes offline
_ An isolated cpuset partition is created on CPU 2 (so the only
  remaining online housekeeper is CPU 0)
_ K is affine to CPU 2 but this CPU is offline so it fails and goes back
  to its previous affinity where only CPU 3 is online. Yet it is
  isolated.

The fix makes sure the fallback affinity is always a set of online
housekeeper.

----------------------------------------------------------------
Avi Weiss (1):
      kthread: Fall back when no preferred housekeeping CPU is online

 kernel/kthread.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)


Thanks.

Re: [GIT PULL] kthread fix

[Linus Torvalds]

On Thu, 29 Oct 2026 at 05:25, Frederic Weisbecker <frederic@kernel.org> wrote:
>
> For example in a system with 3 CPUs:

That example made no sense what-so-ever. You say "3 CPUs", but the
example had four CPU numbers (0..3) and the numbers in the example
also never made sense.

I cut out the example from the merge message because it just made
things clear as mud.  Please be more careful.

               Linus

Re: [GIT PULL] kthread fix

[pr-tracker-bot]

The pull request you sent on Thu, 29 Oct 2026 16:25:26 +0100:

> git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git tags/kthread-fix-for-linus

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/d011f648a708b231f7ef28c18ff30c815b07fe56

Thank you!

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