Re: [PATCH 00/17] cgroup/cpuset: Fix partition CPU ownership and isolation accounting

[Ridong Chen <ridong.chen@linux.dev>]

On 8/20/2026 8:41 PM, Guopeng Zhang wrote:
> From: Guopeng Zhang <zhangguopeng@kylinos.cn>
> 
> update_prstate() uses effective_xcpus for isolation accounting and
> housekeeping checks when switching a partition between root and
> isolated. The mask also includes CPUs granted to valid child partitions.
> Such a type change can alter isolation accounting for child-owned CPUs
> or fail a housekeeping check because of a CPU the parent does not own.
> 
> A rejected type change can leave CPUs assigned to the invalidated
> partition instead of returning them to the partition that owns the
> invalidated subtree. When cpuset.cpus changes, child validation can use
> the old parent mask, and a remote update can observe stale cpus_allowed
> when it revisits a cpuset. Direct and propagated invalidation can leave
> isolated_cpus reflecting the released partition's type instead of the
> type of the partition receiving its CPUs. Releasing an isolated
> partition can clear boot-isolated CPUs from isolated_cpus.
> 
> Limit type-change checks and accounting to CPUs owned directly by the
> partition. Preserve boot-isolated CPUs when a partition is released,
> return CPUs after rejected type changes, validate children against the
> new parent mask, and publish cpus_allowed before a partition update can
> revisit the cpuset. Fix isolation accounting during direct and
> propagated invalidation.
> 
> Patch 1 removes an invalid selftest comparison that makes
> test_cpuset_prs.sh fail when boot-time domain isolation is configured.
> Each kernel fix is followed by a focused selftest update.
> 
> Guopeng Zhang (17):
>    selftests/cgroup: Drop invalid boot isolation comparison
>    cgroup/cpuset: Preserve boot-isolated CPUs on partition release
>    selftests/cgroup: Test boot-isolated CPU partition release
>    cgroup/cpuset: Limit type-change accounting to owned CPUs
>    selftests/cgroup: Test isolated CPU accounting on type changes
>    cgroup/cpuset: Validate type changes against owned CPUs
>    selftests/cgroup: Test type-change validation with child-owned CPUs
>    cgroup/cpuset: Release CPUs when a type change is rejected
>    selftests/cgroup: Test rejected partition type changes
>    cgroup/cpuset: Fix isolated accounting on direct child invalidation
>    selftests/cgroup: Test isolation accounting on direct child
>      invalidation
>    cgroup/cpuset: Invalidate children outside the new CPU mask
>    selftests/cgroup: Test child invalidation after shrinking cpuset.cpus
>    cgroup/cpuset: Publish cpus_allowed before partition updates
>    selftests/cgroup: Test shrinking cpuset.cpus in a remote partition
>    cgroup/cpuset: Fix isolated accounting on propagated invalidation
>    selftests/cgroup: Test isolation accounting on propagated invalidation
> 
>   kernel/cgroup/cpuset.c                        | 162 ++++++++++--
>   .../selftests/cgroup/test_cpuset_prs.sh       | 231 +++++++++++++++++-
>   2 files changed, 361 insertions(+), 32 deletions(-)
> 
> 
> base-commit: 6a746cd265aed59107ebdaa9ce039bb832922969

Hi Guopeng,

This is a fairly large series, which may make the review process challenging. I 
would suggest splitting it into smaller, more focused patches. It would also be 
very helpful if you could provide a reproducer for each bug you are trying to 
fix, so that we can verify the issue and the fix more effectively.

-- 
Best regards
Ridong