linux-kernel - Re: [PATCH RFC v2 00/22] cpuset: rework local partition logic

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <31b58b15-0b46-4eba-bd50-afc99203695a@huaweicloud.com>
Date: Mon, 3 Nov 2025 19:18:52 +0800
From: Chen Ridong <chenridong@...weicloud.com>
To: longman@...hat.com, tj@...nel.org, hannes@...xchg.org, mkoutny@...e.com
Cc: cgroups@...r.kernel.org, linux-kernel@...r.kernel.org,
 lujialin4@...wei.com, chenridong@...wei.com
Subject: Re: [PATCH RFC v2 00/22] cpuset: rework local partition logic



On 2025/10/25 14:48, Chen Ridong wrote:
> From: Chen Ridong <chenridong@...wei.com>
> 
> The current local partition implementation consolidates all operations
> (enable, disable, invalidate, and update) within the large
> update_parent_effective_cpumask() function, which exceeds 300 lines.
> This monolithic approach has become increasingly difficult to understand
> and maintain. Additionally, partition-related fields are updated in
> multiple locations, leading to redundant code and potential corner case
> oversights.
> 
> This patch series refactors the local partition logic by separating
> operations into dedicated functions: local_partition_enable(),
> local_partition_disable(), and local_partition_update(), creating
> symmetry with the existing remote partition infrastructure.
> 
> The series is organized as follows:
> 
> 1. Fix a bug that isolcpus stat in root partition.
> 
> 2. Infrastructure Preparation (Patches 2-3):
>    - Code cleanup and preparation for the refactoring work
> 
> 3. Introduce partition operation helpers (Patches 4-6):
>    - Intoduce out partition_enable(), partition_disable(), and
>      partition_update() functions.
> 
> 4. Use new helpers for remote partition (Patches 7-9)
> 
> 5. Local Partition Implementation (Patches 10-13):
>    - Separate update_parent_effective_cpumask() into dedicated functions:
>      * local_partition_enable()
>      * local_partition_disable()
>      * local_partition_invalidate()
>      * local_partition_update()
> 
> 6. Optimization and Cleanup (Patches 14-22):
>    - Remove redundant partition-related operations
>    - Additional optimizations based on the new architecture
> 
> ---
> 
> Changes in v2:
> - Added bugfix for root partition isolcpus at series start.
> - Completed helper function implementations when first introduced.
> - Split larger patches into smaller, more reviewable units.
> - Incorporated feedback from Longman.
> 
> Chen Ridong (22):
>   cpuset: fix isolcpus stay in root when isolated partition changes to
>     root
>   cpuset: add early empty cpumask check in partition_xcpus_add/del
>   cpuset: generalize validate_partition() interface
>   cpuset: introduce partition_enable()
>   cpuset: introduce partition_disable()
>   cpuset: introduce partition_update()
>   cpuset: use partition_enable() for remote partition enablement
>   cpuset: use partition_disable() for remote partition disablement
>   cpuset: use partition_update() for remote partition update
>   cpuset: introduce local_partition_enable()
>   cpuset: introduce local_partition_disable()
>   cpuset: introduce local_partition_invalidate()
>   cpuset: introduce local_partition_update()
>   cpuset: remove update_parent_effective_cpumask
>   cpuset: remove redundant partition field updates
>   cpuset: simplify partition update logic for hotplug tasks
>   cpuset: unify local partition disable and invalidate
>   cpuset: use partition_disable for compute_partition_effective_cpumask
>   cpuset: use validate_local_partition in local_partition_enable
>   cpuset: introduce validate_remote_partition
>   cpuset: simplify update_prstate() function
>   cpuset: remove prs_err clear when notify_partition_change
> 
>  kernel/cgroup/cpuset.c | 1000 +++++++++++++++++++---------------------
>  1 file changed, 463 insertions(+), 537 deletions(-)
> 

Hi Longman,

I'd appreciate it if you could have a look at this series when you have a moment.

-- 
Best regards,
Ridong