linux-kernel - Re: [-next v2 4/4] cpuset: add helpers for cpus read and cpuset

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: <750ac0bd-42f9-47fa-8274-0ff4e4a7fa3d@huaweicloud.com>
Date: Thu, 14 Aug 2025 08:44:57 +0800
From: Chen Ridong <chenridong@...weicloud.com>
To: Waiman Long <llong@...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, christophe.jaillet@...adoo.fr
Subject: Re: [-next v2 4/4] cpuset: add helpers for cpus read and cpuset_mutex
 locks



On 2025/8/14 4:09, Waiman Long wrote:
> On 8/13/25 4:29 AM, Chen Ridong wrote:
>> From: Chen Ridong <chenridong@...wei.com>
>>
>> cpuset: add helpers for cpus_read_lock and cpuset_mutex
>>
>> Replace repetitive locking patterns with new helpers:
>> - cpus_read_cpuset_lock()
>> - cpus_read_cpuset_unlock()
>>
>> This makes the code cleaner and ensures consistent lock ordering.
>>
>> Signed-off-by: Chen Ridong <chenridong@...wei.com>
>> ---
>>   kernel/cgroup/cpuset-internal.h |  2 ++
>>   kernel/cgroup/cpuset-v1.c       | 12 +++------
>>   kernel/cgroup/cpuset.c          | 48 +++++++++++++++------------------
>>   3 files changed, 28 insertions(+), 34 deletions(-)
>>
>> diff --git a/kernel/cgroup/cpuset-internal.h b/kernel/cgroup/cpuset-internal.h
>> index 75b3aef39231..6fb00c96044d 100644
>> --- a/kernel/cgroup/cpuset-internal.h
>> +++ b/kernel/cgroup/cpuset-internal.h
>> @@ -276,6 +276,8 @@ int cpuset_update_flag(cpuset_flagbits_t bit, struct cpuset *cs, int turning_on)
>>   ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
>>                       char *buf, size_t nbytes, loff_t off);
>>   int cpuset_common_seq_show(struct seq_file *sf, void *v);
>> +void cpus_read_cpuset_lock(void);
>> +void cpus_read_cpuset_unlock(void);
> 
> The names are not intuitive. I would prefer just extend the cpuset_lock/unlock to include
> cpus_read_lock/unlock and we use cpuset_lock/unlock consistently in the cpuset code. Also, there is
> now no external user of cpuset_lock/unlock, we may as well remove them from include/linux/cpuset.h.
> 
> Cheers,
> Longman

I like the idea and have considered it.
However, I noticed that cpuset_locked is being used in __sched_setscheduler.

-- 
Best regards,
Ridong