Re: [PATCH v4 5/5] cgroup: use subsystem-specific rstat locks to avoid contention

[JP Kobryn <inwardvessel@gmail.com>]

On 4/4/25 1:28 PM, Tejun Heo wrote:
> On Thu, Apr 03, 2025 at 06:10:50PM -0700, JP Kobryn wrote:
>> It is possible to eliminate contention between subsystems when
>> updating/flushing stats by using subsystem-specific locks. Let the existing
>> rstat locks be dedicated to the cgroup base stats and rename them to
>> reflect that. Add similar locks to the cgroup_subsys struct for use with
>> individual subsystems.
>>
>> Lock initialization is done in the new function ss_rstat_init(ss) which
>> replaces cgroup_rstat_boot(void). If NULL is passed to this function, the
>> global base stat locks will be initialized. Otherwise, the subsystem locks
>> will be initialized.
>>
>> Change the existing lock helper functions to accept a reference to a css.
>> Then within these functions, conditionally select the appropriate locks
>> based on the subsystem affiliation of the given css. Add helper functions
>> for this selection routine to avoid repeated code.
>>
>> Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
> 4-5 look fine to me. I'll wait for others to chime in before applying.
>
> Thanks.
>
Michal, Yosry, can you give patches 4 and 5 a look? I think the changes 
requested up to this

point have been worked into the series.