Messages in this thread | | | Date | Tue, 16 Aug 2022 07:52:51 -1000 | From | Tejun Heo <> | Subject | Re: [PATCH v4 3/3] cgroup/cpuset: Keep user set cpus affinity |
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Hello,
On Tue, Aug 16, 2022 at 01:38:17PM -0400, Waiman Long wrote: > Yes, a race like this is possible. To completely eliminate the race may > require taking task_rq_lock() and then calling > __set_cpus_allowed_ptr_locked() which is internal to kernel/sched/core.c. > > Alternatively, we can check user_cpus_ptr again after the scond > set_cpus_allowed_ptr() and retry it with the other path if set. That will > probably address your concern. Please let me know if you are OK with that.
I think this would look better if structured the other way around - make the scheduler side call out to cpuset to query the current restrictions and apply it atomically.
Thanks.
-- tejun
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