Re: [PATCH v5 3/3] cgroup/cpuset: Keep user set cpus affinity

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 8/16/22 18:19, Tejun Heo wrote:
Hello,

On Tue, Aug 16, 2022 at 06:11:03PM -0400, Waiman Long wrote:
It is hard to synchronize different subsystems atomically without running
into locking issue. Let me think about what can be done in this case.
I have a hard time seeing why this would be particularly difficult. cpuset
just needs to make the latest cpumask available to sched core in an easily
accessible form and whenever that changes, trigger a set_cpus_allowed call.
There's no need to entangle operations across the whole subsystems. All
that's needed to be communicated is the current cpumask.

Is using a sequence number to check for race with retry good enough?
It seems unnecessarily fragile and complicated to me. If we're gonna change
it, let's change it right.

Thanks for the suggestion. I think I get what you want. I am going to migrate the cpuset_set_cpus_allowed_ptr() logic into set_cpus_allowed_ptr() itself. IOW, if user_cpus_ptr is defined, it will be an additional mask to be applied on top. It does affect all callers of set_cpus_allowed_ptr() though. I am going to drop this cpuset specific patch.

BTW, I will be on PTO starting tomorrow until next Tuesday. So I will be slow in responding to emails.

Cheers,
Longman

Cheers,
Longman




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]     [Monitors]

  Powered by Linux