Messages in this thread | | | Date | Sat, 25 Mar 2023 18:08:18 -0400 | Subject | Re: [PATCH 3/5] cgroup/cpuset: Find another usable CPU if none found in current cpuset | From | Waiman Long <> |
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On 3/24/23 14:19, Michal Koutný wrote: > On Fri, Mar 24, 2023 at 02:32:50PM +0000, Will Deacon <will@kernel.org> wrote: >> So approaches such as killing tasks or rejecting system calls tend not >> to work as well, since you inevitably get divergent behaviour leading >> to functional breakage rather than e.g. performance anomalies. > What about temporary performance drop from 100% to 0% aka freezing the > tasks for the duration of the mismatching affinity config?
That can be a lot of extra work to freeze it. I will prefer something simpler.
Without this patch, I believe it will lead to a cpumask of 0 which will cause the scheduler to pick a fallback cpu. It looks like the fallback code may be able to pick up the right cpu or it may panic the system (less likely).
Cheers, Longman > > >> Having said that, the behaviour we currently have in mainline seems to >> be alright, so please don't go out of your way to accomodate these SoCs. > I see. (Just wondering what you think about the fourth option above.) > > Thanks, > Michal
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