On 3/24/23 14:19, Michal Koutný wrote:
On Fri, Mar 24, 2023 at 02:32:50PM +0000, Will Deacon <will@xxxxxxxxxx> 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
