Re: [PATCH] blk-mq: add module parameter to not run block kworker on isolated CPUs

From: Frederic Weisbecker
Date: Fri Oct 13 2023 - 07:26:15 EST


On Tue, Oct 10, 2023 at 08:45:44AM -1000, Tejun Heo wrote:
> > +static bool respect_cpu_isolation;
> > +module_param(respect_cpu_isolation, bool, 0444);
> > +MODULE_PARM_DESC(respect_cpu_isolation,
> > + "Don't schedule blk-mq worker on isolated CPUs passed in "
> > + "isolcpus= or nohz_full=. User need to guarantee to not run "
> > + "block IO on isolated CPUs (default: false)");
>
> Any chance we can centralize these? It's no fun to try to hunt down module
> params to opt in different subsystems and the housekeeping interface does
> have some provisions for selecting different parts. I'd much prefer to see
> these settings to be collected into a central place.

Do we need this parameter in the first place? Shouldn't we avoid scheduling
blk-mq worker on isolated CPUs in any case?

Thanks.

>
> Thanks.
>
> --
> tejun