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

From: Ming Lei
Date: Fri Oct 13 2023 - 08:24:36 EST


On Fri, Oct 13, 2023 at 01:26:08PM +0200, Frederic Weisbecker wrote:
> 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?

Yeah, I think this parameter isn't necessary, will remove it in V2.


Thanks,
Ming