Re: [PATCH v3 04/10] sched/fair: Let low-priority cores help high-priority busy SMT cores

From: Ricardo Neri
Date: Fri Feb 10 2023 - 07:56:16 EST


On Fri, Feb 10, 2023 at 09:41:14AM +0100, Peter Zijlstra wrote:
> On Thu, Feb 09, 2023 at 04:43:33PM -0800, Ricardo Neri wrote:
> > On Thu, Feb 09, 2023 at 12:53:41PM +0100, Peter Zijlstra wrote:
> > > On Wed, Feb 08, 2023 at 08:56:32AM +0100, Vincent Guittot wrote:
> > >
> > > > > + if (env->sd->flags & SD_SHARE_CPUCAPACITY ||
> > > > > + (!(env->sd->flags & SD_SHARE_CPUCAPACITY) && is_core_idle(i)))
> > > >
> > > > This 2nd if could be merged with the upper one
> > >
> > > Wasn't this exact same condition used in the previous patch as well?
> > > Does it wants to be a helper perhaps?
> >
> > Patch 3 focuses on the destination CPU: make sure that it and its SMT
> > siblings are idle before attempting to do asym_packing balance.
> >
> > This patch focuses on the busiest group: if the busiest group is an SMT
> > core with more than one busy sibling, help it even if it has higher
> > priority.
>
> Yeah, so? If its a recurring expression a helper never hurts.

Ah! I get your point now. You meant a helper function. Thank you for the
clarification.

Sure! I can add this helper function.