Re: [PATCH 4/4] sched/fair: Use a recently used CPU as an idle candidate and the basis for SIS

From: Peter Zijlstra
Date: Fri Feb 02 2018 - 07:58:59 EST


On Fri, Feb 02, 2018 at 12:42:29PM +0100, Rafael J. Wysocki wrote:
> > Yes, too many synchronous IPIs, which themselves are typically already
> > more expensive than the MSR access.
>
> We could do all of the updates in one IPI (as Srinivas said), but it would be
> more code, and custom code for that matter.
>
> Is this really worth it for a slow path like this one?

Probably not, still, the pattern really annoys me ;-)