Re: [PATCH 10/31] sched: Add @reason to sched_class->rq_{on|off}line()

From: Tejun Heo
Date: Mon Dec 12 2022 - 13:07:11 EST


On Mon, Dec 12, 2022 at 12:57:36PM +0100, Peter Zijlstra wrote:
> On Tue, Nov 29, 2022 at 10:22:52PM -1000, Tejun Heo wrote:
> > ->rq_{on|off}line are called either during CPU hotplug or cpuset partition
> > updates. Let's add an argument to distinguish the two cases. The argument
> > will be used by a new sched_class to track CPU hotplug events.
>
> Again, utter lack of why.

sched_ext wants to tell the BPF scheduler about CPU hotplugs in a way that's
synchronized with rq state changes, so it needs to distinguish the two
cases. Will update the description.

Thanks.

--
tejun