Messages in this thread |  | | Date | Thu, 26 Nov 2020 11:35:43 +1100 | From | Balbir Singh <> | Subject | Re: [PATCH -tip 04/32] sched: Core-wide rq->lock |
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On Tue, Nov 24, 2020 at 09:16:17AM +0100, Peter Zijlstra wrote: > On Sun, Nov 22, 2020 at 08:11:52PM +1100, Balbir Singh wrote: > > On Tue, Nov 17, 2020 at 06:19:34PM -0500, Joel Fernandes (Google) wrote: > > > From: Peter Zijlstra <peterz@infradead.org> > > > > > > Introduce the basic infrastructure to have a core wide rq->lock. > > > > > > > Reading through the patch, it seems like all the CPUs have to be > > running with sched core enabled/disabled? Is it possible to have some > > cores with core sched disabled? > > Yep, patch even says so: > > + * XXX entirely possible to selectively enable cores, don't bother for now.
Yes, it does in the comments, I looked at just the changelog :)
> > > I don't see a strong use case for it, > > but I am wondering if the design will fall apart if that assumption is > > broken? > > The use-case I have is not using stop-machine. That is, stopping a whole > core at a time, instead of the whole sodding machine. It's on the todo > list *somewhere*.... > >
Good to know, I guess that would need a transition of the entire core to idle and maintenance of a mask that prevents tasks that need core scheduling from getting off of CPUs that enable core scheduling.
Balbir Singh.
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