Groups > linux.kernel > #1199483

Re: [PATCH 07/10] sched: Migrate sched to use new tick dependency mask model

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 07/10] sched: Migrate sched to use new tick dependency mask model
Date	2015-08-04 09:50 +0200
Message-ID	<pTF90-41P-11@gated-at.bofh.it> (permalink)
References	(1 earlier) <pPrQZ-3Wb-1@gated-at.bofh.it> <pToBc-5iK-45@gated-at.bofh.it> <pTpnA-6dA-13@gated-at.bofh.it> <pTrps-W6-95@gated-at.bofh.it> <pTrSq-1uf-13@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Mon, Aug 03, 2015 at 07:30:32PM +0200, Frederic Weisbecker wrote:
> > But you've forgotten about SCHED_DEADLINE, we count those in:
> > rq->dl.dl_nr_running.
> 
> Indeed. Hmm, there is no preemption between SCHED_DEALINE tasks, right?
> So I can treat it like SCHED_FIFO.

Sadly no. Even though EDF has static job priority (once a job is
activated its priority doesn't change anymore) DEADLINE also has a CBS
component and that needs the tick regardless, even with a single task.

So any deadline task running means we cannot stop the tick.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Re: [PATCH 07/10] sched: Migrate sched to use new tick dependency  mask model Peter Zijlstra <peterz@infradead.org> - 2015-08-03 16:10 +0200
  Re: [PATCH 07/10] sched: Migrate sched to use new tick dependency  mask model Frederic Weisbecker <fweisbec@gmail.com> - 2015-08-03 17:00 +0200
    Re: [PATCH 07/10] sched: Migrate sched to use new tick dependency  mask model Peter Zijlstra <peterz@infradead.org> - 2015-08-03 19:10 +0200
      Re: [PATCH 07/10] sched: Migrate sched to use new tick dependency  mask model Frederic Weisbecker <fweisbec@gmail.com> - 2015-08-03 19:40 +0200
        Re: [PATCH 07/10] sched: Migrate sched to use new tick dependency  mask model Peter Zijlstra <peterz@infradead.org> - 2015-08-04 09:50 +0200

csiph-web