Groups > linux.kernel > #1311901

Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port

From	Mike Galbraith <umgwanakikbuti@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port
Date	2016-01-19 03:40 +0100
Message-ID	<qSun8-1go-13@gated-at.bofh.it> (permalink)
References	<qSdZ0-6VF-3@gated-at.bofh.it> <qSorp-5DG-23@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Mon, 2016-01-18 at 21:18 +0100, Sebastian Andrzej Siewior wrote:

> > --- a/kernel/sched/core.c
> > +++ b/kernel/sched/core.c
> > @@ -3542,6 +3542,15 @@ asmlinkage __visible void __sched notrac
> > 	if (likely(!preemptible()))
> > 		return;
> > 
> > +#ifdef CONFIG_PREEMPT_LAZY
> > +	/*
> > +	 * Check for lazy preemption
> > +	 */
> > +	if (current_thread_info()->preempt_lazy_count &&
> > +	    !test_thread_flag(TIF_NEED_RESCHED))
> > +		return;
> > +#endif
> > +
> 
> And this is a new piece. So you forbid that tasks leave the CPU if
> lazy_count > 0. Let me look closed why this is happening and if this is
> v4.1 … v4.4 or not.

We should probably just add the lazy bits to preemptible().

	-Mike

Thread

[rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-01-18 10:10 +0100
  Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-01-18 21:20 +0100
    Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-01-19 03:40 +0100
      Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-01-21 14:00 +0100
        Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Grygorii Strashko <grygorii.strashko@ti.com> - 2016-01-22 13:30 +0100
          Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-01-22 14:20 +0100
            Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Grygorii Strashko <grygorii.strashko@ti.com> - 2016-01-22 14:40 +0100
              Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-01-22 15:20 +0100
                Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Grygorii Strashko <grygorii.strashko@ti.com> - 2016-01-22 16:10 +0100
                Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Grygorii Strashko <grygorii.strashko@ti.com> - 2016-01-22 19:30 +0100
    Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-01-19 05:50 +0100
      Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-01-19 06:20 +0100
    Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Grygorii Strashko <grygorii.strashko@ti.com> - 2016-01-22 13:00 +0100
      Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-01-22 14:00 +0100
        Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-01-22 21:50 +0100
          Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Grygorii Strashko <grygorii.strashko@ti.com> - 2016-01-25 18:20 +0100

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