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From: Frederic Weisbecker <fweisbec@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 5/7] sched: Pull preemption disablement duty up to __schedule() callers
Date: Mon, 11 May 2015 17:56:36 +0200	[thread overview]
Message-ID: <20150511155634.GB32512@lerouge> (raw)
In-Reply-To: <20150511155213.GY21418@twins.programming.kicks-ass.net>

On Mon, May 11, 2015 at 05:52:13PM +0200, Peter Zijlstra wrote:
> On Mon, May 11, 2015 at 05:08:22PM +0200, Frederic Weisbecker wrote:
> > +++ b/kernel/sched/core.c
> > @@ -2723,9 +2723,7 @@ again:
> >   *          - return from syscall or exception to user-space
> >   *          - return from interrupt-handler to user-space
> >   *
> > - * WARNING: all callers must re-check need_resched() afterward and reschedule
> > - * accordingly in case an event triggered the need for rescheduling (such as
> > - * an interrupt waking up a task) while preemption was disabled in __schedule().
> > + * WARNING: must be called with preemption disabled!
> >   */
> >  static void __sched __schedule(void)
> >  {
> > @@ -2734,7 +2732,6 @@ static void __sched __schedule(void)
> >  	struct rq *rq;
> >  	int cpu;
> >  
> > -	preempt_disable();
> >  	cpu = smp_processor_id();
> >  	rq = cpu_rq(cpu);
> >  	rcu_note_context_switch();
> > @@ -2798,8 +2795,6 @@ static void __sched __schedule(void)
> >  		raw_spin_unlock_irq(&rq->lock);
> >  
> >  	post_schedule(rq);
> > -
> > -	sched_preempt_enable_no_resched();
> >  }
> 
> Ah, see, you need to fold this patch into the previous one.

Yeah I hesitated. I'm going to fold then.

Thanks.

  reply	other threads:[~2015-05-11 15:56 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-11 15:08 [RFC PATCH 0/7] preempt: A few headers cleanups and preempt_schedule*() optimizations Frederic Weisbecker
2015-05-11 15:08 ` [PATCH 1/7] preempt: Merge preempt_mask.h into preempt.h Frederic Weisbecker
2015-05-11 15:08 ` [PATCH 2/7] preempt: Rearrange a few symbols after headers merge Frederic Weisbecker
2015-05-11 15:08 ` [PATCH 3/7] preempt: Rename PREEMPT_CHECK_OFFSET to PREEMPT_DISABLE_OFFSET Frederic Weisbecker
2015-05-11 15:08 ` [PATCH 4/7] preempt: Disable preemption from preempt_schedule*() callers Frederic Weisbecker
2015-05-11 15:51   ` Peter Zijlstra
2015-05-11 15:08 ` [PATCH 5/7] sched: Pull preemption disablement duty up to __schedule() callers Frederic Weisbecker
2015-05-11 15:52   ` Peter Zijlstra
2015-05-11 15:56     ` Frederic Weisbecker [this message]
2015-05-11 15:08 ` [PATCH 6/7] preempt: Fix out of date comment Frederic Weisbecker
2015-05-11 15:08 ` [PATCH 7/7] preempt: Remove PREEMPT_ACTIVE unmasking off in_atomic() Frederic Weisbecker

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