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From: luca abeni <luca.abeni@santannapisa.it>
To: Juri Lelli <juri.lelli@arm.com>
Cc: linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Claudio Scordino <claudio@evidence.eu.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Tommaso Cucinotta <tommaso.cucinotta@sssup.it>,
	Daniel Bristot de Oliveira <bristot@redhat.com>,
	Mathieu Poirier <mathieu.poirier@linaro.org>
Subject: Re: [PATCH] sched/deadline: fix switching to -deadline
Date: Fri, 21 Apr 2017 11:59:07 +0200	[thread overview]
Message-ID: <20170421115907.4044665a@nowhere> (raw)
In-Reply-To: <20170421094729.GR23862@e106622-lin>

On Fri, 21 Apr 2017 10:47:29 +0100
Juri Lelli <juri.lelli@arm.com> wrote:
[...]
> > > > *dl_se, update_dl_entity(dl_se, pi_se);
> > > >  	else if (flags & ENQUEUE_REPLENISH)
> > > >  		replenish_dl_entity(dl_se, pi_se);
> > > > +	else if ((flags & ENQUEUE_RESTORE) &&    
> > > 
> > > Not sure I understand how this works. AFAICT we are doing
> > > __sched_setscheduler() when we want to catch the case of a new
> > > dl_entity (SCHED_{OTHER,FIFO} -> SCHED_DEADLINE}, but queue_flags
> > > (which are passed to enqueue_task()) don't seem to have
> > > ENQUEUE_RESTORE set?  
> > 
> > I was under the impression sched_setscheduler() sets
> > ENQUEUE_RESTORE... 
> 
> Oh, I think it works "by coincidence", as ENQUEUE_RESTORE ==
> DEQUEUE_SAVE == 0x02 ? :)

Not sure if this is a conincidence... By looking at the comments in
sched/sched.h I got the impression the two values match by design (and
__sched_setscheduler() is using this property to simplify the code :)



			Luca

  reply	other threads:[~2017-04-21  9:59 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-20 19:30 [PATCH] sched/deadline: fix switching to -deadline luca abeni
2017-04-21  9:39 ` Juri Lelli
2017-04-21  9:42   ` luca abeni
2017-04-21  9:47     ` Juri Lelli
2017-04-21  9:59       ` luca abeni [this message]
2017-04-21 10:18         ` Peter Zijlstra
2017-04-21 10:26         ` Juri Lelli
2017-04-21 19:08           ` luca abeni
2017-04-24 10:16             ` Juri Lelli
2017-04-24 10:36               ` Luca Abeni
2017-04-24 10:53                 ` Juri Lelli
2017-04-21 10:17       ` Peter Zijlstra
2017-04-21  9:54     ` luca abeni
2017-04-21 13:39       ` Steven Rostedt
2017-07-24  7:49 ` Luca Abeni

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