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From: Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
To: Benjamin Herrenschmidt
	<benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
Cc: linux-m32r-ja-rQhvJZKUsGBRYuoOT4C5/9i2O/JbrIOy@public.gmane.org,
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	linux-sh-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Heiko Carstens
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	Jesper Nilsson <jesper.nilsson-VrBV9hrLPhE@public.gmane.org>,
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	Russell King <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>,
	Takata <takata-TMSiXQfHlQjsTix1lMzHGQ@public.gmane.org>,
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	"James E.J. Bottomley"
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	Chris-ZG0+EudsQA8dtHy/vicBwGD2FQJk+8+b@public.gmane.org,
	Matt Turner <mattst88-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	uclinux-dist-devel-ZG0+EudsQA8dtHy/vicBwGD2FQJk+8+b@public.gmane.org,
	Fen
Subject: Re: [PATCH] sched: provide scheduler_ipi() callback in response to smp_send_reschedule()
Date: Mon, 17 Jan 2011 21:43:03 +0100	[thread overview]
Message-ID: <1295296983.30950.369.camel@laptop> (raw)
In-Reply-To: <1295296310.2148.29.camel@pasglop>

On Tue, 2011-01-18 at 07:31 +1100, Benjamin Herrenschmidt wrote:
> 
> Beware of false positive, I've used "fake" reschedule IPIs in the past
> for other things (like kicking a CPU out of sleep state for unrelated
> reasons). Nothing that I know that is upstream today but some of that
> might come back. I'd like to avoid having to add an atomic to know if
> it's a real reschedule, will the scheduler be smart enough to not bother
> with false positives ? 

Yes it can deal with that, some will be for reschedules, some will be
for ttwu tail ends and x86 too uses this ipi for a few random other
things like kicking kvm out of guest context..

  reply	other threads:[~2011-01-17 20:43 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1295262433.30950.53.camel@laptop>
2011-01-17 11:26 ` [PATCH] sched: provide scheduler_ipi() callback in response to smp_send_reschedule() Russell King - ARM Linux
2011-01-17 11:31   ` Peter Zijlstra
2011-01-17 11:41     ` Peter Zijlstra
2011-01-17 11:57       ` Russell King - ARM Linux
2011-01-17 13:52       ` Chris Metcalf
2011-01-17 13:58       ` Jesper Nilsson
2011-01-24 23:03       ` Ralf Baechle
2011-01-17 12:18 ` Martin Schwidefsky
2011-01-17 19:18 ` David Daney
2011-01-17 19:49 ` Mike Frysinger
     [not found]   ` <AANLkTik3hE=_34Lbs944MzKpkNzqY+kCxpxmncUM2HB7-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-01-17 20:16     ` Peter Zijlstra
2011-01-17 20:31 ` Benjamin Herrenschmidt
2011-01-17 20:43   ` Peter Zijlstra [this message]
2011-02-06 23:26 ` Benjamin Herrenschmidt
2011-02-07 13:54   ` Peter Zijlstra
2011-02-09  6:14     ` Benjamin Herrenschmidt
2011-02-09  9:37       ` Peter Zijlstra

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