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,
linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org,
linux-m32r-rQhvJZKUsGBRYuoOT4C5/9i2O/JbrIOy@public.gmane.org,
linux-ia64-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-sh-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Heiko Carstens
<heiko.carstens-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org>,
Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Paul Mackerras <paulus-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>,
"H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>,
sparclinux-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Linux-Arch <linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
linux-s390-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Jesper Nilsson <jesper.nilsson-VrBV9hrLPhE@public.gmane.org>,
Mikael-ZG0+EudsQA8dtHy/vicBwGD2FQJk+8+b@public.gmane.org,
Russell King <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>,
Takata <takata-TMSiXQfHlQjsTix1lMzHGQ@public.gmane.org>,
x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
"James E.J. Bottomley"
<jejb-6jwH94ZQLHl74goWV3ctuw@public.gmane.org>,
virtualization-qjLDD68F18O7TbgM5vRIOg@public.gmane.org,
Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
xen-devel-GuqFBffKawuULHF6PoxzQEEOCMrvLtNR@public.gmane.org,
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..
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Matt Turner <mattst88@gmail.com>,
Russell King <linux@arm.linux.org.uk>,
Mike Frysinger <vapier@gentoo.org>,
Mikael Starvik <starvik@axis.com>,
Jesper Nilsson <jesper.nilsson@axis.com>,
Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Hirokazu Takata <takata@linux-m32r.org>,
Ralf Baechle <ralf@linux-mips.org>,
David Howells <dhowells@redhat.com>,
Koichi Yasutake <yasutake.koichi@jp.panasonic.com>,
Kyle McMartin <kyle@mcmartin.ca>, Helge Deller <deller@gmx.de>,
"James E.J. Bottomley" <jejb@parisc-linux.org>,
Paul Mackerras <paulus@samba.org>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
linux390@de.ibm.com, Paul Mundt <lethal@linux-sh.org>,
"David S. Miller" <davem@davemloft.net>,
Chris Metcalf <cmetcalf@tilera.com>,
Jeff Dike <jdike@addtoit.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org,
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
uclinux-dist-devel@blackfin.uclinux.org,
linux-cris-kernel@axis.com, linux-ia64@vger.kernel.org,
linux-m32r@ml.linux-m32r.org, linux-m32r-ja@ml.linux-m32r.org,
linux-mips@linux-mips.org, linux-am33-list@redhat.com,
linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-s390@vger.kernel.org, linux-sh@vger.kernel.org,
sparclinux@vger.kernel.org,
user-mode-linux-devel@lists.sourceforge.net,
user-mode-linux-user@lists.sourceforge.net,
xen-devel@lists.xensource.com, virtualization@lists.osdl.org,
Linux-Arch <linux-arch@vger.kernel.org>
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..
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux-m32r-ja@ml.linux-m32r.org, linux-mips@linux-mips.org,
linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org,
"H. Peter Anvin" <hpa@zytor.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Paul Mackerras <paulus@samba.org>, Helge Deller <deller@gmx.de>,
sparclinux@vger.kernel.org,
Linux-Arch <linux-arch@vger.kernel.org>,
linux-s390@vger.kernel.org,
Jesper Nilsson <jesper.nilsson@axis.com>,
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
Russell King <linux@arm.linux.org.uk>,
Hirokazu Takata <takata@linux-m32r.org>,
x86@kernel.org, "James E.J. Bottomley" <jejb@parisc-linux.org>,
virtualization@lists.osdl.org, Ingo Molnar <mingo@redhat.com>,
Matt Turner <mattst88@gmail.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Mike Frysinger <vapier@gentoo.org>,
user-mode-linux-devel@lists.sourceforge.net,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Jeff Dike <jdike@addtoit.com>,
Chris Metcalf <cmetcalf@tilera.com>,
xen-devel@lists.xensource.com, Mikael Starvik <starvik@axis.com>,
linux-m32r@ml.linux-m32r.org,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
user-mode-linux-user@lists.sourceforge.net,
uclinux-dist-devel@blackfin.uclinux.org,
Thomas Gleixner <tglx@linutronix.de>,
linux-arm-kernel@lists.infradead.org,
Richard Henderson <rth@twiddle.net>,
Tony Luck <tony.luck@intel.com>,
linux-parisc@vger.kernel.org, linux-cris-kernel@axis.com,
linux-am33-list@redhat.com, linux-kernel@vger.kernel.org,
Ralf Baechle <ralf@linux-mips.org>,
Kyle McMartin <kyle@mcmartin.ca>,
Paul Mundt <lethal@linux-sh.org>,
linux-alpha@vger.kernel.org,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
linux390@de.ibm.com,
Koichi Yasutake <yasutake.koichi@jp.panasonic.com>,
linuxppc-dev@lists.ozlabs.org,
"David S. Miller" <davem@davemloft.net>
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:
>=20
> 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 ?=20
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..
WARNING: multiple messages have this Message-ID (diff)
From: peterz@infradead.org (Peter Zijlstra)
To: linux-arm-kernel@lists.infradead.org
Subject: [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..
next prev parent reply other threads:[~2011-01-17 20:43 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-17 11:07 [PATCH] sched: provide scheduler_ipi() callback in response to smp_send_reschedule() Peter Zijlstra
2011-01-17 11:07 ` Peter Zijlstra
2011-01-17 11:07 ` Peter Zijlstra
2011-01-17 11:26 ` Russell King - ARM Linux
2011-01-17 11:26 ` Russell King - ARM Linux
2011-01-17 11:26 ` Russell King - ARM Linux
2011-01-17 11:26 ` Russell King - ARM Linux
2011-01-17 11:26 ` Russell King - ARM Linux
2011-01-17 11:31 ` Peter Zijlstra
2011-01-17 11:31 ` Peter Zijlstra
2011-01-17 11:31 ` Peter Zijlstra
2011-01-17 11:31 ` Peter Zijlstra
2011-01-17 11:31 ` Peter Zijlstra
2011-01-17 11:41 ` Peter Zijlstra
2011-01-17 11:41 ` Peter Zijlstra
2011-01-17 11:41 ` Peter Zijlstra
2011-01-17 11:57 ` Russell King - ARM Linux
2011-01-17 11:57 ` Russell King - ARM Linux
2011-01-17 11:57 ` Russell King - ARM Linux
2011-01-17 11:57 ` Russell King - ARM Linux
2011-01-17 13:52 ` Chris Metcalf
2011-01-17 13:52 ` Chris Metcalf
2011-01-17 13:52 ` Chris Metcalf
2011-01-17 13:52 ` Chris Metcalf
2011-01-17 13:52 ` Chris Metcalf
2011-01-17 13:58 ` Jesper Nilsson
2011-01-17 13:58 ` Jesper Nilsson
2011-01-17 13:58 ` Jesper Nilsson
2011-01-17 13:58 ` Jesper Nilsson
2011-01-24 23:03 ` Ralf Baechle
2011-01-24 23:03 ` Ralf Baechle
2011-01-24 23:03 ` Ralf Baechle
2011-01-17 12:18 ` Martin Schwidefsky
2011-01-17 12:18 ` Martin Schwidefsky
2011-01-17 12:18 ` Martin Schwidefsky
2011-01-17 12:18 ` Martin Schwidefsky
2011-01-17 12:18 ` Martin Schwidefsky
2011-01-17 19:18 ` David Daney
2011-01-17 19:18 ` David Daney
2011-01-17 19:18 ` David Daney
2011-01-17 19:18 ` David Daney
2011-01-17 19:49 ` Mike Frysinger
2011-01-17 19:49 ` [uclinux-dist-devel] " Mike Frysinger
2011-01-17 19:49 ` Mike Frysinger
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 20:16 ` [uclinux-dist-devel] " Peter Zijlstra
2011-01-17 20:16 ` Peter Zijlstra
2011-01-17 20:16 ` Peter Zijlstra
2011-01-17 20:16 ` Peter Zijlstra
2011-01-17 20:16 ` [uclinux-dist-devel] " Peter Zijlstra
2011-01-17 20:31 ` Benjamin Herrenschmidt
2011-01-17 20:31 ` Benjamin Herrenschmidt
2011-01-17 20:31 ` Benjamin Herrenschmidt
2011-01-17 20:31 ` Benjamin Herrenschmidt
2011-01-17 20:31 ` Benjamin Herrenschmidt
2011-01-17 20:43 ` Peter Zijlstra [this message]
2011-01-17 20:43 ` Peter Zijlstra
2011-01-17 20:43 ` Peter Zijlstra
2011-01-17 20:43 ` Peter Zijlstra
2011-02-06 23:26 ` Benjamin Herrenschmidt
2011-02-06 23:26 ` Benjamin Herrenschmidt
2011-02-06 23:26 ` Benjamin Herrenschmidt
2011-02-06 23:26 ` Benjamin Herrenschmidt
2011-02-07 13:54 ` Peter Zijlstra
2011-02-07 13:54 ` Peter Zijlstra
2011-02-07 13:54 ` Peter Zijlstra
2011-02-07 13:54 ` Peter Zijlstra
2011-02-09 6:14 ` Benjamin Herrenschmidt
2011-02-09 6:14 ` Benjamin Herrenschmidt
2011-02-09 6:14 ` Benjamin Herrenschmidt
2011-02-09 6:14 ` Benjamin Herrenschmidt
2011-02-09 9:37 ` Peter Zijlstra
2011-02-09 9:37 ` Peter Zijlstra
2011-02-09 9:37 ` Peter Zijlstra
2011-02-09 9:37 ` Peter Zijlstra
-- strict thread matches above, loose matches on Subject: below --
2011-01-17 11:07 Peter Zijlstra
2011-01-17 11:07 Peter Zijlstra
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