From: Peter Zijlstra <peterz@infradead.org>
To: rostedt@goodmis.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
Linus Torvalds <torvalds@linux-foundation.org>,
akpm@linux-foundation.org, Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Nicholas Miell <nmiell@comcast.net>,
laijs@cn.fujitsu.com, dipankar@in.ibm.com, josh@joshtriplett.org,
dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de,
Valdis.Kletnieks@vt.edu, dhowells@redhat.com
Subject: Re: [patch 2/3] scheduler: add full memory barriers upon task switch at runqueue lock/unlock
Date: Mon, 01 Feb 2010 17:29:34 +0100 [thread overview]
Message-ID: <1265041774.24455.209.camel@laptop> (raw)
In-Reply-To: <1265041477.29013.54.camel@gandalf.stny.rr.com>
On Mon, 2010-02-01 at 11:24 -0500, Steven Rostedt wrote:
>
> Doesn't set_bit imply a wmb()? If so couldn't we do:
Nope, that's what we have smp_mb__{before,after}_set_bit() for.
On x86 its a LOCK'ed op, so sure it implies a full membarrier, but not
in generic.
on x86 we have plenty serializing instructions before and after rq->curr
is set so none of the crazyness is needed at all. The only thing is !
x86.
next prev parent reply other threads:[~2010-02-01 16:30 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-31 20:52 [patch 0/3] introduce sys_membarrier(): process-wide memory barrier (v8) Mathieu Desnoyers
2010-01-31 20:52 ` [patch 1/3] Create spin lock/spin unlock with distinct memory barrier Mathieu Desnoyers
2010-02-01 7:25 ` Nick Piggin
2010-02-01 14:08 ` Mathieu Desnoyers
2010-02-01 7:28 ` Nick Piggin
2010-02-01 14:10 ` Mathieu Desnoyers
2010-02-01 15:22 ` Linus Torvalds
2010-02-01 15:41 ` Steven Rostedt
2010-01-31 20:52 ` [patch 2/3] scheduler: add full memory barriers upon task switch at runqueue lock/unlock Mathieu Desnoyers
2010-02-01 7:33 ` Nick Piggin
2010-02-01 9:42 ` Peter Zijlstra
2010-02-01 10:11 ` Nick Piggin
2010-02-01 10:36 ` Peter Zijlstra
2010-02-01 10:49 ` Nick Piggin
2010-02-01 14:47 ` Mathieu Desnoyers
2010-02-01 14:58 ` Nick Piggin
2010-02-01 15:23 ` Steven Rostedt
2010-02-01 15:44 ` Steven Rostedt
2010-02-01 16:00 ` Mike Galbraith
2010-02-01 15:27 ` Linus Torvalds
2010-02-01 16:09 ` Mathieu Desnoyers
2010-02-01 16:23 ` Linus Torvalds
2010-02-01 16:48 ` Mathieu Desnoyers
2010-02-01 16:56 ` Linus Torvalds
2010-02-01 17:45 ` Mathieu Desnoyers
2010-02-01 18:00 ` Steven Rostedt
2010-02-01 18:36 ` Linus Torvalds
2010-02-01 19:56 ` Mathieu Desnoyers
2010-02-01 20:42 ` Linus Torvalds
2010-02-01 22:42 ` Mathieu Desnoyers
2010-02-01 20:33 ` Steven Rostedt
2010-02-01 20:52 ` Linus Torvalds
2010-02-01 22:39 ` Steven Rostedt
2010-02-01 23:09 ` Steven Rostedt
2010-02-01 17:13 ` Steven Rostedt
2010-02-01 17:34 ` Linus Torvalds
2010-02-01 16:24 ` Steven Rostedt
2010-02-01 16:29 ` Peter Zijlstra [this message]
2010-02-01 16:46 ` Steven Rostedt
2010-02-01 16:11 ` Steven Rostedt
2010-01-31 20:52 ` [patch 3/3] introduce sys_membarrier(): process-wide memory barrier (v8) Mathieu Desnoyers
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