From: Andi Kleen <andi@firstfloor.org>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Ingo Molnar <mingo@elte.hu>,
Jeremy Fitzhardinge <jeremy@goop.org>,
Harvey Harrison <harvey.harrison@gmail.com>,
Andi Kleen <andi@firstfloor.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Steven Rostedt <rostedt@goodmis.org>,
Steven Rostedt <srostedt@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
David Miller <davem@davemloft.net>,
Roland McGrath <roland@redhat.com>,
Ulrich Drepper <drepper@redhat.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Gregory Haskins <ghaskins@novell.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
"Luis Claudio R. Goncalves" <lclaudio@uudg.org>,
Clark Williams <williams@redhat.com>,
Christoph Lameter <cl@linux-foundation.org>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH] x86 alternatives : fix LOCK_PREFIX race with preemptible kernel and CPU hotplug
Date: Thu, 14 Aug 2008 23:20:36 +0200 [thread overview]
Message-ID: <20080814212036.GD13814@one.firstfloor.org> (raw)
In-Reply-To: <20080814205815.GA14076@Krystal>
> So, unless these calculus are completely bogus, the difference between the nop
> and the DS case seems not to be statistically significant.
My understanding was that the nops only make a measurable difference in the
-pg/mcount/ftrace patched out case where every function call starts with a 5
byte nop.
Presumably function calls are much more common than lock prefix operations.
-Andi
next prev parent reply other threads:[~2008-08-14 21:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-14 20:58 [PATCH] x86 alternatives : fix LOCK_PREFIX race with preemptible kernel and CPU hotplug Mathieu Desnoyers
2008-08-14 21:20 ` Andi Kleen [this message]
2008-08-14 21:43 ` H. Peter Anvin
2008-08-15 16:06 ` Linus Torvalds
2008-08-15 16:45 ` [PATCH] x86 : revert replace LOCK_PREFIX in futex.h Mathieu Desnoyers
2008-08-15 16:56 ` [PATCH] x86 : spinlock use LOCK_PREFIX Mathieu Desnoyers
2008-08-15 17:31 ` Linus Torvalds
2008-08-15 20:27 ` H. Peter Anvin
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