From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <42F21A05.1050102@yahoo.com.au> Date: Thu, 04 Aug 2005 23:37:09 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [patch] make spin_lock_prefetch a noop for UP References: <42F212F4.5020609@yahoo.com.au> <20050804131037.GC9112@wotan.suse.de> <42F21526.90700@yahoo.com.au> <20050804132539.GU8266@wotan.suse.de> In-Reply-To: <20050804132539.GU8266@wotan.suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit To: Andi Kleen Cc: linux-arch@vger.kernel.org, Linus Torvalds , Andrew Morton List-ID: Andi Kleen wrote: >>>From include/linux/prefetch.h: >> >>"spin_lock_prefetch(x) - prefectches the spinlock *x for taking" >> >>So this would reduce icache footprint and possibly memory >>traffic on UP where taking a spinlock is a noop. > > > Ah you want to disable it on UP? > Ok that makes more sense. Why didn't you just say that? :) > Well I did, in a confusing kind of way ;) ... with the alternative input stuff being used here, "noop" becomes ambiguous I guess. > Anyways, even on UP it might be useful on all these mutex or whatever > lock is envogue these days preemptive kernels. > I'm sure it would be useful. Though it is something that could be maintained out of tree. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com