From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 9 Jul 2007 11:11:36 -0700 (PDT) From: Christoph Lameter Subject: Re: [patch 00/10] [RFC] SLUB patches for more functionality, performance and maintenance In-Reply-To: <46925B5D.8000507@google.com> Message-ID: References: <20070708034952.022985379@sgi.com> <46925B5D.8000507@google.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Martin Bligh Cc: Andi Kleen , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Mon, 9 Jul 2007, Martin Bligh wrote: > Those numbers came from Mathieu Desnoyers (LTTng) if you > want more details. Okay the source for these numbers is in his paper for the OLS 2006: Volume 1 page 208-209? I do not see the exact number that you referred to there. He seems to be comparing spinlock acquire / release vs. cmpxchg. So I guess you got your material from somewhere else? Also the cmpxchg used there is the lockless variant. cmpxchg 29 cycles w/o lock prefix and 112 with lock prefix. I see you reference another paper by Desnoyers: http://tree.celinuxforum.org/CelfPubWiki/ELC2006Presentations?action=AttachFile&do=get&target=celf2006-desnoyers.pdf I do not see anything relevant there. Where did those numbers come from? The lockless cmpxchg is certainly an interesting idea. Certain for some platforms I could disable preempt and then do a lockless cmpxchg. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org