Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751079AbVICRIB (ORCPT ); Sat, 3 Sep 2005 13:08:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751094AbVICRIB (ORCPT ); Sat, 3 Sep 2005 13:08:01 -0400 Received: from [81.2.110.250] ([81.2.110.250]:25794 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S1751079AbVICRIA (ORCPT ); Sat, 3 Sep 2005 13:08:00 -0400 Subject: Re: [PATCH 2.6.13] lockless pagecache 2/7 From: Alan Cox To: Nick Piggin Cc: Andi Kleen , Linux Memory Management , linux-kernel In-Reply-To: <4318FF2B.6000805@yahoo.com.au> References: <4317F071.1070403@yahoo.com.au> <4317F0F9.1080602@yahoo.com.au> <4317F136.4040601@yahoo.com.au> <1125666486.30867.11.camel@localhost.localdomain> <4318C28A.5010000@yahoo.com.au> <1125705471.30867.40.camel@localhost.localdomain> <4318FF2B.6000805@yahoo.com.au> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Sat, 03 Sep 2005 18:31:36 +0100 Message-Id: <1125768697.14987.7.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.2.2 (2.2.2-5) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 729 Lines: 15 On Sad, 2005-09-03 at 11:40 +1000, Nick Piggin wrote: > We'll see how things go. I'm fairly sure that for my usage it will > be a win even if it is costly. It is replacing an atomic_inc_return, > and a read_lock/read_unlock pair. Make sure you bench both AMD and Intel - I'd expect it to be a big loss on AMD because the AMD stuff will perform atomic locked operations very efficiently if they are already exclusive on this CPU or a prefetch_w() on them was done 200+ clocks before. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/