Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762006AbYAKRC4 (ORCPT ); Fri, 11 Jan 2008 12:02:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760274AbYAKRCs (ORCPT ); Fri, 11 Jan 2008 12:02:48 -0500 Received: from twinlark.arctic.org ([208.69.40.136]:57830 "EHLO twinlark.arctic.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760647AbYAKRCr (ORCPT ); Fri, 11 Jan 2008 12:02:47 -0500 Date: Fri, 11 Jan 2008 09:02:46 -0800 (PST) From: dean gaudet To: Ingo Molnar cc: Andi Kleen , linux-kernel@vger.kernel.org, Thomas Gleixner , "H. Peter Anvin" , Venki Pallipadi , suresh.b.siddha@intel.com, Arjan van de Ven , Dave Jones Subject: Re: CPA patchset In-Reply-To: <20080111071936.GA16175@elte.hu> Message-ID: References: <20080103424.989432000@suse.de> <20080110093126.GA360@elte.hu> <20080110095337.GK25945@bingen.suse.de> <20080110100443.GB28209@elte.hu> <20080110100712.GO25945@bingen.suse.de> <20080110105726.GD28209@elte.hu> <20080110111248.GR25945@bingen.suse.de> <20080111071936.GA16175@elte.hu> User-Agent: Alpine 0.999999 (DEB 847 2007-12-06) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1089 Lines: 30 On Fri, 11 Jan 2008, Ingo Molnar wrote: > * Andi Kleen wrote: > > > Cached requires the cache line to be read first before you can write > > it. > > nonsense, and you should know it. It is perfectly possible to construct > fully written cachelines, without reading the cacheline first. MOVDQ is > SSE1 so on basically in every CPU today - and it is 16 byte aligned and > can generate full cacheline writes, _without_ filling in the cacheline > first. did you mean to write MOVNTPS above? > Bulk ops (string ops, etc.) will do full cacheline writes too, > without filling in the cacheline. on intel with fast strings enabled yes. mind you intel gives hints in the documentation these operations don't respect coherence... and i asked about this when they posted their memory ordering paper but got no response. -dean -- 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/