Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758848AbZAOHPY (ORCPT ); Thu, 15 Jan 2009 02:15:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754804AbZAOHPI (ORCPT ); Thu, 15 Jan 2009 02:15:08 -0500 Received: from byss.tchmachines.com ([208.76.80.75]:49885 "EHLO byss.tchmachines.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754833AbZAOHPH (ORCPT ); Thu, 15 Jan 2009 02:15:07 -0500 Date: Wed, 14 Jan 2009 23:15:00 -0800 From: Ravikiran G Thirumalai To: Ingo Molnar Cc: Peter Zijlstra , Frederik Deweerdt , andi@firstfloor.org, tglx@linutronix.de, hpa@zytor.com, linux-kernel@vger.kernel.org, shai@scalex86.org Subject: Re: [patch] tlb flush_data: replace per_cpu with an array Message-ID: <20090115071500.GA23269@localdomain> References: <20090112213539.GA10720@gambetta> <20090112223421.GA20594@localdomain> <20090112230052.GB18771@elte.hu> <1231848016.442.112.camel@twins> <20090113123317.GA29926@elte.hu> <20090113181311.GA8075@localdomain> <20090113183420.GB10065@elte.hu> <20090113184202.GB8075@localdomain> <20090114073146.GA14767@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090114073146.GA14767@elte.hu> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - byss.tchmachines.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - scalex86.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1419 Lines: 30 On Wed, Jan 14, 2009 at 08:31:46AM +0100, Ingo Molnar wrote: > >* Ravikiran G Thirumalai wrote: > >> > You do have hardware help too to do efficient cross-node memory >> > traffic, dont you? >> >> Of course. A fast backplane interconnect. > >... so it's PCs clustered together, and called vSMP, right? ;-) > Well, it depends on how you define a cluster. You can even call a SMP mother board a cluster of cpus :). In that case even Sequent NUMA were clusters, and so are some of the large core count shared memory systems made of multiple similar boards/bricks/books (based on vendor terminology) with a custom interconnect for cache coherency. A vSMP system is multiple similar cpu mother boards, usually dual socket, each board having multiple cpus and a commodity fast interconnect for cache coherency. There is a VMM which among other tasks also takes care of the coherency, and each 'board' or 'node' can access physical memory from another board. There is one instance of OS running on the entire system unlike the classical cluster where there are multiple instances of OS and the apps under the OS have to work together as a cluster. -- 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/