Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761689AbZATPOT (ORCPT ); Tue, 20 Jan 2009 10:14:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756673AbZATPOJ (ORCPT ); Tue, 20 Jan 2009 10:14:09 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:52975 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755955AbZATPOG (ORCPT ); Tue, 20 Jan 2009 10:14:06 -0500 Date: Tue, 20 Jan 2009 16:13:47 +0100 From: Ingo Molnar To: Nick Piggin Cc: Linux Kernel Mailing List , Linus Torvalds , hpa@zytor.com, jeremy@xensource.com, chrisw@sous-sol.org, zach@vmware.com, rusty@rustcorp.com.au, Andrew Morton Subject: Re: lmbench lat_mmap slowdown with CONFIG_PARAVIRT Message-ID: <20090120151347.GA4309@elte.hu> References: <20090120110542.GE19505@wotan.suse.de> <20090120112634.GA20858@elte.hu> <20090120140324.GA26424@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090120140324.GA26424@elte.hu> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 738 Lines: 18 * Ingo Molnar wrote: > That shows the expected $cache risks here as well: i ran this on an > Extreme Edition CPU which has a ton of L2 cache [4MB] which mutes L2 > $cache misses quite a bit. [ there's no such thing as "L2 $cache misses" - what i wanted to say is that while the instruction cache size is rather small and static, a large L2 cache helps in keeping the costs of instruction-cache misses low - hence my measurement skews in favor of paravirt. ] Ingo -- 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/