From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262551AbVGFVB4 (ORCPT ); Wed, 6 Jul 2005 17:01:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262544AbVGFU6r (ORCPT ); Wed, 6 Jul 2005 16:58:47 -0400 Received: from mx1.redhat.com ([66.187.233.31]:58600 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S262288AbVGFUx3 (ORCPT ); Wed, 6 Jul 2005 16:53:29 -0400 Date: Wed, 6 Jul 2005 16:53:15 -0400 From: Dave Jones To: "David S. Miller" Cc: pmarques@grupopie.com, linux-kernel@vger.kernel.org Subject: Re: Slowdown with randomize_va_space in 2.6.12.2 Message-ID: <20050706205315.GC27630@redhat.com> Mail-Followup-To: Dave Jones , "David S. Miller" , pmarques@grupopie.com, linux-kernel@vger.kernel.org References: <42CBE97C.2060208@grupopie.com> <20050706.125719.08321870.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050706.125719.08321870.davem@davemloft.net> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 06, 2005 at 12:57:19PM -0700, David S. Miller wrote: > From: Paulo Marques > Date: Wed, 06 Jul 2005 15:23:56 +0100 > > > What is weird is that most of the extra time is being accounted as > > user-space time, but the user-space application is exactly the same in > > both runs, only the "randomize_va_space" parameter changed. > > It might be attributable to more cpu cache misses in userspace since > the virtual addresses of everything are changing each and every > invocation. On Transmeta CPUs that probably triggers a retranslation of x86->native bytecode, if it thinks it hasn't seen code at that address before. Dave