From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261652AbVGFUPW (ORCPT ); Wed, 6 Jul 2005 16:15:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262215AbVGFUNz (ORCPT ); Wed, 6 Jul 2005 16:13:55 -0400 Received: from dsl027-180-168.sfo1.dsl.speakeasy.net ([216.27.180.168]:18096 "EHLO sunset.davemloft.net") by vger.kernel.org with ESMTP id S262438AbVGFT53 (ORCPT ); Wed, 6 Jul 2005 15:57:29 -0400 Date: Wed, 06 Jul 2005 12:57:19 -0700 (PDT) Message-Id: <20050706.125719.08321870.davem@davemloft.net> To: pmarques@grupopie.com Cc: linux-kernel@vger.kernel.org Subject: Re: Slowdown with randomize_va_space in 2.6.12.2 From: "David S. Miller" In-Reply-To: <42CBE97C.2060208@grupopie.com> References: <42CBE97C.2060208@grupopie.com> X-Mailer: Mew version 4.2 on Emacs 21.4 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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. But 2 seconds more of execution time is quite a lot.