From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752053AbXCHAzm (ORCPT ); Wed, 7 Mar 2007 19:55:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752119AbXCHAzm (ORCPT ); Wed, 7 Mar 2007 19:55:42 -0500 Received: from gw.goop.org ([64.81.55.164]:57354 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752053AbXCHAzm (ORCPT ); Wed, 7 Mar 2007 19:55:42 -0500 Message-ID: <45EF5F0C.5070102@goop.org> Date: Wed, 07 Mar 2007 16:55:40 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.9 (X11/20070212) MIME-Version: 1.0 To: tim.c.chen@linux.intel.com CC: zach@vmware.com, linux-kernel@vger.kernel.org, Virtualization Mailing List Subject: Re: system call time increase when turning on CONFIG_PARAVIRT References: <1172866274.4898.14.camel@localhost.localdomain> <45E89CFB.4090905@goop.org> <1172877111.8383.4.camel@localhost.localdomain> <45E8BE79.40200@goop.org> <1173312124.8383.35.camel@localhost.localdomain> In-Reply-To: <1173312124.8383.35.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Tim Chen wrote: > It turned out that VDSO was turned off by CONFIG_PARAVIRT option, > causing the system call to use inefficient int 0x80 which led to the > increase system_call time I was seeing. I noted that Ingo has caught > this problem and proposed a patch to correct this issue in another mail > thread. Thanks for identifying this. We'll be posting a more general fix for COMPAT_VDSO soon which will address this. J