From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755818AbYFGTrd (ORCPT ); Sat, 7 Jun 2008 15:47:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752422AbYFGTr0 (ORCPT ); Sat, 7 Jun 2008 15:47:26 -0400 Received: from one.firstfloor.org ([213.235.205.2]:49778 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752225AbYFGTr0 (ORCPT ); Sat, 7 Jun 2008 15:47:26 -0400 Message-ID: <484AE5C9.9070306@firstfloor.org> Date: Sat, 07 Jun 2008 21:47:21 +0200 From: Andi Kleen User-Agent: Thunderbird 1.5.0.12 (X11/20060911) MIME-Version: 1.0 To: Vegard Nossum CC: Pekka Enberg , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] kmemcheck: don't track pages allocated with interrupts disabled References: <20080607143242.GA2893@damson.getinternet.no> <484AC165.7000702@firstfloor.org> <19f34abd0806071115s3e50d662p190a65fa2f091c7b@mail.gmail.com> In-Reply-To: <19f34abd0806071115s3e50d662p190a65fa2f091c7b@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Maybe we can do the splitting when kmemcheck is enabled for the first > time, either with the proc handler or at boot if kmemcheck=1 is passed > on the command line. Both of these contexts should/can be > !irqs_disabled(), I think. You could always split at boot when the CONFIG is enabled. I assume the CONFIG alone has already quite a lot of overhead and it will be only on in debug kernels and adding some more TLB misses shouldn't be really a problem. Using 2MB pages in kernel is merely an optimization. -Andi