From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763755AbYFGSST (ORCPT ); Sat, 7 Jun 2008 14:18:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761084AbYFGSSM (ORCPT ); Sat, 7 Jun 2008 14:18:12 -0400 Received: from rv-out-0506.google.com ([209.85.198.233]:51993 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760174AbYFGSSL (ORCPT ); Sat, 7 Jun 2008 14:18:11 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=c1tMpdu+lVUVJ2l8Cb5a2YvfqKq6kyvpAPopdV+dO0Atm+iZ/bAUM/mUyllpqPgxi8 PqnKiYwaWHIL7k1aFqDceBgBjNxfiZdtHi8CLDnRTlEUhWvOYFHjBiINtcsxw6DzHt14 N+wHDq/yEYB00raAC6fuFFtWDTfXWhDLpxFlc= Message-ID: <19f34abd0806071118j1089d940r42440abbcf7e9829@mail.gmail.com> Date: Sat, 7 Jun 2008 20:18:11 +0200 From: "Vegard Nossum" To: "Andi Kleen" Subject: Re: [PATCH] kmemcheck: don't track pages allocated with interrupts disabled Cc: "Pekka Enberg" , "Ingo Molnar" , linux-kernel@vger.kernel.org In-Reply-To: <484AC165.7000702@firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080607143242.GA2893@damson.getinternet.no> <484AC165.7000702@firstfloor.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jun 7, 2008 at 7:12 PM, Andi Kleen wrote: > But a far better solution is to just split all the pages in the system > with set_memory_4k() at boot time (and memory hot add time) when you > know you're not in interrupt context. > > I believe that would be the right solution for DEBUG_PAGEALLOC too. Ah, this is very true for more than one reason. We only ever touch kernel pages with kmemcheck. So this means that userspace can still use large pages and save memory with that. This wouldn't work when we disable PSE entirely. Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036