From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754201AbYEZJaB (ORCPT ); Mon, 26 May 2008 05:30:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752202AbYEZJ3y (ORCPT ); Mon, 26 May 2008 05:29:54 -0400 Received: from il.qumranet.com ([212.179.150.194]:37257 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752107AbYEZJ3y (ORCPT ); Mon, 26 May 2008 05:29:54 -0400 Message-ID: <483A8310.6030309@qumranet.com> Date: Mon, 26 May 2008 12:29:52 +0300 From: Avi Kivity User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Vegard Nossum CC: Ingo Molnar , Pekka Enberg , linux-kernel@vger.kernel.org, Pekka Paalanen Subject: Re: [PATCH] kmemcheck: SMP support References: <20080523141759.GA1833@damson.getinternet.no> <20080523150622.GA9782@elte.hu> <19f34abd0805230830o3af93956h8152de3f6e350a09@mail.gmail.com> In-Reply-To: <19f34abd0805230830o3af93956h8152de3f6e350a09@mail.gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vegard Nossum wrote: > On Fri, May 23, 2008 at 5:06 PM, Ingo Molnar wrote: > >> Vegard, wanna have a look at introducing per CPU kernel pagetables? I >> tried that once in the past and it wasnt too horrible. (the patches are >> gone though) We could do it before bringing other CPUs online, i.e. much >> of the really yucky boot time pagetable juggling phase would be over >> already. Hm? >> > > Ingo. > > It really doesn't matter how easy it was for you. > > You're one of the x86 maintainers. > > And I think you're forgetting how hard these things are for a newbie. > I don't even know which one comes first of pmds and puds. > > Per-cpu page tables sounds about on the same scale of as, say, > rewriting the VM or some other major subsystem. Epic! > > You might be able to pull off a simple implementation using paravirt_ops, without impacting the core VM. Basically, you keep the current global pagetables, but never set them as real pagetables. Instead you keep per-cpu copies of these pagetables and sync them from the master pagetable as needed. -- error compiling committee.c: too many arguments to function