From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754380AbZCKJd5 (ORCPT ); Wed, 11 Mar 2009 05:33:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752821AbZCKJdt (ORCPT ); Wed, 11 Mar 2009 05:33:49 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:44713 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752527AbZCKJds (ORCPT ); Wed, 11 Mar 2009 05:33:48 -0400 Date: Wed, 11 Mar 2009 10:33:38 +0100 From: Ingo Molnar To: Thomas Hellstrom Cc: "Pallipadi, Venkatesh" , "Eric W. Biederman" , Linux kernel mailing list , "Siddha, Suresh B" , Nick Piggin Subject: Re: 2.6.29 pat issue Message-ID: <20090311093338.GC12814@elte.hu> References: <1233856988.4286.83.camel@localhost.localdomain> <498B5ADE.3090602@vmware.com> <498C062C.201@vmware.com> <20090304060857.GA18318@linux-os.sc.intel.com> <130CA3A191875048A0624FB523A55EC7075DA7CA@PA-EXMBX51.vmware.com> <20090310013953.GA11312@linux-os.sc.intel.com> <49B6232B.4050503@vmware.com> <1236706959.4529.56.camel@localhost.localdomain> <49B781B6.3060704@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49B781B6.3060704@vmware.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Thomas Hellstrom wrote: > Pallipadi, Venkatesh wrote: >> On Tue, 2009-03-10 at 01:22 -0700, Thomas Hellstrom wrote: >> >>> Pallipadi, Venkatesh wrote: >>> >>>> On Fri, Mar 06, 2009 at 03:44:07PM -0800, Thomas Hellstrom wrote: >>>> >>>>> We get the warning when we insert RAM pages using vm_insert_pfn(). >>>>> Having normal RAM pages backing a PFN papping is a valid thing. >>>>> >>>>> >>>> OK. Below is the updated patch that should fix this fully. Can you confirm? >>>> >>>> Thanks, >>>> Venki >>>> >>>> >>> Yes, this patch should fix the problem. I'm still concerned about the >>> overhead of going through the >>> RAM test for each inserted page. >>> >>> Why can't a pfn_valid() test be used in vm_insert_pfn()? >>> >>> >> >> Because we may have to track the RAM pages as well in future. We are >> changing the e820 RAM check and making it use pfn_valid. But, for that >> we have to change more things in tracking of RAM pages. Today we use one >> bit in page struct without any refcounting. But, more changes there are >> on ts way. This change here should keep the current kernel fine without >> any regression. >> >> Thanks, >> Venki >> >> > Ok, I understand. > and yes, the regression should be fixed with the patch. Good. Venki, mind resending the patch against tip:master, with a proper subject line, changelog and Acked-by in place? Thanks, Ingo