From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <48A494B0.3050509@goop.org> Date: Thu, 14 Aug 2008 13:25:20 -0700 From: Jeremy Fitzhardinge MIME-Version: 1.0 Subject: Re: [rfc][patch] mm: dirty page accounting race fix References: <20080814094537.GA741@wotan.suse.de> <1218716318.10800.209.camel@twins> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Hugh Dickins Cc: Peter Zijlstra , Nick Piggin , Linux Memory Management List , Linux Kernel Mailing List List-ID: Hugh Dickins wrote: > I realized that was the intended optimization, what I'd missed is that > dirty_accountable can only be true there if (vma->vm_flags & VM_WRITE): > that's checked in vma_wants_writenotify(), which is how dirty_accountable > gets to be set. > > So those lines are okay, panic over, phew. > I got bitten by precisely the same train of thought. I think that code officially Non Obvious (or at least Not Immediately Obvious, which is bad in security-sensitive code). J -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org