From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sd0208e0.au.ibm.com (d23rh904.au.ibm.com [202.81.18.202]) by ausmtp04.au.ibm.com (8.13.8/8.13.8) with ESMTP id l1EH84OM274752 for ; Thu, 15 Feb 2007 04:08:04 +1100 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.250.242]) by sd0208e0.au.ibm.com (8.13.8/8.13.8/NCO v8.2) with ESMTP id l1EGtxDL155722 for ; Thu, 15 Feb 2007 03:56:00 +1100 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l1EGqTFx028037 for ; Thu, 15 Feb 2007 03:52:29 +1100 Message-ID: <45D33E49.8070909@in.ibm.com> Date: Wed, 14 Feb 2007 22:22:25 +0530 From: Balbir Singh Reply-To: balbir@in.ibm.com MIME-Version: 1.0 Subject: Re: [rfc][patch] rmap: more sanity checks References: <20070214090425.GA14932@wotan.suse.de> In-Reply-To: <20070214090425.GA14932@wotan.suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Linux Memory Management List , Andrea Arcangeli , Petr Tesarik , Hugh Dickins List-ID: Nick Piggin wrote: > We have seen a bug in SLES9 that only gets picked up with Andrea's extra > rmap checks that were removed from mainline. > > Petr Tesarik has got a fix for the problem, which he is planning to send > upstream. The issue is a specific condition that causes an anon page to be > incorrectly inserted into the pagetables, outside a valid vma. > > It would be nice to get some of these checks back into mainline, IMO. I > wonder if I'm correct in thinking that checking the page index and mapping > is not actually racy? > I hope so, if that is indeed the case my patches for tracking and accounting shared rss pages at http://marc.theaimsgroup.com/?l=linux-mm&m=116738715329816&w=2 will get much simpler. There used to be a rmap lock (PG_maplock bit) earlier to protect rmap information Please see http://marc.theaimsgroup.com/?l=linux-mm&m=116738715302690&w=2 and http://lkml.org/lkml/2004/7/12/241 Regards, Balbir Singh -- 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