From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id C5B496B004F for ; Wed, 26 Aug 2009 16:29:43 -0400 (EDT) Date: Wed, 26 Aug 2009 21:29:07 +0100 (BST) From: Hugh Dickins Subject: Re: [PATCH 13/12] ksm: fix munlock during exit_mmap deadlock In-Reply-To: <20090826194444.GB14722@random.random> Message-ID: References: <20090825145832.GP14722@random.random> <20090825152217.GQ14722@random.random> <20090825181019.GT14722@random.random> <20090825194530.GU14722@random.random> <20090826194444.GB14722@random.random> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Andrea Arcangeli Cc: Izik Eidus , Rik van Riel , Chris Wright , Nick Piggin , Andrew Morton , "Justin M. Forbes" , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Wed, 26 Aug 2009, Andrea Arcangeli wrote: > On Wed, Aug 26, 2009 at 08:17:50PM +0100, Hugh Dickins wrote: > > Has anyone looked at why Rawhide's mlockall is not faulting in the > > pages, I wonder if there's a separate bug there?) > > I reproduced only with self compiled mmotm kernel with full self > compiled userland with just a mlockall and exit (not rawhide > kernel/userland) so there's certainly no bug in rawhide, or at least > nothing special about it. I just tried again and got it myself: the faulting page is a PROT_NONE page of libc, yes, that figures: mlocking would not fault it in, but munlocking would (in its current implementation) insist on faulting it. I don't know what my difficulty was yesterday: perhaps that page isn't always PROT_NONE, perhaps I got confused and was testing the wrong kernel, one without KSM or one with my follow_page munlock. Hugh -- 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