From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 25 Feb 2003 11:57:08 -0600 From: Dave McCracken Subject: Re: 2.5.62-mm3 - no X for me Message-ID: <131360000.1046195828@[10.1.1.5]> In-Reply-To: <20030225015537.4062825b.akpm@digeo.com> References: <20030223230023.365782f3.akpm@digeo.com> <3E5A0F8D.4010202@aitel.hist.no><20030224121601.2c998cc5.akpm@digeo.com> <20030225094526.GA18857@gemtek.lt> <20030225015537.4062825b.akpm@digeo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Zilvinas Valinskas , helgehaf@aitel.hist.no, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: --On Tuesday, February 25, 2003 01:55:37 -0800 Andrew Morton wrote: > Ah, thank you. > > kernel BUG at mm/rmap.c:248! > > The fickle finger of fate points McCrackenwards. Yep. He tripped over my sanity check that pages not marked anon actually have a real mapping pointer. Apparently X allocates a page that should be marked anon but isn't. My main reason for adding the anon flag was to prove to myself that the mapping pointer can be trusted. Apparently it can, generally, but it looks like I haven't successfully tracked down all the places that should set it. It looks like anon pages can come from random sources, so it might be an impossible task to find them all. I know you said you like the idea of having the flag, but I think the cleanest fix would be to change the check from if (PageAnon(page)) to if (page->mapping && !PageSwapCache(page)) Or I could set the anon flag based on that test. I know page flags are getting scarce, so I'm leaning toward removing the flag entirely. What would you recommend? Dave McCracken -- 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: aart@kvack.org