From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f44.google.com (mail-pa0-f44.google.com [209.85.220.44]) by kanga.kvack.org (Postfix) with ESMTP id 0CEB86B0072 for ; Wed, 10 Sep 2014 15:11:31 -0400 (EDT) Received: by mail-pa0-f44.google.com with SMTP id kx10so8250753pab.17 for ; Wed, 10 Sep 2014 12:11:31 -0700 (PDT) Received: from mail-pa0-x230.google.com (mail-pa0-x230.google.com [2607:f8b0:400e:c03::230]) by mx.google.com with ESMTPS id iu9si28784360pbd.251.2014.09.10.12.11.30 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 10 Sep 2014 12:11:31 -0700 (PDT) Received: by mail-pa0-f48.google.com with SMTP id hz1so10936043pad.21 for ; Wed, 10 Sep 2014 12:11:30 -0700 (PDT) Date: Wed, 10 Sep 2014 12:09:40 -0700 (PDT) From: Hugh Dickins Subject: Re: mm: BUG in unmap_page_range In-Reply-To: <54104E24.5010402@oracle.com> Message-ID: References: <20140805144439.GW10819@suse.de> <53E17F06.30401@oracle.com> <53E989FB.5000904@oracle.com> <53FD4D9F.6050500@oracle.com> <20140827152622.GC12424@suse.de> <540127AC.4040804@oracle.com> <54082B25.9090600@oracle.com> <20140908171853.GN17501@suse.de> <540DEDE7.4020300@oracle.com> <20140909213309.GQ17501@suse.de> <540F7D42.1020402@oracle.com> <54104E24.5010402@oracle.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: Hugh Dickins , Mel Gorman , "linux-mm@kvack.org" , Andrew Morton , Dave Jones , LKML , "Kirill A. Shutemov" , Peter Zijlstra , Rik van Riel , Johannes Weiner , Cyrill Gorcunov On Wed, 10 Sep 2014, Sasha Levin wrote: > On 09/09/2014 10:45 PM, Hugh Dickins wrote: > > Sasha, you say you're getting plenty of these now, but I've only seen > > the dump for one of them, on Aug26: please post a few more dumps, so > > that we can look for commonality. > > I wasn't saving older logs for this issue so I only have 2 traces from > tonight. If that's not enough please let me know and I'll try to add > a few more. Thanks, these two are useful, mainly because the register contents most likely to be ptes are in both of these ...900, with no sign of a ...902. So the RW bit I got excited about yesterday is clearly not necessary for the bug (though it's still possible that it was good for implicating page migration, and page migration still play a part in the story). > > And please attach a disassembly of change_protection_range() (noting > > which of the dumps it corresponds to, in case it has changed around): > > "Code" just shows a cluster of ud2s for the unlikely bugs at end of the > > function, we cannot tell at all what should be in the registers by then. > > change_protection_range() got inlined into change_protection(), it applies to > both traces above: Thanks for supplying, but the change in inlining means that change_protection_range() and change_protection() are no longer relevant for these traces, we now need to see change_pte_range() instead, to confirm that what I expect are ptes are indeed ptes. If you can include line numbers (objdump -ld) in the disassembly, so much the better, but should be decipherable without. (Or objdump -Sd for source, but I often find that harder to unscramble, can't say why.) Thanks, 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