Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751965AbaBLMDs (ORCPT ); Wed, 12 Feb 2014 07:03:48 -0500 Received: from www62.your-server.de ([213.133.104.62]:36916 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751435AbaBLMDq (ORCPT ); Wed, 12 Feb 2014 07:03:46 -0500 Message-ID: <52FB62EE.7070205@iogearbox.net> Date: Wed, 12 Feb 2014 13:02:54 +0100 From: Daniel Borkmann User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Vlastimil Babka , Andrew Morton , linux-kernel , Michel Lespinasse , linux-mm , Jared Hulbert , netdev , Thomas Hellstrom , John David Anglin , HATAYAMA Daisuke , Konstantin Khlebnikov , Carsten Otte , Peter Zijlstra Subject: Re: [BUG] at include/linux/page-flags.h:415 (PageTransHuge) References: <52D03A9E.2030309@iogearbox.net> <20140110222248.4e8419ca.akpm@linux-foundation.org> <52D147F1.3040803@iogearbox.net> <52D3BCE9.4020405@suse.cz> <52D3D060.1010301@iogearbox.net> <52D69AB4.6000309@suse.cz> <52D6B213.4020602@iogearbox.net> <52EBB5E6.8010007@suse.cz> <20140207185816.GA7764@order.stressinduktion.org> In-Reply-To: <20140207185816.GA7764@order.stressinduktion.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-Sender: borkmann@iogearbox.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vlastimil, On 02/07/2014 07:58 PM, Hannes Frederic Sowa wrote: > On Fri, Jan 31, 2014 at 03:40:38PM +0100, Vlastimil Babka wrote: >> From: Vlastimil Babka >> Date: Fri, 31 Jan 2014 11:50:21 +0100 >> Subject: [PATCH] mm: include VM_MIXEDMAP flag in the VM_SPECIAL list to avoid >> m(un)locking >> >> Daniel Borkmann reported a bug with VM_BUG_ON assertions failing where >> munlock_vma_pages_range() thinks it's unexpectedly in the middle of a THP page. >> This can be reproduced in tools/testing/selftests/net/ by running make and >> then ./psock_tpacket. >> >> The problem is that an order=2 compound page (allocated by >> alloc_one_pg_vec_page() is part of the munlocked VM_MIXEDMAP vma (mapped by >> packet_mmap()) and mistaken for a THP page and assumed to be order=9. >> >> The checks for THP in munlock came with commit ff6a6da60b89 ("mm: accelerate >> munlock() treatment of THP pages"), i.e. since 3.9, but did not trigger a bug. >> It just makes munlock_vma_pages_range() skip such compound pages until the next >> 512-pages-aligned page, when it encounters a head page. This is however not a >> problem for vma's where mlocking has no effect anyway, but it can distort the >> accounting. >> Since commit 7225522bb ("mm: munlock: batch non-THP page isolation and >> munlock+putback using pagevec") this can trigger a VM_BUG_ON in PageTransHuge() >> check. >> >> This patch fixes the issue by adding VM_MIXEDMAP flag to VM_SPECIAL - a list of >> flags that make vma's non-mlockable and non-mergeable. The reasoning is that >> VM_MIXEDMAP vma's are similar to VM_PFNMAP, which is already on the VM_SPECIAL >> list, and both are intended for non-LRU pages where mlocking makes no sense >> anyway. Thanks a lot for your efforts. Is your patch queued up somewhere for mainline and stable? > I also ran into this problem and wanted to ask what the status of this > patch is? Does it need further testing? I can surely help with that. ;) > > Thanks, > > Hannes > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/