From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753773Ab1LUU4N (ORCPT ); Wed, 21 Dec 2011 15:56:13 -0500 Received: from acsinet15.oracle.com ([141.146.126.227]:64807 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750915Ab1LUU4I (ORCPT ); Wed, 21 Dec 2011 15:56:08 -0500 Message-ID: <4EF24758.5030704@oracle.com> Date: Wed, 21 Dec 2011 14:53:44 -0600 From: Dave Kleikamp User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111108 Thunderbird/8.0 MIME-Version: 1.0 To: Andrew Morton CC: Hugh Dickins , Linus Torvalds , "Rafael J. Wysocki" , jfs-discussion@lists.sourceforge.net, Kernel Testers List , LKML , Maciej Rutecki , Florian Mickler , davem@davemloft.net, Al Viro , linux-mm@kvack.org Subject: Re: [PATCH v2] vfs: __read_cache_page should use gfp argument rather than GFP_KERNEL References: <201112210054.46995.rjw@sisk.pl> <4EF15F42.4070104@oracle.com> <4EF211EC.7090002@oracle.com> <20111221122843.18f673c7.akpm@linux-foundation.org> In-Reply-To: <20111221122843.18f673c7.akpm@linux-foundation.org> X-Enigmail-Version: 1.3.4 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet21.oracle.com [156.151.31.93] X-CT-RefId: str=0001.0A090202.4EF2475E.003D,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/21/2011 02:28 PM, Andrew Morton wrote: > On Wed, 21 Dec 2011 11:05:48 -0600 > Dave Kleikamp wrote: > >> [ updated to remove now-obsolete comment in read_cache_page_gfp()] >> >> lockdep reports a deadlock in jfs because a special inode's rw semaphore >> is taken recursively. The mapping's gfp mask is GFP_NOFS, but is not used >> when __read_cache_page() calls add_to_page_cache_lru(). > > Well hang on, it's not just a lockdep splat. The kernel actually will > deadlock if we reenter JFS via this GFP_KERNEL allocation attempt, yes? Yes, it could result in a real deadlock. > Was that GFP_NOFS allocation recently added to JFS? If not then we > should backport this deadlock fix into -stable, no? Yes, that would make sense. Shaggy From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Kleikamp Subject: Re: [PATCH v2] vfs: __read_cache_page should use gfp argument rather than GFP_KERNEL Date: Wed, 21 Dec 2011 14:53:44 -0600 Message-ID: <4EF24758.5030704@oracle.com> References: <201112210054.46995.rjw@sisk.pl> <4EF15F42.4070104@oracle.com> <4EF211EC.7090002@oracle.com> <20111221122843.18f673c7.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20111221122843.18f673c7.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Andrew Morton Cc: Hugh Dickins , Linus Torvalds , "Rafael J. Wysocki" , jfs-discussion@lists.sourceforge.net, Kernel Testers List , LKML , Maciej Rutecki , Florian Mickler , davem@davemloft.net, Al Viro , linux-mm@kvack.org On 12/21/2011 02:28 PM, Andrew Morton wrote: > On Wed, 21 Dec 2011 11:05:48 -0600 > Dave Kleikamp wrote: > >> [ updated to remove now-obsolete comment in read_cache_page_gfp()] >> >> lockdep reports a deadlock in jfs because a special inode's rw semaphore >> is taken recursively. The mapping's gfp mask is GFP_NOFS, but is not used >> when __read_cache_page() calls add_to_page_cache_lru(). > > Well hang on, it's not just a lockdep splat. The kernel actually will > deadlock if we reenter JFS via this GFP_KERNEL allocation attempt, yes? Yes, it could result in a real deadlock. > Was that GFP_NOFS allocation recently added to JFS? If not then we > should backport this deadlock fix into -stable, no? Yes, that would make sense. Shaggy -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org