From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94C7DC5DF60 for ; Tue, 5 Nov 2019 20:47:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5479E214B2 for ; Tue, 5 Nov 2019 20:47:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727821AbfKEUrx (ORCPT ); Tue, 5 Nov 2019 15:47:53 -0500 Received: from sandeen.net ([63.231.237.45]:43224 "EHLO sandeen.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727401AbfKEUrw (ORCPT ); Tue, 5 Nov 2019 15:47:52 -0500 Received: from Liberator-6.local (liberator [10.0.0.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by sandeen.net (Postfix) with ESMTPSA id 82A5B17DE3; Tue, 5 Nov 2019 14:46:44 -0600 (CST) Subject: Re: XFS: possible memory allocation deadlock in kmem_alloc To: Blake Golliher Cc: Chris Holcombe , "Darrick J. Wong" , linux-xfs@vger.kernel.org References: <20191105000138.GT4153244@magnolia> <450b41a6-4fd5-6244-229c-b7cc9512c2a7@sandeen.net> <982194a0-4ab4-d3ca-dfc0-31427ace87fe@sandeen.net> From: Eric Sandeen Autocrypt: addr=sandeen@sandeen.net; prefer-encrypt=mutual; keydata= mQINBE6x99QBEADMR+yNFBc1Y5avoUhzI/sdR9ANwznsNpiCtZlaO4pIWvqQJCjBzp96cpCs nQZV32nqJBYnDpBDITBqTa/EF+IrHx8gKq8TaSBLHUq2ju2gJJLfBoL7V3807PQcI18YzkF+ WL05ODFQ2cemDhx5uLghHEeOxuGj+1AI+kh/FCzMedHc6k87Yu2ZuaWF+Gh1W2ix6hikRJmQ vj5BEeAx7xKkyBhzdbNIbbjV/iGi9b26B/dNcyd5w2My2gxMtxaiP7q5b6GM2rsQklHP8FtW ZiYO7jsg/qIppR1C6Zr5jK1GQlMUIclYFeBbKggJ9mSwXJH7MIftilGQ8KDvNuV5AbkronGC sEEHj2khs7GfVv4pmUUHf1MRIvV0x3WJkpmhuZaYg8AdJlyGKgp+TQ7B+wCjNTdVqMI1vDk2 BS6Rg851ay7AypbCPx2w4d8jIkQEgNjACHVDU89PNKAjScK1aTnW+HNUqg9BliCvuX5g4z2j gJBs57loTWAGe2Ve3cMy3VoQ40Wt3yKK0Eno8jfgzgb48wyycINZgnseMRhxc2c8hd51tftK LKhPj4c7uqjnBjrgOVaVBupGUmvLiePlnW56zJZ51BR5igWnILeOJ1ZIcf7KsaHyE6B1mG+X dmYtjDhjf3NAcoBWJuj8euxMB6TcQN2MrSXy5wSKaw40evooGwARAQABtCVFcmljIFIuIFNh bmRlZW4gPHNhbmRlZW5Ac2FuZGVlbi5uZXQ+iQI7BBMBAgAlAhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgAUCUzMzbAIZAQAKCRAgrhaS4T3e4Fr7D/wO+fenqVvHjq21SCjDCrt8HdVj aJ28B1SqSU2toxyg5I160GllAxEHpLFGdbFAhQfBtnmlY9eMjwmJb0sCIrkrB6XNPSPA/B2B UPISh0z2odJv35/euJF71qIFgWzp2czJHkHWwVZaZpMWWNvsLIroXoR+uA9c2V1hQFVAJZyk EE4xzfm1+oVtjIC12B9tTCuS00pY3AUy21yzNowT6SSk7HAzmtG/PJ/uSB5wEkwldB6jVs2A sjOg1wMwVvh/JHilsQg4HSmDfObmZj1d0RWlMWcUE7csRnCE0ZWBMp/ttTn+oosioGa09HAS 9jAnauznmYg43oQ5Akd8iQRxz5I58F/+JsdKvWiyrPDfYZtFS+UIgWD7x+mHBZ53Qjazszox gjwO9ehZpwUQxBm4I0lPDAKw3HJA+GwwiubTSlq5PS3P7QoCjaV8llH1bNFZMz2o8wPANiDx 5FHgpRVgwLHakoCU1Gc+LXHXBzDXt7Cj02WYHdFzMm2hXaslRdhNGowLo1SXZFXa41KGTlNe 4di53y9CK5ynV0z+YUa+5LR6RdHrHtgywdKnjeWdqhoVpsWIeORtwWGX8evNOiKJ7j0RsHha WrePTubr5nuYTDsQqgc2r4aBIOpeSRR2brlT/UE3wGgy9LY78L4EwPR0MzzecfE1Ws60iSqw Pu3vhb7h3bkCDQROsffUARAA0DrUifTrXQzqxO8aiQOC5p9Tz25Np/Tfpv1rofOwL8VPBMvJ X4P5l1V2yd70MZRUVgjmCydEyxLJ6G2YyHO2IZTEajUY0Up+b3ErOpLpZwhvgWatjifpj6bB SKuDXeThqFdkphF5kAmgfVAIkan5SxWK3+S0V2F/oxstIViBhMhDwI6XsRlnVBoLLYcEilxA 2FlRUS7MOZGmRJkRtdGD5koVZSM6xVZQSmfEBaYQ/WJBGJQdPy94nnlAVn3lH3+N7pXvNUuC GV+t4YUt3tLcRuIpYBCOWlc7bpgeCps5Xa0dIZgJ8Louu6OBJ5vVXjPxTlkFdT0S0/uerCG5 1u8p6sGRLnUeAUGkQfIUqGUjW2rHaXgWNvzOV6i3tf9YaiXKl3avFaNW1kKBs0T5M1cnlWZU Utl6k04lz5OjoNY9J/bGyV3DSlkblXRMK87iLYQSrcV6cFz9PRl4vW1LGff3xRQHngeN5fPx ze8X5NE3hb+SSwyMSEqJxhVTXJVfQWWW0dQxP7HNwqmOWYF/6m+1gK/Y2gY3jAQnsWTru4RV TZGnKwEPmOCpSUvsTRXsVHgsWJ70qd0yOSjWuiv4b8vmD3+QFgyvCBxPMdP3xsxN5etheLMO gRwWpLn6yNFq/xtgs+ECgG+gR78yXQyA7iCs5tFs2OrMqV5juSMGmn0kxJUAEQEAAYkCHwQY AQIACQUCTrH31AIbDAAKCRAgrhaS4T3e4BKwD/0ZOOmUNOZCSOLAMjZx3mtYtjYgfUNKi0ki YPveGoRWTqbis8UitPtNrG4XxgzLOijSdOEzQwkdOIp/QnZhGNssMejCnsluK0GQd+RkFVWN mcQT78hBeGcnEMAXZKq7bkIKzvc06GFmkMbX/gAl6DiNGv0UNAX+5FYh+ucCJZSyAp3sA+9/ LKjxnTedX0aygXA6rkpX0Y0FvN/9dfm47+LGq7WAqBOyYTU3E6/+Z72bZoG/cG7ANLxcPool LOrU43oqFnD8QwcN56y4VfFj3/jDF2MX3xu4v2OjglVjMEYHTCxP3mpxesGHuqOit/FR+mF0 MP9JGfj6x+bj/9JMBtCW1bY/aPeMdPGTJvXjGtOVYblGZrSjXRn5++Uuy36CvkcrjuziSDG+ JEexGxczWwN4mrOQWhMT5Jyb+18CO+CWxJfHaYXiLEW7dI1AynL4jjn4W0MSiXpWDUw+fsBO Pk6ah10C4+R1Jc7dyUsKksMfvvhRX1hTIXhth85H16706bneTayZBhlZ/hK18uqTX+s0onG/ m1F3vYvdlE4p2ts1mmixMF7KajN9/E5RQtiSArvKTbfsB6Two4MthIuLuf+M0mI4gPl9SPlf fWCYVPhaU9o83y1KFbD/+lh1pjP7bEu/YudBvz7F2Myjh4/9GUAijrCTNeDTDAgvIJDjXuLX pA== Message-ID: <33b9bde4-fd14-8754-f98a-ae0f363e76be@sandeen.net> Date: Tue, 5 Nov 2019 14:47:50 -0600 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On 11/5/19 2:36 PM, Blake Golliher wrote: > We don't get anything more then this messages. > > [Tue Nov  5 11:18:34 2019] XFS: nginx(2540) possible memory allocation deadlock size 63960 in kmem_alloc (mode:0x250) > > [Tue Nov  5 11:18:34 2019] XFS: nginx(2517) possible memory allocation deadlock size 56880 in kmem_alloc (mode:0x250) > > [Tue Nov  5 11:18:34 2019] XFS: nginx(2540) possible memory allocation deadlock size 63960 in kmem_alloc (mode:0x250) > > [Tue Nov  5 11:18:35 2019] XFS: nginx(2517) possible memory allocation deadlock size 56880 in kmem_alloc (mode:0x250) > > [Tue Nov  5 11:18:36 2019] XFS: nginx(2514) possible memory allocation deadlock size 63960 in kmem_alloc (mode:0x250) > > [Tue Nov  5 11:18:36 2019] XFS: nginx(2540) possible memory allocation deadlock size 63960 in kmem_alloc (mode:0x250) > > [Tue Nov  5 11:18:37 2019] XFS: nginx(2517) possible memory allocation deadlock size 56880 in kmem_alloc (mode:0x250) no sure what to say. In that kernel, when we print the message: xfs_err(NULL, "%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)", current->comm, current->pid, (unsigned int)size, __func__, lflags); xfs_err() is: define_xfs_printk_level(xfs_err, KERN_ERR); which is the macro: #define define_xfs_printk_level(func, kern_level) \ void func(const struct xfs_mount *mp, const char *fmt, ...) \ { \ struct va_format vaf; \ va_list args; \ int level; \ \ va_start(args, fmt); \ \ vaf.fmt = fmt; \ vaf.va = &args; \ \ __xfs_printk(kern_level, mp, &vaf); \ va_end(args); \ \ if (!kstrtoint(kern_level, 0, &level) && \ level <= 3 /* LOGLEVEL_ERR */ && \ xfs_error_level >= XFS_ERRLEVEL_HIGH) \ xfs_stack_trace(); \ } \ which should dump a stack if called w/ ERR priority and the xfs_error_level is at 11. I suppose your general kernel ring buffer needs to be turned up high enough as well (i.e. dmesg -n 8 to be sure?) The resulting stack trace would tell us exactly how you got to the allocation message. -Eric