From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752827AbbIXTGQ (ORCPT ); Thu, 24 Sep 2015 15:06:16 -0400 Received: from mail-by2on0091.outbound.protection.outlook.com ([207.46.100.91]:8560 "EHLO na01-by2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751802AbbIXTE5 (ORCPT ); Thu, 24 Sep 2015 15:04:57 -0400 Authentication-Results: spf=pass (sender IP is 63.163.107.173) smtp.mailfrom=sandisk.com; lst.de; dkim=none (message not signed) header.d=none;lst.de; dmarc=bestguesspass action=none header.from=sandisk.com; X-AuditID: ac160a69-f79f76d000007db2-fd-560449520eee Subject: Re: [PATCH 3/3] blk-mq: Fix the queue freezing mechanism To: Ming Lei References: <560323AB.80900@sandisk.com> <56032432.6080006@sandisk.com> <20150924112251.2ec061fd@tom-T450> CC: Jens Axboe , Christoph Hellwig , Tejun Heo , "linux-kernel@vger.kernel.org" , Akinobu Mita From: Bart Van Assche Message-ID: <56044952.7040600@sandisk.com> Date: Thu, 24 Sep 2015 12:04:50 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20150924112251.2ec061fd@tom-T450> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupgkeLIzCtJLcpLzFFi42JZI8azSDfIkyXM4MdVYYtXBzoYLf7vOcZm sXL1USaLy7vmsFn8Wn6U0eL9j+vsDmweE5vfsXvsnHWX3WPTqk42j903G9g8Pm+SC2CN4rJJ Sc3JLEst0rdL4MpY9mgaS8FUwYpFH14yNTC28XcxcnJICJhILNvezw5hi0lcuLeerYuRi0NI 4ASjRPf3FiYIZwejxLr98xhhOu7NmcgCkdgElJh8BaxdWMBR4tTM/SwgtoiAisSjns1gcSGB HIm157YxgjQwCxxilLg1bR4TSIJNwEji2/uZYA28AloSU04cZQOxWQRUJS5/Og/WLCoQIXHq 7Fs2iBpBiZMzn4DVcwroS2x98QdoKAfQUE2J9bv0QcLMAvIS29/OYYY49CKrxJ0jCRA3qEuc XDKfaQKjyCwkk2YhdM9C0r2AkXkVo1huZk5xbnpqgaGRXnFiXkpmcbZecn7uJkZw/HBl7mBc Mcn8EKMAB6MSD+8MHeYwIdbEsuLKXKAHOZiVRHgPiLCECfGmJFZWpRblxxeV5qQWH2KU5mBR EuftzdUJFRJITyxJzU5NLUgtgskycXBKNTDWd235q7bAoeWKo2U34wN5w0VNn7OW9Xz/u/Cf 9ZmLb38VSGR9n+6V7vsj6u7t+6HqTZnnPNbOuKHJaXhA5Gic6Yx7d6UiVpn/bAy6p8k84aTy jW0M+dMjVwmqGmz2SPlntUhAa1nS7Dt/PVh6/Jrzcq7UloW5C1b1/ze4vjExOlEo6Mq+bSpK LMUZiYZazEXFiQDYyXp3mwIAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpgluLIzCtJLcpLzFFi42Lh2siRohvkyRJmcOYrh8WrAx2MFv/3HGOz WLn6KJPF5V1z2Cx+LT/KaPH+x3V2BzaPic3v2D12zrrL7rFpVSebx+6bDWwenzfJBbBGcdmk pOZklqUW6dslcGUsezSNpWCqYMWiDy+ZGhjb+LsYOTkkBEwk7s2ZyAJhi0lcuLeerYuRi0NI YAOjxM0V59hBEsICjhKnZu4HKxIRUJF41LMZLC4kkCOx9tw2RpAGZoEjjBILGh4xgiTYBIwk vr2fCdbAK6AlMeXEUTYQm0VAVeLyp/NgzaICERKnzr5lg6gRlDg58wlYPaeAvsTWF3/A5jAL qEv8mXeJGcKWl9j+dg7zBEb+WUhaZiEpm4WkbAEj8ypGsdzMnOLc9MwCQ0O94sS8lMzibL3k /NxNjOAw5ozcwfh0ovkhRiYOTqkGxp7WulVhWtWSMR0bHxzTFZg344zvFfOXB52nOS5JN+mt k/1sqfXYaruo7e/Px60W1831Mfu/8ajunnNLZnadkF7RZq65ekpzRVZa3ot9l0SVLIQvv/n+ VSBk0eSWLQpCP7Skf30+mnZk6oX27XWf0g7KuDm+q0zdFDLF7GTOZbMIW9eH9kutVyixFGck GmoxFxUnAgAkqjUKEwIAAA== X-EOPAttributedMessage: 0 X-Microsoft-Exchange-Diagnostics: 1;BY2FFO11OLC008;1:8UIhYBasSdtXmEHYZd5eG0yauwRxoActXpja5FZsy/ynQG+Wu4MYHbTpCbWFpebnd5/CcwlQz52969CoABFvoLYvQvaEcNYReh1oMQTMikgujYBE3Ms2GAciwO6DtKTqyzSlD48p4qqjTgroSv3QQo1cPBFRBts5w2SfP3bMLJf3JVy51WGEb53B3ESjoKVGRSSnGFJ9I6sG3OJR41tJixLpFWfxSvOw936XsUSdBZJ7o3Ng73JVxUoUuwKirXXlD9Lqfv6rBAa/W0cL5s6M60u1PlnvqZHQ3xRWgq2ZIGJlCyT8OiJdckEX6HJXy3ytGCZVbuCxrTsGu1V/TTKLTWvMJPxq+SwxDsp6XiJtjsg2E4uHXucNnlMJ+hw3jlxi X-Forefront-Antispam-Report: CIP:63.163.107.173;CTRY:US;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10009020)(6009001)(2980300002)(438002)(209900001)(199003)(189002)(24454002)(479174004)(377454003)(51234002)(77096005)(19580395003)(106466001)(5007970100001)(11100500001)(15975445007)(99136001)(92566002)(65816999)(15395725005)(77156002)(68736005)(62966003)(69596002)(54356999)(50466002)(46102003)(86362001)(50986999)(76176999)(87266999)(83506001)(87936001)(23676002)(2950100001)(64706001)(65806001)(47776003)(59896002)(5001860100001)(4001540100001)(65956001)(97736004)(5001830100001)(110136002)(36756003)(5001960100002)(4001350100001)(81156007)(189998001)(117636001)(64126003)(62816006)(6606295002);DIR:OUT;SFP:1101;SCL:1;SRVR:BN1PR0201MB0738;H:milsmgep12.sandisk.com;FPR:;SPF:Pass;PTR:ErrorRetry;A:1;MX:1;LANG:en; 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Has that patch been tested against a debug kernel ? The following call trace is triggered by that patch: WARNING: CPU: 3 PID: 200 at kernel/sched/core.c:7485 __might_sleep+0x77/0x80() do not call blocking ops when !TASK_RUNNING; state=1 set at [] prepare_to_wait_event+0x63/0xf0 Modules linked in: ib_srp(O) scsi_transport_srp(O) netconsole configfs af_packet msr sg coretemp x86_pkg_temp_thermal crct10dif_pclmul crc32c_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ipmi_devintf ablk_helper cryptd tg3 lpc_ich microcode pcspkr libphy mfd_core ipmi_si ipmi_msghandler ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad dm_multipath dm_mod rdma_cm ib_cm acpi_power_meter hwmon iw_cm processor button wmi ext4 crc16 mbcache jbd2 mlx4_ib mlx4_en ib_sa ptp pps_core ib_mad ib_core ib_addr sd_mod sr_mod cdrom hid_generic usbhid hid ahci libahci libata ehci_pci ehci_hcd mlx4_core usbcore usb_common scsi_mod autofs4 [last unloaded: brd] CPU: 3 PID: 200 Comm: kworker/u16:9 Tainted: G O 4.3.0-rc2-debug+ #1 Hardware name: Dell Inc. PowerEdge R430/03XKDV, BIOS 1.0.2 11/17/2014 Workqueue: events_unbound async_run_entry_fn Call Trace: [] dump_stack+0x4b/0x68 [] warn_slowpath_common+0x86/0xc0 [] warn_slowpath_fmt+0x4c/0x50 [] ? prepare_to_wait_event+0x63/0xf0 [] ? prepare_to_wait_event+0x63/0xf0 [] __might_sleep+0x77/0x80 [] mutex_lock_nested+0x33/0x3b0 [] ? trace_hardirqs_on+0xd/0x10 [] ? prepare_to_wait_event+0x95/0xf0 [] blk_mq_queue_enter+0x17a/0x2d0 [] ? blk_mq_queue_enter+0x33/0x2d0 [] ? prepare_to_wait_event+0xf0/0xf0 [] blk_mq_map_request+0x2e/0x330 [] ? __lock_is_held+0x49/0x70 [] blk_sq_make_request+0x91/0x430 [ ... ]