From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754422AbdEIGHT (ORCPT ); Tue, 9 May 2017 02:07:19 -0400 Received: from mout.gmx.net ([212.227.15.18]:58147 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753355AbdEIGHR (ORCPT ); Tue, 9 May 2017 02:07:17 -0400 Message-ID: <1494310029.20252.44.camel@gmx.de> Subject: get/put_cpu() usage in block/blk-mq.c From: Mike Galbraith To: Jens Axboe Cc: LKML Date: Tue, 09 May 2017 08:07:09 +0200 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:zdtgn51OTcmZ2j7ks65It1ZMBatU5n3GyDbtJl16JoCppWBfzrm VvmUaVUcFWJMJHixc2JERTuwztXIzCgmfoYfONhJjAY54n5gDjgOvTB01kDB1P9jPoVE/U2 +CT/G/SY0a6JHMTPaTic6gyWxvTyfdTlcOiB9hKSi2lYKfdigRTMQXVX/p22OGmBWV6dAQT /y5sg55Fz9txp175vhEAg== X-UI-Out-Filterresults: notjunk:1;V01:K0:kkPGDV3Riug=:r77GVlmmikjOU3d968V1Bv OZSllaFOlsTK/0FuMLt0RnYSSb9+tBkZ3w3AVaBL3CVQBonq4SEHBG/mYbq7GghwnzhFP0KAm ZMWsY0YuEerWIRF7S3D1yTTTFKpcDPMf/RPkd/npuQV3Meb7ywVHo+qRLtsIGB81XoNDDsaqh m2BZDV/TVQm/Tzatg4ENwvjK9Ik+ZLYcd5McF3nD8ElctxCL2Jbr13G/c4XbGrz8WqO+R4Jg1 u1YNfQ7g1seuwxARD+h8xcWFjgaGhehPkHo1/q1Cca7ywC3kix9OW+OgOb6hSqdtNcNtYO9zK avNeeEvvFBDqlcIIKRr+4Gr8xY05UhRmD2Dxt7Xm/QGVPy1qA+hZdenDNjU0/ObQIRo63xeLT iU1usnd36Bzk/DV3kX37TtcJHdEZvZJlRPs16SzCwlvKUODj8wAnGalNDgrwWxJxvH9VKQXTE PvUhWUcxEhP+gwEfk9XoRkDIFxvLmOAFZL2yoOYYHhOZr6bgH3ln+erN+FPm/b9JpF5QUPjwI lvB9HQO4EXten0j6vi5gz+Tbmwdbd+R8NNsibY8MXHhoJP4Q81eGY+SrRa4Zb1ySgxTq+Kjcy QXJ6BRvDyEStWbwlGrnTYt12OtOU0O/xxwX2WPF1XFTOvPtgVcgxD87b8q4ZHYXHMV/mYwgVJ 27OQGEsbTTiwxBPvqsubyLE9nkxYkVfhUBNy1RMHbCCFYfC2bXfc30CKO1mAcFGXz4+dTpdb0 d7y17EQssA52a+0pf+mgEvDulor/rPjUxIiGnc5DAP86gEvSEkO0W6a6DTUeviT4291WW7xXr S1xC3WC Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jens, I was about to fix up this splat.. [ 445.022141] loop: module loaded [ 445.078116] BUG: using smp_processor_id() in preemptible [00000000] code: loop0/3801 [ 445.085873] caller is debug_smp_processor_id+0x17/0x20 [ 445.091016] CPU: 7 PID: 3801 Comm: loop0 Tainted: G E 4.12.0-default #40 [ 445.098838] Hardware name: IBM System x3550 M3 -[7944K3G]-/69Y5698 , BIOS -[D6E150AUS-1.10]- 12/15/2010 [ 445.108564] Call Trace: [ 445.111016] dump_stack+0x65/0x89 [ 445.114330] check_preemption_disabled+0xde/0xf0 [ 445.118945] debug_smp_processor_id+0x17/0x20 [ 445.123300] blk_stat_add+0xb0/0x130 [ 445.126876] __blk_mq_complete_request+0xb5/0x150 [ 445.131575] blk_mq_complete_request+0x16/0x20 [ 445.136020] loop_queue_work+0x5f/0xaa0 [loop] [ 445.140461] ? _raw_spin_unlock_irq+0x21/0x40 [ 445.144816] ? finish_task_switch+0x85/0x270 [ 445.149085] ? __schedule+0x291/0x8c0 [ 445.152747] kthread_worker_fn+0xc2/0x1d0 [ 445.156754] kthread+0x114/0x150 [ 445.159983] ? __kthread_init_worker+0xb0/0xb0 [ 445.164424] ? kthread_park+0x60/0x60 [ 445.168085] ret_from_fork+0x2c/0x40 ..but then noticed that __blk_mq_run_hw_queue() is also called under get_cpu(), but recently grew a might_sleep(), so maybe wants some block layer eyeballs. -Mike