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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F247BC433F5 for ; Mon, 16 May 2022 02:39:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239378AbiEPCjm (ORCPT ); Sun, 15 May 2022 22:39:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235140AbiEPCjj (ORCPT ); Sun, 15 May 2022 22:39:39 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A490FD00 for ; Sun, 15 May 2022 19:39:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1652668778; x=1684204778; h=date:from:to:cc:subject:message-id:mime-version; bh=rr5dtgu/wlB8YyV/1zjNYHWRK23YPLr8hnwK/EGLo24=; b=DbVSj37MpN69nUYoGwc2OQDqenjtw9Fc6wpyvxzKvvAnDtfVNj76RVVr uqC4Ke0/R5kr33i+YAY5SFECwl9E8y5BSmm4W6Pfn9tJPyUeQtfJe4oj9 F2g7K4jx6Mz4WEbFRYoeGxiVFZQ0WfH73UvNr1p7eE+CI82PxhjvQ0+mD 2KTzLCXV+eHAbsEN5z9VBVh8ll36eNu1JHVPZ9AyDJZf9MKuUWk6wPYxa 1SbXn3LXcxpDjLjDrWeEjehSGM3KidqbwtpblcN+YywBKanEPNYp2C+CT m03Iql0s2SVwUWaRsQQ6As3cok1kgvUP4b9KprgzSc3PR6NEBe0K5B0QI A==; X-IronPort-AV: E=McAfee;i="6400,9594,10348"; a="269536696" X-IronPort-AV: E=Sophos;i="5.91,229,1647327600"; d="scan'208";a="269536696" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 May 2022 19:39:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.91,229,1647327600"; d="scan'208";a="713182353" Received: from lkp-server01.sh.intel.com (HELO d1462bc4b09b) ([10.239.97.150]) by fmsmga001.fm.intel.com with ESMTP; 15 May 2022 19:39:37 -0700 Received: from kbuild by d1462bc4b09b with local (Exim 4.95) (envelope-from ) id 1nqQe0-00026X-C5; Mon, 16 May 2022 02:39:36 +0000 Date: Mon, 16 May 2022 10:39:30 +0800 From: kernel test robot To: Tetsuo Handa Cc: kbuild-all@lists.01.org, linux-kernel@vger.kernel.org, 0day robot Subject: kernel/workqueue.c:2798: warning: expecting prototype for flush_workqueue(). Prototype was for void() instead Message-ID: <202205161030.Dv3ad4T3-lkp@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org tree: https://github.com/intel-lab-lkp/linux/commits/UPDATE-20220516-093322/Tetsuo-Handa/checkpatch-warn-about-flushing-system-wide-workqueues/20220425-073327 head: cd007363b7985a824de0ec5e05f0cb0705e59c88 commit: cd007363b7985a824de0ec5e05f0cb0705e59c88 workqueue: Wrap flush_workqueue() using a macro date: 63 minutes ago config: um-i386_defconfig (https://download.01.org/0day-ci/archive/20220516/202205161030.Dv3ad4T3-lkp@intel.com/config) compiler: gcc-11 (Debian 11.2.0-20) 11.2.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/cd007363b7985a824de0ec5e05f0cb0705e59c88 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review UPDATE-20220516-093322/Tetsuo-Handa/checkpatch-warn-about-flushing-system-wide-workqueues/20220425-073327 git checkout cd007363b7985a824de0ec5e05f0cb0705e59c88 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=um SUBARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): kernel/workqueue.c:2798: warning: Function parameter or member 'flush_workqueue' not described in 'void' >> kernel/workqueue.c:2798: warning: expecting prototype for flush_workqueue(). Prototype was for void() instead vim +2798 kernel/workqueue.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 2789 0fcb78c22f0634 Rolf Eike Beer 2006-07-30 2790 /** ^1da177e4c3f41 Linus Torvalds 2005-04-16 2791 * flush_workqueue - ensure that any scheduled work has run to completion. 0fcb78c22f0634 Rolf Eike Beer 2006-07-30 2792 * @wq: workqueue to flush ^1da177e4c3f41 Linus Torvalds 2005-04-16 2793 * c5aa87bbf4b23f Tejun Heo 2013-03-13 2794 * This function sleeps until all work items which were queued on entry c5aa87bbf4b23f Tejun Heo 2013-03-13 2795 * have finished execution, but it is not livelocked by new incoming ones. ^1da177e4c3f41 Linus Torvalds 2005-04-16 2796 */ cd007363b7985a Tetsuo Handa 2022-05-16 2797 void (flush_workqueue)(struct workqueue_struct *wq) ^1da177e4c3f41 Linus Torvalds 2005-04-16 @2798 { 73f53c4aa732ec Tejun Heo 2010-06-29 2799 struct wq_flusher this_flusher = { 73f53c4aa732ec Tejun Heo 2010-06-29 2800 .list = LIST_HEAD_INIT(this_flusher.list), 73f53c4aa732ec Tejun Heo 2010-06-29 2801 .flush_color = -1, fd1a5b04dfb899 Byungchul Park 2017-10-25 2802 .done = COMPLETION_INITIALIZER_ONSTACK_MAP(this_flusher.done, wq->lockdep_map), 73f53c4aa732ec Tejun Heo 2010-06-29 2803 }; 73f53c4aa732ec Tejun Heo 2010-06-29 2804 int next_color; f293ea92007419 Oleg Nesterov 2007-05-09 2805 3347fa0928210d Tejun Heo 2016-09-16 2806 if (WARN_ON(!wq_online)) 3347fa0928210d Tejun Heo 2016-09-16 2807 return; 3347fa0928210d Tejun Heo 2016-09-16 2808 87915adc3f0acd Johannes Berg 2018-08-22 2809 lock_map_acquire(&wq->lockdep_map); 87915adc3f0acd Johannes Berg 2018-08-22 2810 lock_map_release(&wq->lockdep_map); 87915adc3f0acd Johannes Berg 2018-08-22 2811 3c25a55daadc7e Lai Jiangshan 2013-03-25 2812 mutex_lock(&wq->mutex); 73f53c4aa732ec Tejun Heo 2010-06-29 2813 73f53c4aa732ec Tejun Heo 2010-06-29 2814 /* 73f53c4aa732ec Tejun Heo 2010-06-29 2815 * Start-to-wait phase 73f53c4aa732ec Tejun Heo 2010-06-29 2816 */ 73f53c4aa732ec Tejun Heo 2010-06-29 2817 next_color = work_next_color(wq->work_color); 73f53c4aa732ec Tejun Heo 2010-06-29 2818 73f53c4aa732ec Tejun Heo 2010-06-29 2819 if (next_color != wq->flush_color) { 73f53c4aa732ec Tejun Heo 2010-06-29 2820 /* 73f53c4aa732ec Tejun Heo 2010-06-29 2821 * Color space is not full. The current work_color 73f53c4aa732ec Tejun Heo 2010-06-29 2822 * becomes our flush_color and work_color is advanced 73f53c4aa732ec Tejun Heo 2010-06-29 2823 * by one. 73f53c4aa732ec Tejun Heo 2010-06-29 2824 */ 6183c009f6cd94 Tejun Heo 2013-03-12 2825 WARN_ON_ONCE(!list_empty(&wq->flusher_overflow)); 73f53c4aa732ec Tejun Heo 2010-06-29 2826 this_flusher.flush_color = wq->work_color; 73f53c4aa732ec Tejun Heo 2010-06-29 2827 wq->work_color = next_color; 73f53c4aa732ec Tejun Heo 2010-06-29 2828 73f53c4aa732ec Tejun Heo 2010-06-29 2829 if (!wq->first_flusher) { 73f53c4aa732ec Tejun Heo 2010-06-29 2830 /* no flush in progress, become the first flusher */ 6183c009f6cd94 Tejun Heo 2013-03-12 2831 WARN_ON_ONCE(wq->flush_color != this_flusher.flush_color); 73f53c4aa732ec Tejun Heo 2010-06-29 2832 73f53c4aa732ec Tejun Heo 2010-06-29 2833 wq->first_flusher = &this_flusher; 73f53c4aa732ec Tejun Heo 2010-06-29 2834 112202d9098aae Tejun Heo 2013-02-13 2835 if (!flush_workqueue_prep_pwqs(wq, wq->flush_color, 73f53c4aa732ec Tejun Heo 2010-06-29 2836 wq->work_color)) { 73f53c4aa732ec Tejun Heo 2010-06-29 2837 /* nothing to flush, done */ 73f53c4aa732ec Tejun Heo 2010-06-29 2838 wq->flush_color = next_color; 73f53c4aa732ec Tejun Heo 2010-06-29 2839 wq->first_flusher = NULL; 73f53c4aa732ec Tejun Heo 2010-06-29 2840 goto out_unlock; 73f53c4aa732ec Tejun Heo 2010-06-29 2841 } 73f53c4aa732ec Tejun Heo 2010-06-29 2842 } else { 73f53c4aa732ec Tejun Heo 2010-06-29 2843 /* wait in queue */ 6183c009f6cd94 Tejun Heo 2013-03-12 2844 WARN_ON_ONCE(wq->flush_color == this_flusher.flush_color); 73f53c4aa732ec Tejun Heo 2010-06-29 2845 list_add_tail(&this_flusher.list, &wq->flusher_queue); 112202d9098aae Tejun Heo 2013-02-13 2846 flush_workqueue_prep_pwqs(wq, -1, wq->work_color); 73f53c4aa732ec Tejun Heo 2010-06-29 2847 } 73f53c4aa732ec Tejun Heo 2010-06-29 2848 } else { 73f53c4aa732ec Tejun Heo 2010-06-29 2849 /* 73f53c4aa732ec Tejun Heo 2010-06-29 2850 * Oops, color space is full, wait on overflow queue. 73f53c4aa732ec Tejun Heo 2010-06-29 2851 * The next flush completion will assign us 73f53c4aa732ec Tejun Heo 2010-06-29 2852 * flush_color and transfer to flusher_queue. 73f53c4aa732ec Tejun Heo 2010-06-29 2853 */ 73f53c4aa732ec Tejun Heo 2010-06-29 2854 list_add_tail(&this_flusher.list, &wq->flusher_overflow); 73f53c4aa732ec Tejun Heo 2010-06-29 2855 } 73f53c4aa732ec Tejun Heo 2010-06-29 2856 fca839c00a12d6 Tejun Heo 2015-12-07 2857 check_flush_dependency(wq, NULL); fca839c00a12d6 Tejun Heo 2015-12-07 2858 3c25a55daadc7e Lai Jiangshan 2013-03-25 2859 mutex_unlock(&wq->mutex); 73f53c4aa732ec Tejun Heo 2010-06-29 2860 73f53c4aa732ec Tejun Heo 2010-06-29 2861 wait_for_completion(&this_flusher.done); 73f53c4aa732ec Tejun Heo 2010-06-29 2862 73f53c4aa732ec Tejun Heo 2010-06-29 2863 /* 73f53c4aa732ec Tejun Heo 2010-06-29 2864 * Wake-up-and-cascade phase 73f53c4aa732ec Tejun Heo 2010-06-29 2865 * 73f53c4aa732ec Tejun Heo 2010-06-29 2866 * First flushers are responsible for cascading flushes and 73f53c4aa732ec Tejun Heo 2010-06-29 2867 * handling overflow. Non-first flushers can simply return. 73f53c4aa732ec Tejun Heo 2010-06-29 2868 */ 00d5d15b0641f4 Chris Wilson 2020-03-10 2869 if (READ_ONCE(wq->first_flusher) != &this_flusher) 73f53c4aa732ec Tejun Heo 2010-06-29 2870 return; 73f53c4aa732ec Tejun Heo 2010-06-29 2871 3c25a55daadc7e Lai Jiangshan 2013-03-25 2872 mutex_lock(&wq->mutex); 73f53c4aa732ec Tejun Heo 2010-06-29 2873 4ce48b37bfedc2 Tejun Heo 2010-07-02 2874 /* we might have raced, check again with mutex held */ 4ce48b37bfedc2 Tejun Heo 2010-07-02 2875 if (wq->first_flusher != &this_flusher) 4ce48b37bfedc2 Tejun Heo 2010-07-02 2876 goto out_unlock; 4ce48b37bfedc2 Tejun Heo 2010-07-02 2877 00d5d15b0641f4 Chris Wilson 2020-03-10 2878 WRITE_ONCE(wq->first_flusher, NULL); 73f53c4aa732ec Tejun Heo 2010-06-29 2879 6183c009f6cd94 Tejun Heo 2013-03-12 2880 WARN_ON_ONCE(!list_empty(&this_flusher.list)); 6183c009f6cd94 Tejun Heo 2013-03-12 2881 WARN_ON_ONCE(wq->flush_color != this_flusher.flush_color); 73f53c4aa732ec Tejun Heo 2010-06-29 2882 73f53c4aa732ec Tejun Heo 2010-06-29 2883 while (true) { 73f53c4aa732ec Tejun Heo 2010-06-29 2884 struct wq_flusher *next, *tmp; 73f53c4aa732ec Tejun Heo 2010-06-29 2885 73f53c4aa732ec Tejun Heo 2010-06-29 2886 /* complete all the flushers sharing the current flush color */ 73f53c4aa732ec Tejun Heo 2010-06-29 2887 list_for_each_entry_safe(next, tmp, &wq->flusher_queue, list) { 73f53c4aa732ec Tejun Heo 2010-06-29 2888 if (next->flush_color != wq->flush_color) 73f53c4aa732ec Tejun Heo 2010-06-29 2889 break; 73f53c4aa732ec Tejun Heo 2010-06-29 2890 list_del_init(&next->list); 73f53c4aa732ec Tejun Heo 2010-06-29 2891 complete(&next->done); 73f53c4aa732ec Tejun Heo 2010-06-29 2892 } 73f53c4aa732ec Tejun Heo 2010-06-29 2893 6183c009f6cd94 Tejun Heo 2013-03-12 2894 WARN_ON_ONCE(!list_empty(&wq->flusher_overflow) && 73f53c4aa732ec Tejun Heo 2010-06-29 2895 wq->flush_color != work_next_color(wq->work_color)); 73f53c4aa732ec Tejun Heo 2010-06-29 2896 73f53c4aa732ec Tejun Heo 2010-06-29 2897 /* this flush_color is finished, advance by one */ 73f53c4aa732ec Tejun Heo 2010-06-29 2898 wq->flush_color = work_next_color(wq->flush_color); 73f53c4aa732ec Tejun Heo 2010-06-29 2899 73f53c4aa732ec Tejun Heo 2010-06-29 2900 /* one color has been freed, handle overflow queue */ 73f53c4aa732ec Tejun Heo 2010-06-29 2901 if (!list_empty(&wq->flusher_overflow)) { 73f53c4aa732ec Tejun Heo 2010-06-29 2902 /* 73f53c4aa732ec Tejun Heo 2010-06-29 2903 * Assign the same color to all overflowed 73f53c4aa732ec Tejun Heo 2010-06-29 2904 * flushers, advance work_color and append to 73f53c4aa732ec Tejun Heo 2010-06-29 2905 * flusher_queue. This is the start-to-wait 73f53c4aa732ec Tejun Heo 2010-06-29 2906 * phase for these overflowed flushers. 73f53c4aa732ec Tejun Heo 2010-06-29 2907 */ 73f53c4aa732ec Tejun Heo 2010-06-29 2908 list_for_each_entry(tmp, &wq->flusher_overflow, list) 73f53c4aa732ec Tejun Heo 2010-06-29 2909 tmp->flush_color = wq->work_color; 73f53c4aa732ec Tejun Heo 2010-06-29 2910 73f53c4aa732ec Tejun Heo 2010-06-29 2911 wq->work_color = work_next_color(wq->work_color); 73f53c4aa732ec Tejun Heo 2010-06-29 2912 73f53c4aa732ec Tejun Heo 2010-06-29 2913 list_splice_tail_init(&wq->flusher_overflow, 73f53c4aa732ec Tejun Heo 2010-06-29 2914 &wq->flusher_queue); 112202d9098aae Tejun Heo 2013-02-13 2915 flush_workqueue_prep_pwqs(wq, -1, wq->work_color); 73f53c4aa732ec Tejun Heo 2010-06-29 2916 } 73f53c4aa732ec Tejun Heo 2010-06-29 2917 73f53c4aa732ec Tejun Heo 2010-06-29 2918 if (list_empty(&wq->flusher_queue)) { 6183c009f6cd94 Tejun Heo 2013-03-12 2919 WARN_ON_ONCE(wq->flush_color != wq->work_color); 73f53c4aa732ec Tejun Heo 2010-06-29 2920 break; 73f53c4aa732ec Tejun Heo 2010-06-29 2921 } 73f53c4aa732ec Tejun Heo 2010-06-29 2922 73f53c4aa732ec Tejun Heo 2010-06-29 2923 /* 73f53c4aa732ec Tejun Heo 2010-06-29 2924 * Need to flush more colors. Make the next flusher 112202d9098aae Tejun Heo 2013-02-13 2925 * the new first flusher and arm pwqs. 73f53c4aa732ec Tejun Heo 2010-06-29 2926 */ 6183c009f6cd94 Tejun Heo 2013-03-12 2927 WARN_ON_ONCE(wq->flush_color == wq->work_color); 6183c009f6cd94 Tejun Heo 2013-03-12 2928 WARN_ON_ONCE(wq->flush_color != next->flush_color); 73f53c4aa732ec Tejun Heo 2010-06-29 2929 73f53c4aa732ec Tejun Heo 2010-06-29 2930 list_del_init(&next->list); 73f53c4aa732ec Tejun Heo 2010-06-29 2931 wq->first_flusher = next; 73f53c4aa732ec Tejun Heo 2010-06-29 2932 112202d9098aae Tejun Heo 2013-02-13 2933 if (flush_workqueue_prep_pwqs(wq, wq->flush_color, -1)) 73f53c4aa732ec Tejun Heo 2010-06-29 2934 break; 73f53c4aa732ec Tejun Heo 2010-06-29 2935 73f53c4aa732ec Tejun Heo 2010-06-29 2936 /* 73f53c4aa732ec Tejun Heo 2010-06-29 2937 * Meh... this color is already done, clear first 73f53c4aa732ec Tejun Heo 2010-06-29 2938 * flusher and repeat cascading. 73f53c4aa732ec Tejun Heo 2010-06-29 2939 */ 73f53c4aa732ec Tejun Heo 2010-06-29 2940 wq->first_flusher = NULL; 73f53c4aa732ec Tejun Heo 2010-06-29 2941 } 73f53c4aa732ec Tejun Heo 2010-06-29 2942 73f53c4aa732ec Tejun Heo 2010-06-29 2943 out_unlock: 3c25a55daadc7e Lai Jiangshan 2013-03-25 2944 mutex_unlock(&wq->mutex); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2945 } 1dadafa86a7798 Tim Gardner 2015-08-04 2946 EXPORT_SYMBOL(flush_workqueue); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2947 -- 0-DAY CI Kernel Test Service https://01.org/lkp