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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 AD1C4C432C0 for ; Mon, 25 Nov 2019 23:03:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 827E820733 for ; Mon, 25 Nov 2019 23:03:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574722994; bh=V5myIoi+TkGF78Dq2cQKGEetssgdzrwL1cU7IB/74DI=; h=Date:From:To:Cc:Subject:Reply-To:List-ID:From; b=QAEAZeLN5t5rzz7yGxbcJp/oSitPfPVcXOgoSssQsO9RKvT1615qsUmalrf3CVSZt hHaMzY8jHVEd0w6XUdrQPSBkKMTKWcRTBt72Cp7oB9ZnxfYAhJMgxtvdu1gDNCUWc4 SliLTdL2B19j6WM6RVS/m4/QgB32tm+TNz+zfUTE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726970AbfKYXDN (ORCPT ); Mon, 25 Nov 2019 18:03:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:50406 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725940AbfKYXDN (ORCPT ); Mon, 25 Nov 2019 18:03:13 -0500 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BD8CF20733; Mon, 25 Nov 2019 23:03:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574722992; bh=V5myIoi+TkGF78Dq2cQKGEetssgdzrwL1cU7IB/74DI=; h=Date:From:To:Cc:Subject:Reply-To:From; b=TR4KUVPBCbIfN99ArwvHsc2FoU95ZOrzHGfNz5TeVAoriNm6VOnhyUmyhBrbzfG33 uV2anc+e6O3hthYn5CWCmKVKfysZMd8FHZ0fCsBX/FFerapQaNEENbx8LhItbGnGWB zOpAO+0aXxgkFvJxEVwK/z+pSRgwwFSrZ7i5eyAQ= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 64CA83522A71; Mon, 25 Nov 2019 15:03:12 -0800 (PST) Date: Mon, 25 Nov 2019 15:03:12 -0800 From: "Paul E. McKenney" To: tj@kernel.org, jiangshanlai@gmail.com Cc: linux-kernel@vger.kernel.org Subject: Workqueues splat due to ending up on wrong CPU Message-ID: <20191125230312.GP2889@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! I am seeing this occasionally during rcutorture runs in the presence of CPU hotplug. This is on v5.4-rc1 in process_one_work() at the first WARN_ON(): WARN_ON_ONCE(!(pool->flags & POOL_DISASSOCIATED) && raw_smp_processor_id() != pool->cpu); What should I do to help further debug this? Thanx, Paul ------------------------------------------------------------------------ [ 7119.309435] WARNING: CPU: 1 PID: 4 at kernel/workqueue.c:2179 process_one_work+0x86/0x510 [ 7119.310449] Modules linked in: [ 7119.310849] CPU: 1 PID: 4 Comm: rcu_par_gp Not tainted 5.4.0-rc1+ #21 [ 7119.311656] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.11.0-2.el7 04/01/2014 [ 7119.312693] RIP: 0010:process_one_work+0x86/0x510 [ 7119.313250] Code: ee 05 48 89 44 24 10 48 8b 46 38 41 83 e6 01 41 f6 44 24 44 04 48 89 44 24 28 75 10 65 8b 05 39 7d 98 7b 41 3b 44 24 38 74 02 <0f> 0b 48 89 de 4c 89 e7 e8 7d cd ff ff 48 85 c0 0f 85 0e 04 00 00 [ 7119.315555] RSP: 0000:ffff9aba4002fe30 EFLAGS: 00010002 [ 7119.316189] RAX: 0000000000000001 RBX: ffffffff85c65f68 RCX: 0000000000000000 [ 7119.317064] RDX: ffff97a5df22d400 RSI: ffffffff85c65f68 RDI: ffff97a5dec95600 [ 7119.317943] RBP: ffff97a5dec95600 R08: ffffffff85c65f70 R09: ffffffff86856140 [ 7119.318812] R10: 0000000000000000 R11: 0000000000000001 R12: ffff97a5df228a80 [ 7119.319703] R13: ffff97a5df22d400 R14: 0000000000000000 R15: ffff97a5dec95600 [ 7119.320602] FS: 0000000000000000(0000) GS:ffff97a5df240000(0000) knlGS:0000000000000000 [ 7119.321581] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 7119.322301] CR2: 0000000000000148 CR3: 0000000015c1e000 CR4: 00000000000006e0 [ 7119.323188] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 7119.324069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 7119.324957] Call Trace: [ 7119.325288] rescuer_thread+0x1b5/0x2e0 [ 7119.325772] kthread+0xf3/0x130 [ 7119.326164] ? worker_thread+0x3c0/0x3c0 [ 7119.326655] ? kthread_cancel_delayed_work_sync+0x10/0x10 [ 7119.327349] ret_from_fork+0x35/0x40 [ 7119.327795] ---[ end trace 6dd6d520676d8e8e ]---