From patchwork Thu Nov 26 09:51:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Wagner X-Patchwork-Id: 11933149 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 B1FAAC63777 for ; Thu, 26 Nov 2020 09:52:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A9D5208CA for ; Thu, 26 Nov 2020 09:52:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387413AbgKZJv7 (ORCPT ); Thu, 26 Nov 2020 04:51:59 -0500 Received: from mx2.suse.de ([195.135.220.15]:46630 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387418AbgKZJv6 (ORCPT ); Thu, 26 Nov 2020 04:51:58 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id DDFF1ACA3; Thu, 26 Nov 2020 09:51:56 +0000 (UTC) From: Daniel Wagner To: linux-block@vger.kernel.org Cc: Jens Axboe , linux-kernel@vger.kernel.org, Ming Lei , Daniel Wagner Subject: [PATCH] blk-mq: Make running from the wrong CPU less scary Date: Thu, 26 Nov 2020 10:51:52 +0100 Message-Id: <20201126095152.19151-1-dwagner@suse.de> X-Mailer: git-send-email 2.16.4 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The current warning looks aweful like a proper crash. This is confusing. There is not much information to gained from the stack trace anyway, let's drop it. While at it print the cpumask as there might be additial helpful information when debugging the sitation. Signed-off-by: Daniel Wagner --- Hi, We got a report from a customer because he was concerned about the log entries. As it turns out, it fooled me too to be honest. What do you think about making it a bit less look-a-like a kernel oops? smpboot: Booting Node 0 Processor 12 APIC 0x26 WARNING, didn't collect load info for all cpus, balancing is broken run queue from wrong CPU 0, hctx active CPU: 0 PID: 42300 Comm: kworker/13:2H Kdump: loaded Tainted: G OE X 5.3.18-109.$ Hardware name: IBM System x3650 M5 -[5462AC1]-/00KG915, BIOS -[TCE144J-3.11]- 12/03/2019 Workqueue: kblockd blk_mq_run_work_fn Call Trace: dump_stack+0x66/0x8b __blk_mq_run_hw_queue+0xee/0x100 process_one_work+0x1f4/0x3e0 worker_thread+0x2d/0x3e0 ? process_one_work+0x3e0/0x3e0 kthread+0x10d/0x130 ? kthread_park+0xa0/0xa0 ret_from_fork+0x35/0x40 run queue from wrong CPU 0, hctx active CPU: 0 PID: 42300 Comm: kworker/13:2H Kdump: loaded Tainted: G OE X 5.3.18-109.$ Hardware name: IBM System x3650 M5 -[5462AC1]-/00KG915, BIOS -[TCE144J-3.11]- 12/03/2019 Workqueue: kblockd blk_mq_run_work_fn Thanks, Daniel block/blk-mq.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 55bcee5dc032..0427b719d9c4 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1514,10 +1514,8 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) */ if (!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) && cpu_online(hctx->next_cpu)) { - printk(KERN_WARNING "run queue from wrong CPU %d, hctx %s\n", - raw_smp_processor_id(), - cpumask_empty(hctx->cpumask) ? "inactive": "active"); - dump_stack(); + printk(KERN_WARNING "run queue from wrong CPU %d, hctx %*pbl\n", + raw_smp_processor_id(), cpumask_pr_args(hctx->cpumask)); } /*