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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 D2CBAC433E0 for ; Fri, 26 Jun 2020 21:05:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A24DF2075D for ; Fri, 26 Jun 2020 21:05:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593205508; bh=bcnEDY2baADluA2OfBYZhXvSSPnVEiJFwVXnomA4i0o=; h=Date:From:To:Cc:Subject:Reply-To:List-ID:From; b=vqEL88WlNE/LpVIOxwt+M3FatJnkzpSbF2YyXjhSHMxjB9lHajn1s2YEziLmQydYS LgkMbP5Rb7cT4cBU317dyI/PAgEkX91vn5eH1U+Bq7iTUG3GVTG5hzH8napOcK/Usu oNjo3FNS/EytocHMMDu6ziMtKulCFFQm6/BVvytg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725998AbgFZVFH (ORCPT ); Fri, 26 Jun 2020 17:05:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:49410 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725781AbgFZVFG (ORCPT ); Fri, 26 Jun 2020 17:05:06 -0400 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 43B7920720; Fri, 26 Jun 2020 21:05:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593205506; bh=bcnEDY2baADluA2OfBYZhXvSSPnVEiJFwVXnomA4i0o=; h=Date:From:To:Cc:Subject:Reply-To:From; b=TdkF652cvhtJnzyzi3Cm98ECt/CSWSN92xiu4XFPBKfoFc+UTfHkwn0sHbgF4ByJ1 GLPT13ntMa1Fn6UluhoM7etb4gVWrRPJ5RtHhR4MQv5+45utfFIHDnX+Poi2lXtfw0 FJvfY3QNGWoi6kY8r1m2dzjbKK2cU8H+xdChs5AQ= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 2A6E535230EC; Fri, 26 Jun 2020 14:05:06 -0700 (PDT) Date: Fri, 26 Jun 2020 14:05:06 -0700 From: "Paul E. McKenney" To: fweisbec@gmail.com, tglx@linutronix.de, mingo@kernel.org Cc: linux-kernel@vger.kernel.org, luto@kernel.org, kernel-team@fb.com Subject: [PATCH tick-sched] Clarify "NOHZ: local_softirq_pending" warning Message-ID: <20200626210506.GA27189@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 Currently, can_stop_idle_tick() prints "NOHZ: local_softirq_pending HH" (where "HH" is the hexadecimal softirq vector number) when one or more non-RCU softirq handlers are still enablded when checking to stop the scheduler-tick interrupt. This message is not as enlightening as one might hope, so this commit changes it to "NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #HH. Reported-by: Andy Lutomirski Signed-off-by: Paul E. McKenney --- tick-sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index f0199a4..349a25a 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -927,7 +927,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts) if (ratelimit < 10 && (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) { - pr_warn("NOHZ: local_softirq_pending %02x\n", + pr_warn("NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #%02x\n", (unsigned int) local_softirq_pending()); ratelimit++; }