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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED, USER_AGENT_MUTT 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 A8140C433F5 for ; Thu, 30 Aug 2018 15:13:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63D8A20834 for ; Thu, 30 Aug 2018 15:13:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="1e6SM07j" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 63D8A20834 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727234AbeH3TPf (ORCPT ); Thu, 30 Aug 2018 15:15:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:55258 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727200AbeH3TPf (ORCPT ); Thu, 30 Aug 2018 15:15:35 -0400 Received: from localhost (LFbn-NCY-1-241-207.w83-194.abo.wanadoo.fr [83.194.85.207]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4DB3E205F4; Thu, 30 Aug 2018 15:12:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1535641977; bh=UEdj/Gvxc1E4fi6Ekzt0jkGxF/qoD117BFuS/9wgM6Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=1e6SM07jZRZcEwfwdDjn8diIvaHEUJPwRAiVkWpHeHe58f2d5UoCQdbwNdbNeTR6b rYYhk2+M76qsSMWitj1cGXWt3uId8wEZsWKYwAJJGBvk03BUuS24LYr8qbxMh5BvEs T/xbKu/wHm42BK/4FU4g2Q7QT4j7uSWR+RDOkJII= Date: Thu, 30 Aug 2018 17:12:54 +0200 From: Frederic Weisbecker To: Thomas Gleixner Cc: John Crispin , LKML , Ingo Molnar , Anna-Maria Gleixner , Greg Kroah-Hartman , stable@vger.kernel.org Subject: Re: [PATCH stable] tick/nohz: Prevent bogus softirq pending warning Message-ID: <20180830151253.GB27947@lerouge> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 30, 2018 at 05:05:19PM +0200, Thomas Gleixner wrote: > Commit 0a0e0829f990 ("nohz: Fix missing tick reprogram when interrupting an > inline softirq") got backported to stable trees and now causes the NOHZ > softirq pending warning to trigger. It's not an upstream issue as the NOHZ > update logic has been changed there. > > The problem is when a softirq disabled section gets interrupted and on > return from interrupt the tick/nohz state is evaluated, which then can > observe pending soft interrupts. These soft interrupts are legitimately > pending because they cannot be processed as long as soft interrupts are > disabled and the interrupted code will correctly process them when soft > interrupts are reenabled. > > Add a check for softirqs disabled to the pending check to prevent the > warning. > > Reported-by: Grygorii Strashko > Reported-by: John Crispin > Signed-off-by: Thomas Gleixner > Tested-by: Grygorii Strashko > Tested-by: John Crispin Acked-by: Frederic Weisbecker Thanks for cooking the patch!