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 60AC9C433F5 for ; Wed, 30 Mar 2022 11:19:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343586AbiC3LVc (ORCPT ); Wed, 30 Mar 2022 07:21:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235372AbiC3LV3 (ORCPT ); Wed, 30 Mar 2022 07:21:29 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AADE109A4A; Wed, 30 Mar 2022 04:19:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1648639184; x=1680175184; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=hNn5VlT2gG+pVF4p+g9iABCXPtmNiVuS8fWlHnCJL5s=; b=G3kgL2k0Gk+C4Zt1XDedP5SqrptKJthosK8psreKas2IfUHA2Odg4jXN 83HjoySbHB8qZ5owdXSmPuFpxheflLumeOc9fCec8mMoKmirKTTjmt66L 9FLX9cOqfacLDllNiEdtbghwVrpQjTiapzuwvN2AzC+MjDhJpR05WkEMW adsD70/eyv5rBKeWgecTeM/V2h3MvydRMziURWSeIsjmi1w8UfW8QcM/M 264wcBMBW7imRnQWzb9ySdDtpDkY0ryRObSXG/1XI9Pcm+oGlA9xd28lG G6f/zLcU3nLqUUsjp7BaMeHt9n/7ndnesrNjfHcx9Kwy8tKIbxtfxSH7V g==; X-IronPort-AV: E=McAfee;i="6200,9189,10301"; a="345954414" X-IronPort-AV: E=Sophos;i="5.90,222,1643702400"; d="scan'208";a="345954414" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Mar 2022 04:19:44 -0700 X-IronPort-AV: E=Sophos;i="5.90,222,1643702400"; d="scan'208";a="565495185" Received: from zq-optiplex-7090.bj.intel.com ([10.238.156.125]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Mar 2022 04:19:42 -0700 From: Zqiang To: paulmck@kernel.org, frederic@kernel.org Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] rcu-tasks: Check the atomic variable trc_n_readers_need_end again when wait timeout Date: Wed, 30 Mar 2022 19:20:14 +0800 Message-Id: <20220330112014.2587148-1-qiang1.zhang@intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the trc_wait waitqueue timeout, the atomic variable trc_n_readers_need_end need to be checked again, perhaps the conditions have been established at this time, avoid invalid stall information output. Signed-off-by: Zqiang --- kernel/rcu/tasks.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 65d6e21a607a..b73a2b362d6b 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1544,7 +1544,7 @@ static void rcu_tasks_trace_postgp(struct rcu_tasks *rtp) trc_wait, atomic_read(&trc_n_readers_need_end) == 0, READ_ONCE(rcu_task_stall_timeout)); - if (ret) + if (ret || !atomic_read(&trc_n_readers_need_end)) break; // Count reached zero. // Stall warning time, so make a list of the offenders. rcu_read_lock(); -- 2.25.1