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 3460AC433EF for ; Wed, 13 Apr 2022 07:43:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233443AbiDMHqP (ORCPT ); Wed, 13 Apr 2022 03:46:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229582AbiDMHqJ (ORCPT ); Wed, 13 Apr 2022 03:46:09 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B03932E69C; Wed, 13 Apr 2022 00:43:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1649835829; x=1681371829; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=9LnT73jUESFVZOk+Ffoh5evZ5ZtPW8CwyMo+B2FIm2w=; b=av3yyfp1BfjByYv/XvOuhIrXsZ/hb/C9DvCo/CTt/acArZAlMF9Uuczj isOBV1vImuXI4ggs3aLzy1RCrRdX2TcCylqEuA36ro3qdvDvTuX/wiThh Y6KVZ5ydBccTJSp+/rEXbA266Y/qYegF+Y3vp1Jlajyl7MfyDL+4cnp4U Lv4i2GfW7kNnuWEszeAgF9V5ghcJiheVhCZSlcsQC0/Vih1WogRSGUowN HBhpeqCG8z945BuDyTGdl7gJpYE9Ad3WK4oUA7m3wrYd6GM+RJq/4SGKE w+ajfBeiNYip7wh3qx0m67qw0m+6hu67gWZb7LFA3kxrdRnjOJfbmhe9q A==; X-IronPort-AV: E=McAfee;i="6400,9594,10315"; a="323044265" X-IronPort-AV: E=Sophos;i="5.90,256,1643702400"; d="scan'208";a="323044265" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2022 00:43:49 -0700 X-IronPort-AV: E=Sophos;i="5.90,256,1643702400"; d="scan'208";a="573159281" 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; 13 Apr 2022 00:43:47 -0700 From: Zqiang To: paulmck@kernel.org, frederic@kernel.org Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] rcu: Dump all rcuc kthreads status for CPUs that not report quiescent state Date: Wed, 13 Apr 2022 15:44:11 +0800 Message-Id: <20220413074411.2369623-1-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 If the rcutree.use_softirq is configured, when RCU Stall event happened, dump status of all rcuc kthreads who due to starvation prevented grace period ends on CPUs that not report quiescent state. Signed-off-by: Zqiang --- kernel/rcu/tree_stall.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index d7956c03edbd..e6ecc32cfe23 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -348,6 +348,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp, unsigned long flags) } #endif /* #else #ifdef CONFIG_PREEMPT_RCU */ +static void rcuc_kthread_dump(struct rcu_data *rdp); /* * Dump stacks of all tasks running on stalled CPUs. First try using * NMIs, but fall back to manual remote stack tracing on architectures @@ -368,6 +369,7 @@ static void rcu_dump_cpu_stacks(void) pr_err("Offline CPU %d blocking current GP.\n", cpu); else if (!trigger_single_cpu_backtrace(cpu)) dump_cpu_task(cpu); + rcuc_kthread_dump(per_cpu_ptr(&rcu_data, cpu)); } raw_spin_unlock_irqrestore_rcu_node(rnp, flags); } @@ -471,6 +473,9 @@ static void rcuc_kthread_dump(struct rcu_data *rdp) unsigned long j; struct task_struct *rcuc; + if (use_softirq) + return; + rcuc = rdp->rcu_cpu_kthread_task; if (!rcuc) return; @@ -659,9 +664,6 @@ static void print_cpu_stall(unsigned long gps) rcu_check_gp_kthread_expired_fqs_timer(); rcu_check_gp_kthread_starvation(); - if (!use_softirq) - rcuc_kthread_dump(rdp); - rcu_dump_cpu_stacks(); raw_spin_lock_irqsave_rcu_node(rnp, flags); -- 2.25.1