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 17D60ECAAD4 for ; Tue, 30 Aug 2022 08:25:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231435AbiH3IZx (ORCPT ); Tue, 30 Aug 2022 04:25:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230430AbiH3IZv (ORCPT ); Tue, 30 Aug 2022 04:25:51 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1031253000; Tue, 30 Aug 2022 01:25:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1661847951; x=1693383951; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=FM2Nw6OVv3oANgo8eVrCve+EM/odlJq6l1r72WRUiCU=; b=AMdaVOefmx3cat1jWPp1TxPxt+elMIwRs+K3p5i7rDGxRb7SEDcc4nEt 996zMz708/UXcjQbAcJetzsFbhCXuTz5J4pidbZniMr3VppKokDRUKaNh wbQF9P3UNvY3Ukiv2g6+htqQoOnfzajg1qtPpbIljpBfipaLDxaOFAtwJ lI2l44ynQTc3mcN32GDbpSvoEukdLktrog05TYhL+x2yxlAcJC3xjH8gb /kNjPP6JI7TmvYKlrgIfgEBG04oaZheZF5OUlZMUbx5De+B/uSbwI7Gav zbN14GU6XeAhhF+tOXSDCGD+Fwmk/YkJYLQTeYEfSpe81KB754xqjJYFa A==; X-IronPort-AV: E=McAfee;i="6500,9779,10454"; a="275517826" X-IronPort-AV: E=Sophos;i="5.93,274,1654585200"; d="scan'208";a="275517826" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2022 01:25:50 -0700 X-IronPort-AV: E=Sophos;i="5.93,274,1654585200"; d="scan'208";a="672751679" Received: from zq-optiplex-7090.bj.intel.com ([10.238.156.129]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2022 01:25:49 -0700 From: Zqiang To: paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com, joel@joelfernandes.org Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] rcu: Remove duplicate RCU exp QS report from rcu_report_dead() Date: Tue, 30 Aug 2022 16:31:51 +0800 Message-Id: <20220830083151.396561-1-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 For PREEMPT_RCU, the rcu_report_dead() is invoked means that the outgoing CPU mask is clear from leaf rcu_node and has no further need of RCU, so invoke rcu_preempt_depth() return value is always zero in rcu_report_dead(), if the current outgoing CPU rcu_data structure's cpu_no_qs.b.exp is true, the rcu_preempt_deferred_qs() will invoke rcu_report_exp_rdp() to report exp QS. for non-PREEMPT_RCU, the rcu_preempt_deferred_qs() is equivalent to rcu_report_exp_rdp(). Signed-off-by: Zqiang --- kernel/rcu/tree.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 6bb8e72bc815..0ca21ac0f064 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4276,8 +4276,6 @@ void rcu_report_dead(unsigned int cpu) // Do any dangling deferred wakeups. do_nocb_deferred_wakeup(rdp); - /* QS for any half-done expedited grace period. */ - rcu_report_exp_rdp(rdp); rcu_preempt_deferred_qs(current); /* Remove outgoing CPU from mask in the leaf rcu_node structure. */ -- 2.25.1