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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 4FD1CC1B0F2 for ; Wed, 20 Jun 2018 08:47:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8C29220846 for ; Wed, 20 Jun 2018 08:47:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8C29220846 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lge.com 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 S933163AbeFTIr2 (ORCPT ); Wed, 20 Jun 2018 04:47:28 -0400 Received: from lgeamrelo13.lge.com ([156.147.23.53]:45304 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933111AbeFTIrY (ORCPT ); Wed, 20 Jun 2018 04:47:24 -0400 Received: from unknown (HELO lgeamrelo02.lge.com) (156.147.1.126) by 156.147.23.53 with ESMTP; 20 Jun 2018 17:47:22 +0900 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: byungchul.park@lge.com Received: from unknown (HELO localhost.localdomain) (10.177.222.33) by 156.147.1.126 with ESMTP; 20 Jun 2018 17:47:22 +0900 X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com From: Byungchul Park To: jiangshanlai@gmail.com, paulmck@linux.vnet.ibm.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com Cc: linux-kernel@vger.kernel.org, kernel-team@lge.com, joel@joelfernandes.org Subject: [RFC 1/2] rcu: Do prepare and cleanup idle depending on in_nmi() Date: Wed, 20 Jun 2018 17:47:19 +0900 Message-Id: <1529484440-20634-1-git-send-email-byungchul.park@lge.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Get rid of dependency on ->dynticks_nmi_nesting. Signed-off-by: Byungchul Park --- kernel/rcu/tree.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index deb2508..59ae94e 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -797,6 +797,11 @@ void rcu_nmi_exit(void) return; } + if (!in_nmi()) { + rcu_prepare_for_idle(); + rcu_dynticks_task_enter(); + } + /* This NMI interrupted an RCU-idle CPU, restore RCU-idleness. */ trace_rcu_dyntick(TPS("Startirq"), rdtp->dynticks_nmi_nesting, 0, rdtp->dynticks); WRITE_ONCE(rdtp->dynticks_nmi_nesting, 0); /* Avoid store tearing. */ @@ -824,14 +829,8 @@ void rcu_nmi_exit(void) */ void rcu_irq_exit(void) { - struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks); - lockdep_assert_irqs_disabled(); - if (rdtp->dynticks_nmi_nesting == 1) - rcu_prepare_for_idle(); rcu_nmi_exit(); - if (rdtp->dynticks_nmi_nesting == 0) - rcu_dynticks_task_enter(); } /* @@ -944,6 +943,11 @@ void rcu_nmi_enter(void) if (rcu_dynticks_curr_cpu_in_eqs()) { rcu_dynticks_eqs_exit(); incby = 1; + + if (!in_nmi()) { + rcu_dynticks_task_exit(); + rcu_cleanup_after_idle(); + } } trace_rcu_dyntick(incby == 1 ? TPS("Endirq") : TPS("++="), rdtp->dynticks_nmi_nesting, @@ -977,14 +981,8 @@ void rcu_nmi_enter(void) */ void rcu_irq_enter(void) { - struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks); - lockdep_assert_irqs_disabled(); - if (rdtp->dynticks_nmi_nesting == 0) - rcu_dynticks_task_exit(); rcu_nmi_enter(); - if (rdtp->dynticks_nmi_nesting == 1) - rcu_cleanup_after_idle(); } /* -- 1.9.1