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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 80F1BECDE43 for ; Fri, 19 Oct 2018 01:45:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5012520866 for ; Fri, 19 Oct 2018 01:45:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5012520866 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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 S1726903AbeJSJti (ORCPT ); Fri, 19 Oct 2018 05:49:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58564 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725934AbeJSJth (ORCPT ); Fri, 19 Oct 2018 05:49:37 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ED91A83F45; Fri, 19 Oct 2018 01:45:47 +0000 (UTC) Received: from llong.com (ovpn-121-107.rdu2.redhat.com [10.10.121.107]) by smtp.corp.redhat.com (Postfix) with ESMTP id DC74886B41; Fri, 19 Oct 2018 01:45:46 +0000 (UTC) From: Waiman Long To: Peter Zijlstra , Ingo Molnar , Will Deacon , Thomas Gleixner Cc: linux-kernel@vger.kernel.org, Waiman Long Subject: [PATCH 2/2] locking/lockdep: Make global debug_locks* variables read-mostly Date: Thu, 18 Oct 2018 21:45:18 -0400 Message-Id: <1539913518-15598-2-git-send-email-longman@redhat.com> In-Reply-To: <1539913518-15598-1-git-send-email-longman@redhat.com> References: <1539913518-15598-1-git-send-email-longman@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 19 Oct 2018 01:45:48 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make the frequently used lockdep global variable debug_locks read-mostly. As debug_locks_silent is sometime used together with debug_locks, it is also made read-mostly so that they can be close together. With false cacheline sharing, cacheline contention problem can happen depending on what get put into the same cacheline as debug_locks. Signed-off-by: Waiman Long --- include/linux/debug_locks.h | 4 ++-- lib/debug_locks.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h index 120225e..257ab3c 100644 --- a/include/linux/debug_locks.h +++ b/include/linux/debug_locks.h @@ -8,8 +8,8 @@ struct task_struct; -extern int debug_locks; -extern int debug_locks_silent; +extern int debug_locks __read_mostly; +extern int debug_locks_silent __read_mostly; static inline int __debug_locks_off(void) diff --git a/lib/debug_locks.c b/lib/debug_locks.c index 124fdf2..ce51749 100644 --- a/lib/debug_locks.c +++ b/lib/debug_locks.c @@ -21,7 +21,7 @@ * that would just muddy the log. So we report the first one and * shut up after that. */ -int debug_locks = 1; +int debug_locks __read_mostly = 1; EXPORT_SYMBOL_GPL(debug_locks); /* @@ -29,7 +29,7 @@ * 'silent failure': nothing is printed to the console when * a locking bug is detected. */ -int debug_locks_silent; +int debug_locks_silent __read_mostly; EXPORT_SYMBOL_GPL(debug_locks_silent); /* -- 1.8.3.1