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=-7.0 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 686B6C43441 for ; Mon, 19 Nov 2018 18:57:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FD1220851 for ; Mon, 19 Nov 2018 18:57:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3FD1220851 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 S1730746AbeKTFWm (ORCPT ); Tue, 20 Nov 2018 00:22:42 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47882 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730712AbeKTFWk (ORCPT ); Tue, 20 Nov 2018 00:22:40 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E2AED58E5A; Mon, 19 Nov 2018 18:57:46 +0000 (UTC) Received: from llong.com (dhcp-17-55.bos.redhat.com [10.18.17.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4B0726090A; Mon, 19 Nov 2018 18:57:45 +0000 (UTC) From: Waiman Long To: Peter Zijlstra , Ingo Molnar , Will Deacon , Thomas Gleixner Cc: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Petr Mladek , Sergey Senozhatsky , Andrey Ryabinin , Tejun Heo , Andrew Morton , Waiman Long Subject: [PATCH v2 16/17] delay_acct: Mark task's delays->lock as terminal spinlock Date: Mon, 19 Nov 2018 13:55:25 -0500 Message-Id: <1542653726-5655-17-git-send-email-longman@redhat.com> In-Reply-To: <1542653726-5655-1-git-send-email-longman@redhat.com> References: <1542653726-5655-1-git-send-email-longman@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 19 Nov 2018 18:57:47 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org By making task's delays->lock a terminal spinlock, it reduces the lockdep overhead when this lock is used. Signed-off-by: Waiman Long --- kernel/delayacct.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 2a12b98..49dd8d3 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -43,8 +43,10 @@ void delayacct_init(void) void __delayacct_tsk_init(struct task_struct *tsk) { tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL); - if (tsk->delays) + if (tsk->delays) { raw_spin_lock_init(&tsk->delays->lock); + lockdep_set_terminal_class(&tsk->delays->lock); + } } /* -- 1.8.3.1