From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) by kanga.kvack.org (Postfix) with ESMTP id 811286B1BF7 for ; Mon, 19 Nov 2018 13:57:48 -0500 (EST) Received: by mail-qk1-f199.google.com with SMTP id f22so69981425qkm.11 for ; Mon, 19 Nov 2018 10:57:48 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id o127si7092133qkd.13.2018.11.19.10.57.47 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 19 Nov 2018 10:57:47 -0800 (PST) From: 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> Sender: owner-linux-mm@kvack.org List-ID: 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 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