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 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 50BDFC43382 for ; Tue, 25 Sep 2018 14:41:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13BDC2082C for ; Tue, 25 Sep 2018 14:41:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 13BDC2082C 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 S1729371AbeIYUtU (ORCPT ); Tue, 25 Sep 2018 16:49:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11589 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729175AbeIYUtU (ORCPT ); Tue, 25 Sep 2018 16:49:20 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E4FD0368E7; Tue, 25 Sep 2018 14:41:30 +0000 (UTC) Received: from llong.com (dhcp-17-8.bos.redhat.com [10.18.17.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id A554D60BF6; Tue, 25 Sep 2018 14:41:29 +0000 (UTC) From: Waiman Long To: Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Will Deacon Cc: linux-kernel@vger.kernel.org, Yang Shi , Arnd Bergmann , chuhu@redhat.com, Waiman Long Subject: [PATCH v2 0/2] debugobjects: Fix potential hard lockup by disabling lockdep Date: Tue, 25 Sep 2018 10:41:07 -0400 Message-Id: <1537886469-18227-1-git-send-email-longman@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 25 Sep 2018 14:41:31 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org v2: - Add a lockdep patch to fix a dmesg warning message due to the use of the novalidate class. The only locking used by the debugobjects code is just 2 sets of raw spinlocks for synchronization purpose. When lockdep is enabled, the locking operation itself will become much more expensive especially if a number of locks have already been acquired previously. In some extreme cases, it may lead to hard lockup. As there isn't much value in debugging the debugobjects internal locks, lockdep checking is now disabled for those internal locks. That will speed up system operation without compromising the lock checking operation of production code. Waiman Long (2): locking/lockdep: Don't warn class/lock name mismatch for novalidate class debugobjects: Disable lockdep tracking of debugobjects internal locks kernel/locking/lockdep.c | 7 +++++-- lib/debugobjects.c | 9 ++++++++- 2 files changed, 13 insertions(+), 3 deletions(-) -- 2.18.0