From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934543AbcIWHNA (ORCPT ); Fri, 23 Sep 2016 03:13:00 -0400 Received: from merlin.infradead.org ([205.233.59.134]:47772 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932127AbcIWHM6 (ORCPT ); Fri, 23 Sep 2016 03:12:58 -0400 Date: Fri, 23 Sep 2016 09:12:46 +0200 From: Peter Zijlstra To: Babu Moger Cc: mingo@redhat.com, akpm@linux-foundation.org, keescook@chromium.org, dan.j.williams@intel.com, aryabinin@virtuozzo.com, tj@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] Ajust lockdep static allocations Message-ID: <20160923071246.GJ2794@worktop> References: <1474569816-170269-1-git-send-email-babu.moger@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1474569816-170269-1-git-send-email-babu.moger@oracle.com> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 22, 2016 at 11:43:34AM -0700, Babu Moger wrote: > These patches adjust the static allocations for lockdep > data structures used for debugging locking correctness. The current > code reserves about 4MB extra space for these data structures. Most > of the configurations do not need these many data structures. While > testing, I have not seen it go beyond 20% of already reserved entries. > > $grep "lock-classes" /proc/lockdep_stats > lock-classes: 1560 [max: 8191] > > Reserving even more space seems unreasonable. So, keeping the default > entries small as before the Commit 1413c0389333 ("lockdep: Increase static > allocations"). Added new CONFIG_PROVE_LOCKING_PLUS in case someone > needs more entries to debug their large configuration. Why make this more complicated? There's absolutely no upside to this change as far as I can see.