Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752627AbdI1J0O (ORCPT ); Thu, 28 Sep 2017 05:26:14 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:55295 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751999AbdI1J0N (ORCPT ); Thu, 28 Sep 2017 05:26:13 -0400 Date: Thu, 28 Sep 2017 11:26:00 +0200 From: Peter Zijlstra To: Govindarajulu Varadarajan Cc: benve@cisco.com, bhelgaas@google.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, jlbec@evilplan.org, hch@lst.de, mingo@redhat.com Subject: Re: [PATCH 4/4] lockdep: make MAX_LOCK_DEPTH configurable from Kconfig Message-ID: <20170928092600.qvehxzikcjr65hvw@hirez.programming.kicks-ass.net> References: <20170927214220.41216-1-gvaradar@cisco.com> <20170927214220.41216-5-gvaradar@cisco.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170927214220.41216-5-gvaradar@cisco.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 441 Lines: 9 On Wed, Sep 27, 2017 at 02:42:20PM -0700, Govindarajulu Varadarajan wrote: > Make MAX_LOCK_DEPTH configurable. It is set to 48 right now. Number of > VFs under a PCI pf bus can exceed 48 and this disables lockdep. > > lockdep currently allows max of 63 held_locks. But why a config knob? Why not just raise the number to 64 unconditionally? And is that sufficient; you only state 48 is insufficient, you don't actually state the VF limit.