From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755045Ab0ASA4z (ORCPT ); Mon, 18 Jan 2010 19:56:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754938Ab0ASA4x (ORCPT ); Mon, 18 Jan 2010 19:56:53 -0500 Received: from e3.ny.us.ibm.com ([32.97.182.143]:44331 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753300Ab0ASA4w (ORCPT ); Mon, 18 Jan 2010 19:56:52 -0500 Date: Mon, 18 Jan 2010 16:56:46 -0800 From: "Paul E. McKenney" To: Josh Triplett Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com Subject: Re: [PATCH tip/core/rcu 8/9] idr: apply lockdep-based diagnostics to rcu_dereference() uses Message-ID: <20100119005646.GA6196@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20100115010157.GA28221@linux.vnet.ibm.com> <20100118233604.GE29076@feather> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100118233604.GE29076@feather> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 18, 2010 at 03:36:04PM -0800, Josh Triplett wrote: > On Thu, Jan 14, 2010 at 05:02:45PM -0800, Paul E. McKenney wrote: > > From: Paul E. McKenney > > > > Because idr can be used with any of a number of locks or with any > > flavor of RCU, just disable the lockdep-based diagnostics. If idr > > needs diagnostics, the check expression will need to be passed into > > the relevant idr primitives as an additional argument. > > > > Signed-off-by: Paul E. McKenney > > The subject line of this patch seems wrong. Like the preceding patches > for radix tree and list operations, this *disables* the checking by > using _raw. It does indeed use _raw. If we start having enough issues with these interfaces, this will need to change. At the moment, the obvious change is to provide multiple interfaces as was done for rcu_dereference(). For example, idr_find(), idr_find_bh(), idr_find_sched(), idr_find_srcu(), idr_find_rcu(), and idr_find_check(). Probably only a few of these are actually in use, but even so, I decided to see how rcu_dereference() turned out before pushing up to the higher-level APIs. My guess would be that the list APIs would be most pressing, but we will see. ;-) Thanx, Paul