From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754120AbaHFV4Y (ORCPT ); Wed, 6 Aug 2014 17:56:24 -0400 Received: from mail-pd0-f180.google.com ([209.85.192.180]:58888 "EHLO mail-pd0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753710AbaHFV4W (ORCPT ); Wed, 6 Aug 2014 17:56:22 -0400 Date: Wed, 6 Aug 2014 14:56:20 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Bart Van Assche cc: Ingo Molnar , Andrew Morton , Peter Zijlstra , "David S. Miller" , linux-kernel Subject: Re: [PATCH v2] spin_lock_nested(): Always evaluate second argument In-Reply-To: <53E2618F.6040208@acm.org> Message-ID: References: <53CE1019.10708@acm.org> <20140722133716.cff957eff4eff1cc9c1d9968@linux-foundation.org> <53E260D9.6030803@acm.org> <53E2618F.6040208@acm.org> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 6 Aug 2014, Bart Van Assche wrote: > diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h > index 3f2867f..485d5dc 100644 > --- a/include/linux/spinlock.h > +++ b/include/linux/spinlock.h > @@ -197,7 +197,8 @@ static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) > _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ > } while (0) > #else > -# define raw_spin_lock_nested(lock, subclass) _raw_spin_lock(lock) > +# define raw_spin_lock_nested(lock, subclass) \ > + ((void)(subclass), _raw_spin_lock(lock)) > # define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock) > #endif > I think it would be nice to comment why we're evaluating the subclass when CONFIG_DEBUG_LOCK_ALLOC=n so that nobody comes along and unknowingly changes it back. Thanks for posting the updated version and keeping at it!