From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756375AbaHHKcn (ORCPT ); Fri, 8 Aug 2014 06:32:43 -0400 Received: from sf1.bxl.stone.is ([87.238.167.36]:32839 "EHLO sf1.bxl.stone.is" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755618AbaHHKcl (ORCPT ); Fri, 8 Aug 2014 06:32:41 -0400 X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network Message-ID: <53E4A73D.5080801@acm.org> Date: Fri, 08 Aug 2014 12:32:29 +0200 From: Bart Van Assche User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: David Rientjes CC: Ingo Molnar , Andrew Morton , Peter Zijlstra , "David S. Miller" , linux-kernel Subject: Re: [PATCH v2] spin_lock_nested(): Always evaluate second argument References: <53CE1019.10708@acm.org> <20140722133716.cff957eff4eff1cc9c1d9968@linux-foundation.org> <53E260D9.6030803@acm.org> <53E2618F.6040208@acm.org> In-Reply-To: Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Filter-ID: XtLePq6GTMn8G68F0EmQvdthj6rk7ohlAkaRQG+cDaLZlN3ufQ0ZRHdy43341LQ0JYRGiu4wDuX/ sGw1Y7RAsZ3WBw9ZlycipwBG3jGu9D8JBgu10R0foqIRsBJqRnurUO/XCGxJVedBWv8BXp6lSPrf oA0XngOaR5RLFk6kKY8+X6tyUZ34Ozy6TOwmaHPzFR2lHDoBQ4zwtMehH4SfWgLcNhHqvET8hkHK 4DD3CZT4SL0VvzAbTStaxE3e6xctxkHXgTSJC2+q+O2n2sPwh+CpLQk2sgUsKd5RNPNJeN3I5L/U AJH41ve/RciJD7RwcMm6IODZgOZ9Y8BEoKFU+ThPpKKNyD6EWtbIyxh4MHoccBIk1Sag4dKiqCrF 8eZZsQYibGPulATAPqOguWXWenmy4p4jVbvkvQrOImHI+zH4ns3e6vWEaK66hz4t87L5hVQSL57W w8nd1cTP1twpFFTUuHOuOBA828Pfce2frIKvtUus/ypEW5W6Dw4DmSZF9OoIMWCP9bnVs5BJWbbt 5dM+m4WpRRDP6YzwkAPgQJZcv8AnfPB9HqHgcyCJwUz8oOSQKVK4yyKUlGmQMgPOfIQtTQXMrNAv J7CbCYezRVuhdlkpfoNhtgWYwB/e4S2rpoRvMJWweGFGUUnI6wOX8j4FS3UlU37B6qPMab0LB93J IFkIZaBCBQxuHnm838r5oXZZKX6DYbYFmMAf3uEtq0CVt0DUeFU/MBWnkHtFiUWUs1IAPjDts3+I etSNQKiFa27IsDu2NxxouWmZdcGOChVo3Ylh8ywfjYp979CTGJlcA0OL1mkTp3S7nD3AxhtVMS+4 ayUpOtEhdxekWDmK9g== X-Report-Abuse-To: spam@sf1.bxl.stone.is X-Filter-Fingerprint: cPaH8lomer6UwsJ3BnJDyh/24V0ZnPLChpTdx0aQyMi0VFDyP20las9Mq1v6nXmfrqKtWpHLpkE8 c09GKJn2t//Iv3SA9yqL/o+tgER5K01MqRJTan78INzQLlEGX/jFRST5X0bRoOLYozD+qqgg13U4 H51jyCSmLdA2hPaiVpwYWaeThsiFlmPt/lOSmjPeIry8YqBAImlpW4iUkiWie2qK95LAXg+Ea3Jb F9WwpaZ//Un1C5ivAWoOksRE8XtOTT9J6CK2j8j7/AJ9TNml+IbyXSJXjZjMx+Tok7jY2RMVEkZR xMpnILpnPlb/BDIPR3BzrtNvug17DaoVb9RvKuKFkKyIMhEyqFjdRcrNMObE3nrK/nhevL/uAoHg xNXar0XzbLB8Pru9OEB7tNjak+6bpnvFzMd6SECQNf1u/wGWAJzP31LdUHDVnH0aZDcVCxO6ac9X hDc8gFJxmNF1qg== X-Originating-IP: 87.238.167.34 X-SpamExperts-Domain: stone.is X-SpamExperts-Username: 87.238.167.34 Authentication-Results: bxl.stone.is; auth=pass smtp.auth=87.238.167.34 X-SpamExperts-Outgoing-Class: ham X-SpamExperts-Outgoing-Evidence: Combined (0.02) X-Recommended-Action: accept Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/06/14 23:56, David Rientjes wrote: > 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! This morning I received an e-mail from Wu Fengguang reporting that this patch breaks the build for CONFIG_SMP=n. I will post a third version. Bart.