From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751650AbdJRPjy (ORCPT ); Wed, 18 Oct 2017 11:39:54 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:32970 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751058AbdJRPjw (ORCPT ); Wed, 18 Oct 2017 11:39:52 -0400 Date: Wed, 18 Oct 2017 08:39:46 -0700 From: "Paul E. McKenney" To: Sebastian Andrzej Siewior Cc: kbuild test robot , kbuild-all@01.org, Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , linux-kernel@vger.kernel.org Subject: Re: [PATCH] rcu: do not include rtmutex_common.h unconditionally Reply-To: paulmck@linux.vnet.ibm.com References: <201710180754.irSSdw3W%fengguang.wu@intel.com> <20171018041447.GF3521@linux.vnet.ibm.com> <20171018073209.7l4p3lloqiw4bm6y@linutronix.de> <20171018083436.mlbwx2zvakp54gbw@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20171018083436.mlbwx2zvakp54gbw@linutronix.de> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17101815-0048-0000-0000-000001F793A2 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007914; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000237; SDB=6.00932956; UDB=6.00469868; IPR=6.00713246; BA=6.00005647; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017593; XFM=3.00000015; UTC=2017-10-18 15:39:49 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17101815-0049-0000-0000-000042E92249 Message-Id: <20171018153946.GH3521@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-10-18_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710180217 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 18, 2017 at 10:34:36AM +0200, Sebastian Andrzej Siewior wrote: > Since commit bcda31a26594 ("rcu: Suppress lockdep false-positive > ->boost_mtx complaints") the rtmutex_common.h is included > unconditionally. This break CONFIG_FUTEX=n configs which do not have > CONFIG_RT_MUTEX enabled which leads to the lack of certain members in > task_struct which are accessed in rtmutex_common.h as reported by the kbuild > test robot: > | In file included from include/uapi/linux/stddef.h:1:0, > | from include/linux/stddef.h:4, > | from include/uapi/linux/posix_types.h:4, > | from include/uapi/linux/types.h:13, > | from include/linux/types.h:5, > | from kernel/rcu/tree.c:30: > | kernel/rcu/../locking/rtmutex_common.h: In function 'task_has_pi_waiters': > |>> kernel/rcu/../locking/rtmutex_common.h:62:26: error: 'struct task_struct' has no member named 'pi_waiters'; did you mean 'cpu_timers'? > > among other things. > I move the include back to the RCU_BOOST ifdef and add there the > rt_mutex_futex_unlock define like we already have it for rt_mutex_owner > for the same reason. > While at it, I remove the second rtmutex_common.h include within the > RCU_BOOST block because one of those is enough. > > Fixes: bcda31a26594 ("rcu: Suppress lockdep false-positive ->boost_mtx complaints") > Reported-by: kbuild test robot > Signed-off-by: Sebastian Andrzej Siewior Thank you very much, hand-applied as a preparatory patch for "Suppress lockdep false-positive ->boost_mtx complaints", please see below. What I don't understand is why 0day test robot didn't complain about my copy of the exact same patch. Or maybe it did and I fat-fingered it? Except that I have gotten "BUILD SUCCESS" reports for commits including that one. Ah well, hopefully all is well that ends well... > --- > On 2017-10-18 09:32:09 [+0200], To Paul E. McKenney wrote: > > I will > > look at this once I made some slides… > > slides, who needs those anyway… Best of everything on the presentation, and hope that I didn't mess you up too badly. Thanx, Paul ------------------------------------------------------------------------ commit a06f537e75ea0a9e81245ede1b97bb3a5762b81b Author: Sebastian Andrzej Siewior Date: Wed Oct 18 08:33:44 2017 -0700 rcu: do not include rtmutex_common.h unconditionally This commit adjusts include files and provides definitions in preparation for suppressing lockdep false-positive ->boost_mtx complaints. Without this preparation, architectures not supporting rt_mutex will get build failures. Reported-by: kbuild test robot Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Paul E. McKenney diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index fed95fa941e6..969eae45f05d 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -54,6 +54,7 @@ DEFINE_PER_CPU(char, rcu_cpu_has_work); * This probably needs to be excluded from -rt builds. */ #define rt_mutex_owner(a) ({ WARN_ON_ONCE(1); NULL; }) +#define rt_mutex_futex_unlock(x) WARN_ON_ONCE(1) #endif /* #else #ifdef CONFIG_RCU_BOOST */ @@ -911,8 +912,6 @@ void exit_rcu(void) #ifdef CONFIG_RCU_BOOST -#include "../locking/rtmutex_common.h" - static void rcu_wake_cond(struct task_struct *t, int status) { /*