From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753859AbeDQRGX (ORCPT ); Tue, 17 Apr 2018 13:06:23 -0400 Received: from mx2.suse.de ([195.135.220.15]:41894 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753088AbeDQRGW (ORCPT ); Tue, 17 Apr 2018 13:06:22 -0400 Date: Tue, 17 Apr 2018 09:52:10 -0700 From: Davidlohr Bueso To: kbuild test robot Cc: kbuild-all@01.org, peterz@infradead.org, tglx@linutronix.de, mingo@kernel.org, longman@redhat.com, linux-kernel@vger.kernel.org, Davidlohr Bueso Subject: Re: [PATCH 2/2] rtmutex: Reduce top-waiter blocking on a lock Message-ID: <20180417165210.xxtplqjkv46q4d4f@linux-n805> References: <20180410162750.8290-2-dave@stgolabs.net> <201804112023.tAv7vUah%fengguang.wu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <201804112023.tAv7vUah%fengguang.wu@intel.com> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 11 Apr 2018, kbuild test robot wrote: >Hi Davidlohr, > >I love your patch! Perhaps something to improve: > >[auto build test WARNING on linus/master] >[also build test WARNING on v4.16 next-20180411] >[if your patch is applied to the wrong git tree, please drop us a note to help improve the system] > >url: https://github.com/0day-ci/linux/commits/Davidlohr-Bueso/locking-rtmutex-Delete-save_state-member-of-struct-rt_mutex/20180411-155733 >reproduce: > # apt-get install sparse > make ARCH=x86_64 allmodconfig > make C=1 CF=-D__CHECK_ENDIAN__ Ok. > > >sparse warnings: (new ones prefixed by >>) > >>> kernel/locking/rtmutex_common.h:62:9: sparse: context imbalance in '__rt_mutex_slowlock' - unexpected unlock I did: make C=1 CF=-D__CHECK_ENDIAN__ kernel/locking/rtmutex.o But cannot trigger this message. There are however a ton of other sparse issues with 'indirect_branch'. Ie: ./arch/x86/include/asm/nospec-branch.h:144:38: warning: Unknown escape '@' ./include/linux/init.h:134:6: error: attribute 'indirect_branch': unknown attribute ./include/linux/init.h:135:5: error: attribute 'indirect_branch': unknown attribute More importantly, I don't follow where this "unexpected unlock" would come from considering that rtmutex doesn't use __acquires/__releases annotations. Nor do I understand why this patch would produce a new context imbalance. Thanks, Davidlohr