From: Davidlohr Bueso <dave@stgolabs.net>
To: kbuild test robot <lkp@intel.com>
Cc: kbuild-all@01.org, peterz@infradead.org, tglx@linutronix.de,
mingo@kernel.org, longman@redhat.com,
linux-kernel@vger.kernel.org, Davidlohr Bueso <dbues@suse.de>
Subject: Re: [PATCH 2/2] rtmutex: Reduce top-waiter blocking on a lock
Date: Tue, 17 Apr 2018 09:52:10 -0700 [thread overview]
Message-ID: <20180417165210.xxtplqjkv46q4d4f@linux-n805> (raw)
In-Reply-To: <201804112023.tAv7vUah%fengguang.wu@intel.com>
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
next prev parent reply other threads:[~2018-04-17 17:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-10 16:27 [PATCH 1/2] locking/rtmutex: Delete save_state member of struct rt_mutex Davidlohr Bueso
2018-04-10 16:27 ` [PATCH 2/2] rtmutex: Reduce top-waiter blocking on a lock Davidlohr Bueso
2018-04-11 12:51 ` kbuild test robot
2018-04-17 16:52 ` Davidlohr Bueso [this message]
2018-04-20 15:50 ` Peter Zijlstra
2018-04-20 16:48 ` Mike Galbraith
2018-04-22 2:39 ` Davidlohr Bueso
2018-06-17 17:26 ` Davidlohr Bueso
2018-04-20 15:25 ` [PATCH 3/2] rtmutex: Use waiter debug init,free magic numbers Davidlohr Bueso
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