From: Dan Carpenter <error27@gmail.com>
To: Jens Axboe <jaxboe@fusionio.com>
Cc: Namhyung Kim <namhyung@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] generic-ipi: add lock context annotations
Date: Tue, 23 Nov 2010 12:40:16 +0300 [thread overview]
Message-ID: <20101123094016.GC8882@bicker> (raw)
In-Reply-To: <4CEB8034.80400@fusionio.com>
On Tue, Nov 23, 2010 at 09:49:56AM +0100, Jens Axboe wrote:
> I guess what Peter means is that the fact that the function grabs the
> lock is apparent in the code, if sparse was a bit "smarter", it would
> see and note this itself.
The sparse warning messages should have been included in the commit
message. Here they are:
kernel/smp.c:513:6: warning: context imbalance in 'ipi_call_lock' - wrong count at exit
kernel/smp.c:518:6: warning: context imbalance in 'ipi_call_unlock' - unexpected unlock
kernel/smp.c:523:6: warning: context imbalance in 'ipi_call_lock_irq' - wrong count at exit
kernel/smp.c:528:6: warning: context imbalance in 'ipi_call_unlock_irq' - unexpected unlock
What happens is that sparse *does* see that the locks are unlocked and
that's what it complains about.
Sparse works before the code is linked so this change doesn't affect
anything outside kernel/smp.c. If we added these annotations to
include/linux/smp.h then they would be used for checking
kernel/smpboot.c
regards,
dan carpenter
next prev parent reply other threads:[~2010-11-23 9:40 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-22 7:33 [PATCH] generic-ipi: add lock context annotations Namhyung Kim
2010-11-22 12:46 ` Peter Zijlstra
2010-11-23 3:19 ` Namhyung Kim
2010-11-23 8:49 ` Jens Axboe
2010-11-23 9:40 ` Dan Carpenter [this message]
2010-11-24 5:24 ` Namhyung Kim
2010-11-24 5:43 ` Dan Carpenter
2010-11-24 14:29 ` Namhyung Kim
2010-11-24 14:33 ` Peter Zijlstra
2010-11-24 15:03 ` Namhyung Kim
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