From: Johannes Berg <johannes@sipsolutions.net>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>,
linux1394-devel@lists.sourceforge.net,
linux-kernel@vger.kernel.org
Subject: Re: lockdep false positive? -- firewire-core transaction timer vs. scsi-core host lock
Date: Tue, 17 Aug 2010 00:27:13 +0200 [thread overview]
Message-ID: <1281997633.3683.50.camel@jlt3.sipsolutions.net> (raw)
In-Reply-To: <1281994939.1926.2075.camel@laptop>
On Mon, 2010-08-16 at 23:42 +0200, Peter Zijlstra wrote:
> softirq:
> spin_lock(&t->split_timeout_timer);
>
> IRQ:
> spin_lock(&(shost->host_lock)->rlock);
> spin_lock(&t->split_timeout_timer);
Actually, I think it's worried that you could have
CPU 0 CPU 1
softirq: softirq:
spin_lock(timer) spin_lock(rlock)
irq:
spin_lock(rlock)
spin_lock(timer) [still in softirq]
because it has previously seen the nesting that I put on CPU 1, and now
found that the timer "lock" is used with interrupts enabled.
At least that's a scenario I could understand?
I'm convinced it's a false positive though, question is how to shut it
up :-)
johannes
next prev parent reply other threads:[~2010-08-16 22:27 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-16 18:42 lockdep false positive? -- firewire-core transaction timer vs. scsi-core host lock Stefan Richter
2010-08-16 21:42 ` Peter Zijlstra
2010-08-16 22:09 ` Johannes Berg
2010-08-16 22:27 ` Johannes Berg [this message]
2010-08-17 16:22 ` Stefan Richter
2010-08-18 13:17 ` Stefan Richter
2010-08-17 14:35 ` Yong Zhang
2010-08-17 16:23 ` Stefan Richter
2010-08-18 7:01 ` Clemens Ladisch
2010-08-18 8:09 ` Stefan Richter
2010-08-18 8:53 ` Clemens Ladisch
2010-08-18 9:08 ` Yong Zhang
2010-08-18 8:59 ` Peter Zijlstra
2010-08-18 9:26 ` Clemens Ladisch
2010-08-18 9:43 ` Peter Zijlstra
2010-08-18 12:50 ` Stefan Richter
2010-08-18 13:05 ` Clemens Ladisch
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