From: David Woodhouse <dwmw2@infradead.org>
To: Chris Mason <chris.mason@oracle.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: kernel BUG at extent_map.c:275!
Date: Tue, 22 Jul 2008 10:35:43 -0400 [thread overview]
Message-ID: <1216737343.18980.98.camel@shinybook.infradead.org> (raw)
In-Reply-To: <1216722065.6932.125.camel@think.oraclecorp.com>
On Tue, 2008-07-22 at 06:21 -0400, Chris Mason wrote:
> What kind of box is this? The current code should be fine on big
> endian, but that hasn't been tested recently.
It's a PowerBook (ppc32).
The bug is a BUG_ON(spin_trylock(&tree->lock)) in
lookup_extent_mapping() -- I didn't think endianness was a likely factor
in that.
Being uniprocessor might be though -- don't we hard-code spin_trylock()
to _always_ succeed on UP, unless spinlock debugging is enabled?
I think that test needs to happen only if spinlocks aren't no-ops. Or
have you moved past the point where you need it now, so can we just
remove it?
T'would be nice if lockdep or sparse could handle this for us -- we
already have annotations which indicate that a function 'acquires' or
'releases' locks. I wonder if we could also do 'requires'?
--
dwmw2
next prev parent reply other threads:[~2008-07-22 14:35 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-22 3:32 [PATCH] Use do_div() instead of native 64-bit division in btrfs_ordered_sum_size() David Woodhouse
2008-07-22 3:36 ` kernel BUG at extent_map.c:275! David Woodhouse
2008-07-22 10:21 ` Chris Mason
2008-07-22 14:35 ` David Woodhouse [this message]
2008-07-22 17:03 ` Chris Mason
2008-07-22 17:41 ` David Woodhouse
2008-07-22 17:42 ` Zach Brown
2008-07-22 18:04 ` David Woodhouse
2008-07-24 14:34 ` Chris Mason
2008-07-22 18:12 ` Chris Mason
2008-07-22 14:43 ` [PATCH] Remove BUG_ON(spin_trylock()) checks which have false positives on UP David Woodhouse
2008-07-23 11:13 ` [PATCH] Use do_div() instead of native 64-bit division in btrfs_ordered_sum_size() Christoph Hellwig
2008-07-23 13:28 ` Chris Mason
2008-07-23 21:07 ` David Woodhouse
2008-07-24 0:19 ` Chris Mason
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