[PATCH] spinlock: __raw_spin_is_locked() should return true for UP
torvalds at linux-foundation.org
Wed Aug 19 09:20:43 EST 2009
On Tue, 18 Aug 2009, Kumar Gala wrote:
> For some reason __raw_spin_is_locked() has been returning false for the
> uni-processor, non-CONFIG_DEBUG_SPINLOCK. The UP + CONFIG_DEBUG_SPINLOCK
> handles this correctly.
> Found this by enabling CONFIG_DEBUG_VM on PPC and hitting always hitting
> a BUG_ON that was testing to make sure the pte_lock was held.
> Signed-off-by: Kumar Gala <galak at kernel.crashing.org>
> Linus, a fix for 2.6.31
This really isn't all that clear.
The thing is, some people may assert that a lock is held, but others could
easily be looping until it's not held using something like
so it's hard to tell whether it should return true or false in the case
where spin-locking simply doesn't exist.
More information about the Linuxppc-dev