Messages in this thread | | | Date | Wed, 7 Aug 2002 14:08:55 -0700 | From | Jesse Barnes <> | Subject | Re: [PATCH] lock assertion macros for 2.5.30 |
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On Wed, Aug 07, 2002 at 06:02:19PM -0300, Rik van Riel wrote: > On Wed, 7 Aug 2002, Jesse Barnes wrote: > > > +++ linux-2.5.30-lockassert/drivers/scsi/scsi.c Wed Aug 7 11:35:32 2002 > > @@ -262,7 +262,7 @@ > > > + MUST_NOT_HOLD(q->queue_lock); > > ... > > > +#if defined(CONFIG_DEBUG_SPINLOCK) && defined(CONFIG_SMP) > > +#define MUST_HOLD(lock) BUG_ON(!spin_is_locked(lock)) > > +#define MUST_NOT_HOLD(lock) BUG_ON(spin_is_locked(lock)) > > Please tell me the MUST_NOT_HOLD thing is a joke. > > What is to prevent another CPU in another code path > from holding this spinlock when the code you've > inserted the MUST_NOT_HOLD in is on its merry way > not holding the lock ?
Nothing at all, but isn't that how the scsi ASSERT_LOCK(&lock, 0) macro worked before? I could just remove all those checks in the scsi code I guess.
After I posted the last patch, a few people asked for MUST_NOT_HOLD so I added it back in. Do you think it's a bad idea? See the last thread if you're curious (Joshua's comments in particular): http://marc.theaimsgroup.com/?t=102764009400001&r=1&w=2
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