On Wed 31-07-19 21:40:42, Thomas Gleixner wrote:

On Wed, 31 Jul 2019, Jan Kara wrote:

quoted

BH_State lock is definitely worth it. In fact, if you placed the spinlock
inside struct journal_head (which is the structure whose members are in
fact protected by it), I'd be even fine with just using the spinlock always
instead of the bit spinlock. journal_head is pretty big anyway (and there's
even 4-byte hole in it for 64-bit archs) and these structures are pretty
rare (only for actively changed metadata buffers).

Just need to figure out what to do with the ASSERT_JH(state_is_locked) case for
UP. Perhaps just return true for UP && !DEBUG_SPINLOCK?

Yes, that makes sense.

								Honza
-- 
Jan Kara [off-list ref]
SUSE Labs, CR