On 2019-11-12 11:09:51 [-0500], Mikulas Patocka wrote: > =================================================================== > --- linux-2.6.orig/drivers/md/dm-snap.c 2019-11-12 16:44:36.000000000 +0100 > +++ linux-2.6/drivers/md/dm-snap.c 2019-11-12 17:01:46.000000000 +0100 … > static void dm_exception_table_lock(struct dm_exception_table_lock *lock) > { > +#ifndef CONFIG_PREEMPT_RT_BASE > hlist_bl_lock(lock->complete_slot); > hlist_bl_lock(lock->pending_slot); > +#else > + spin_lock(lock->lock); if you also set the lowest bit for complete_slot + pending_slot then patch 2 of this mini series wouldn't be required. That means we could keep the debug code on -RT. Or am I missing something? > +#endif > } Sebastian