Merge branch 'slab/for-6.1/slub_validation_locking' into slab/for-next

My series [1] to fix validation races for caches with enabled debugging.

By decoupling the debug cache operation more from non-debug fastpaths,
additional locking simplifications were possible and done afterwards.

Additional cleanup of PREEMPT_RT specific code on top, by Thomas Gleixner.

[1] https://lore.kernel.org/all/[email protected]/

Author: tehcaster