From the changelog:
Oops. Don't use pre1 without removing the "DEBUG_LRU_PAGE()" line in mm/swap.c: __del_cache_del() - I uploaded an old diff, and since it's 4:30 AM I'm too tired to generate the correct one. (Not removing the line will cause a nice oops very early on, nothing bad will happen). Linus "off to sleep" Torvalds