v6.8 works. v6.9-rc1 fails with: kernel BUG at include/linux/swapops.h:119 117 static inline unsigned long swp_offset_pfn(swp_entry_t entry) 118 { 119 VM_BUG_ON(!is_pfn_swap_entry(entry)); 120 return swp_offset(entry) & SWP_PFN_MASK; 121 }