AMDGPU_PAGEFAULT_HASH_BITS
AMDGPU_PAGEFAULT_HASH_BITS, 8, 0);
if (fault_hash->count >= (1 << (AMDGPU_PAGEFAULT_HASH_BITS-1)))
DECLARE_CHASH_TABLE(hash, AMDGPU_PAGEFAULT_HASH_BITS, 8, 0);