MAX_LOCKDEP_CHAINS_BITS  268 kernel/lockdep.c #define CHAINHASH_BITS		(MAX_LOCKDEP_CHAINS_BITS-1)
MAX_LOCKDEP_CHAINS_BITS   21 kernel/lockdep_internals.h #define MAX_LOCKDEP_CHAINS	(1UL << MAX_LOCKDEP_CHAINS_BITS)