BufFreelistLock,
			/* X - all - each time we allocate a new buffer for data block I/O
			 * Never held across I/O
			 */
	ShmemIndexLock,				
			/* X - all - create/attach to shared memory
			 * Never held across I/O
			 */
	OidGenLock,
			/* X - all - each GetNewOid() and each GetNewRelFileNode()
			 * S - bgwriter - acquired during checkpoint
			 * Writes WAL record every 8192 OIDs, so vanishing chance
			 * of being held across I/O
			 */
	XidGenLock,
			/* X - all - for each GetNewTransactionId()
			 * 			check whether we need to call ExtendClog or ExtendSubtrans
			 * 			could be held across I/O if clog or subtrans buffers
			 * 			have a dirty LRU page
			 * S - all - for each ReadNewTransactionId()
*5			 * 			called by GetNextXidAndEpoch(), 
			 * 			once per VACUUM of each relation
			 * 			once per start of autovacuum worker
			 * X - all - for each SetTransactionIdLimit()
			 * 			called after each VACUUM of whole database and 
			 * 			at EOXact if we update catalogs and write relcache file
			 * X - bgwriter - acquired during checkpoint
			 */
	ProcArrayLock,	
			/* X - all - adding/removing procs from procarray
			 * 			backend start or exit, two phase commits
*1			 * X - all - XidCacheRemoveRunningXids()
			 * S - all - TransactionIdIsInProgress(), TransactionIdIsActive(),
			 *			GetOldestXmin(), GetSnapshotData(), GetTransactionsInCommit()
			 * 			HaveTransactionsInCommit(), BackendPidGetProc(),
			 *			BackendXidGetProc(), GetCurrentVirtualXids(),
			 *			CountDBBackends(), CountUserBackends(),
*2			 *			CheckOtherDBBackends(), CountActiveBackends()
			 */
	SInvalLock,
			/* X - all - backend startup or exit
			 * X - all - send SInval message
			 * S - all - receive SInval message
*3			 * X - all - release dead SInval messages
			 */
	FreeSpaceLock,
			/* X - access to the FSM to reuse a block, record freespace
			 * X - held during VACUUM to record free space, maybe rearrange FSM
			 * Never held across I/O, except at database startup/shutdown
			 */
	WALInsertLock,
			/* X - insert data into WAL buffers
			 * Holder may acquire WALWriteLock if WAL buffers full
			 */
	WALWriteLock,
			/* X - any - write WAL buffers to disk - Always held across I/O
*4			 * S - bgwriter - each loop checks GetLastSegSwitchTime()
			 * Holder conditionally acquiresmay WALInsertLock to perform
			 * piggyback I/O on WAL 
			 */
	ControlFileLock,
			/* X - any - must be held to read/write from Control file 
			 * Always held across I/O
			 */ 
	CheckpointLock,
			/* X - bgwriter - must be held to perform CreateCheckpoint
			 * Holder always acquires WALInsertLock, XidGenLock, OidGenLock,
			 * ProcArrayLock and ControlFileLock 
			 */
	CLogControlLock,
	SubtransControlLock,
	MultiXactGenLock,
	MultiXactOffsetControlLock,
	MultiXactMemberControlLock,
			/* SLRU locks
			 */
	RelCacheInitLock,
	BgWriterCommLock,
	TwoPhaseStateLock,
	TablespaceCreateLock,
	BtreeVacuumLock,
	AddinShmemInitLock,
	AutovacuumLock,
	AutovacuumScheduleLock,
	SyncScanLock,
			/* X - any - once per large SeqScan, plus conditionally once 
			 * 				per ~16 blocks, during ss_report_location()
			 */
	/* Individual lock IDs end here */
	FirstBufMappingLock,
*6	FirstLockMgrLock = FirstBufMappingLock + NUM_BUFFER_PARTITIONS,

	/* must be last except for MaxDynamicLWLock: */
	NumFixedLWLocks = FirstLockMgrLock + NUM_LOCK_PARTITIONS,

	MaxDynamicLWLock = 1000000000