Tom Lane wrote:
Also, it'd be interesting to count time spent holding shared lock
separately from time spent holding exclusive.
Tom,
Here is the break down between exclusive & shared LWLocks. Do the
numbers look reasonable to you?
Regards,
-Robert
bash-3.00# time ./Tom_lwlock_acquire.d `pgrep -n postgres`
********** LWLock Count: Exclusive **********
Lock Id Mode Count
ControlFileLock Exclusive 1
FreeSpaceLock Exclusive 9
XidGenLock Exclusive 202
CLogControlLock Exclusive 203
WALWriteLock Exclusive 203
BgWriterCommLock Exclusive 222
BufFreelistLock Exclusive 305
BufMappingLock Exclusive 305
ProcArrayLock Exclusive 405
FirstLockMgrLock Exclusive 670
WALInsertLock Exclusive 1616
********** LWLock Count: Shared **********
Lock Id Mode Count
CheckpointStartLock Shared 202
CLogControlLock Shared 450
SubtransControlLock Shared 776
XidGenLock Shared 2020
ProcArrayLock Shared 3778
SInvalLock Shared 4040
BufMappingLock Shared 40838
********** LWLock Time: Exclusive **********
Lock Id Combined Time (ns)
ControlFileLock 8301
FreeSpaceLock 80590
CLogControlLock 1603557
BgWriterCommLock 1607122
BufFreelistLock 1997406
XidGenLock 2312442
BufMappingLock 3161683
FirstLockMgrLock 5392575
ProcArrayLock 6034396
WALInsertLock 12277693
WALWriteLock 324869744
********** LWLock Time: Shared **********
Lock Id Combined Time (ns)
CLogControlLock 3183788
SubtransControlLock 6956229
XidGenLock 12012576
SInvalLock 35567976
ProcArrayLock 45400779
BufMappingLock 300669441
CheckpointStartLock 4056134243
real 0m24.718s
user 0m0.382s
sys 0m0.181s
