The following SVG files contains a sample report of pgbench with

  -c 80 -j 80 -M prepared -T 300

running on Intel Xeon 28C/56T w/ 256Gb memory, and 2 x RAID10 SSD (data + xlog).

Log entries format:

PID 55803 lwlock XidGenLock: shacq 8 shmax 1 exacq 1 exmax 1 blk 0 spindelay 0 dequeue self 0 maxw 0

or

PID 55803 lwlock main 5234: shacq 2 shmax 1 exacq 1 exmax 1 blk 0 spindelay 0 dequeue self 0 maxw 0

The Y-axis is 'maxw' - e.g. maximum queue size for the lock in question. The width of each lock
is specific to each report, as noted below.

All graphs are generated using FlameGraph:

 http://www.brendangregg.com/flamegraphs.html
 https://github.com/brendangregg/FlameGraph


lwstats_weight.svg:
-------------------

The weight of each lock is calculated as

 weight = 10 * exacq + shacq

lwstats_spin.svg:
-----------------

'spindelay' based

Filtered on > 0

lwstats_block.svg:
------------------

'blk' based

Filtered on > 0

lwstats_shared.svg:
-------------------

'shmax' based

Filtered on > 1

lwstats_exclusive.svg:
----------------------

'exmax' based

Filtered on > 1
