Matthew Wakeling <matthew@flymine.org> writes:
> That sucks. However, as another observation, no calls to "gistfindnext"
> are recorded in the profile either, and that's in the same source file as
> "gistnext" which is recorded. Could it have been inlined?
Probably.
> Shouldn't inlining be switched off on a profiling build?
Why? You generally want to profile the code's actual behavior, or as
near as you can get to observing that. Defeating compiler optimizations
doesn't sound like something that -pg should do on its own. If you
really want it, there's a switch for it.
> Oprofile scares me with the sheer number of options.
You can ignore practically all of them; the defaults are pretty sane.
The recipe I usually follow is:
Initial setup (only needed once per system boot):
sudo opcontrol --init
sudo opcontrol --setup --no-vmlinux
(If you need detail about what the kernel is doing, you need kernel
debug symbols and then specify them on the previous line)
Start/stop profiling
sudo opcontrol --start
sudo opcontrol --reset
... exercise your debug-enabled program here ...
sudo opcontrol --dump ; sudo opcontrol --shutdown
The test case should run at least a minute or two to get numbers with
reasonable accuracy.
Analysis:
opreport --long-filenames | more
opreport -l image:/path/to/postgres | more
if you really want detail:
opannotate --source /path/to/postgres >someplace
regards, tom lane
