Re: [Gimp-developer] gimp-plugin profiling

[Tibor Bamhor <tiborb95 gmail com>]

Hi,

Thank for you interest. Today I spent some time reading about perf - it is quite complex tool or rather it measures things that I am not familiar with. However I did some primitive testing and got this output:

____7729.437618_task-clock________________#____0.386_CPUs_utilized__________
___________8556_context-switches__________#____0.001_M/sec__________________
______________0_cpu-migrations____________#____0.000_K/sec__________________
____________899_page-faults_______________#____0.116_K/sec__________________
____20346686795_cycles____________________#____2.632_GHz_____________________[92.65%]
______________0_stalled-cycles-frontend___#____0.00%_frontend_cycles_idle____[99.92%]
______588881284_stalled-cycles-backend____#____2.89%_backend__cycles_idle____[67.69%]
_____2234245557_instructions______________#____0.11__insns_per_cycle________
__________________________________________#____0.26__stalled_cycles_per_insn_[71.21%]
______931561726_branches__________________#__120.521_M/sec___________________[77.62%]
_____1877007958_branch-misses_____________#__201.49%_of_all_branches_________[84.88%]

I dont dare to interpret it, but the "201.49%" in last line was in red so there is obviously a problem there. Here I would start.

If you (or anybody else) can point me at some source on internet I would be thankfull. Or perhaps shortly explain how to mitigate the problem. But I understand this is not gimp-specific issue...

BTW, I consider my question answered now, thanks :)


Tibor

2013/3/10 Ville Sokk <ville sokk gmail com>

I'm sorry you didn't get any help. But I would like to note that gprof
is generally not considered a good tool for profiling, especially if
threads are involved. People suggest statistical profilers like perf
(Linux kernel profiler, works in userspace too), gperftools, oprofile,
dtrace (not just a profiler). If you have a mac you can use its GUI
for dtrace. If you are adventurous you can use the Linux equivalents
of dtrace called systemtap and LTTng. Jon Nordby likes gperftools
IIRC, you can analyse its output with kcachegrind. For perf you can
use gprof2dot to get a graphical callgraph instead of the CLI one.