README.md

poor-profiler

This is a (rather poor) attempt at building a profiler for card10. The idea is based on the poor man's profiler. Essentially, it uses stack-traces gathered using GDB. This means, execution will be significantly slowed down which might make certain features of the firmware misbehave. Use with care!

That said, here is how to use it:

1. Configure the profiler by adjusting nsamples and sleeptime in poor-profiler.sh. (If anyone wants to send a patch which makes this script use proper commandline args, please do!)
2. Start profiling! Just call

   ./tools/poor-profiler/poor-profiler.sh >/tmp/samples

   from the firmware repository root.
3. Next, collapse the samples using the poor-collapse.sh script:

   $ ./tools/poor-profiler/poor-collapse.sh /tmp/samples >/tmp/samples.collapsed

4. Finally, feed the collapsed samples into the Brendan Gregg's FlameGraph script which will create an svg you can view (and interact with!) in your browser:

   $ /path/to/FlameGraph/flamegraph.pl /tmp/samples.collapsed >/tmp/flamegraph.svg
   $ firefox /tmpflamegraph.svg

   (If you feel that a perl script is not modern enough, you can also use inferno-flamegraph which is written in Rust ...)

Happy profiling!