crissaegrim

4 ms·

1.
by crissaegrim 2y ago
You might be interested to use Intel VTune then if you have an Intel CPU. I believe it has a profiling option that shows memory bandwidth over time [1]. [1]: https://www.intel.com/content/www/us/en/docs&#
2.
by crissaegrim 2y ago
Perfetto is pretty cool (if not a very overloaded term since there's the perfetto UI, perfetto backend, etc.), but we were generally interested in fairly low-level aspects like waiting on memory, etc. which require low-overhead tracing
3.
by crissaegrim 2y ago
So the book is split into four major sections: Measurement, Observation, KUtrace, Reasoning. "Measurement" delves into understanding and measuring four fundamental resources: CPU, Memory, Disk/SSD, and Network. This section i
4.
by crissaegrim 2y ago
What are you precisely trying to measure? Theoretically if you know the performance counters you want to measure, you can replace the IPC counter in the kernel module. I believe Dick has a different version of the kernel module which measur
5.
by crissaegrim 2y ago
No it unfortunately does not. You require root to remount the read-only system partition, to insert the kernel modules, and to turn SELinux off. We used a "userdebug" build to get root, but I imagine most of this could also be don
6.
by crissaegrim 2y ago
KUtrace stands for "Kernel-User" trace as (most of) the tracepoints are at the kernel-userspace boundary. So it is a coincidence.
7.
by crissaegrim 2y ago
I had the pleasure to work with Dick on getting KUtrace to work on Android devices last year. It was a great experience to work with one of the greats in systems performance. He was a wealth of information regarding performance bottlenecks