Re: Latency profiling?

[Eli Zaretskii]

> From: Sebastian Sturm <address@hidden>
> Date: Sun, 18 Mar 2018 21:29:54 +0100
> 
> What is the best way to emulate interactive user input and reliably 
> assess the speed with which said input is processed?

If the slowdown is related to display, you can't do that except
interactively.

> Also, is there a way to profile not throughput, but latency (i.e. time 
> elapsed between key press and Emacs being ready for further input)?

What's the difference?  There will be no latency if the time that
takes to process a command is short.

> As far as I can see, there are hooks invoked on self-insert-command,
> but I didn't find a hook that fires when redisplay is done. Anything
> that uses external tracing frameworks would also be fine in my book,
> as long as it runs on Linux.

If you suspect (or have evidence) that the time is spent in the C
code, I suggest to use perf.