Re: [RFC][PATCH] ring-buffer: Have nested events still record running time stamp

[Steven Rostedt]

On Mon, 29 Jun 2020 23:13:32 -0400 (EDT)
Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:

> -> This configuration's avg varies between 239 and 256 ns based on your benchmark methodology. The std. dev. varies between  
> 138 and 201 ns.
> 
> In the benchmark results you collected, config #1 appeared to have little delta between xadd and cmpxchg, whereas
> config #2 and #3 had some avg difference. Did you try running this test many times on each machine to see if the
> result was indeed stable ?


Yes, but as we discussed on IRC, my machines are much smaller than this
one, and that makes it a bit more deterministic. I also run them with
distro configs. When there's debugging enabled, I get much more erratic
results.

-- Steve