Re: [REGRESSION] Re: [PATCH 00/24] Complete EEVDF

[Peter Zijlstra <peterz@infradead.org>]

On Sat, Jan 18, 2025 at 04:09:02PM -0800, Doug Smythies wrote:
> Hi Peter,
> 
> An update.
> 
> On 2025.01.14 02:59 Peter Zijlstra wrote:
> > On Mon, Jan 13, 2025 at 12:03:12PM +0100, Peter Zijlstra wrote:
> >> On Sun, Jan 12, 2025 at 03:14:17PM -0800, Doug Smythies wrote:
> 
> >>> means that there were 19 occurrences of turbostat interval times
> >>> between 1.016 and 1.016999 seconds.
> >> 
> >> OK, let me lower my threshold to 10ms and change the turbostat
> >> invocation -- see if I can catch me some wabbits :-)
> >
> > I've had it run overnight and have not caught a single >10ms event :-(
> 
> Okay, so both you and I have many many hours of testing and
> never see >= 10ms in that area of the turbostat code anymore.

Hehe, yeah, I actually had it run for 3 solid days in the end.

> The lingering >= 10ms (but I have never seen more than 25 ms)
> is outside of that timing. As previously reported, I thought it might
> be in the sampling interval sleep step, but I did a bunch of testing
> and it doesn't appear to be there. That leaves:
> 
> delta_platform(&platform_counters_even, &platform_counters_odd);
> compute_average(ODD_COUNTERS);
> format_all_counters(ODD_COUNTERS);
> flush_output_stdout();
> 
> I modified your tracing trigger thing in turbostat to this:

Shiny!

What turbostat invocation do I use? I think the last I had was:

  tools/power/x86/turbostat/turbostat --quiet --show Busy%,IRQ,Time_Of_Day_Seconds,CPU,usec --interval 1

I've started a new run of yes-vs-turbostate with the modified trigger
condition. Lets see what pops out.