Re: [chrony-users] Fwd: Chrony malfunctioning at beaglebones

[ Thread Index | Date Index | More Archives ]

On Fri, Nov 20, 2015 at 6:54 AM, Miroslav Lichvar <mlichvar@xxxxxxxxxx> wrote:
> Does the recompiled kernel have the same CONFIG_HZ as the one you
> tried before?


I'm still collecting data to be more sure. But it looks for now:

1 - nohz=off does not have any effect.

2 - With a kernel without Dynamic ticks enabled the latencies are
actually always greater, and they increase with system load! They
still decrease if I have a periodic thread waking very frequently.

That is: Threads waking regularly and for short intervals decrease
latency. Threads waking infrequently but doing a log of work increase

So with this my conclusions for now are:

1 - Linux command line option nohz is broken.

2 - There is something else on the beaglebone happening beside (1)
nohz, (2) cpuidle, (3) cpufreq, that is affected by a thread waking
very frequently.

I will share some annotated plots in a few days to make this very
clear. Anyway do you have any idea what can be happening here? Maybe
some cpuidle states are being entered despite being disabled?


To unsubscribe email chrony-users-request@xxxxxxxxxxxxxxxxxxxx 
with "unsubscribe" in the subject.
For help email chrony-users-request@xxxxxxxxxxxxxxxxxxxx 
with "help" in the subject.
Trouble?  Email listmaster@xxxxxxxxxxxxxxxxxxxx.

Mail converted by MHonArc 2.6.19+