lkml.org 
[lkml]   [2015]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] clocksource: Allow toggling between runtime and persistent clocksource for idle
From
On Mon, Jul 6, 2015 at 8:46 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Mon, 6 Jul 2015, Tony Lindgren wrote:
>> * Thomas Gleixner <tglx@linutronix.de> [150706 07:20]:
>> > On Mon, 6 Jul 2015, Tony Lindgren wrote:
>> The timekeeping accuracy issue certainly needs some thinking, and
>> also the resolution between the clocksources can be different.. In the
>> test case I have the slow timer is always on and of a lower resolution
>> than the ARM global timer being used during runtime.
>>
>> Got some handy timer test in mind you want me to run to provide data
>> on the accuracy?
>
> John Stultz might have something.

You can turn on ntp stats in your ntp.conf and chart the loopstats
data w/ gnuplot:

set terminal png
set output "loopstat.png"
plot "/var/log/ntpstats/loopstats.<dateoftest>" using 2:3 with linespoints


I also have the drift-log.py and graph-log.py scripts I use here:
https://github.com/johnstultz-work/timetests

But those aren't really ready for mass consumption, as they're
probably not very cross-distro compatible.

thanks
-john


\
 
 \ /
  Last update: 2015-07-06 20:21    [W:0.046 / U:0.792 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site