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Date:      Sun, 21 Sep 2014 13:06:02 +0400
From:      Maxim V FIlimonov <che@bein.link>
To:        Ian Lepore <ian@freebsd.org>
Cc:        freebsd-arm <freebsd-arm@freebsd.org>
Subject:   Re: FreeBSD-11.0-CURRENT on ARM: performance and load average
Message-ID:  <16223180.9Q4Ic3raYi@quad>
In-Reply-To: <1411256769.66615.155.camel@revolution.hippie.lan>
References:  <7351653.A2UeEk9AA3@quad> <1989123.lKm0QJoZES@quad> <1411256769.66615.155.camel@revolution.hippie.lan>

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On Saturday 20 September 2014 17:46:09 Ian Lepore wrote:
> 
> 60 times as fast doesn't make much sense for changing a divisor to 16.
> 
> Without that patch, what is the output of
> 
>  sysctl kern.eventtimer
>  sysctl kern.timecounter

Here it is:
root@cubie:~ # sysctl kern.eventtimer
kern.eventtimer.et.a10_timer Eventtimer.flags: 3
kern.eventtimer.et.a10_timer Eventtimer.frequency: 24000000
kern.eventtimer.et.a10_timer Eventtimer.quality: 1000
kern.eventtimer.choice: a10_timer Eventtimer(1000)
kern.eventtimer.singlemul: 4
kern.eventtimer.idletick: 0
kern.eventtimer.timer: a10_timer Eventtimer
kern.eventtimer.periodic: 1
root@cubie:~ # sysctl kern.timecounter
kern.timecounter.tc.a10_timer timer0.mask: 4294967295
kern.timecounter.tc.a10_timer timer0.counter: 4271639596
kern.timecounter.tc.a10_timer timer0.frequency: 24000000
kern.timecounter.tc.a10_timer timer0.quality: 1000
kern.timecounter.stepwarnings: 0
kern.timecounter.alloweddeviation: 5
kern.timecounter.hardware: a10_timer timer0
kern.timecounter.choice: a10_timer timer0(1000) dummy(-1000000)
kern.timecounter.tick: 1
kern.timecounter.fast_gettime: 1


> 
> If you repeatedly do "ntpdate -q <some server>" every 15 seconds for a
> couple minutes, does the offset stay pretty much the same?  (like no big
> changes in the first two decimal places)  Don't use a server like
> pool.ntp.org where you might get a different server every time, instead
> do "host pool.ntp.org" and pick one of the IPs and use it every time.
> 

root@cubie:~ # ntpdate time.nist.gov
21 Sep 13:04:55 ntpdate[2236]: adjust time server 24.56.178.140 offset 
-0.117727 sec
root@cubie:~ # ntpdate time.nist.gov
21 Sep 13:04:57 ntpdate[2237]: adjust time server 24.56.178.140 offset 
-0.117018 sec
root@cubie:~ # ntpdate time.nist.gov
21 Sep 13:05:00 ntpdate[2238]: adjust time server 24.56.178.140 offset 
-0.116026 sec
root@cubie:~ # ntpdate time.nist.gov
21 Sep 13:05:08 ntpdate[2241]: adjust time server 24.56.178.140 offset 
-0.111525 sec
root@cubie:~ # ntpdate time.nist.gov
21 Sep 13:05:26 ntpdate[2242]: adjust time server 24.56.178.140 offset 
-0.103121 sec
root@cubie:~ # ntpdate time.nist.gov
21 Sep 13:05:34 ntpdate[2243]: adjust time server 24.56.178.140 offset 
-0.099055 sec

So as you could notice, the offset doesn't change much.

> -- Ian
-- 
wbr, Maxim Filimonov
che@bein.link



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