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Date:      Sun, 7 Aug 2011 20:28:09 -0300
From:      Mario Lobo <lobo@bsd.com.br>
To:        bf1783@gmail.com
Cc:        freebsd-questions@freebsd.org
Subject:   Re: High interrupt rate
Message-ID:  <201108072028.09658.lobo@bsd.com.br>
In-Reply-To: <CAGFTUwNPAJOPEzzPsd=4kdyMkQH-y6LrNkeZD11578uPY5eO0g@mail.gmail.com>
References:  <CAGFTUwNPAJOPEzzPsd=4kdyMkQH-y6LrNkeZD11578uPY5eO0g@mail.gmail.com>

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On Sunday 07 August 2011 18:34:27 b. f. wrote:
> > I know 75% idle is not bad but this machine, when not under load on a
> > saturday night like today, used to be at around 98% idle 99% of the
> > time. Now its is at 72% idle 99.9% of the time. It has been like this
> > all day.
> > 
> > The only things with a high interrupt rate are
> > 
> > cpu0: timer                     46922025       2000
> > cpu1: timer                     46918117       1999
> > 
> > What could be causing this?
> 
> I don't know that 2 timer interrupts per-cpu, per kern.hz, is
> altogether unexpected for some configurations, under some conditions.
> What happens if you boot with kern.hz="100" in /boot/loader.conf, or
> set via the loader command line?  What happens if you remove the
> DEVICE_POLLING option from your kernel (and _not_ just disable polling
> per-device)?  What is the output from "sysctl kern.timecounter
> kern.eventtimer"?
> 
> b.

Thanks b. !

[~]>sysctl kern.timecounter
kern.timecounter.tick: 1
kern.timecounter.choice: TSC(-100) ACPI-safe(850) i8254(0) dummy(-1000000)
kern.timecounter.hardware: ACPI-safe
kern.timecounter.stepwarnings: 0
kern.timecounter.tc.i8254.mask: 65535
kern.timecounter.tc.i8254.counter: 39201
kern.timecounter.tc.i8254.frequency: 1193182
kern.timecounter.tc.i8254.quality: 0
kern.timecounter.tc.ACPI-safe.mask: 16777215                                                                                                                                                                           
kern.timecounter.tc.ACPI-safe.counter: 1055460                                                                                                                                                                         
kern.timecounter.tc.ACPI-safe.frequency: 3579545                                                                                                                                                                       
kern.timecounter.tc.ACPI-safe.quality: 850                                                                                                                                                                             
kern.timecounter.tc.TSC.mask: 4294967295                                                                                                                                                                               
kern.timecounter.tc.TSC.counter: 1200011080                                                                                                                                                                            
kern.timecounter.tc.TSC.frequency: 1995401152                                                                                                                                                                          
kern.timecounter.tc.TSC.quality: -100                                                                                                                                                                                  
kern.timecounter.smp_tsc: 0                                                                                                                                                                                            
kern.timecounter.invariant_tsc: 1  

[~]>sysctl kern.hz
kern.hz: 1000

[~]>sysctl kern.eventtimer
sysctl: unknown oid 'kern.eventtimer'

I'll wait for your views on those before disabling polling on the kernel and 
hz=100.


Thanks again.
-- 
Mario Lobo
http://www.mallavoodoo.com.br
FreeBSD since 2.2.8 [not Pro-Audio.... YET!!] (99% winblows FREE)



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