[asterisk-users] Terrible dahdi_test results

Wed May 14 15:41:47 CDT 2014

Hi Eric,

I plugged an E1 into the card and it doesn't make any difference.

# dahdi_test 
Opened pseudo dahdi interface, measuring accuracy...
88.829% 87.806% 88.988% 88.854% 88.944% 88.952% 88.967% 88.841% 
88.889% 88.946% 88.933% 88.841% 88.885% 89.050% 88.904% 87.933% 
88.912% 88.949% 88.913% 88.886% 88.891% 88.798% 88.746% 89.009% 
88.934% 88.870% 88.875% 89.003% 88.925% 88.863% 89.018% 88.093% 
88.447% 88.691% 89.034% 88.703% 88.815% 89.011% 88.919% 88.825% 
etc.

I will try the card in an older machine tomorrow.

Ironic is that i bought this card because it has a PCI express
interface so I can use it in recent servers.... but it uses an
older chipset and driver than I was using.

Thanks for the help,

Mike

On Wed, 2014-05-14 at 15:54 -0400, Eric Wieling wrote:
> Try the card in another machine with a different brand of motherboard.  If it works you know it is a hardware issue. 
> 
> Do you have an actual T-1 plugged into your card?  If not, try that and see if there is any difference.    
> 
> -----Original Message-----
> From: asterisk-users-bounces at lists.digium.com [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Mike Leddy
> Sent: Wednesday, May 14, 2014 3:43 PM
> To: asterisk-users at lists.digium.com
> Subject: Re: [asterisk-users] Terrible dahdi_test results
> 
> 
> I remembered I have an older box with a Wildcard TE12xP that uses the wcte12xp module with a newer 3.9.11 kernel that works perfectly.
> 
> I setup the problematic machine with the same kernel in the hope that this might be relevant. Unfortunately the same situation persists.
> 
> I used the /proc/timer_stats to see how the timers were used:
> 
> Timer Stats Version: v0.2
> Sample period: 10.002 s
> ....
>   311, 15081 kworker/u:0      mod_timer (te12xp_timer)
> ....
> 
> With the TE110P I couldn't find any entry.... It seems that the timing mechanism is different, it doesn't use mod_timer.
> 
> I'm running out of ideas. Please help.
> 
> Thanks,
> 
> Mike
> 
> On Tue, 2014-05-13 at 17:56 -0300, Mike Leddy wrote:
> > Thanks again Russ,
> > 
> > Just a quick reply for now.
> > 
> > No virtualization, but yes I am running a tickless kernel:
> > 
> > #
> > # Processor type and features
> > #
> > CONFIG_NO_HZ=y
> > 
> > Standard for debian kernels. I booted with nohz=off and the behaviour 
> > changed. Unfortunately for the worse:
> > 
> > # dahdi_test
> > Opened pseudo dahdi interface, measuring accuracy...
> > 66.653% 66.683% 66.683% 66.807% 67.705% 66.666% 66.651% 66.679% 
> > 67.516% 66.882% 66.649% 66.657% 66.678% 66.668% 66.672% 66.664% 
> > 66.675% 66.675% 66.659% 66.692% 66.631% 66.187% 66.650% 66.710% 
> > 66.648% 66.633% 66.714% 66.638% 66.688% 66.794% 66.645% 66.696%
> > --- Results after 32 passes ---
> > Best: 67.705% -- Worst: 66.187% -- Average: 66.726523%
> > 
> > Comparing the boot messages without nohz=off:
> > 
> > [    0.000000] hpet clockevent registered
> > [    0.000000] Fast TSC calibration failed
> > [    0.000000] TSC: Unable to calibrate against PIT
> > [    0.000000] TSC: using HPET reference calibration
> > [    0.000000] Detected 2593.456 MHz processor.
> > 
> > and with nohz=off:
> > 
> > [    0.000000] hpet clockevent registered
> > [    0.000000] Fast TSC calibration using PIT
> > [    0.000000] Detected 2593.225 MHz processor.
> > 
> > I am encouraged that we seem to be homing in on the problem. I need to 
> > read up a bit more on the subject.... and look at possible power 
> > saving issues on this machine.
> > 
> > Best regards,
> > 
> > Mike
> > 
> > 
> > On Tue, 2014-05-13 at 15:26 -0500, Russ Meyerriecks wrote:
> > > On Tue, May 13, 2014 at 7:28 AM, Mike Leddy <mike at loop.com.br> wrote:
> > >         But on examination the /etc/init.d/dahdi start was only
> > >         loading
> > >         the dahdi module.
> > > 
> > > 
> > > With this in mind I might start looking around the system for things 
> > > which might cause jitter in the servicing of system timer interrupts:
> > > 
> > > 
> > > Are you running under a virtualized environment?
> > > Are you running a tickless kernel? (maybe try adding nohz=off to 
> > > your kernel boot parameters) Is there some sort of processor power 
> > > saving or frequency scaling going on that interrupts the system 
> > > timer?
> > > 
> > > 
> > > --
> > > Russ Meyerriecks
> > > Digium, Inc. | Linux Kernel Developer
> > > 445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
> > > direct: +1 256-428-6025
> > > Check us out at: www.digium.com & www.asterisk.org
> > 
> > 
> > 
> 
> 
> 
> --
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