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 <m...@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 -- _____________________________________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
