Hi Eric I was not running through a switch.
I tried what you suggested, and can confirm that the CPUs are not being throttled. I have then discovered that for some reason I can only get the problem to occur on one of my two host PCs. I am trying to install the new Ubuntu (actually, the 64-bit version thereof) for the time being, after formatting the hard drive, and am hoping it will work on this PC afterwards. Cheers Ian. -----Original Message----- From: Eric Blossom [mailto:e...@comsec.com] Sent: Thursday, 13 May 2010 4:07 AM To: Ian Holland Cc: discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] Unexplained out-of-sequence packets... On Wed, May 12, 2010 at 04:34:36PM +0930, Ian Holland wrote: > Hi Eric > > It seems this has not fixed the problem. Does anyone have any other > suggestions as to the possible cause? Note, I also found power cycling > the USRP2 can sometimes avoid the same problem. > > Ian. Ian, I still suspect something in your host setup. Is the USRP2 connected directly to the host or does it go through a switch? If there's a switch in the path, please remove it. Note that the cpu throttling / clock scaling hypothesis would explain why it works better under higher load than lower load. Are you sure that your cpu isn't being throttled? When you're seeing the problem, try: $ grep 'cpu MHz' /proc/cpuinfo and see if all cores are running at full speed. E.g., Idling laptop (throttled back from 1.83GHz): [...@cyan ~]$ grep 'cpu MHz' /proc/cpuinfo cpu MHz : 1000.000 cpu MHz : 1000.000 Server with cpu scaling disabled: [...@octo swig]$ grep 'cpu MHz' /proc/cpuinfo cpu MHz : 2999.488 cpu MHz : 2999.488 cpu MHz : 2999.488 cpu MHz : 2999.488 cpu MHz : 2999.488 cpu MHz : 2999.488 cpu MHz : 2999.488 cpu MHz : 2999.488 Eric > -----Original Message----- > From: discuss-gnuradio-bounces+ian.holland=rlmgroup.com...@gnu.org > [mailto:discuss-gnuradio-bounces+ian.holland=rlmgroup.com...@gnu.org] On > Behalf Of Ian Holland > Sent: Tuesday, 11 May 2010 11:14 AM > To: Eric Blossom > Cc: discuss-gnuradio@gnu.org > Subject: RE: [Discuss-gnuradio] Unexplained out-of-sequence packets... > > Thanks Eric > > I checked the power management preferences and couldn't see anything > about CPU throttling, though I did verify it would never go to sleep > after inactivity. Then, I found some info on > http://blog.mpathirage.com/2009/10/04/how-to-disable-dynamic-frequency-s > calingcpu-throttling-in-ubuntu-jaunty9-04/ to disable the CPU throttling > (I know I am using 9.10, not 9.04, but I imagine it should be the same). > > After rebooting (only once), I haven't yet seen the problem again. > Unfortunately, given the seemingly random nature of the problem, I guess > it is a wait-and-see matter as to whether it ever does resurface. > > Cheers > > Ian. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio