On Tue, May 29, 2007 at 07:04:26PM -0700, Dave Gotwisner wrote: > Eric Blossom wrote: > > The software is running ubuntu linux with the hard drive being an NFS > mount. I am not writing any of the data to disk, so the disk I/O / > network I/O should essentially be limited to output across telnet back > to my host (another linux running VNC), and any demand paging that the > program is doing. Running or not running oprofile makes no difference, > the load average hovers between 0.00 and 0.10. My program consumes at > most 20% of the cpu.
> The ext2/3 stuff was with respect to someone elses query, not mine. I > spent today trying to get to the bottom of start/stop timings and only > spent about an hour on the overruns. If you think putting the code on a > EXT2 fs vs a network fs will make a difference, I will do so, but, I > doubt it, since I am not writing to disk. OK, sorry, confused two sets of issues. > >That's what real time scheduling is for. Increasing the total buffersize > >increases the worst case latency that you have to account for if you > >leave everything running. Hence our choice of smaller values. > > > > # Attempt to enable realtime scheduling > > r = gr.enable_realtime_scheduling() > > if r == gr.RT_OK: > > realtime = True > > else: > > realtime = False > > print "Note: failed to enable realtime scheduling" > > > >In C++ it's called gr_enable_realtime_scheduling(). > >See gr_realtime.h > > > > > I'll pursue this more tomorrow. Good. That should keep the usrp from being shut out by the X-server, etc. > >>The amount of CPU resource we need should be out of the > >>available CPU after other things run, rather than as the highest > >>priority task. From calculations based upon your proposed buffering, I > >>get (4096*16)/32 MB/s) = ~2 milliseconds of buffering, we feel we need a > >>minimum of about 50 milliseconds of buffering, hence the large numbers > >>for fusb_block_size. > >> > >>FYI, I tried building the trunk code on my ubuntu box, and when I did > >>the "./configure" command, > >> > >> > > > >did you do a ./bootstrap first? > > > > > > Yes. I did everything as me, not as root, though, if that makes a > difference. Nope. FWIW, I compile and install everything as my normal user. Principle of least priviledge. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
