Monday, December 25, 2006


Pf tracing results

Pf.gaunlet is now able to make plots of "intervals" and "speed". "An interval" is the count of CPU cycles between two consequent interrupt events. "Speed" is determined as (1 / interval), it is plotted with blue color, while "intervals" are plotted with brown.

On the first screenshot you can see a plot that was made for all interrupt events in the system. The noise at the left is the result of my system being a samba file server, somebody was downloading a movie at the moment. A bit of idle time follows, and then another download had began according to smbstatus output. Bold crossing lines are the result of local APIC timer and i8253 PIT timer being set for almost the same frequency, with a slight difference due to different clock sources of these timers.

The second plot is for a real-time interrupt only. I was performing fast manual movements at that time. The plot shows linear speed increasing (constant acceleration). At the top speed (5Khz frequency in this case) some noise is noticeable, that's how "2.6.19-mync" kernel performs. The worst-case interrupt latency seems to be around 25 microseconds, which is a usual limit for PC hardware.

Thursday, December 14, 2006


...and the second binary release

The first livecd release contained a pair of unfortunate bugs causing rare system hangs on speed changes and terminal crashes. I've fixed those. And when booted from the livecd, the GUI feels noticably slower than under my Ubuntu installation. This has to be addressed as well.

Tuesday, December 12, 2006


First binary release

Compiling and deploying MyNC system is not an obvious task, but it is not hard either. I think that a project like MyNC should be distributed in two forms: source code tarballs and LiveCD images, plus SVN repository for developers. LiveCD that I've prepared seems to work, I've tested it on several computers already and everything went fine except on my old system with Matrox G400 video adapter: refuses to work with it. Problems with the kernel have been holding me for almost two weeks: instantly I've discovered that my last modifications were working only on systems with IO-APIC, so I've decided to upgrade to the newest kernel version and have reworked the patch. The result is now available through file release system. And this is the first time I disclose the patch, here it is:

This page is powered by Blogger. Isn't yours?