Hi Per No help on the SMP compile and run. I don't have such a mobo here. I do have an Athalon64 on a N8V mobo. I do not see any big jump in latency every 6 or so iterations of the test.
I must admit when running with an 8000 base period that I was violating the sentence in the troubleshooting wiki page http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?TroubleShooting "There should be no overruns, and 'lat max' should probably be below your BASE_PERIOD setting." I did not see any overruns from the latency test but the 8000 was below the 12000 lat max for that box. Rayh On Sat, 2007-01-13 at 15:07 +0100, Per Willför wrote: > Hi! > > I've got some serious problems to build an SMP kernel with RTAI > extensions, and I'm thinking that maybe someone else may have already > achieved this. I have a system with an Athlon 64 X2 4600+ on an Asus M2V > motherboard (K8T890 chipset), and I'm using Ubuntu 6.06.1 LTS with EMC2 > loaded per the script on the linuxcnc.org homepage. Everything works > just great in UP mode, but I'm missing the additional processor that > sits there idle. My goal is to squeeze BASE_PERIOD as low as possible > (to get the highest stepping freq possible, or less jitter for lower > step rates), and I think an SMP kernel wold help substantially in this > regard. In UP mode BASE_PERIOD can only be lowered to about 20 µs, and I > would like to get down to 5-8 µs - I read a post by Ray H that he set > BASE_PERIOD to 8000... When I run the RTAI test program (have forgot > it's name) i get good delay numbers for 4-5 rows and then there's > something that "gets in the way" every 5th - 6 th row with much longer > latencies. My idea was to not optimize the interrupt handling and > graphics drivers or whatever, but rather enabling the other CPU. Having > tried all sorts of magma as well as vanilla kernels, it always fails > when I use the combination of SMP and RTAI. > > For starters, I thought I could just use the magma kernel source and > change one thing - enable SMP - but this wasn't the case. The machine > just rebooted after i selected "magma-smp" in GRUB, if there was any > error message flashing by I'm not fast enough to read it. About the same > problems has occured with different vanilla kernels as well, sometimes > the machine just reboots after GRUB selection, sometimes I get some > output from the kernel before it freezes or crashes (BTW, is there a way > to capture the console output, like "tee:ing" it to a serial port?) > > Please note that I haven't come as far as trying to start EMC2 on an SMP > kernel; I'm still trying to boot a kernel with SMP enabled and RTAI > patches. For the vanilla kernels I have been using rtai-3.4-cv and > 2.6.17.6 (I started with 2.6.17.14 and went backwards unit the patch > file from RTAI could be applied without errors). > > What am I doing wrong? > > Per W > SWEDEN > -- > > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share your > opinions on IT & business topics through brief surveys - and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
