On Fri, 2007-03-23 at 14:04 +0000, [EMAIL PROTECTED] wrote: > Hello, > > I have been working on trying to find the optimal linux kernel configuration > and have noticed a couple problems. > No matter what I do it seems that while cpu #2 is detected, nothing gets > scheduled on it.
If not already done, try building the Xenomai nucleus as a module instead of statically into the kernel. Is the situation normal with respect to load balancing between CPUs before you eventually modprobe this module? > Also, there is always a modprobe process running at 100%cpu that I can't kill. modprobe of which module? > The command that is showed in top is "modprobe -s ac". If I run it from > the command line it hangs as well. > Latencies are however very acceptable when running xeno-test. I do however > see some negative values > in the test output. Negative values are (mostly) ok. This only means that your machine is faster than pre-calibrated for, which causes the timer shots to be ahead of time, due to a pessimistic calibration. Check /proc/xenomai/latency, this gives the intrinsic latency Xenomai anticipates when programming timer shots (i.e. interrupt latency + scheduling latency altogether), given as a count of nanoseconds. You can change this value on the fly while the latency test is running; just echo a new value to this file. You should try lowering it until all the values (particularly the leftmost ones, i.e. "min lat") raise slightly above zero. > > The config file that I am using currently is the same as the one below just > with CONFIG_XENO_HW_SMI_ALL. > This seems to give me the best latencies. > > Mike > > -------------- Original message ---------------------- > From: Gilles Chanteperdrix <[EMAIL PROTECTED]> > > [EMAIL PROTECTED] wrote: > > > -------------- Original message ---------------------- > > > From: Gilles Chanteperdrix <[EMAIL PROTECTED]> > > > > > >>[EMAIL PROTECTED] wrote: > > >> > > >>># > > >>># SMI workaround > > >>># > > >>># CONFIG_XENO_HW_SMI_DETECT_DISABLE is not set > > >>>CONFIG_XENO_HW_SMI_DETECT=y > > >>>CONFIG_XENO_HW_SMI_WORKAROUND=y > > >>># CONFIG_XENO_HW_SMI_ALL is not set > > >>># CONFIG_XENO_HW_SMI_INTEL_USB2 is not set > > >>># CONFIG_XENO_HW_SMI_LEGACY_USB2 is not set > > >>># CONFIG_XENO_HW_SMI_PERIODIC is not set > > >>># CONFIG_XENO_HW_SMI_TCO is not set > > >>># CONFIG_XENO_HW_SMI_MC is not set > > >>>CONFIG_XENO_HW_SMI_APMC=y > > >>># CONFIG_XENO_HW_SMI_LEGACY_USB is not set > > >>>CONFIG_XENO_HW_SMI_BIOS=y > > >> > > >>Chances are that the latencies you get are due to the SMI you leave > > >>enabled (APMC or BIOS). Could you try first with only > > >>CONFIG_XENO_HW_SMI_ALL ? > > >> > > > WOW!!! I did try that with the 2.6.17 kernel but it wouldnt boot, > > > I had to enable APM. It is working like charm now. Max latency > > > is 4-5 us while running X. If I drag a window around it goes up > > > to 7us or so. Deffinately a step in the righ direction! Thanks. > > > > Good news. > > > > -- > > Gilles Chanteperdrix > > > _______________________________________________ > Xenomai-help mailing list > [email protected] > https://mail.gna.org/listinfo/xenomai-help -- Philippe. _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
