Hi Gilles, On Friday 21 July 2006 15:25, Gilles Chanteperdrix wrote: > Julien Heyman wrote: > > Hi, > > > > I am currently trying to evaluate Xenomai, and my current setup is : > > VIA C3 533Mhz processor, Kubuntu 6.06 Linux distribution. > > I am using Xenomai-2.1.0 over a 2.6.17.4 kernel. > > When I run the latency part of the testsuite (in a console under KDE), I > > get results that I cannot understand, so I probably did something wrong > > (execution trace included below). > > I get reasonable values during the first seconds, then all of a sudden > > latencies begin to rise, continuously, to very large values. > > - I did check that DMA transfer is activated on my HD. > > - I did select "Enable SMI workaround" + "Globally disable SMI" in the > > Xenomai > > options while configuring the kernel. > > - I have disabled power management at BIOS level and disabled ACPI > > support and > > CPU frequency scaling during kernel configuration. > > - I checked that I don't have anything called "legacy USB" in my BIOS. I > > do have an "OnChip USB" option enable in the BIOS though. > > > > Any advice would be appreciated ! > > Some platforms stop their tsc when idle, this would cause serious > trouble for Xenomai. Linux detect such behaviour and print the message: > > Losing too many ticks! > TSC cannot be used as a timesource. > Possible reasons for this are: > You're running with Speedstep, > You don't have DMA enabled for your hard disk (see hdparm), > Incorrect TSC synchronization on an SMP system (see dmesg). > Falling back to a sane timesource now. > > Do you see such message in kernel logs ?
No, no trace of such messages in dmesg / kern.log when the pb occurs. (am I checking the "right" logs by the way ? I am a newbie on Linux) > > If this is the issue you are having, then you may try passing idle=poll > on kernel boot line. Or recompile the kernel selecting a processor that > has no tsc (for example 486), xenomai will then use the 8254 counter to > emulate the tsc. Ok, I will try selecting CPU=486, disabling TSC in Xenomai config and using the latest Xenomai release, for the sake of testing. Regards, Julien Heyman _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
