On 2011-05-18 17:40, Benner Bernd (MH/EES) wrote: > Hello, > > I have rebuild my Kernel 2.6.37.6-x86 and uses xenomai-head.git. ( is this > xenomai-2.6 git ? ) > This version has the same problems on the Core 2 Duo E8400 machines. > > But there are some strange kernel messages on startup: > > May 18 16:07:33 (none) user.warn kernel: CE: hpet3 increased min_delta_ns to > 7500 nsec > May 18 16:07:33 (none) user.warn kernel: CE: hpet3 increased min_delta_ns to > 11250 nsec > May 18 16:07:33 (none) user.warn kernel: hrtimer: interrupt took 5978 ns > ... > May 18 16:07:33 (none) user.warn kernel: CE: hpet2 increased min_delta_ns to > 11250 nsec > ... > after a start of latency ( via ssh ) the linux domain will slow down and > the sata driver will come in trouble. > > > If I rebuild my Kernel with CONFIG_HPET_TIMER disabled, latency will run > normally on the Core 2 Duo E8400 machines. > > CONFIG_HPET_TIMER has to be disabled on faster Core 2 Duo machines! There > must be a consistency problem! ( probably in > io_apic- handling with CONFIG_HPET_TIMER enabled ) > > I will rebuild and test my kernel with stable 2.5.X xenomai versions and > ADEOS patches with CONFIG_HPET_TIMER disabled!
Ah! I bet you have >3 HPET timers, and they are MSI capable. In that case, Linux will actually prefer them over the LAPIC as clockevent device, and Xenomai breaks apart. I didn't discovered this as my test "machine" (QEMU/KVM) requires extra switches to enable that scenario. However, it's getting more and more common on modern hardware, we should take some measures to catch this conflict. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
