Messages in this thread | | | Subject | RE: 2.6.11, IDE: Strange scheduling behaviour: high-pri RT process not scheduled? | Date | Fri, 1 Apr 2005 11:07:54 +0200 | From | "kus Kusche Klaus" <> |
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> > The following tests are made with 'IRQ 8' at 95, rtc_wakeup > at 89(99): > > * Heavy mmap load, no oom: max jitter: 42.1% ( 51 usec) > > * Heavy mmap load, oom: max jitter: 11989.2% (14635 usec) > > (but still "missed irqs: 0", so IRQ 8 was also blocked for 14 ms) > > did you get any kernel messages in that time? (about missed > irqs, etc.) > Please do a 'dmesg -n 0' to minimize the effect of kernel messages.
Excellent, thanks!
It turned out that the latencies are not caused by the kernel messages themselves, but by sending them to a serial console (which was off), in all my high latency cases at rtpri 89(99).
After removing the serial console from the boot parameters, * the OOM timings are back to normal (around 50 microseconds) * the USB error and remove timings are back to normal * the USB plugin timings are in the range of the USB read (which is up to 1 ms - still bad)
However, latencies at rtprio 2 are still very frustrating (details will follow).
-- Klaus Kusche Entwicklung Software - Steuerung Software Development - Control
KEBA AG A-4041 Linz Gewerbepark Urfahr Tel +43 / 732 / 7090-3120 Fax +43 / 732 / 7090-8919 E-Mail: kus@keba.com www.keba.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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