I'm performing realtime latency tests (for details about the hardware and software, see my mail "[BUG] 2.6.11: Random SCSI/USB errors when reading from USB memory stick" erlier today).
Even when the errors described in my previous mail does not occur, massive USB stick transfers cause latencies of 1 to 2 milliseconds, which is way too much for realtime control systems. I observe these latencies on a vanilla 2.6.11 at any rtprio (even 99), and on realtime-preempt-2.6.12-rc1-V0.7.41-11 at low rtprio (1). When running the program on realtime-preempt-2.6.12-rc1-V0.7.41-11 with rtprio 99, the latencies are gone, but using a rtprio higher than the interrupt handlers is not realistic. Is there anything which can be done about it? 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: [EMAIL PROTECTED] > www.keba.com > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
