Hi all, We run linux kernel 3.2.34 + ipipe-core-3.2.21-x86-1 + xenomai 2.6.1 on two platforms, one with Xeon E5620 and the other with Xeon E5-1650.
E5-1650 shows higher latencies than E5620 when running the following test on an idle system: latency -t 2 -T60 -q ; latency -t 1 -T60 -q ; latency -t 0 -T60 -q ++++++ Xeon E5-1650 ++++++ == Test mode: in-kernel timer handler ---|-----------|-----------|-----------|--------|------|------------------------- RTS| -3.156| -2.073| 10.554| 0| 0| 00:01:00/00:01:00 == Test mode: in-kernel periodic task ---|-----------|-----------|-----------|--------|------|------------------------- RTS| -2.694| -1.215| 16.683| 0| 0| 00:01:00/00:01:00 == Test mode: periodic user-mode task ---|-----------|-----------|-----------|--------|------|------------------------- RTS| -2.445| -0.412| 15.308| 0| 0| 00:01:00/00:01:00 ++++++ Xeon E5620 ++++++ == Test mode: in-kernel timer handler ---|-----------|-----------|-----------|--------|------|------------------------- RTS| -3.759| -2.669| 1.056| 0| 0| 00:01:00/00:01:00 == Test mode: in-kernel periodic task ---|-----------|-----------|-----------|--------|------|------------------------- RTS| -2.656| -1.567| 6.852| 0| 0| 00:01:00/00:01:00 == Test mode: periodic user-mode task ---|-----------|-----------|-----------|--------|------|------------------------- RTS| -2.060| -0.964| 7.631| 0| 0| 00:01:00/00:01:00 I have read that "The most common reason for high latencies on x86 are SMIs". But the SMI workaround does not manage the Patsburg LPC controller. I tried to add the PCI ID [8086:1d41] to ksrc/arch/x86/smi.c with this result: [ 1.926417] Xenomai: SMI-enabled chipset found [ 1.926490] Xenomai: SMI workaround failed! Should the SMI workaround be managed for the C602 chipset ? Could it explain the above latency results ? Thanks, Sylvie _______________________________________________ Xenomai mailing list [email protected] http://www.xenomai.org/mailman/listinfo/xenomai
