Messages in this thread | | | From | Darren Hart <> | Subject | Re: rt20 scheduling latency testcase and failure data | Date | Sat, 13 May 2006 16:01:31 -0700 |
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On Saturday 13 May 2006 11:21, Lee Revell wrote: > On Sat, 2006-05-13 at 11:06 -0700, Darren Hart wrote: > > 1 [softirq-timer/0] > > What happens if you set the softirq-timer threads to 99? >
After setting all 4 softirq-timer threads to prio 99 I seemed to get only 2 failures in 100 runs. #51 slept too long (10ms too long!), the latency appeared after the sleep in #90 (nearly 483ms worth). Those latencies seem huge to me.
ITERATIONS 0-50 Passed
ITERATION 51 ------------------------------- Scheduling Latency -------------------------------
Running 10000 iterations with a period of 5 ms Expected running time: 50 s
ITERATION DELAY(US) MAX_DELAY(US) FAILURES --------- --------- ------------- -------- 7000 10197 10197 1
PERIOD MISSED! scheduled delta: 4079 us actual delta: 14263 us latency: 10183 us --------------------------------------- previous start: 35010197 us now: 35011117 us scheduled start: 35005000 us next scheduled start is in the past!
Start Latency: 114 us: FAIL Min Latency: 9 us: PASS Avg Latency: 7 us: PASS Max Latency: 10197 us: FAIL Failed Iterations: 1
ITERATIONS 52-89 Passed
ITERATION 90 ------------------------------- Scheduling Latency -------------------------------
Running 10000 iterations with a period of 5 ms Expected running time: 50 s
ITERATION DELAY(US) MAX_DELAY(US) FAILURES --------- --------- ------------- -------- 2747 9 20 0
PERIOD MISSED! scheduled delta: 4072 us actual delta: 4079 us latency: 6 us --------------------------------------- previous start: 13735009 us now: 14218183 us scheduled start: 13740000 us next scheduled start is in the past!
Start Latency: 112 us: FAIL Min Latency: 8 us: PASS Avg Latency: 2 us: PASS Max Latency: 20 us: PASS Failed Iterations: 0
ITERATIONS 91-99 Passed
Thanks,
-- Darren Hart IBM Linux Technology Center Realtime Linux Team - 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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