8.3. Runtime Instrumentation Testing - N1SDP

For this test we used the N1 System Development Platform (N1SDP), which contains an SoC consisting of two dual-core Arm N1 clusters.

The following source trees were used:

Please see the Runtime Instrumentation Testing Methodology page for more details. The tests were ran using the tf-psci-lava-instr/n1sdp-runtime-instrumentation,n1sdp-runtime-instrumentation:n1sdp-fip.tftf-firmware configuration in CI.

8.3.1. Results

8.3.1.1. CPU_SUSPEND to deepest power level

CPU_SUSPEND latencies (µs) to deepest power level in parallel (v2.13)

Cluster

Core

Powerdown

Wakeup

Cache Flush

0

0

3.32

13.42 (-45.40%)

0.28 (-69.57%)

0

0

4.02 (-35.78%)

18.14 (-52.88%)

0.28

1

0

2.7 (-27.42%)

17.38 (-49.36%)

0.26

1

0

2.96

10.86 (-73.64%)

0.26

CPU_SUSPEND latencies (µs) to deepest power level in parallel (v2.12)

Cluster

Core

Powerdown

Wakeup

Cache Flush

0

0

2.58

24.14

0.28 (-69.57%)

0

0

4.24 (-32.27%)

40.1

0.3

1

0

3.58

35.54

0.28

1

0

3.28

42.36

0.3

CPU_SUSPEND latencies (µs) to deepest power level in serial (v2.13)

Cluster

Core

Powerdown

Wakeup

Cache Flush

0

0

1.62

10.14 (-58.10%)

0.3

0

0

1.86

10.62 (-56.44%)

0.28 (-26.32%)

1

0

1.8

10.16 (-57.84%)

0.32

1

0

2.16

10.6 (-56.84%)

0.5 (+56.25%)

CPU_SUSPEND latencies (µs) to deepest power level in serial (v2.12)

Cluster

Core

Powerdown

Wakeup

Cache Flush

0

0

1.9

23.8

0.36

0

0

2.26

23.86

0.34

1

0

2.02

23.4

0.36

1

0

2.24

23.84

0.36

8.3.1.2. CPU_SUSPEND to power level 0

CPU_SUSPEND latencies (µs) to power level 0 in parallel (v2.13)

Cluster

Core

Powerdown

Wakeup

Cache Flush

0

0

0.8 (-57.45%)

11.98 (-61.75%)

0.26

0

0

1.54 (-30.63%)

16.44 (-53.74%)

0.26

1

0

1.62 (-30.77%)

16.1 (-53.92%)

0.3

1

0

1.8

10.54 (-55.30%)

0.2 (-33.33%)

CPU_SUSPEND latencies (µs) to power level 0 in parallel (v2.12)

Cluster

Core

Powerdown

Wakeup

Cache Flush

0

0

1.46

31.7

0.32

0

0

2.06

35.5

0.48 (+60.00%)

1

0

1.96

35.7

0.32

1

0

2.08

23.38

0.28

CPU_SUSPEND latencies (µs) to power level 0 in serial (v2.13)

Cluster

Core

Powerdown

Wakeup

Cache Flush

0

0

1.44

9.9 (-58.05%)

0.3

0

0

1.74 (-25.64%)

10.4 (-56.23%)

0.28 (-33.33%)

1

0

1.8

10.04 (-57.71%)

0.34

1

0

1.96

10.46 (-56.23%)

0.44

CPU_SUSPEND latencies (µs) to power level 0 in serial (v2.12)

Cluster

Core

Powerdown

Wakeup

Cache Flush

0

0

1.66

23.22

0.36

0

0

2.58

23.72

0.78 (+85.71%)

1

0

2.02

23.84

0.38

1

0

2.16

23.92

0.34

8.3.1.3. CPU_OFF on all non-lead CPUs

CPU_OFF on all non-lead CPUs in sequence then, CPU_SUSPEND on the lead core to the deepest power level.

CPU_OFF latencies (µs) on all non-lead CPUs (v2.13)

Cluster

Core

Powerdown

Wakeup

Cache Flush

0

0

1.64

10.24 (-57.72%)

0.3

0

0

13.92

17.7 (-43.74%)

0.3

1

0

13.54

16.74 (-44.90%)

0.3 (-37.50%)

1

0

14.12

18.28 (-41.93%)

0.3 (-44.44%)

CPU_OFF latencies (µs) on all non-lead CPUs (v2.12)

Cluster

Core

Powerdown

Wakeup

Cache Flush

0

0

1.84

23.82

0.36

0

0

14.18

31.78

0.56 (+86.67%)

1

0

13.64

30.54

0.36

1

0

14.18

31.82

0.68

8.3.1.4. CPU_VERSION in parallel

CPU_VERSION latency (µs) in parallel on all cores (v2.13)

Cluster

Core

Latency

0

0

0.12

0

0

0.2 (-28.57%)

1

0

0.2

1

0

0.24 (-25.00%)

CPU_VERSION latency (µs) in parallel on all cores (v2.12)

Cluster

Core

Latency

0

0

0.14

0

0

0.2 (-28.57%)

1

0

0.2

1

0

0.26


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