Reduce unittest runtime

[cydrain]

The current runtime for unittest is around 2 hours, and this time needs to be reduced to less than 1 hour.
Check following file for detailed case runtime:
ut_runtime.txt

[cydrain]

/assign @zhengbuqian

[zhengbuqian]

/assign @sparknack

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/assign @sparknack

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[sparknack]

ack

[zhengbuqian]

/assign @sparknack