packetdrill: implement relative time tolerance #42
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wdebruij
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Aug 13, 2020
sheepx86
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packetdrill tries to accommodate difference between expected time and observed time using a (configurable) maximum value of the difference. Add a percentage based tolerance, which is helpful for long running tests. Default of 0.5 % means that 5ms of drift per second is allowed. If one event happens 10 seconds after the last one, the tolerance would be 50 ms. Can be changed with --tolerance_percent=<percentage>
Packetdrill calculates the dynamic tolerance based on delta between time of the last and current event. This delta value is irrelevant for a blocking system call and the last event is unpredictable and depends on the timing. Instead we can use the delta between the start and end time specified in the packetdrill with an ellipse.
Packetdrill checks difference between expected time and observed time using a tolerance, which is set as the higher of a fixed value (tolerance_usecs) or a percentage(tolerance_percent) times duration. Extend this check for SCM_TIMESTAMPING records.
dcaratti
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Feb 25, 2021
mptcp: new syscall test for full DATA_FIN handshake after close
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Packetdrill tries to accommodate difference between expected time and observed time using a (configurable) maximum value of the difference.
For tests runing on slow hosts or with long running tests, the fixed tolerance may cause the test fail.
Add a new flag
--tolerance_percentto allow the tolerance relative to the time difference of events. Default of 0.5 % means that 5ms of drift per second is allowed. The flag also applies to SCM_TIMESTAMPING records.