Latency Tests
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5.2. Test Scenario 1 (TS1)

TS1 was designed to be the baseline test. The target operates with virtually no load. The results track the amount of time it takes from a hardware interrupt for data to flow to one user-space process then back out through the same hardware device.

5.2.1. Host

Table 5-1. TS1 Host

Component	Parameters
latency-server	/dev/ttyS0 infifo -p500000 -i 3000 -l logfile &
echo	"{00000000111111111122222222223333333333444444444455555555556666}" > infifo

5.2.2. Target

Table 5-2. TS1 Target

Component	Parameters	Instances
latency-client	/dev/ttyS0[a] 0	0 drones
Notes: a. this is an on-board serial port

This can be accomplished by running the following:

# latency-client /dev/<serial device> 0 &
# chrtgroup.sh -n 98
# nicegroup.sh
(now you have to find the PID of the process running the interrupt used
for the serial device you specified above. NOTE: this is only available
for the RT kernels)
# chrt -fp 99 <pid>