SchedCnt is a simple program that interfaces the LatSched kernel patch to fetch data from the scheduler cycle sampler. Its code is also an example on how to use the LatSched kernel patch.
BUILD:
gcc -o schedcnt schedcnt.c
USAGE:
schedcnt [--samples n] [--sttime u] [--klimit k] [-- cmdpath [arg] ...]
--samples = Set the size of the sample buffer
--ttime = Set the sample time in seconds
--sttime = Set the sample time in microseconds
--klimit = Set the cut factor for samples. Samples > AVSC*klimit are not evalued in KAVS
cmdpath = Command to be executed
arg = Command arguments
The output is, for each CPU:
CPU NSAMP
SAMP[0]
...
SAMP[NSAMP-1]
AVSC CHSQ KAVS
CPU = CPU number
NSAMP = Number of readed samples
AVSC = Average schedule() cycles
CHSQ = ChiSquare of the CSCH distribution
KAVS = High cut average schedule() cycles
SAMP[i] is in the form :
CENT CEXT CSCH PPID RTIM
CENT = Cycle counter at schedule() entry
CEXT = Cycle counter at schedule() exit
CSCH = Cycle duration of schedule()
PPID = New scheduled PID
RTIM = Cycles run time ( this maybe incorrect some time due schedule() nesting )
Product's homepage
Find us on Google+
