calculating correct memory utilization from invalid output of pidstat - linux

Question

I used, pidstat -r -p <pid> <interval> >> log_Path/MemStat.CSV & command to to collect the memory stat.
after running this command I found that RSS VSZ %MEM values are increased continuously, which is not expected, as pidstat provides the the values considering the interval.
After searching on net I found that there is bug in pidstat and I need to update the syssat package.
(please refer last few statements by pidstat author on this link : http://sebastien.godard.pagesperso-orange.fr/tutorial.html)
Now, my question is, how do I calculate the correct %MEM utilization from the current output as we cannot run the test again.
sample output :
Time PID minflt/s majflt/s VSZ RSS %MEM
9:55:22 AM 18236 1280 0 26071488 119136 0.36
9:55:23 AM 18236 4273 0 27402768 126276 0.38
9:55:24 AM 18236 9831 0 27402800 162468 0.49
9:55:25 AM 18236 161 0 27402800 169092 0.51
9:55:26 AM 18236 51 0 27402800 175416 0.53
9:55:27 AM 18236 6859 0 27402800 198340 0.6
9:55:28 AM 18236 1440 0 27402800 203608 0.62

Answer 1

On the Sysstat tutorial page you refer to it is said:
I noticed that pidstat had a memory footprint (VSZ and RSS fields)
that was constantly increasing as the time went by. I quickly found
that I had forgotten to close a file descriptor in a function of my
code and that was responsible for the memory leak...!
So, the output of pidstat has never been invalid; on the contrary, the author wrote
pidstat helped me to detect a memory leak in the pidstat command
itself.