Memory balloon.
It's may be useful to prevent using of disk cache in IO-tests on machines with large amount of RAM.
# make
To fill 248 Gb of RAM:
# sudo ./memory-balloon 248
try to fill 248 GB
press enter to exit...
Then you see press enter to exit... - it means memory allocated and locked in RAM. Now free should show that memory as used:
# free -h
total used free shared buff/cache available
Mem: 251G 250G 694M 2.7M 817M 558M
Swap: 8.0G 27M 8.0G
The code is licenced with GPL (https://www.gnu.org/licenses/gpl.html)