How to benchmark filesystem in Linux?

sysbench fileio --file-total-size=20G prepare
sysbench fileio --file-total-size=20G --file-test-mode=rndrw run

How to benchmark a CPU in Linux?

A legacy syntax:

sysbench --test=fileio --file-total-size=20G prepare
sysbench --test=fileio --file-total-size=20G --file-test-mode=rndrw run