watch-function-frequency: Simple script to identify common call stacks for a function

Signed-off-by: Mel Gorman <mgorman@suse.de>
loopdd: Add a basic configuration

Signed-off-by: Mel Gorman <mgorman@suse.de>
watch-function-frequency: Bodge around overflows

It grinds the system to a halt and stap needs to be killed in a separate
console but it does the job.

Signed-off-by: Mel Gorman <mgorman@suse.de>