#!/bin/bash
pname=""
verbose=""

function usage {
	echo "Usage: funccount [process]"
}
if [ $# -eq 1 ]; then
	pname=$1
fi

echo "Creating and building SystemTap module..."

stap "$verbose" -e '
global timebyfunc, pages, page_sz
global start, pname_str, totcalls

probe begin {
	pname_str = "'$pname'"
	printf("Collecting data for %s - type Ctrl-C to print output and exit...\n", pname_str);
}

probe kernel.function("mpage_readpages")
{
	if ($nr_pages && execname() ==  pname_str)  {
		start[$nr_pages] = gettimeofday_ns()
		pages=$nr_pages
	}
}
probe kernel.function("mpage_readpages").return
{
	if (pages == 0) 
		next

	delta = gettimeofday_ns() -  start[pages]
	timebyfunc[pages] <<< delta
	page_sz[pages] = pages
	
	delete start[pages]
	pages=0
}
function print_header() {
	printf("%-19s %10s %12s\n",
	       "Call", "Count", "Total ns")
}
probe end {
	print_header()
	foreach (page in page_sz-) {
		printf("mpage_readpages(%d) %10d %12d\n", page_sz[page],
			@count(timebyfunc[page]), @sum(timebyfunc[page]))
		totcalls += @count(timebyfunc[page])
	}
	printf("Total Calls: %d\n", totcalls);

	delete page_sz
	delete timebyfunc
}'