global read_pages_start_time, read_pages_time, read_pages_longest,num_pages 

probe module("nfs").function("nfs_readpages")
{
	num_pages = $nr_pages
	read_pages_start_time = gettimeofday_us()
}
probe module("nfs").function("nfs_readpages").return
{
	read_pages_time <<< gettimeofday_us() - read_pages_start_time
	if (@max(read_pages_time) > read_pages_longest) {
		printf ("%s: %s time avg %d max %d pages %d\n", execname(), probefunc(), 
			@avg(read_pages_time), @max(read_pages_time), num_pages)
	}
	read_pages_longest = @max(read_pages_time)
}
/*
probe kernel.function("__do_page_cache_readahead")
{
	printf("%s: back trace\n", probefunc())
	print_stack(backtrace())
	printf("\n");
}
*/
probe begin { log("starting nfs_readpages probe") }
probe end { log("ending nfs_readpages probe") }