#!/bin/rc
#
# why - "why is this machine so slow"
# usage: why [sampletime]

t=1
if(! ~ $#* 0)
	t = $1
{
	cd /proc
	for(i in [0-9]*){
		cat $i/status && echo $i
	}
	echo
	sleep $t
	for(i in [0-9]*){
		cat $i/status && echo $i
	}
} | awk '
	phase == 0 && /./ {
		t0[$13] = $4+$5+$7+$8;
		rt0[$13] = $6
		next
	}
	phase == 0 && /^$/ {
		phase = 1;
		next
	}
	phase != 0 {
		t1[$13] = $4+$5+$7+$8
		rt1[$13] = $6
		line[$13] = $0
	}
	END {
		for(i in line){
			n = split(line[i], p, " ");
			dt = ((t1[i] - t0[i] + 0.0) / (rt1[i] - rt0[i])) * 100
			utime = (p[4]+p[4]+p[7]+p[8]) / 1000;
			size = p[9];
			if(dt >= 1 || utime >= 1){
				printf("%-10s %8s %3d%% %4d.%.2d %7dK %-8.8s %s\n",
					p[2],
					i,
					dt,
					utime/60, utime%60,
					size,
					p[3],
					p[1]);
			}
		}
	}' |
	sort +2rn -3rn +3rn |
	sed 's/(^[^ ]+ +[0-9]+ +[0-9]+% +[0-9]+)\./\1:/'