i was about to say that i'd find it useful if the atime of /proc/n
reflected the last run time of a process, to make it easier to find
cpu hogs, but russ's point about ls -lt /proc's uselessness is bang
on.
so, by way of a little script to help with the above problem, which
bugs me every so often, here's "hogs", a poor man's replacement for
unix's "top" - it's like ps except that it sorts the processes by the
amount of time they've used over the last t (default 1) seconds.
it displays percentage of time used over the sample time (this might
be >100% with multiple cpus), and combines user, syscall and child
time into the second time column (to make it easier to find processes
that spawn lots of transient cpu-eating processes but don't do much
themselves); otherwise the output format is the same as for ps(1).
YMMV - i imagine others have similar scripts.
cat >$home/bin/rc/hogs <<'EOF'
#!/bin/rc
# usage: hogs [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:/'
EOF
