Especiall if there is chance it will be used on something like OpenWRT. Yesterday I installed Munin on my OpenWRT router. Now I can see that sometimes statistics drop to zero, because it didn't manage to catch them.
I looked for most CPU hungry plugins and those are
processes. I rememeber that I already had to rewrite
because it was damn slow, so I only used that version (it should be also
somewhere in their tracker, but I can not find it right now).
processes plugin was also quite easy to optimise, compare old and
# time find /proc -type d | grep [0-9]$ | tr -d "/proc/" | grep ^[0-9]*$ | wc -l real 0m 0.77s user 0m 0.28s sys 0m 0.39s # time ls -d /proc/[1-9]* | wc -l real 0m 0.06s user 0m 0.04s sys 0m 0.00s