ss -p is much too slow

ss -p is much too slow

> On closer inspection, it appears that ss -p does a quadratic scan. It
> rescans every entry in /proc/*/fd/* repeatedly (once per listening
> port? per process? I don't remember what I figured out.)
>
> I humbly suggest that this is not a good idea.

Yep, this is junk.  Please give this patch a try:

ss: Avoid quadradic complexity with '-p'

Scan the process list of open sockets once, and store in a hash
table to be used by subsequent find_user() calls.

Reported-by: Steve Fink <sphink@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>