Re: pid ranges

Janis Papanagnou <janis_papanagnou+ng@hotmail.com> writes:

On 07.10.2024 13:53, Kenny McCormack wrote:

Personally, I don't really see the point (in increasing the max pid
#).  For practical purposes, it seems unlikely you'll ever need it
(*), but then again, maybe there really are big systems out there
that need to be running more than 32K processes at a time.

>
Yes, any [multi-user] server system will likely need larger limits
(nowadays). I forgot that my (de facto) "single-user" system is in
principle able to serve hundreds of users (or more) and must be
able to handle all their processes.

My computer has a baseline of about 360 PIDs, rising to about 430 after
logging in and starting a few typical applications. 15-bit PIDs could
handle a hundred of me with plenty of room to spare.

_On Linux_ process IDs and thread IDs share the same number space which
changes the picture quite a bit: 15 bits would only support a handful of
users (with my profile) since some of those typical applications create
many threads.

All this assumes desktop users (a system serving terminal-only users
might have a lot more headroom) and that no other resource runs out
first.

--
https://www.greenend.org.uk/rjk/