Re: + pid-delete-reserved_pids.patch added to -mm tree

From: Oleg Nesterov
Date: Tue Oct 03 2017 - 11:53:22 EST

Hi Alexey,

On 10/02, Andrew Morton wrote:
> From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
> Subject: pid: delete RESERVED_PIDS
> RESERVED_PIDS had a noble goal: to protect root from PID exhaustion since
> at least ~2.5.40

I am just curious, where did you find the change which documents this goal?

> except it never did that because there was no capability
> or uid checks.
> Allow small pids to be allocated after rollover, there is nothing sacred
> about them.
> Resource exhaustion should be handled by rlimits and/or kernel memory
> accounting.

I won't argue, but I always thought that the only purpose of RESERVED_PIDS
is to make the system/kernek daemons started at boot time more "visible" in
/usr/bin/ps output.