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Date: Fri, 21 Feb 2025 16:18:54 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Michal =?ISO-8859-1?Q?Koutn=FD?= <mkoutny@suse.com>
Cc: Christian Brauner <brauner@kernel.org>, Alexander Mikhalitsyn
 <alexander@mihalicyn.com>, linux-doc@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
 linux-trace-kernel@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>, Kees
 Cook <kees@kernel.org>, "Eric W . Biederman" <ebiederm@xmission.com>, Oleg
 Nesterov <oleg@redhat.com>
Subject: Re: [PATCH 2/2] pid: Optional first-fit pid allocation
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On Fri, 21 Feb 2025 18:02:49 +0100 Michal Koutn=FD <mkoutny@suse.com> wrote:

> --- a/Documentation/admin-guide/sysctl/kernel.rst
> +++ b/Documentation/admin-guide/sysctl/kernel.rst
> @@ -1043,6 +1043,8 @@ The last pid allocated in the current (the one task=
 using this sysctl
>  lives in) pid namespace. When selecting a pid for a next task on fork
>  kernel tries to allocate a number starting from this one.
> =20
> +When set to -1, first-fit pid numbering is used instead of the next-fit.
> +

This seems thin.  Is there more we can tell our users?  What are the
visible effects of this?  What are the benefits?  Why would they want
to turn it on?

I mean, there are veritable paragraphs in the changelogs, but just a
single line in the user-facing docs.  Seems there could be more...