Re: [PATCH 2/5] daemons: make sure /proc is properly set up

[Ludovic Courtès]

Justus Winter <4winter@informatik.uni-hamburg.de> skribis:

> Quoting Ludovic =?utf-8?Q?Court=C3=A8s?= (2013-09-19 12:19:00)
>> Justus Winter <4winter@informatik.uni-hamburg.de> skribis:
>> 
>> > This patch makes runsystem.sh check whether /proc is set up and does
>> > so using settrans -c if it is not.
>> 
>> I think this should be a Debian patch rather, because while /proc is a
>> useful Linux compatibility feature, it’s not a mandatory part of the Hurd.
>
> Ah yes, of course. I keep getting those mixed up in my head ;)
>
> Then again, I always wondered why the procfs lives outside the Hurd
> source. Yes, Linux has /proc, but so do many other Unixes and - if
> memory serves right - /proc is a gift from plan9, no?
>
> And the Hurd uses the filesystem as namespace for server lookups, that
> seems to follow closely the everything-is-a-file philosophy right? And
> if everything is a file, processes should be as well, hence /proc.

Passing data around as text is what Plan 9 does, whereas the Hurd uses
dedicated interfaces and RPCs.

RPCs are a richer way to exchange information than plain text since
their arguments and return values are typed; they can also be easily
interposed on, etc.

The information that Linux-style /proc provides can be obtained through
appropriate RPCs to the proc server, to the msg interface of POSIX
processes, etc.

But you already know all this.  :-)

It suppose Debian uses tools coming from Linux that expect /proc to be
present (such as ‘procps’), in which case it makes sense for Debian to
have /proc mounted early.

Ludo’.