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Re: If Linux Is About Choice, Why Then ...

On Fri, Apr 14, 2017 at 6:20 AM, Nicolas George <george@nsup.org> wrote:
> Le quartidi 24 germinal, an CCXXV, Jonathan de Boyne Pollard a écrit :
>> Nicolas George:
>> > The process with PID one is the only immortal process on the system, and
>> > adopts all orphan processes.
>> Wrong.  Indeed, it was the systemd people who drove the making it wrong.
> I have no idea what that sentence means.
>> * https://unix.stackexchange.com/a/177361/5132
> Summary: Linux has a new system call to allow process to register as
> adopters for orphan processes.

Ick. I hope they don't register directly with pid1.

> Ok, Linux has a new mutant power that I did not know about, and half my
> sentence was wrong.
> Yet, PID 1 is still the only immortal process, unless you have another
> new mutant power to produce, and that property is needed to have a
> reliable monitoring system. Otherwise, the monitoring process could be
> killed, and nobody would notice.

Or you could have pid1 monitor only the monitoring process, to keep pid1 simple.

> So I stand by my claim: monitoring systems must be anchored at PID 1,
> and that makes monitoring part of init's job.

Conflicting requirements generally indicates a refactoring is necessary.

Of course, it's possible to refactor things incorrectly.

> (Immortal, in this context, does not mean that it cannot die: of course,
> it can die, but if it does, the kernel panics and the hardware watchdog
> reboots it. And of course, it means it cannot be killed by things like
> the OOM killer.)

pid1 seems to be doing a lot of other things in systemd. Is it
cooperatively multitasking with itself yet? Or have they borrowed
threads to define a new kind of process concept, so that pid1 can
multitask with itself preemptively?

I should go look at the source to see, I suppose, if I could only find
the time. I assume they will eventually recognize that pid1 is doing
too much and start pushing some of the conceptual changes outside

I, of course, being superhuman, if I could find someone to fund my
efforts, could solve all these problems without mistake. ;->


Still it can be painful to watch them make the mistakes they are
making. I would want them to be trying different solutions. But if I
back-seat drive over in the Fedora tech lists, it will be distracting
to them, so I back-seat drive over here.

And try not to get into too much of a panic, since that doesn't seem to help.

(If I could find someone to fund my efforts, I would sure like to try
to develop an alternative. Sometimes life is not fair. :-/ )

Joel Rees

I'm imagining I'm a novelist:
More of my delusions:

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