process 0

process 0

[ic]

Hi.
Maybe this is a little off topic, but does what is the real status of
Process 0 (swapper) ?
Some people keep telling me it doesn't exist, but on some kernel crashes
I can see "process swapper (pid 0, process nr 0, ...)"

Can someone help me ?

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 Michel Luczak	       <michel@speka.net>       +33 6 62 71 37 30
 SpeKa|Networks SARL			http://speka-networks.com
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Re: process 0

[Rik van Riel]

On Fri, 23 Aug 2002 ic@aleph1.net wrote:

> Maybe this is a little off topic, but does what is the real status of
> Process 0 (swapper) ?
> Some people keep telling me it doesn't exist, but on some kernel crashes
> I can see "process swapper (pid 0, process nr 0, ...)"

It's the idle task.  Only exists to keep the CPU occupied when
nothing else wants to run.

Rik
-- 
Bravely reimplemented by the knights who say "NIH".

http://www.surriel.com/		http://distro.conectiva.com/

Re: process 0

[Richard B. Johnson]

On Fri, 23 Aug 2002 ic@aleph1.net wrote:

> Hi.
> Maybe this is a little off topic, but does what is the real status of
> Process 0 (swapper) ?
> Some people keep telling me it doesn't exist, but on some kernel crashes
> I can see "process swapper (pid 0, process nr 0, ...)"
> 
> Can someone help me ?

Well, it kind-of exists. It's what the CPU does when there is nothing
else to do. Sort of like:

		for(;;)
                    schedule();

It's also where it 'goes' if init returns <grin>.

Cheers,
Dick Johnson
Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).
The US military has given us many words, FUBAR, SNAFU, now ENRON.
Yes, top management were graduates of West Point and Annapolis.

Re: process 0

[george anzinger]

"Richard B. Johnson" wrote:
> 
> On Fri, 23 Aug 2002 ic@aleph1.net wrote:
> 
> > Hi.
> > Maybe this is a little off topic, but does what is the real status of
> > Process 0 (swapper) ?
> > Some people keep telling me it doesn't exist, but on some kernel crashes
> > I can see "process swapper (pid 0, process nr 0, ...)"
> >
> > Can someone help me ?
> 
> Well, it kind-of exists. It's what the CPU does when there is nothing
> else to do. Sort of like:
> 
>                 for(;;)
>                     schedule();
> 
> It's also where it 'goes' if init returns <grin>.

ALSO, FWIW on a N way SMP there will be N process 0s.  So
much for unique pids :)

-- 
George Anzinger   george@mvista.com
High-res-timers: 
http://sourceforge.net/projects/high-res-timers/
Preemption patch:
http://www.kernel.org/pub/linux/kernel/people/rml