Re: Fwd: NPTL

[Bernd Petrovitsch <bernd@firmix.at>]

On Thu, 2007-07-12 at 15:58 +0300, Ni@m wrote:
[...]
> >>No, a process also contains an address space.
> Of course .. I ment they are _almoust_ similar.

Not really. A process has one or more threads, (virtual) memory, open
file descriptors, a uid, a gid and several other resources.

Historically there were only "processes". "Threads" were invented later
on so there is (usually) some confusion remaining  here .....

> >>No, that is creating a schedule unit (task) without an address space.
> Ok, I've already found that in kernel code ... and correctly understood.
> 
> >>Surely you need some context switch when switching between runnable
> contexts.
> Hm. If the thread is running after it's sister or parent process - you
> do not have to switich the process context. Is this done in kernel??

"switch process context" is misleading wording - "task switch" is better
(and "task" is usually the kernels view on a thread). You have at least
to store the registers of the old task somewhere and load the ones from
the new task.

> Sorry if my thought are idiotic .. I'm a newby and trying to
> investigate the kernel.

Hmm, you might invest in a book about operating systems to learn the
basic concepts.

	Bernd
-- 
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