Re: How to Power off with ACPI/APM?

J . A . Magallon
2001-01-05T09:33:31Z

On 2001.01.05 Dominik Kubla wrote:
> On Fri, Jan 05, 2001 at 10:18:46AM +0100, J . A . Magallon wrote:
> >
> > Silly question, but have you realized that you don't have to enable
> > SMP in kernel to do multithreading ?
> >
>
> That depends on your definition: If you really want to run multiple
> threads simultaneously (as opposed to concurrent i guess) i imagine
> you will either need more than one CPU or one of those new beasties
> which support multiple threads in parallel on their various execution
> units...
>

Nope. You can run multiple threads "simultaneously" on an uniprocessor,
so simultaneous as the rest of the processes the cpu is running.
Of course the efficiency of multi-threading drops on an uni-processor
if your threads only do hard math work and no IO, but a thread can
be crunchin numbers at the same time one other is waiting for IO even
on a one cpu box. Think on an app that does read-process-write in loop.
Two parallel threads on an uniprocessor can overlap IO and process
and be more efficient than a non-threaded version.

--
J.A. Magallon $> cd pub
mailto:jamagallon@able.es $> more beer

Linux werewolf 2.2.19-pre6 #1 SMP Wed Jan 3 21:28:10 CET 2001 i686