Re: 2.6.11-mm2

From: J.A. Magallon
Date: Tue Mar 08 2005 - 19:24:21 EST



On 03.09, Robert Love wrote:
> On Tue, 2005-03-08 at 23:36 +0000, J.A. Magallon wrote:
>
> > Can cpu affinity really be changed for a running process ?
>
> Yes.
>
> > Does it need something like io or yielding to take effect ?
>
> No.
>
...
>
> Although, you have the syntax wrong. It should be
>
> taskset -c 0 -p 8277
>

That was what I first tried, but:

werewolf:~> ps -ef | grep box
magallon 8638 8629 99 00:47 pts/0 00:01:54 box-d --out box.srf @opt
magallon 8733 8643 0 00:48 pts/2 00:00:00 grep box
werewolf:~> taskset -c 0 -p 8638
execvp: No such file or directory
failed to execute -p

>
> > The program uses posix threads, 2 in this case. The two threads change from
> > cpu sometimes (not too often), but do not go into the same processor
> > immediately as when I start the program directly with runon/taskset.
>
> You have to bind all of the threads individually.
>

Ahh, damn, that explains it. I use a main thread that does nothing but
wait for the worker threads. So it sure gets moved to CPU0, but as it
does not waste CPU time, I do not see it...

Thanks. Will see what can I do with my threads. cpusets, perhaps...

--
J.A. Magallon <jamagallon()able!es> \ Software is like sex:
werewolf!able!es \ It's better when it's free
Mandrakelinux release 10.2 (Cooker) for i586
Linux 2.6.11-jam3 (gcc 3.4.3 (Mandrakelinux 10.2 3.4.3-3mdk)) #1


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/