lkml.org 
[lkml]   [2002]   [Oct]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: 2.4.20pre8aa2
On Wed, Oct 02, 2002 at 11:45:40PM +0200, J.A. Magallon wrote:
>
> On 2002.10.02 Andrea Arcangeli wrote:
> >URL:
> >
> > http://www.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.20pre8aa2.gz
> > http://www.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.20pre8aa2/
> >
> >Changelog between 2.4.20pre8aa1 and 2.4.20pre8aa2:
> >
>
> I was rediffing the task_cpu patch, when reached a new hunk in -aa:
>
> kernel/sched.c::sched_init(void):
>
> + current->cpu = smp_processor_id();
>
> As include/asm-i386/smp.h says,
>
> #define smp_processor_id() (current->cpu)
>
> So you have a harmless and useless assignment...
> unless you really wanted to do any other thing, or
> smp_processor_id() != current->cpu in some arch.

yes, it's a superflous line, it's the equivalent of the 2.5.40 line
here:

rq->idle = current;
set_task_cpu(current, smp_processor_id());
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
wake_up_process(current);

it is a superflous bit in the o1 scheduler changes. If the boot cpu
isn't id 0 it must be initialized by the architectural code in arch/.
Either that or sched_init must use hard_smp_processor_id(). On most
archs the boot cpu is id 0 so it probably doesn't trigger if needed.

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

\
 
 \ /
  Last update: 2005-03-22 13:29    [W:0.613 / U:0.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site