* nr_cpus cmdline parameter not working
@ 2011-09-28 15:35 Mark Salter
2011-10-01 16:23 ` Russell King - ARM Linux
0 siblings, 1 reply; 3+ messages in thread
From: Mark Salter @ 2011-09-28 15:35 UTC (permalink / raw)
To: linux-arm-kernel
I noticed that nr_cpus=1 doesn't appear to have any effect on a
pandaboard (and probably others from the looks of things). This
changes seems to be needed, but I'm not really sure if this is
the right thing or not.
diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
index ce65e93..a1198ac 100644
--- a/arch/arm/mach-omap2/omap-smp.c
+++ b/arch/arm/mach-omap2/omap-smp.c
@@ -117,6 +117,9 @@ void __init smp_init_cpus(void)
ncores = NR_CPUS;
}
+ if (ncores > nr_cpu_ids)
+ ncores = nr_cpu_ids;
+
for (i = 0; i < ncores; i++)
set_cpu_possible(i, true);
--Mark
^ permalink raw reply related [flat|nested] 3+ messages in thread
* nr_cpus cmdline parameter not working
2011-09-28 15:35 nr_cpus cmdline parameter not working Mark Salter
@ 2011-10-01 16:23 ` Russell King - ARM Linux
2011-10-03 13:47 ` Mark Salter
0 siblings, 1 reply; 3+ messages in thread
From: Russell King - ARM Linux @ 2011-10-01 16:23 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Sep 28, 2011 at 11:35:16AM -0400, Mark Salter wrote:
> I noticed that nr_cpus=1 doesn't appear to have any effect on a
> pandaboard (and probably others from the looks of things). This
> changes seems to be needed, but I'm not really sure if this is
> the right thing or not.
>
> diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
> index ce65e93..a1198ac 100644
> --- a/arch/arm/mach-omap2/omap-smp.c
> +++ b/arch/arm/mach-omap2/omap-smp.c
> @@ -117,6 +117,9 @@ void __init smp_init_cpus(void)
> ncores = NR_CPUS;
> }
>
> + if (ncores > nr_cpu_ids)
> + ncores = nr_cpu_ids;
> +
This potentially affects all SMP platforms, so the patch needs to be
bigger than this.
Also, I think the test above should be modified to use nr_cpu_ids
rather than NR_CPUS, to be inline with what x86 does:
/* nr_cpu_ids could be reduced via nr_cpus= */
if (possible > nr_cpu_ids) {
printk(KERN_WARNING
"%d Processors exceeds NR_CPUS limit of %d\n",
possible, nr_cpu_ids);
possible = nr_cpu_ids;
}
(This is essentially the same check that we're doing.)
Could you have a look at this and cook up another patch covering the
other SMP platforms please?
Thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
* nr_cpus cmdline parameter not working
2011-10-01 16:23 ` Russell King - ARM Linux
@ 2011-10-03 13:47 ` Mark Salter
0 siblings, 0 replies; 3+ messages in thread
From: Mark Salter @ 2011-10-03 13:47 UTC (permalink / raw)
To: linux-arm-kernel
On Sat, 2011-10-01 at 17:23 +0100, Russell King - ARM Linux wrote:
> On Wed, Sep 28, 2011 at 11:35:16AM -0400, Mark Salter wrote:
> > I noticed that nr_cpus=1 doesn't appear to have any effect on a
> > pandaboard (and probably others from the looks of things). This
> > changes seems to be needed, but I'm not really sure if this is
> > the right thing or not.
> >
> > diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
> > index ce65e93..a1198ac 100644
> > --- a/arch/arm/mach-omap2/omap-smp.c
> > +++ b/arch/arm/mach-omap2/omap-smp.c
> > @@ -117,6 +117,9 @@ void __init smp_init_cpus(void)
> > ncores = NR_CPUS;
> > }
> >
> > + if (ncores > nr_cpu_ids)
> > + ncores = nr_cpu_ids;
> > +
>
> This potentially affects all SMP platforms, so the patch needs to be
> bigger than this.
>
> Also, I think the test above should be modified to use nr_cpu_ids
> rather than NR_CPUS, to be inline with what x86 does:
>
> /* nr_cpu_ids could be reduced via nr_cpus= */
> if (possible > nr_cpu_ids) {
> printk(KERN_WARNING
> "%d Processors exceeds NR_CPUS limit of %d\n",
> possible, nr_cpu_ids);
> possible = nr_cpu_ids;
> }
>
> (This is essentially the same check that we're doing.)
>
> Could you have a look at this and cook up another patch covering the
> other SMP platforms please?
Ok, I'll do that.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2011-09-28 15:35 nr_cpus cmdline parameter not working Mark Salter
2011-10-01 16:23 ` Russell King - ARM Linux
2011-10-03 13:47 ` Mark Salter
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