/sys/devices/system/cpu/cpuX/online are missing

[Heiko Carstens]

On Tue, Mar 13, 2007 at 01:39:25AM +0100, Andreas Schwab wrote:
> Giuliano Pochini <pochini at denise.shiny.it> writes:
> 
> > I had a look at arch/powerpc/kernel/smp.c but I'm not familiar at all with 
> > those parts of the kernel.
> 
> See arch/powerpc/kernel/sysfs.c:topology_init.  I don't think there is
> anything to do here.  You probably don't have CONFIG_HOTPLUG_CPU enabled.

I was referring to arch/ppc not arch/powerpc. But it seems that arch/ppc
doesn't support cpu hotplug anyway. So I guess it's indeed just a missing
config option.

Grepping a bit further shows that arm suffered by the change that inverted
the logic if the 'online' attribute for cpus should appear. Since arm
supports cpu hotplug but the patch left arm out, it doesn't work there
anymore (cc'ing arm people: changeset 72486f1f8f0a2bc828b9d30cf4690cf2dd6807fc
is most probably disabling cpu hotplug support on arm like it did on s390).