Re: [PATCH 2.6][resend] Add DEVPATH env variable to hotplug helper call

Andrew Morton
2004-10-04T19:48:17Z

Keshavamurthy Anil S <anil.s.keshavamurthy@intel.com> wrote:
>
> On Sun, Oct 03, 2004 at 04:20:12PM -0700, Andrew Morton wrote:
> > Does CPU hotplug behave correctly wrt /sys/devices/system/cpu? Given that
> > register_cpu() is still marked __init, I assume not.
>
> Currently what we have in the kernel is logical cpu hotplug, i.e once the
> cpu is registered via register_cpu() that cpu can only go offline and still
> the entry for that cpu will be present in the /sys/devices/system/cpu/cpuX/online.
>
> So __init register_cpu() is fine untill we support unregister_cpu()
> which is required for physical cpu hotplug case.
>
> I have submitted ACPI based physical cpu hotplug patches and waiting to here from
> ACPI mainitainer Len Brown, there I have taken care to support unregister_cpu()
> and register_cpu() is marked as __devinit in those patches.

OK...

But still, cpu_run_sbin_hotplug() should not exist. It is duplicating
(indeed, emulating) kobject_hotplug() behaviour. To the extent that it now
has a hardwired sysfs path embedded in it:

sprintf(devpath_str, "DEVPATH=devices/system/cpu/cpu%d", cpu);

which should have been obtained from kobject_get_path().