Re: [PATCH v3 5/5] acpi_processor: do not mark present at boot but not onlined CPU as onlined

From: Ingo Molnar
Date: Mon Apr 14 2014 - 05:22:03 EST



* Igor Mammedov <imammedo@xxxxxxxxxx> wrote:

> acpi_processor_add() assumes that present at boot CPUs
> are always onlined, it is not so if a CPU failed to become
> onlined. As result acpi_processor_add() will mark such CPU
> device as onlined in sysfs and following attempts to
> online/offline it using /sys/device/system/cpu/cpuX/online
> attribute will fail.
>
> Do not poke into device internals in acpi_processor_add()
> and touch "struct device { .offline }" attribute, since
> for CPUs onlined at boot it's set by:
> topology_init() -> arch_register_cpu() -> register_cpu()
> before ACPI device tree is parsed, and for hotplugged
> CPUs it's set when userspace onlines CPU via sysfs.
>
> Signed-off-by: Igor Mammedov <imammedo@xxxxxxxxxx>
> ---
> drivers/acpi/acpi_processor.c | 3 ---
> 1 files changed, 0 insertions(+), 3 deletions(-)

Can this fix be moved first too, or does it have undesirable side
effects on unmodified kernels?

Thanks,

Ingo
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