Re: [PATCH 1/2] acpi : cpu hot-remove returns error when cpu_down() fails

From: Rafael J. Wysocki
Date: Fri Oct 19 2012 - 00:09:06 EST


On Friday 28 of September 2012 19:36:02 Yasuaki Ishimatsu wrote:
> Even if cpu_down() fails, acpi_processor_remove() continues to remove the cpu.
> But in this case, it should return error number since some process may run on
> the cpu. If the cpu has a running process and the cpu is turned the power off,
> the system may not work well.
>
> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
> Reviewed-by: Toshi Kani <toshi.kani@xxxxxx>
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
>
> ---
> drivers/acpi/processor_driver.c | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> Index: linux-3.6-rc7/drivers/acpi/processor_driver.c
> ===================================================================
> --- linux-3.6-rc7.orig/drivers/acpi/processor_driver.c 2012-09-24 10:10:57.000000000 +0900
> +++ linux-3.6-rc7/drivers/acpi/processor_driver.c 2012-09-28 19:16:33.207858261 +0900
> @@ -605,7 +605,7 @@ err_free_pr:
> static int acpi_processor_remove(struct acpi_device *device, int type)
> {
> struct acpi_processor *pr = NULL;
> -
> + int ret;
>
> if (!device || !acpi_driver_data(device))
> return -EINVAL;
> @@ -616,8 +616,9 @@ static int acpi_processor_remove(struct
> goto free;
>
> if (type == ACPI_BUS_REMOVAL_EJECT) {
> - if (acpi_processor_handle_eject(pr))
> - return -EINVAL;
> + ret = acpi_processor_handle_eject(pr);
> + if (ret)
> + return ret;
> }
>
> acpi_processor_power_exit(pr, device);
> @@ -848,12 +849,17 @@ static acpi_status acpi_processor_hotadd
>
> static int acpi_processor_handle_eject(struct acpi_processor *pr)
> {
> - if (cpu_online(pr->id))
> - cpu_down(pr->id);
> + int ret = 0;
> +
> + if (cpu_online(pr->id)) {
> + ret = cpu_down(pr->id);

If you defined ret here ...

> + if (ret)
> + return ret;
> + }
>
> arch_unregister_cpu(pr->id);
> acpi_unmap_lsapic(pr->id);
> - return (0);
> + return ret;

... this line wouldn't need to be changed.

> }
> #else
> static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)

Thanks,
Rafael


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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