[PATCH] acpi memory hotplug, add parameter to disable memory hotplug [v3]

[David Rientjes]

On Tue, 14 Jan 2014, Prarit Bhargava wrote:

> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index b9e9bd8..ea93f75 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -343,6 +343,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>  			no: ACPI OperationRegions are not marked as reserved,
>  			no further checks are performed.
>  
> +	acpi_no_memhotplug [ACPI] Disable memory hotplug.  Useful for kexec
> +			   and kdump kernels.
> +
>  	add_efi_memmap	[EFI; X86] Include EFI memory map in
>  			kernel's map of available physical RAM.
>  
> diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> index 551dad7..4a0fa94 100644
> --- a/drivers/acpi/acpi_memhotplug.c
> +++ b/drivers/acpi/acpi_memhotplug.c
> @@ -361,7 +361,19 @@ static void acpi_memory_device_remove(struct acpi_device *device)
>  	acpi_memory_device_free(mem_device);
>  }
>  
> +static bool acpi_no_memhotplug;
> +

I think this should be annotated with __initdata.

>  void __init acpi_memory_hotplug_init(void)
>  {
> +	if (acpi_no_memhotplug)
> +		return;
> +
>  	acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
>  }
> +
> +static int __init disable_acpi_memory_hotplug(char *str)
> +{
> +	acpi_no_memhotplug = true;
> +	return 1;
> +}
> +__setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);