Re: [PATCH] powerpc/pseries hotplug: prevent the reserved mem from removing

[Hari Bathini <hbathini@linux.vnet.ibm.com>]

Hi Pingfan,


On Thursday 27 April 2017 01:13 PM, Pingfan Liu wrote:
> E.g after fadump reserves mem regions, these regions should not be removed
> before fadump explicitly free them.
> Signed-off-by: Pingfan Liu <piliu@redhat.com>
> ---
>   arch/powerpc/platforms/pseries/hotplug-memory.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index e104c71..201be23 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -346,6 +346,8 @@ static int pseries_remove_memblock(unsigned long base, unsigned int memblock_siz
>
>   	if (!pfn_valid(start_pfn))
>   		goto out;
> +	if (memblock_is_reserved(base))
> +		return -EINVAL;

I think memblock reserved regions are not hot removed even without this 
patch.
So, can you elaborate on when/why this patch is needed?

Thanks
Hari