Re: [PATCH v6 6/7] mm/memory_hotplug: Embed vmem_altmap details in memory block

[Michal Hocko <mhocko@suse.com>]

On Thu 27-07-23 13:32:31, Aneesh Kumar K.V wrote:
> With memmap on memory, some architecture needs more details w.r.t altmap
> such as base_pfn, end_pfn, etc to unmap vmemmap memory. Instead of
> computing them again when we remove a memory block, embed vmem_altmap
> details in struct memory_block if we are using memmap on memory block
> feature.
> 
> No functional change in this patch
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
>  drivers/base/memory.c  | 25 +++++++++++-------
>  include/linux/memory.h |  8 ++----
>  mm/memory_hotplug.c    | 58 +++++++++++++++++++++++++++---------------
>  3 files changed, 55 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index b456ac213610..57ed61212277 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -106,6 +106,7 @@ static void memory_block_release(struct device *dev)
>  {
>  	struct memory_block *mem = to_memory_block(dev);
>  
> +	WARN_ON(mem->altmap);

What is this supposed to catch? A comment would be handy so that we know
what to look at should it ever trigger.

>  	kfree(mem);
>  }
-- 
Michal Hocko
SUSE Labs