[PATCH v6 00/22] kho: make boot time huge page allocation work nicely with KHO

[Mike Rapoport]

On Sat, Aug 01, 2026 at 10:48:09AM +0200, Pratyush Yadav wrote:
> From: "Pratyush Yadav (Google)" <pratyush at kernel.org>
> 
> Hi,
> 
> Gigantic huge page allocation is somewhat broken currently with KHO.
> 
> Fix this by introducing the concept of extended scratch areas. They are
> areas that the kernel discovers on boot by walking the radix tree and
> finding free memory ranges. See patch 10 for more details.
> 
> Muchun Song (1):
>   mm/mm_init: simplify deferred_free_pages() migratetype init
> 
> Pratyush Yadav (Google) (21):
>   kho: generalize radix tree APIs
>   kho: make radix max key width more obvious
>   kho: disallow wide keys in radix tree
>   kho: return virtual address of mem_map from kho_get_mem_map()
>   kho: store incoming radix tree in kho_in
>   kho: move all memory retrieval logic to kho_mem_retrieve()
>   kho: add a struct for radix callbacks
>   kho: add callback for table pages
>   kho: add data argument to radix walk callback
>   kho: allow early-boot usage of the KHO radix tree
>   kho: allow destroying KHO radix tree
>   kho: add kho_radix_init_tree()
>   kho: expose kho_scratch_overlap() to kexec_handover.h
>   kho: initialize kho_scratch pointer earlier in boot
>   kho: initialize preserved memory map radix tree earlier
>   mm/mm_init: don't rely on memblock to get KHO scratch migratetype
>   kho: extend scratch
>   memblock: always include KHO headers
>   memblock: make HugeTLB bootmem allocation work with KHO
>   memblock: add memblock_reserved_hugetlb_size()
>   kho: exclude hugetlb memory from scratch size calculation

This is applied now to kho-scratch branch in the liveupdate repo:

https://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux.git/log/?h=kho-scratch

On top of mm-stable-6d098029de09 branch in Andrew's mm.git.

-- 
Sincerely yours,
Mike.