[PATCH v7 0/3] kho: add support for deferred struct page init

[Michal Clapinski]

When CONFIG_DEFERRED_STRUCT_PAGE_INIT (hereinafter DEFERRED) is
enabled, struct page initialization is deferred to parallel kthreads
that run later in the boot process.

Currently, KHO is incompatible with DEFERRED.
This series fixes that incompatibility.
---
v7:
- reimplemented the initialization of kho scratch again
v6:
- reimplemented the initialization of kho scratch
v5:
- rebased
v4:
- added a new commit to fix deferred init of kho scratch
- switched to ulong when refering to pfn
v3:
- changed commit msg
- don't invoke early_pfn_to_nid if CONFIG_DEFERRED_STRUCT_PAGE_INIT=n
v2:
- updated a comment

I took Evangelos's test code:
https://git.infradead.org/?p=users/vpetrog/linux.git;a=shortlog;h=refs/heads/kho-deferred-struct-page-init
and then modified it to this monster test that does 2 allocations:
at core_initcall (early) and at module_init (late). Then kexec, then
2 more allocations at these points, then restore the original 2, then
kexec, then restore the other 2. Basically I test preservation of early
and late allocation both on cold and on warm boot.
Tested it both with and without DEFERRED.

Evangelos Petrongonas (1):
  kho: make preserved pages compatible with deferred struct page init

Michal Clapinski (2):
  kho: make kho_scratch_overlap usable outside debugging
  kho: fix deferred init of kho scratch

 include/linux/kexec_handover.h              |  6 ++
 include/linux/memblock.h                    |  2 -
 kernel/liveupdate/Kconfig                   |  2 -
 kernel/liveupdate/Makefile                  |  1 -
 kernel/liveupdate/kexec_handover.c          | 65 ++++++++++++++++++---
 kernel/liveupdate/kexec_handover_debug.c    | 25 --------
 kernel/liveupdate/kexec_handover_internal.h |  7 ++-
 mm/memblock.c                               | 22 -------
 mm/page_alloc.c                             |  7 +++
 9 files changed, 74 insertions(+), 63 deletions(-)
 delete mode 100644 kernel/liveupdate/kexec_handover_debug.c

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2.53.0.851.ga537e3e6e9-goog