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Unless the whole >>> scratch fit below first_deferred_pfn, some of that will be overwritten >>> either by deferred_init_pages or memmap_init_reserved_pages. >>> >>> To fix it, I modified kho_release_scratch to only set the migratetype >>> on already initialized pages. Then, modified init_pageblock_migratetype >>> to set the migratetype to CMA if the page is located inside scratch. >>> >>> Signed-off-by: Michal Clapinski >>> --- >>> include/linux/memblock.h | 2 -- >>> kernel/liveupdate/kexec_handover.c | 10 ++++++---- >>> mm/memblock.c | 22 ---------------------- >>> mm/page_alloc.c | 7 +++++++ >>> 4 files changed, 13 insertions(+), 28 deletions(-) >>> >> >> >> >>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >>> index ee81f5c67c18..5ca078dde61d 100644 >>> --- a/mm/page_alloc.c >>> +++ b/mm/page_alloc.c >>> @@ -55,6 +55,7 @@ >>> #include >>> #include >>> #include >>> +#include >>> #include >>> #include "internal.h" >>> #include "shuffle.h" >>> @@ -549,6 +550,12 @@ void __meminit init_pageblock_migratetype(struct page *page, >>> migratetype < MIGRATE_PCPTYPES)) >>> migratetype = MIGRATE_UNMOVABLE; >>> >>> + /* >>> + * Mark KHO scratch as CMA so no unmovable allocations are made there. >>> + */ >>> + if (unlikely(kho_scratch_overlap(page_to_phys(page), PAGE_SIZE))) >>> + migratetype = MIGRATE_CMA; >>> + >> >> If this is only for deferred init code, why not put it in deferred_free_pages()? >> Otherwise, all init_pageblock_migratetype() callers need to pay the penalty >> of traversing kho_scratch array. > > Because reserve_bootmem_region() doesn't call deferred_free_pages(). > So I would also have to modify it. > > And the early initialization won't pay the penalty of traversing the > kho_scratch array, since then kho_scratch is NULL. How about hugetlb_bootmem_init_migratetype(), init_cma_pageblock(), init_cma_reserved_pageblock(), __init_page_from_nid(), memmap_init_range(), __init_zone_device_page()? 1. are they having any PFN range overlapping with kho? 2. is kho_scratch NULL for them? 1 tells us whether putting code in init_pageblock_migratetype() could save the hassle of changing all above locations. 2 tells us how many callers are affected by traversing kho_scratch. Thanks. Best Regards, Yan, Zi