Re: [PATCH v2 04/69] mm/hugetlb: Initialize gigantic bootmem hugepage struct pages earlier
From: Oscar Salvador <osalvador@suse.de>
Date: 2026-05-14 08:05:45
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linux-mm, lkml
On Wed, May 13, 2026 at 09:04:32PM +0800, Muchun Song wrote:
Gigantic bootmem HugeTLB pages are currently initialized from hugetlb_init(),
but page_alloc_init_late() runs earlier and walks pageblocks to determine
zone contiguity.
If a bootmem HugeTLB region is marked noinit, set_zone_contiguous() can
observe still-uninitialized struct pages through __pageblock_pfn_to_page().
This may not trigger an immediate failure, but it can make
set_zone_contiguous() compute the wrong zone contiguity state. If extra
poisoned-page checks are added in this path, such as PF_POISONED_CHECK()
in page_zone_id(), it can also trigger an early boot panic.
Initialize gigantic bootmem HugeTLB struct pages from page_alloc_init_late(),
before zone contiguity is evaluated, so later page allocator setup only
sees valid struct page state. This also makes the initialization order
more natural, as struct pages should be initialized before later code
inspects them.
Fixes: fde1c4ecf916 ("mm: hugetlb: skip initialization of gigantic tail struct pages if freed by HVO")
Signed-off-by: Muchun Song <redacted>Acked-by: Oscar Salvador <osalvador@suse.de> but
quoted hunk ↗ jump to hunk
--- include/linux/hugetlb.h | 5 +++++ mm/hugetlb.c | 3 +-- mm/mm_init.c | 1 + 3 files changed, 7 insertions(+), 2 deletions(-)diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 93418625d3c5..52a2c30f866c 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h@@ -173,6 +173,7 @@ extern int movable_gigantic_pages __read_mostly; extern int sysctl_hugetlb_shm_group __read_mostly; extern struct list_head huge_boot_pages[MAX_NUMNODES]; +void hugetlb_struct_page_init(void);
we lost the hint that this only takes care of bootmem pages. So I think hugetlb_bootmem_struct_page_init or something like that would make it more clear? -- Oscar Salvador SUSE Labs