+ hugetlb-optimise-hugetlb_folio_init_tail_vmemmap.patch added to mm-new branch

+ hugetlb-optimise-hugetlb_folio_init_tail_vmemmap.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: hugetlb: optimise hugetlb_folio_init_tail_vmemmap()
has been added to the -mm mm-new branch.  Its filename is
     hugetlb-optimise-hugetlb_folio_init_tail_vmemmap.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/hugetlb-optimise-hugetlb_folio_init_tail_vmemmap.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
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fixup patches in mm-new.

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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: hugetlb: optimise hugetlb_folio_init_tail_vmemmap()
Date: Thu, 6 Nov 2025 20:14:48 +0000

Extract the zone number directly from the folio instead of using the
folio's zone number to look up the zone and asking the zone what its
number is.

Also we should use &folio->page instead of casting from folio to page

Link: https://lkml.kernel.org/r/20251106201452.2292631-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/hugetlb.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/hugetlb.c~hugetlb-optimise-hugetlb_folio_init_tail_vmemmap
+++ a/mm/hugetlb.c
@@ -3246,7 +3246,7 @@ static void __init hugetlb_folio_init_ta
 					unsigned long start_page_number,
 					unsigned long end_page_number)
 {
-	enum zone_type zone = zone_idx(folio_zone(folio));
+	enum zone_type zone = folio_zonenum(folio);
 	int nid = folio_nid(folio);
 	struct page *page = folio_page(folio, start_page_number);
 	unsigned long head_pfn = folio_pfn(folio);
@@ -3279,7 +3279,7 @@ static void __init hugetlb_folio_init_vm
 	ret = folio_ref_freeze(folio, 1);
 	VM_BUG_ON(!ret);
 	hugetlb_folio_init_tail_vmemmap(folio, 1, nr_pages);
-	prep_compound_head((struct page *)folio, huge_page_order(h));
+	prep_compound_head(&folio->page, huge_page_order(h));
 }
 
 static bool __init hugetlb_bootmem_page_prehvo(struct huge_bootmem_page *m)
_

Patches currently in -mm which might be from willy@infradead.org are

hugetlb-optimise-hugetlb_folio_init_tail_vmemmap.patch
migrate-optimise-alloc_migration_target.patch
memory_hotplug-optimise-try_offline_memory_block.patch