[PATCH v2 66/69] mm/cma: Move CMA pageblock initialization into cma_activate_area()
From: Muchun Song <hidden>
Date: 2026-05-13 13:22:58
Also in:
linux-mm, lkml
Subsystem:
hugetlb subsystem, memory management, memory management - misc, the rest · Maintainers:
Muchun Song, Oscar Salvador, Andrew Morton, David Hildenbrand, Linus Torvalds
Move CMA pageblock initialization for early-reserved pages into
cma_activate_area() so CMA pageblock setup is handled in one place.
This keeps init_cma_pageblock() in the CMA core instead of pushing
special handling for early CMA allocations into its callers.
As a side effect, this also fixes the zone->cma_pages accounting race for
early-reserved HugeTLB CMA pages. The accounting is no longer updated from
parallel hugetlb_struct_page_init() workers and is instead performed
serially from cma_activate_area().
Fixes: d2d786714080 ("mm/hugetlb: enable bootmem allocation from CMA areas")
Signed-off-by: Muchun Song <redacted>
---
mm/cma.c | 7 +++++--
mm/hugetlb.c | 8 +++-----
2 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/mm/cma.c b/mm/cma.c
index 0369f04c7ba5..c1896c0db63d 100644
--- a/mm/cma.c
+++ b/mm/cma.c@@ -162,6 +162,10 @@ static void __init cma_activate_area(struct cma *cma) count = early_pfn[r] - cmr->base_pfn; bitmap_count = cma_bitmap_pages_to_bits(cma, count); bitmap_set(cmr->bitmap, 0, bitmap_count); + + for (pfn = cmr->base_pfn; pfn < early_pfn[r]; + pfn += pageblock_nr_pages) + init_cma_pageblock(pfn_to_page(pfn)); } WARN_ON_ONCE(!pfn_valid(cmr->base_pfn));
@@ -1098,8 +1102,7 @@ bool cma_intersects(struct cma *cma, unsigned long start, unsigned long end) * * The caller is responsible for initializing the page structures * in the area properly, since this just points to memblock-allocated - * memory. The caller should subsequently use init_cma_pageblock to - * set the migrate type and CMA stats the pageblocks that were reserved. + * memory. * * If the CMA area fails to activate later, memory obtained through * this interface is not handed to the page allocator, this is
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 7e9f49882395..df798f9386d6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c@@ -3136,9 +3136,7 @@ static void __init hugetlb_bootmem_init_migratetype(struct folio *folio, WARN_ON_ONCE(!pageblock_aligned(folio_pfn(folio))); for (i = 0; i < nr_pages; i += pageblock_nr_pages) { - if (folio_test_hugetlb_cma(folio)) - init_cma_pageblock(folio_page(folio, i)); - else + if (!folio_test_hugetlb_cma(folio)) init_pageblock_migratetype(folio_page(folio, i), MIGRATE_MOVABLE, false); }
@@ -3206,8 +3204,8 @@ static void __init gather_bootmem_prealloc_node(unsigned long nid) * in order to fix confusing memory reports from free(1) and * other side-effects, like CommitLimit going negative. * - * For CMA pages, this is done in init_cma_pageblock - * (via hugetlb_bootmem_init_migratetype), so skip it here. + * For CMA pages, this is done in cma_activate_area(), so skip + * it here. */ if (!folio_test_hugetlb_cma(folio)) adjust_managed_page_count(page, nr_pages);
--
2.54.0