[PATCH v3 13/19] mm/hugetlb: Refactor early boot gigantic hugepage allocation
From: Muchun Song <hidden>
Date: 2026-06-02 10:12:25
Also in:
linux-mm, lkml
Subsystem:
hugetlb subsystem, linux for powerpc (32-bit and 64-bit), memory management, memory management - core, the rest · Maintainers:
Muchun Song, Oscar Salvador, Madhavan Srinivasan, Michael Ellerman, Andrew Morton, David Hildenbrand, Linus Torvalds
The early boot gigantic hugepage allocation helpers currently mix allocation with huge_bootmem_page setup, and leave part of the initialization flow in architecture code. Refactor the interface to return the allocated huge page pointer and move the huge_bootmem_page setup into the generic hugetlb code. This makes the architecture-specific paths focus only on finding memory, while the common code handles node placement and early page metadata setup in one place. This also lets powerpc benefit from memblock_reserved_mark_noinit(), which it did not enable before. In addition, upcoming cross-zone validation for boot-time gigantic hugetlb reservation is common logic. With this refactoring, that logic can stay in the generic code instead of being duplicated in architecture-specific paths. Signed-off-by: Muchun Song <redacted> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Oscar Salvador (SUSE) <osalvador@suse.de> --- v2->v3: - keep powerpc code independent of struct huge_bootmem_page by switching it to void * (per Mike Rapoport) - move huge_bootmem_page internals out of include/linux/hugetlb.h and keep them in mm-private scope so the arch code does not need to see the type (per Mike Rapoport, echoed by Oscar Salvador) --- arch/powerpc/mm/hugetlbpage.c | 13 ++--- include/linux/hugetlb.h | 18 ++----- mm/hugetlb.c | 95 ++++++++++++++--------------------- mm/hugetlb_cma.c | 13 ++--- mm/hugetlb_cma.h | 8 ++- mm/internal.h | 9 ++++ 6 files changed, 64 insertions(+), 92 deletions(-)
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 558fafb82b8a..a298746dc143 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c@@ -104,17 +104,14 @@ void __init pseries_add_gpage(u64 addr, u64 page_size, unsigned long number_of_p } } -static int __init pseries_alloc_bootmem_huge_page(struct hstate *hstate) +static __init void *pseries_alloc_bootmem_huge_page(struct hstate *hstate) { - struct huge_bootmem_page *m; + void *m; if (nr_gpages == 0) - return 0; + return NULL; m = phys_to_virt(gpage_freearray[--nr_gpages]); gpage_freearray[nr_gpages] = 0; - list_add(&m->list, &huge_boot_pages[0]); - m->hstate = hstate; - m->flags = 0; - return 1; + return m; } bool __init hugetlb_node_alloc_supported(void)
@@ -124,7 +121,7 @@ bool __init hugetlb_node_alloc_supported(void) #endif -int __init alloc_bootmem_huge_page(struct hstate *h, int nid) +void *__init arch_alloc_bootmem_huge_page(struct hstate *h, int nid) { #ifdef CONFIG_PPC_BOOK3S_64
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 3700c0a1f6ff..09f28dd773b7 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h@@ -674,19 +674,11 @@ struct hstate { char name[HSTATE_NAME_LEN]; }; -struct cma; - -struct huge_bootmem_page { - struct list_head list; - struct hstate *hstate; - unsigned long flags; - struct cma *cma; -}; - #define HUGE_BOOTMEM_HVO 0x0001 #define HUGE_BOOTMEM_ZONES_VALID 0x0002 #define HUGE_BOOTMEM_CMA 0x0004 +struct huge_bootmem_page; bool hugetlb_bootmem_page_zones_valid(int nid, struct huge_bootmem_page *m); int isolate_or_dissolve_huge_folio(struct folio *folio, struct list_head *list);
@@ -706,8 +698,8 @@ void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, unsigned long address, struct folio *folio); /* arch callback */ -int __init __alloc_bootmem_huge_page(struct hstate *h, int nid); -int __init alloc_bootmem_huge_page(struct hstate *h, int nid); +void *__init __alloc_bootmem_huge_page(struct hstate *h, int nid); +void *__init arch_alloc_bootmem_huge_page(struct hstate *h, int nid); bool __init hugetlb_node_alloc_supported(void); void __init hugetlb_add_hstate(unsigned order);
@@ -1138,9 +1130,9 @@ alloc_hugetlb_folio_nodemask(struct hstate *h, int preferred_nid, return NULL; } -static inline int __alloc_bootmem_huge_page(struct hstate *h) +static inline void *__alloc_bootmem_huge_page(struct hstate *h, int nid) { - return 0; + return NULL; } static inline struct hstate *hstate_file(struct file *f)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 2bf9fe16abb9..5e557c05d80a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c@@ -3027,79 +3027,58 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma, static __init void *alloc_bootmem(struct hstate *h, int nid, bool node_exact) { - struct huge_bootmem_page *m; - int listnode = nid; - if (hugetlb_early_cma(h)) - m = hugetlb_cma_alloc_bootmem(h, &listnode, node_exact); - else { - if (node_exact) - m = memblock_alloc_exact_nid_raw(huge_page_size(h), + return hugetlb_cma_alloc_bootmem(h, nid, node_exact); + + if (node_exact) + return memblock_alloc_exact_nid_raw(huge_page_size(h), huge_page_size(h), 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid); - else { - m = memblock_alloc_try_nid_raw(huge_page_size(h), + + return memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h), 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid); - /* - * For pre-HVO to work correctly, pages need to be on - * the list for the node they were actually allocated - * from. That node may be different in the case of - * fallback by memblock_alloc_try_nid_raw. So, - * extract the actual node first. - */ - if (m) - listnode = early_pfn_to_nid(PHYS_PFN(__pa(m))); - } - - if (m) { - m->flags = 0; - m->cma = NULL; - } - } - - if (m) { - /* - * Use the beginning of the huge page to store the - * huge_bootmem_page struct (until gather_bootmem - * puts them into the mem_map). - * - * Put them into a private list first because mem_map - * is not up yet. - */ - INIT_LIST_HEAD(&m->list); - list_add(&m->list, &huge_boot_pages[listnode]); - m->hstate = h; - } - - return m; } -int alloc_bootmem_huge_page(struct hstate *h, int nid) +void *__init arch_alloc_bootmem_huge_page(struct hstate *h, int nid) __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); -int __alloc_bootmem_huge_page(struct hstate *h, int nid) +void *__init __alloc_bootmem_huge_page(struct hstate *h, int nid) { - struct huge_bootmem_page *m = NULL; /* initialize for clang */ int nr_nodes, node = nid; /* do node specific alloc */ - if (nid != NUMA_NO_NODE) { - m = alloc_bootmem(h, node, true); - if (!m) - return 0; - goto found; - } + if (nid != NUMA_NO_NODE) + return alloc_bootmem(h, node, true); /* allocate from next node when distributing huge pages */ for_each_node_mask_to_alloc(&h->next_nid_to_alloc, nr_nodes, node, - &hugetlb_bootmem_nodes) { - m = alloc_bootmem(h, node, false); - if (!m) - return 0; - goto found; - } + &hugetlb_bootmem_nodes) + return alloc_bootmem(h, node, false); -found: + return NULL; +} + +static bool __init alloc_bootmem_huge_page(struct hstate *h, int nid) +{ + struct huge_bootmem_page *m = arch_alloc_bootmem_huge_page(h, nid); + + if (!m) + return false; + + nid = early_pfn_to_nid(PHYS_PFN(__pa(m))); + /* + * Use the beginning of the huge page to store the huge_bootmem_page + * struct (until gather_bootmem puts them into the mem_map). + * + * Put them into a private list first because mem_map is not up yet. + */ + INIT_LIST_HEAD(&m->list); + list_add(&m->list, &huge_boot_pages[nid]); + m->hstate = h; + if (!hugetlb_early_cma(h)) { + m->cma = NULL; + m->flags = 0; + } /* * Only initialize the head struct page in memmap_init_reserved_pages,
@@ -3111,7 +3090,7 @@ int __alloc_bootmem_huge_page(struct hstate *h, int nid) memblock_reserved_mark_noinit(__pa((void *)m + PAGE_SIZE), huge_page_size(h) - PAGE_SIZE); - return 1; + return true; } /* Initialize [start_page:end_page_number] tail struct pages of a hugepage */
diff --git a/mm/hugetlb_cma.c b/mm/hugetlb_cma.c
index ce999391cc14..e487d0ffffc0 100644
--- a/mm/hugetlb_cma.c
+++ b/mm/hugetlb_cma.c@@ -56,14 +56,13 @@ struct folio *hugetlb_cma_alloc_frozen_folio(int order, gfp_t gfp_mask, return folio; } -struct huge_bootmem_page * __init -hugetlb_cma_alloc_bootmem(struct hstate *h, int *nid, bool node_exact) +void * __init hugetlb_cma_alloc_bootmem(struct hstate *h, int nid, bool node_exact) { struct cma *cma; struct huge_bootmem_page *m; - int node = *nid; + int node; - cma = hugetlb_cma[*nid]; + cma = hugetlb_cma[nid]; m = cma_reserve_early(cma, huge_page_size(h)); if (!m) { if (node_exact)
@@ -71,13 +70,11 @@ hugetlb_cma_alloc_bootmem(struct hstate *h, int *nid, bool node_exact) for_each_node_mask(node, hugetlb_bootmem_nodes) { cma = hugetlb_cma[node]; - if (!cma || node == *nid) + if (!cma || node == nid) continue; m = cma_reserve_early(cma, huge_page_size(h)); - if (m) { - *nid = node; + if (m) break; - } } }
diff --git a/mm/hugetlb_cma.h b/mm/hugetlb_cma.h
index c619c394b1ae..3aa483573d17 100644
--- a/mm/hugetlb_cma.h
+++ b/mm/hugetlb_cma.h@@ -6,8 +6,7 @@ void hugetlb_cma_free_frozen_folio(struct folio *folio); struct folio *hugetlb_cma_alloc_frozen_folio(int order, gfp_t gfp_mask, int nid, nodemask_t *nodemask); -struct huge_bootmem_page *hugetlb_cma_alloc_bootmem(struct hstate *h, int *nid, - bool node_exact); +void *hugetlb_cma_alloc_bootmem(struct hstate *h, int nid, bool node_exact); bool hugetlb_cma_exclusive_alloc(void); unsigned long hugetlb_cma_total_size(void); void hugetlb_cma_validate_params(void);
@@ -23,9 +22,8 @@ static inline struct folio *hugetlb_cma_alloc_frozen_folio(int order, return NULL; } -static inline -struct huge_bootmem_page *hugetlb_cma_alloc_bootmem(struct hstate *h, int *nid, - bool node_exact) +static inline void *hugetlb_cma_alloc_bootmem(struct hstate *h, int nid, + bool node_exact) { return NULL; }
diff --git a/mm/internal.h b/mm/internal.h
index 004a3f1d5006..6b9802460a7c 100644
--- a/mm/internal.h
+++ b/mm/internal.h@@ -23,6 +23,15 @@ #include "vma.h" struct folio_batch; +struct hstate; +struct cma; + +struct huge_bootmem_page { + struct list_head list; + struct hstate *hstate; + unsigned long flags; + struct cma *cma; +}; /* * Maintains state across a page table move. The operation assumes both source
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2.54.0