Add pghint_t *hints parameter to post_alloc_hook() and prep_new_page(). post_alloc_hook() reads PageZeroed, clears it, and returns PGHINT_ZEROED via hints.
This provides a single point where PG_zeroed is consumed and cleared, regardless of whether the page came through PCP or buddy. The flag is set in page_del_and_expand() and survives both paths until post_alloc_hook() consumes it. Only get_page_from_freelist() passes hints through prep_new_page(); all other callers (compaction, bulk alloc, split, contig) pass NULL. Signed-off-by: Michael S. Tsirkin <[email protected]> Assisted-by: Claude:claude-opus-4-6 Assisted-by: cursor-agent:GPT-5.4-xhigh --- mm/compaction.c | 4 ++-- mm/internal.h | 3 ++- mm/page_alloc.c | 25 +++++++++++++++++-------- 3 files changed, 21 insertions(+), 11 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index 1e8f8eca318c..6fcce7756613 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -82,7 +82,7 @@ static inline bool is_via_compact_memory(int order) { return false; } static struct page *mark_allocated_noprof(struct page *page, unsigned int order, gfp_t gfp_flags) { - post_alloc_hook(page, order, __GFP_MOVABLE); + post_alloc_hook(page, order, __GFP_MOVABLE, NULL); set_page_refcounted(page); return page; } @@ -1833,7 +1833,7 @@ static struct folio *compaction_alloc_noprof(struct folio *src, unsigned long da } dst = (struct folio *)freepage; - post_alloc_hook(&dst->page, order, __GFP_MOVABLE); + post_alloc_hook(&dst->page, order, __GFP_MOVABLE, NULL); set_page_refcounted(&dst->page); if (order) prep_compound_page(&dst->page, order); diff --git a/mm/internal.h b/mm/internal.h index 686667b956c0..2964cdfcd31f 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -887,7 +887,8 @@ static inline void prep_compound_tail(struct page *head, int tail_idx) set_page_private(p, 0); } -void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags); +void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags, + pghint_t *hints); extern bool free_pages_prepare(struct page *page, unsigned int order); extern int user_min_free_kbytes; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ece61d02ea96..a4cfd645599a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1863,13 +1863,21 @@ static inline bool should_skip_init(gfp_t flags) } inline void post_alloc_hook(struct page *page, unsigned int order, - gfp_t gfp_flags) + gfp_t gfp_flags, pghint_t *hints) { bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags) && !should_skip_init(gfp_flags); bool zero_tags = init && (gfp_flags & __GFP_ZEROTAGS); + bool zeroed = PageZeroed(page); int i; + __ClearPageZeroed(page); + if (hints) + *hints = zeroed ? PGHINT_ZEROED : 0; + + if (zeroed && !zero_tags) + init = false; + set_page_private(page, 0); arch_alloc_page(page, order); @@ -1918,9 +1926,9 @@ inline void post_alloc_hook(struct page *page, unsigned int order, } static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, - unsigned int alloc_flags) + unsigned int alloc_flags, pghint_t *hints) { - post_alloc_hook(page, order, gfp_flags); + post_alloc_hook(page, order, gfp_flags, hints); if (order && (gfp_flags & __GFP_COMP)) prep_compound_page(page, order); @@ -3991,7 +3999,8 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, page = rmqueue(zonelist_zone(ac->preferred_zoneref), zone, order, gfp_mask, alloc_flags, ac->migratetype); if (page) { - prep_new_page(page, order, gfp_mask, alloc_flags); + prep_new_page(page, order, gfp_mask, alloc_flags, + hints); /* * If this is a high-order atomic allocation then check @@ -4227,7 +4236,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, /* Prep a captured page if available */ if (page) - prep_new_page(page, order, gfp_mask, alloc_flags); + prep_new_page(page, order, gfp_mask, alloc_flags, NULL); /* Try get a page from the freelist if available */ if (!page) @@ -5223,7 +5232,7 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, int preferred_nid, } nr_account++; - prep_new_page(page, 0, gfp, 0); + prep_new_page(page, 0, gfp, 0, NULL); set_page_refcounted(page); page_array[nr_populated++] = page; } @@ -6958,7 +6967,7 @@ static void split_free_frozen_pages(struct list_head *list, gfp_t gfp_mask) list_for_each_entry_safe(page, next, &list[order], lru) { int i; - post_alloc_hook(page, order, gfp_mask); + post_alloc_hook(page, order, gfp_mask, NULL); if (!order) continue; @@ -7164,7 +7173,7 @@ int alloc_contig_frozen_range_noprof(unsigned long start, unsigned long end, struct page *head = pfn_to_page(start); check_new_pages(head, order); - prep_new_page(head, order, gfp_mask, 0); + prep_new_page(head, order, gfp_mask, 0, NULL); } else { ret = -EINVAL; WARN(true, "PFN range: requested [%lu, %lu), allocated [%lu, %lu)\n", -- MST
