From 19fc1a7e8b2b3b0e18fbea84ee26517e1b0f1a6e Mon Sep 17 00:00:00 2001 From: Sidhartha Kumar Date: Tue, 29 Nov 2022 14:50:39 -0800 Subject: [PATCH] mm/hugetlb: change hugetlb allocation functions to return a folio Many hugetlb allocation helper functions have now been converting to folios, update their higher level callers to be compatible with folios. alloc_pool_huge_page is reorganized to avoid a smatch warning reporting the folio variable is uninitialized. [sidhartha.kumar@oracle.com: update alloc_and_dissolve_hugetlb_folio comments] Link: https://lkml.kernel.org/r/20221206233512.146535-1-sidhartha.kumar@oracle.com Link: https://lkml.kernel.org/r/20221129225039.82257-11-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar Reported-by: Wei Chen Suggested-by: John Hubbard Suggested-by: Rasmus Villemoes Reviewed-by: Mike Kravetz Cc: David Hildenbrand Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Mina Almasry Cc: Muchun Song Cc: Tarun Sahu Signed-off-by: Andrew Morton --- mm/hugetlb.c | 134 ++++++++++++++++++++++++--------------------------- 1 file changed, 64 insertions(+), 70 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 903ee75cccd6..8c6fe2286814 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1378,23 +1378,23 @@ static void free_gigantic_folio(struct folio *folio, unsigned int order) } #ifdef CONFIG_CONTIG_ALLOC -static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, +static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask, int nid, nodemask_t *nodemask) { + struct page *page; unsigned long nr_pages = pages_per_huge_page(h); if (nid == NUMA_NO_NODE) nid = numa_mem_id(); #ifdef CONFIG_CMA { - struct page *page; int node; if (hugetlb_cma[nid]) { page = cma_alloc(hugetlb_cma[nid], nr_pages, huge_page_order(h), true); if (page) - return page; + return page_folio(page); } if (!(gfp_mask & __GFP_THISNODE)) { @@ -1405,17 +1405,18 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, page = cma_alloc(hugetlb_cma[node], nr_pages, huge_page_order(h), true); if (page) - return page; + return page_folio(page); } } } #endif - return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); + page = alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); + return page ? page_folio(page) : NULL; } #else /* !CONFIG_CONTIG_ALLOC */ -static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, +static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask, int nid, nodemask_t *nodemask) { return NULL; @@ -1423,7 +1424,7 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, #endif /* CONFIG_CONTIG_ALLOC */ #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ -static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, +static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask, int nid, nodemask_t *nodemask) { return NULL; @@ -1950,7 +1951,7 @@ pgoff_t hugetlb_basepage_index(struct page *page) return (index << compound_order(page_head)) + compound_idx; } -static struct page *alloc_buddy_huge_page(struct hstate *h, +static struct folio *alloc_buddy_hugetlb_folio(struct hstate *h, gfp_t gfp_mask, int nid, nodemask_t *nmask, nodemask_t *node_alloc_noretry) { @@ -1988,11 +1989,6 @@ retry: page = NULL; } - if (page) - __count_vm_event(HTLB_BUDDY_PGALLOC); - else - __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); - /* * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this * indicates an overall state change. Clear bit so that we resume @@ -2009,7 +2005,13 @@ retry: if (node_alloc_noretry && !page && alloc_try_hard) node_set(nid, *node_alloc_noretry); - return page; + if (!page) { + __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); + return NULL; + } + + __count_vm_event(HTLB_BUDDY_PGALLOC); + return page_folio(page); } /* @@ -2019,23 +2021,21 @@ retry: * Note that returned page is 'frozen': ref count of head page and all tail * pages is zero. */ -static struct page *alloc_fresh_huge_page(struct hstate *h, +static struct folio *alloc_fresh_hugetlb_folio(struct hstate *h, gfp_t gfp_mask, int nid, nodemask_t *nmask, nodemask_t *node_alloc_noretry) { - struct page *page; struct folio *folio; bool retry = false; retry: if (hstate_is_gigantic(h)) - page = alloc_gigantic_page(h, gfp_mask, nid, nmask); + folio = alloc_gigantic_folio(h, gfp_mask, nid, nmask); else - page = alloc_buddy_huge_page(h, gfp_mask, + folio = alloc_buddy_hugetlb_folio(h, gfp_mask, nid, nmask, node_alloc_noretry); - if (!page) + if (!folio) return NULL; - folio = page_folio(page); if (hstate_is_gigantic(h)) { if (!prep_compound_gigantic_folio(folio, huge_page_order(h))) { /* @@ -2052,7 +2052,7 @@ retry: } prep_new_hugetlb_folio(h, folio, folio_nid(folio)); - return page; + return folio; } /* @@ -2062,23 +2062,20 @@ retry: static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, nodemask_t *node_alloc_noretry) { - struct page *page; + struct folio *folio; int nr_nodes, node; gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { - page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, - node_alloc_noretry); - if (page) - break; + folio = alloc_fresh_hugetlb_folio(h, gfp_mask, node, + nodes_allowed, node_alloc_noretry); + if (folio) { + free_huge_page(&folio->page); /* free it into the hugepage allocator */ + return 1; + } } - if (!page) - return 0; - - free_huge_page(page); /* free it into the hugepage allocator */ - - return 1; + return 0; } /* @@ -2237,7 +2234,7 @@ int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, int nid, nodemask_t *nmask) { - struct page *page = NULL; + struct folio *folio = NULL; if (hstate_is_gigantic(h)) return NULL; @@ -2247,8 +2244,8 @@ static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, goto out_unlock; spin_unlock_irq(&hugetlb_lock); - page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); - if (!page) + folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask, NULL); + if (!folio) return NULL; spin_lock_irq(&hugetlb_lock); @@ -2260,43 +2257,42 @@ static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, * codeflow */ if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { - SetHPageTemporary(page); + folio_set_hugetlb_temporary(folio); spin_unlock_irq(&hugetlb_lock); - free_huge_page(page); + free_huge_page(&folio->page); return NULL; } h->surplus_huge_pages++; - h->surplus_huge_pages_node[page_to_nid(page)]++; + h->surplus_huge_pages_node[folio_nid(folio)]++; out_unlock: spin_unlock_irq(&hugetlb_lock); - return page; + return &folio->page; } static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, int nid, nodemask_t *nmask) { - struct page *page; + struct folio *folio; if (hstate_is_gigantic(h)) return NULL; - page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); - if (!page) + folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask, NULL); + if (!folio) return NULL; /* fresh huge pages are frozen */ - set_page_refcounted(page); - + folio_ref_unfreeze(folio, 1); /* * We do not account these pages as surplus because they are only * temporary and will be released properly on the last reference */ - SetHPageTemporary(page); + folio_set_hugetlb_temporary(folio); - return page; + return &folio->page; } /* @@ -2745,54 +2741,52 @@ void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, } /* - * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one + * alloc_and_dissolve_hugetlb_folio - Allocate a new folio and dissolve + * the old one * @h: struct hstate old page belongs to - * @old_page: Old page to dissolve + * @old_folio: Old folio to dissolve * @list: List to isolate the page in case we need to * Returns 0 on success, otherwise negated error. */ -static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, - struct list_head *list) +static int alloc_and_dissolve_hugetlb_folio(struct hstate *h, + struct folio *old_folio, struct list_head *list) { gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; - struct folio *old_folio = page_folio(old_page); int nid = folio_nid(old_folio); - struct page *new_page; struct folio *new_folio; int ret = 0; /* - * Before dissolving the page, we need to allocate a new one for the - * pool to remain stable. Here, we allocate the page and 'prep' it + * Before dissolving the folio, we need to allocate a new one for the + * pool to remain stable. Here, we allocate the folio and 'prep' it * by doing everything but actually updating counters and adding to * the pool. This simplifies and let us do most of the processing * under the lock. */ - new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL); - if (!new_page) + new_folio = alloc_buddy_hugetlb_folio(h, gfp_mask, nid, NULL, NULL); + if (!new_folio) return -ENOMEM; - new_folio = page_folio(new_page); __prep_new_hugetlb_folio(h, new_folio); retry: spin_lock_irq(&hugetlb_lock); if (!folio_test_hugetlb(old_folio)) { /* - * Freed from under us. Drop new_page too. + * Freed from under us. Drop new_folio too. */ goto free_new; } else if (folio_ref_count(old_folio)) { /* - * Someone has grabbed the page, try to isolate it here. + * Someone has grabbed the folio, try to isolate it here. * Fail with -EBUSY if not possible. */ spin_unlock_irq(&hugetlb_lock); - ret = isolate_hugetlb(old_page, list); + ret = isolate_hugetlb(&old_folio->page, list); spin_lock_irq(&hugetlb_lock); goto free_new; } else if (!folio_test_hugetlb_freed(old_folio)) { /* - * Page's refcount is 0 but it has not been enqueued in the + * Folio's refcount is 0 but it has not been enqueued in the * freelist yet. Race window is small, so we can succeed here if * we retry. */ @@ -2801,7 +2795,7 @@ retry: goto retry; } else { /* - * Ok, old_page is still a genuine free hugepage. Remove it from + * Ok, old_folio is still a genuine free hugepage. Remove it from * the freelist and decrease the counters. These will be * incremented again when calling __prep_account_new_huge_page() * and enqueue_hugetlb_folio() for new_folio. The counters will @@ -2810,14 +2804,14 @@ retry: remove_hugetlb_folio(h, old_folio, false); /* - * Ref count on new page is already zero as it was dropped + * Ref count on new_folio is already zero as it was dropped * earlier. It can be directly added to the pool free list. */ __prep_account_new_huge_page(h, nid); enqueue_hugetlb_folio(h, new_folio); /* - * Pages have been replaced, we can safely free the old one. + * Folio has been replaced, we can safely free the old one. */ spin_unlock_irq(&hugetlb_lock); update_and_free_hugetlb_folio(h, old_folio, false); @@ -2827,7 +2821,7 @@ retry: free_new: spin_unlock_irq(&hugetlb_lock); - /* Page has a zero ref count, but needs a ref to be freed */ + /* Folio has a zero ref count, but needs a ref to be freed */ folio_ref_unfreeze(new_folio, 1); update_and_free_hugetlb_folio(h, new_folio, false); @@ -2865,7 +2859,7 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list) if (folio_ref_count(folio) && !isolate_hugetlb(&folio->page, list)) ret = 0; else if (!folio_ref_count(folio)) - ret = alloc_and_dissolve_huge_page(h, &folio->page, list); + ret = alloc_and_dissolve_hugetlb_folio(h, folio, list); return ret; } @@ -3083,14 +3077,14 @@ static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid) if (!alloc_bootmem_huge_page(h, nid)) break; } else { - struct page *page; + struct folio *folio; gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; - page = alloc_fresh_huge_page(h, gfp_mask, nid, + folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid, &node_states[N_MEMORY], NULL); - if (!page) + if (!folio) break; - free_huge_page(page); /* free it into the hugepage allocator */ + free_huge_page(&folio->page); /* free it into the hugepage allocator */ } cond_resched(); }