diff options
Diffstat (limited to 'mm/ksm.c')
-rw-r--r-- | mm/ksm.c | 291 |
1 files changed, 148 insertions, 143 deletions
@@ -890,14 +890,14 @@ static void remove_node_from_stable_tree(struct ksm_stable_node *stable_node) free_stable_node(stable_node); } -enum get_ksm_page_flags { - GET_KSM_PAGE_NOLOCK, - GET_KSM_PAGE_LOCK, - GET_KSM_PAGE_TRYLOCK +enum ksm_get_folio_flags { + KSM_GET_FOLIO_NOLOCK, + KSM_GET_FOLIO_LOCK, + KSM_GET_FOLIO_TRYLOCK }; /* - * get_ksm_page: checks if the page indicated by the stable node + * ksm_get_folio: checks if the page indicated by the stable node * is still its ksm page, despite having held no reference to it. * In which case we can trust the content of the page, and it * returns the gotten page; but if the page has now been zapped, @@ -915,10 +915,10 @@ enum get_ksm_page_flags { * a page to put something that might look like our key in page->mapping. * is on its way to being freed; but it is an anomaly to bear in mind. */ -static struct page *get_ksm_page(struct ksm_stable_node *stable_node, - enum get_ksm_page_flags flags) +static struct folio *ksm_get_folio(struct ksm_stable_node *stable_node, + enum ksm_get_folio_flags flags) { - struct page *page; + struct folio *folio; void *expected_mapping; unsigned long kpfn; @@ -926,8 +926,8 @@ static struct page *get_ksm_page(struct ksm_stable_node *stable_node, PAGE_MAPPING_KSM); again: kpfn = READ_ONCE(stable_node->kpfn); /* Address dependency. */ - page = pfn_to_page(kpfn); - if (READ_ONCE(page->mapping) != expected_mapping) + folio = pfn_folio(kpfn); + if (READ_ONCE(folio->mapping) != expected_mapping) goto stale; /* @@ -940,41 +940,41 @@ again: * in folio_migrate_mapping(), it might still be our page, * in which case it's essential to keep the node. */ - while (!get_page_unless_zero(page)) { + while (!folio_try_get(folio)) { /* * Another check for page->mapping != expected_mapping would * work here too. We have chosen the !PageSwapCache test to * optimize the common case, when the page is or is about to * be freed: PageSwapCache is cleared (under spin_lock_irq) * in the ref_freeze section of __remove_mapping(); but Anon - * page->mapping reset to NULL later, in free_pages_prepare(). + * folio->mapping reset to NULL later, in free_pages_prepare(). */ - if (!PageSwapCache(page)) + if (!folio_test_swapcache(folio)) goto stale; cpu_relax(); } - if (READ_ONCE(page->mapping) != expected_mapping) { - put_page(page); + if (READ_ONCE(folio->mapping) != expected_mapping) { + folio_put(folio); goto stale; } - if (flags == GET_KSM_PAGE_TRYLOCK) { - if (!trylock_page(page)) { - put_page(page); + if (flags == KSM_GET_FOLIO_TRYLOCK) { + if (!folio_trylock(folio)) { + folio_put(folio); return ERR_PTR(-EBUSY); } - } else if (flags == GET_KSM_PAGE_LOCK) - lock_page(page); + } else if (flags == KSM_GET_FOLIO_LOCK) + folio_lock(folio); - if (flags != GET_KSM_PAGE_NOLOCK) { - if (READ_ONCE(page->mapping) != expected_mapping) { - unlock_page(page); - put_page(page); + if (flags != KSM_GET_FOLIO_NOLOCK) { + if (READ_ONCE(folio->mapping) != expected_mapping) { + folio_unlock(folio); + folio_put(folio); goto stale; } } - return page; + return folio; stale: /* @@ -998,16 +998,16 @@ static void remove_rmap_item_from_tree(struct ksm_rmap_item *rmap_item) { if (rmap_item->address & STABLE_FLAG) { struct ksm_stable_node *stable_node; - struct page *page; + struct folio *folio; stable_node = rmap_item->head; - page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK); - if (!page) + folio = ksm_get_folio(stable_node, KSM_GET_FOLIO_LOCK); + if (!folio) goto out; hlist_del(&rmap_item->hlist); - unlock_page(page); - put_page(page); + folio_unlock(folio); + folio_put(folio); if (!hlist_empty(&stable_node->hlist)) ksm_pages_sharing--; @@ -1094,11 +1094,11 @@ static inline struct ksm_stable_node *page_stable_node(struct page *page) return folio_stable_node(page_folio(page)); } -static inline void set_page_stable_node(struct page *page, - struct ksm_stable_node *stable_node) +static inline void folio_set_stable_node(struct folio *folio, + struct ksm_stable_node *stable_node) { - VM_BUG_ON_PAGE(PageAnon(page) && PageAnonExclusive(page), page); - page->mapping = (void *)((unsigned long)stable_node | PAGE_MAPPING_KSM); + VM_WARN_ON_FOLIO(folio_test_anon(folio) && PageAnonExclusive(&folio->page), folio); + folio->mapping = (void *)((unsigned long)stable_node | PAGE_MAPPING_KSM); } #ifdef CONFIG_SYSFS @@ -1107,13 +1107,13 @@ static inline void set_page_stable_node(struct page *page, */ static int remove_stable_node(struct ksm_stable_node *stable_node) { - struct page *page; + struct folio *folio; int err; - page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK); - if (!page) { + folio = ksm_get_folio(stable_node, KSM_GET_FOLIO_LOCK); + if (!folio) { /* - * get_ksm_page did remove_node_from_stable_tree itself. + * ksm_get_folio did remove_node_from_stable_tree itself. */ return 0; } @@ -1124,22 +1124,22 @@ static int remove_stable_node(struct ksm_stable_node *stable_node) * merge_across_nodes/max_page_sharing be switched. */ err = -EBUSY; - if (!page_mapped(page)) { + if (!folio_mapped(folio)) { /* - * The stable node did not yet appear stale to get_ksm_page(), - * since that allows for an unmapped ksm page to be recognized + * The stable node did not yet appear stale to ksm_get_folio(), + * since that allows for an unmapped ksm folio to be recognized * right up until it is freed; but the node is safe to remove. - * This page might be in an LRU cache waiting to be freed, - * or it might be PageSwapCache (perhaps under writeback), + * This folio might be in an LRU cache waiting to be freed, + * or it might be in the swapcache (perhaps under writeback), * or it might have been removed from swapcache a moment ago. */ - set_page_stable_node(page, NULL); + folio_set_stable_node(folio, NULL); remove_node_from_stable_tree(stable_node); err = 0; } - unlock_page(page); - put_page(page); + folio_unlock(folio); + folio_put(folio); return err; } @@ -1275,23 +1275,24 @@ static u32 calc_checksum(struct page *page) return checksum; } -static int write_protect_page(struct vm_area_struct *vma, struct page *page, +static int write_protect_page(struct vm_area_struct *vma, struct folio *folio, pte_t *orig_pte) { struct mm_struct *mm = vma->vm_mm; - DEFINE_PAGE_VMA_WALK(pvmw, page, vma, 0, 0); + DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, 0, 0); int swapped; int err = -EFAULT; struct mmu_notifier_range range; bool anon_exclusive; pte_t entry; - pvmw.address = page_address_in_vma(page, vma); + if (WARN_ON_ONCE(folio_test_large(folio))) + return err; + + pvmw.address = page_address_in_vma(&folio->page, vma); if (pvmw.address == -EFAULT) goto out; - BUG_ON(PageTransCompound(page)); - mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, pvmw.address, pvmw.address + PAGE_SIZE); mmu_notifier_invalidate_range_start(&range); @@ -1301,12 +1302,12 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page, if (WARN_ONCE(!pvmw.pte, "Unexpected PMD mapping?")) goto out_unlock; - anon_exclusive = PageAnonExclusive(page); + anon_exclusive = PageAnonExclusive(&folio->page); entry = ptep_get(pvmw.pte); if (pte_write(entry) || pte_dirty(entry) || anon_exclusive || mm_tlb_flush_pending(mm)) { - swapped = PageSwapCache(page); - flush_cache_page(vma, pvmw.address, page_to_pfn(page)); + swapped = folio_test_swapcache(folio); + flush_cache_page(vma, pvmw.address, folio_pfn(folio)); /* * Ok this is tricky, when get_user_pages_fast() run it doesn't * take any lock, therefore the check that we are going to make @@ -1326,20 +1327,20 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page, * Check that no O_DIRECT or similar I/O is in progress on the * page */ - if (page_mapcount(page) + 1 + swapped != page_count(page)) { + if (folio_mapcount(folio) + 1 + swapped != folio_ref_count(folio)) { set_pte_at(mm, pvmw.address, pvmw.pte, entry); goto out_unlock; } /* See folio_try_share_anon_rmap_pte(): clear PTE first. */ if (anon_exclusive && - folio_try_share_anon_rmap_pte(page_folio(page), page)) { + folio_try_share_anon_rmap_pte(folio, &folio->page)) { set_pte_at(mm, pvmw.address, pvmw.pte, entry); goto out_unlock; } if (pte_dirty(entry)) - set_page_dirty(page); + folio_mark_dirty(folio); entry = pte_mkclean(entry); if (pte_write(entry)) @@ -1505,14 +1506,14 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, * ptes are necessarily already write-protected. But in either * case, we need to lock and check page_count is not raised. */ - if (write_protect_page(vma, page, &orig_pte) == 0) { + if (write_protect_page(vma, page_folio(page), &orig_pte) == 0) { if (!kpage) { /* * While we hold page lock, upgrade page from * PageAnon+anon_vma to PageKsm+NULL stable_node: * stable_tree_insert() will update stable_node. */ - set_page_stable_node(page, NULL); + folio_set_stable_node(page_folio(page), NULL); mark_page_accessed(page); /* * Page reclaim just frees a clean page with no dirty @@ -1617,14 +1618,14 @@ bool is_page_sharing_candidate(struct ksm_stable_node *stable_node) return __is_page_sharing_candidate(stable_node, 0); } -static struct page *stable_node_dup(struct ksm_stable_node **_stable_node_dup, - struct ksm_stable_node **_stable_node, - struct rb_root *root, - bool prune_stale_stable_nodes) +static struct folio *stable_node_dup(struct ksm_stable_node **_stable_node_dup, + struct ksm_stable_node **_stable_node, + struct rb_root *root, + bool prune_stale_stable_nodes) { struct ksm_stable_node *dup, *found = NULL, *stable_node = *_stable_node; struct hlist_node *hlist_safe; - struct page *_tree_page, *tree_page = NULL; + struct folio *folio, *tree_folio = NULL; int nr = 0; int found_rmap_hlist_len; @@ -1643,24 +1644,24 @@ static struct page *stable_node_dup(struct ksm_stable_node **_stable_node_dup, * We must walk all stable_node_dup to prune the stale * stable nodes during lookup. * - * get_ksm_page can drop the nodes from the + * ksm_get_folio can drop the nodes from the * stable_node->hlist if they point to freed pages * (that's why we do a _safe walk). The "dup" * stable_node parameter itself will be freed from * under us if it returns NULL. */ - _tree_page = get_ksm_page(dup, GET_KSM_PAGE_NOLOCK); - if (!_tree_page) + folio = ksm_get_folio(dup, KSM_GET_FOLIO_NOLOCK); + if (!folio) continue; nr += 1; if (is_page_sharing_candidate(dup)) { if (!found || dup->rmap_hlist_len > found_rmap_hlist_len) { if (found) - put_page(tree_page); + folio_put(tree_folio); found = dup; found_rmap_hlist_len = found->rmap_hlist_len; - tree_page = _tree_page; + tree_folio = folio; /* skip put_page for found dup */ if (!prune_stale_stable_nodes) @@ -1668,7 +1669,7 @@ static struct page *stable_node_dup(struct ksm_stable_node **_stable_node_dup, continue; } } - put_page(_tree_page); + folio_put(folio); } if (found) { @@ -1733,7 +1734,7 @@ static struct page *stable_node_dup(struct ksm_stable_node **_stable_node_dup, } *_stable_node_dup = found; - return tree_page; + return tree_folio; } static struct ksm_stable_node *stable_node_dup_any(struct ksm_stable_node *stable_node, @@ -1750,7 +1751,7 @@ static struct ksm_stable_node *stable_node_dup_any(struct ksm_stable_node *stabl } /* - * Like for get_ksm_page, this function can free the *_stable_node and + * Like for ksm_get_folio, this function can free the *_stable_node and * *_stable_node_dup if the returned tree_page is NULL. * * It can also free and overwrite *_stable_node with the found @@ -1763,16 +1764,16 @@ static struct ksm_stable_node *stable_node_dup_any(struct ksm_stable_node *stabl * function and will be overwritten in all cases, the caller doesn't * need to initialize it. */ -static struct page *__stable_node_chain(struct ksm_stable_node **_stable_node_dup, - struct ksm_stable_node **_stable_node, - struct rb_root *root, - bool prune_stale_stable_nodes) +static struct folio *__stable_node_chain(struct ksm_stable_node **_stable_node_dup, + struct ksm_stable_node **_stable_node, + struct rb_root *root, + bool prune_stale_stable_nodes) { struct ksm_stable_node *stable_node = *_stable_node; if (!is_stable_node_chain(stable_node)) { if (is_page_sharing_candidate(stable_node)) { *_stable_node_dup = stable_node; - return get_ksm_page(stable_node, GET_KSM_PAGE_NOLOCK); + return ksm_get_folio(stable_node, KSM_GET_FOLIO_NOLOCK); } /* * _stable_node_dup set to NULL means the stable_node @@ -1785,24 +1786,24 @@ static struct page *__stable_node_chain(struct ksm_stable_node **_stable_node_du prune_stale_stable_nodes); } -static __always_inline struct page *chain_prune(struct ksm_stable_node **s_n_d, - struct ksm_stable_node **s_n, - struct rb_root *root) +static __always_inline struct folio *chain_prune(struct ksm_stable_node **s_n_d, + struct ksm_stable_node **s_n, + struct rb_root *root) { return __stable_node_chain(s_n_d, s_n, root, true); } -static __always_inline struct page *chain(struct ksm_stable_node **s_n_d, - struct ksm_stable_node *s_n, - struct rb_root *root) +static __always_inline struct folio *chain(struct ksm_stable_node **s_n_d, + struct ksm_stable_node *s_n, + struct rb_root *root) { struct ksm_stable_node *old_stable_node = s_n; - struct page *tree_page; + struct folio *tree_folio; - tree_page = __stable_node_chain(s_n_d, &s_n, root, false); + tree_folio = __stable_node_chain(s_n_d, &s_n, root, false); /* not pruning dups so s_n cannot have changed */ VM_BUG_ON(s_n != old_stable_node); - return tree_page; + return tree_folio; } /* @@ -1822,28 +1823,30 @@ static struct page *stable_tree_search(struct page *page) struct rb_node *parent; struct ksm_stable_node *stable_node, *stable_node_dup, *stable_node_any; struct ksm_stable_node *page_node; + struct folio *folio; - page_node = page_stable_node(page); + folio = page_folio(page); + page_node = folio_stable_node(folio); if (page_node && page_node->head != &migrate_nodes) { /* ksm page forked */ - get_page(page); - return page; + folio_get(folio); + return &folio->page; } - nid = get_kpfn_nid(page_to_pfn(page)); + nid = get_kpfn_nid(folio_pfn(folio)); root = root_stable_tree + nid; again: new = &root->rb_node; parent = NULL; while (*new) { - struct page *tree_page; + struct folio *tree_folio; int ret; cond_resched(); stable_node = rb_entry(*new, struct ksm_stable_node, node); stable_node_any = NULL; - tree_page = chain_prune(&stable_node_dup, &stable_node, root); + tree_folio = chain_prune(&stable_node_dup, &stable_node, root); /* * NOTE: stable_node may have been freed by * chain_prune() if the returned stable_node_dup is @@ -1877,14 +1880,14 @@ again: * write protected at all times. Any will work * fine to continue the walk. */ - tree_page = get_ksm_page(stable_node_any, - GET_KSM_PAGE_NOLOCK); + tree_folio = ksm_get_folio(stable_node_any, + KSM_GET_FOLIO_NOLOCK); } VM_BUG_ON(!stable_node_dup ^ !!stable_node_any); - if (!tree_page) { + if (!tree_folio) { /* * If we walked over a stale stable_node, - * get_ksm_page() will call rb_erase() and it + * ksm_get_folio() will call rb_erase() and it * may rebalance the tree from under us. So * restart the search from scratch. Returning * NULL would be safe too, but we'd generate @@ -1894,8 +1897,8 @@ again: goto again; } - ret = memcmp_pages(page, tree_page); - put_page(tree_page); + ret = memcmp_pages(page, &tree_folio->page); + folio_put(tree_folio); parent = *new; if (ret < 0) @@ -1906,12 +1909,15 @@ again: if (page_node) { VM_BUG_ON(page_node->head != &migrate_nodes); /* - * Test if the migrated page should be merged - * into a stable node dup. If the mapcount is - * 1 we can migrate it with another KSM page - * without adding it to the chain. + * If the mapcount of our migrated KSM folio is + * at most 1, we can merge it with another + * KSM folio where we know that we have space + * for one more mapping without exceeding the + * ksm_max_page_sharing limit: see + * chain_prune(). This way, we can avoid adding + * this stable node to the chain. */ - if (page_mapcount(page) > 1) + if (folio_mapcount(folio) > 1) goto chain_append; } @@ -1938,26 +1944,26 @@ again: * It would be more elegant to return stable_node * than kpage, but that involves more changes. */ - tree_page = get_ksm_page(stable_node_dup, - GET_KSM_PAGE_TRYLOCK); + tree_folio = ksm_get_folio(stable_node_dup, + KSM_GET_FOLIO_TRYLOCK); - if (PTR_ERR(tree_page) == -EBUSY) + if (PTR_ERR(tree_folio) == -EBUSY) return ERR_PTR(-EBUSY); - if (unlikely(!tree_page)) + if (unlikely(!tree_folio)) /* * The tree may have been rebalanced, * so re-evaluate parent and new. */ goto again; - unlock_page(tree_page); + folio_unlock(tree_folio); if (get_kpfn_nid(stable_node_dup->kpfn) != NUMA(stable_node_dup->nid)) { - put_page(tree_page); + folio_put(tree_folio); goto replace; } - return tree_page; + return &tree_folio->page; } } @@ -1970,8 +1976,8 @@ again: rb_insert_color(&page_node->node, root); out: if (is_page_sharing_candidate(page_node)) { - get_page(page); - return page; + folio_get(folio); + return &folio->page; } else return NULL; @@ -1996,12 +2002,12 @@ replace: &page_node->node, root); if (is_page_sharing_candidate(page_node)) - get_page(page); + folio_get(folio); else - page = NULL; + folio = NULL; } else { rb_erase(&stable_node_dup->node, root); - page = NULL; + folio = NULL; } } else { VM_BUG_ON(!is_stable_node_chain(stable_node)); @@ -2012,16 +2018,16 @@ replace: DO_NUMA(page_node->nid = nid); stable_node_chain_add_dup(page_node, stable_node); if (is_page_sharing_candidate(page_node)) - get_page(page); + folio_get(folio); else - page = NULL; + folio = NULL; } else { - page = NULL; + folio = NULL; } } stable_node_dup->head = &migrate_nodes; list_add(&stable_node_dup->list, stable_node_dup->head); - return page; + return &folio->page; chain_append: /* stable_node_dup could be null if it reached the limit */ @@ -2064,7 +2070,7 @@ chain_append: * This function returns the stable tree node just allocated on success, * NULL otherwise. */ -static struct ksm_stable_node *stable_tree_insert(struct page *kpage) +static struct ksm_stable_node *stable_tree_insert(struct folio *kfolio) { int nid; unsigned long kpfn; @@ -2074,7 +2080,7 @@ static struct ksm_stable_node *stable_tree_insert(struct page *kpage) struct ksm_stable_node *stable_node, *stable_node_dup, *stable_node_any; bool need_chain = false; - kpfn = page_to_pfn(kpage); + kpfn = folio_pfn(kfolio); nid = get_kpfn_nid(kpfn); root = root_stable_tree + nid; again: @@ -2082,13 +2088,13 @@ again: new = &root->rb_node; while (*new) { - struct page *tree_page; + struct folio *tree_folio; int ret; cond_resched(); stable_node = rb_entry(*new, struct ksm_stable_node, node); stable_node_any = NULL; - tree_page = chain(&stable_node_dup, stable_node, root); + tree_folio = chain(&stable_node_dup, stable_node, root); if (!stable_node_dup) { /* * Either all stable_node dups were full in @@ -2110,14 +2116,14 @@ again: * write protected at all times. Any will work * fine to continue the walk. */ - tree_page = get_ksm_page(stable_node_any, - GET_KSM_PAGE_NOLOCK); + tree_folio = ksm_get_folio(stable_node_any, + KSM_GET_FOLIO_NOLOCK); } VM_BUG_ON(!stable_node_dup ^ !!stable_node_any); - if (!tree_page) { + if (!tree_folio) { /* * If we walked over a stale stable_node, - * get_ksm_page() will call rb_erase() and it + * ksm_get_folio() will call rb_erase() and it * may rebalance the tree from under us. So * restart the search from scratch. Returning * NULL would be safe too, but we'd generate @@ -2127,8 +2133,8 @@ again: goto again; } - ret = memcmp_pages(kpage, tree_page); - put_page(tree_page); + ret = memcmp_pages(&kfolio->page, &tree_folio->page); + folio_put(tree_folio); parent = *new; if (ret < 0) @@ -2147,7 +2153,7 @@ again: INIT_HLIST_HEAD(&stable_node_dup->hlist); stable_node_dup->kpfn = kpfn; - set_page_stable_node(kpage, stable_node_dup); + folio_set_stable_node(kfolio, stable_node_dup); stable_node_dup->rmap_hlist_len = 0; DO_NUMA(stable_node_dup->nid = nid); if (!need_chain) { @@ -2425,7 +2431,7 @@ static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_ite * node in the stable tree and add both rmap_items. */ lock_page(kpage); - stable_node = stable_tree_insert(kpage); + stable_node = stable_tree_insert(page_folio(kpage)); if (stable_node) { stable_tree_append(tree_rmap_item, stable_node, false); @@ -2597,14 +2603,14 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page) */ if (!ksm_merge_across_nodes) { struct ksm_stable_node *stable_node, *next; - struct page *page; + struct folio *folio; list_for_each_entry_safe(stable_node, next, &migrate_nodes, list) { - page = get_ksm_page(stable_node, - GET_KSM_PAGE_NOLOCK); - if (page) - put_page(page); + folio = ksm_get_folio(stable_node, + KSM_GET_FOLIO_NOLOCK); + if (folio) + folio_put(folio); cond_resched(); } } @@ -3172,12 +3178,11 @@ again: /* * Collect processes when the error hit an ksm page. */ -void collect_procs_ksm(struct page *page, struct list_head *to_kill, - int force_early) +void collect_procs_ksm(struct folio *folio, struct page *page, + struct list_head *to_kill, int force_early) { struct ksm_stable_node *stable_node; struct ksm_rmap_item *rmap_item; - struct folio *folio = page_folio(page); struct vm_area_struct *vma; struct task_struct *tsk; @@ -3229,11 +3234,11 @@ void folio_migrate_ksm(struct folio *newfolio, struct folio *folio) /* * newfolio->mapping was set in advance; now we need smp_wmb() * to make sure that the new stable_node->kpfn is visible - * to get_ksm_page() before it can see that folio->mapping + * to ksm_get_folio() before it can see that folio->mapping * has gone stale (or that folio_test_swapcache has been cleared). */ smp_wmb(); - set_page_stable_node(&folio->page, NULL); + folio_set_stable_node(folio, NULL); } } #endif /* CONFIG_MIGRATION */ @@ -3256,7 +3261,7 @@ static bool stable_node_dup_remove_range(struct ksm_stable_node *stable_node, if (stable_node->kpfn >= start_pfn && stable_node->kpfn < end_pfn) { /* - * Don't get_ksm_page, page has already gone: + * Don't ksm_get_folio, page has already gone: * which is why we keep kpfn instead of page* */ remove_node_from_stable_tree(stable_node); @@ -3344,7 +3349,7 @@ static int ksm_memory_callback(struct notifier_block *self, * Most of the work is done by page migration; but there might * be a few stable_nodes left over, still pointing to struct * pages which have been offlined: prune those from the tree, - * otherwise get_ksm_page() might later try to access a + * otherwise ksm_get_folio() might later try to access a * non-existent struct page. */ ksm_check_stable_tree(mn->start_pfn, |