#include <linux/mman.h>
#include <linux/pagemap.h>
#include <linux/migrate.h>
+#include <linux/hashtable.h>
#include <asm/tlb.h>
#include <asm/pgalloc.h>
static unsigned int khugepaged_max_ptes_none __read_mostly = HPAGE_PMD_NR-1;
static int khugepaged(void *none);
-static int mm_slots_hash_init(void);
static int khugepaged_slab_init(void);
-static void khugepaged_slab_free(void);
-#define MM_SLOTS_HASH_HEADS 1024
-static struct hlist_head *mm_slots_hash __read_mostly;
+#define MM_SLOTS_HASH_BITS 10
+static __read_mostly DEFINE_HASHTABLE(mm_slots_hash, MM_SLOTS_HASH_BITS);
+
static struct kmem_cache *mm_slot_cache __read_mostly;
/**
struct zone *zone;
int nr_zones = 0;
unsigned long recommended_min;
- extern int min_free_kbytes;
if (!khugepaged_enabled())
return 0;
}
static atomic_t huge_zero_refcount;
-static unsigned long huge_zero_pfn __read_mostly;
+static struct page *huge_zero_page __read_mostly;
-static inline bool is_huge_zero_pfn(unsigned long pfn)
+static inline bool is_huge_zero_page(struct page *page)
{
- unsigned long zero_pfn = ACCESS_ONCE(huge_zero_pfn);
- return zero_pfn && pfn == zero_pfn;
+ return ACCESS_ONCE(huge_zero_page) == page;
}
static inline bool is_huge_zero_pmd(pmd_t pmd)
{
- return is_huge_zero_pfn(pmd_pfn(pmd));
+ return is_huge_zero_page(pmd_page(pmd));
}
-static unsigned long get_huge_zero_page(void)
+static struct page *get_huge_zero_page(void)
{
struct page *zero_page;
retry:
if (likely(atomic_inc_not_zero(&huge_zero_refcount)))
- return ACCESS_ONCE(huge_zero_pfn);
+ return ACCESS_ONCE(huge_zero_page);
zero_page = alloc_pages((GFP_TRANSHUGE | __GFP_ZERO) & ~__GFP_MOVABLE,
HPAGE_PMD_ORDER);
if (!zero_page) {
count_vm_event(THP_ZERO_PAGE_ALLOC_FAILED);
- return 0;
+ return NULL;
}
count_vm_event(THP_ZERO_PAGE_ALLOC);
preempt_disable();
- if (cmpxchg(&huge_zero_pfn, 0, page_to_pfn(zero_page))) {
+ if (cmpxchg(&huge_zero_page, NULL, zero_page)) {
preempt_enable();
__free_page(zero_page);
goto retry;
/* We take additional reference here. It will be put back by shrinker */
atomic_set(&huge_zero_refcount, 2);
preempt_enable();
- return ACCESS_ONCE(huge_zero_pfn);
+ return ACCESS_ONCE(huge_zero_page);
}
static void put_huge_zero_page(void)
return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0;
if (atomic_cmpxchg(&huge_zero_refcount, 1, 0) == 1) {
- unsigned long zero_pfn = xchg(&huge_zero_pfn, 0);
- BUG_ON(zero_pfn == 0);
- __free_page(__pfn_to_page(zero_pfn));
+ struct page *zero_page = xchg(&huge_zero_page, NULL);
+ BUG_ON(zero_page == NULL);
+ __free_page(zero_page);
}
return 0;
if (err)
goto out;
- err = mm_slots_hash_init();
- if (err) {
- khugepaged_slab_free();
- goto out;
- }
-
register_shrinker(&huge_zero_page_shrinker);
/*
return VM_FAULT_OOM;
clear_huge_page(page, haddr, HPAGE_PMD_NR);
+ /*
+ * The memory barrier inside __SetPageUptodate makes sure that
+ * clear_huge_page writes become visible before the set_pmd_at()
+ * write.
+ */
__SetPageUptodate(page);
spin_lock(&mm->page_table_lock);
} else {
pmd_t entry;
entry = mk_huge_pmd(page, vma);
- /*
- * The spinlocking to take the lru_lock inside
- * page_add_new_anon_rmap() acts as a full memory
- * barrier to be sure clear_huge_page writes become
- * visible after the set_pmd_at() write.
- */
page_add_new_anon_rmap(page, vma, haddr);
set_pmd_at(mm, haddr, pmd, entry);
pgtable_trans_huge_deposit(mm, pgtable);
static bool set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long haddr, pmd_t *pmd,
- unsigned long zero_pfn)
+ struct page *zero_page)
{
pmd_t entry;
if (!pmd_none(*pmd))
return false;
- entry = pfn_pmd(zero_pfn, vma->vm_page_prot);
+ entry = mk_pmd(zero_page, vma->vm_page_prot);
entry = pmd_wrprotect(entry);
entry = pmd_mkhuge(entry);
set_pmd_at(mm, haddr, pmd, entry);
if (!(flags & FAULT_FLAG_WRITE) &&
transparent_hugepage_use_zero_page()) {
pgtable_t pgtable;
- unsigned long zero_pfn;
+ struct page *zero_page;
bool set;
pgtable = pte_alloc_one(mm, haddr);
if (unlikely(!pgtable))
return VM_FAULT_OOM;
- zero_pfn = get_huge_zero_page();
- if (unlikely(!zero_pfn)) {
+ zero_page = get_huge_zero_page();
+ if (unlikely(!zero_page)) {
pte_free(mm, pgtable);
count_vm_event(THP_FAULT_FALLBACK);
goto out;
}
spin_lock(&mm->page_table_lock);
set = set_huge_zero_page(pgtable, mm, vma, haddr, pmd,
- zero_pfn);
+ zero_page);
spin_unlock(&mm->page_table_lock);
if (!set) {
pte_free(mm, pgtable);
* a page table.
*/
if (is_huge_zero_pmd(pmd)) {
- unsigned long zero_pfn;
+ struct page *zero_page;
bool set;
/*
* get_huge_zero_page() will never allocate a new page here,
* since we already have a zero page to copy. It just takes a
* reference.
*/
- zero_pfn = get_huge_zero_page();
+ zero_page = get_huge_zero_page();
set = set_huge_zero_page(pgtable, dst_mm, vma, addr, dst_pmd,
- zero_pfn);
+ zero_page);
BUG_ON(!set); /* unexpected !pmd_none(dst_pmd) */
ret = 0;
goto out_unlock;
if (flags & FOLL_WRITE && !pmd_write(*pmd))
goto out;
+ /* Avoid dumping huge zero page */
+ if ((flags & FOLL_DUMP) && is_huge_zero_pmd(*pmd))
+ return ERR_PTR(-EFAULT);
+
page = pmd_page(*pmd);
VM_BUG_ON(!PageHead(page));
if (flags & FOLL_TOUCH) {
int target_nid;
int current_nid = -1;
bool migrated;
- bool page_locked = false;
spin_lock(&mm->page_table_lock);
if (unlikely(!pmd_same(pmd, *pmdp)))
/* Acquire the page lock to serialise THP migrations */
spin_unlock(&mm->page_table_lock);
lock_page(page);
- page_locked = true;
/* Confirm the PTE did not while locked */
spin_lock(&mm->page_table_lock);
/* Migrate the THP to the requested node */
migrated = migrate_misplaced_transhuge_page(mm, vma,
- pmdp, pmd, addr,
- page, target_nid);
- if (migrated)
- current_nid = target_nid;
- else {
- spin_lock(&mm->page_table_lock);
- if (unlikely(!pmd_same(pmd, *pmdp))) {
- unlock_page(page);
- goto out_unlock;
- }
- goto clear_pmdnuma;
- }
+ pmdp, pmd, addr, page, target_nid);
+ if (!migrated)
+ goto check_same;
- task_numa_fault(current_nid, HPAGE_PMD_NR, migrated);
+ task_numa_fault(target_nid, HPAGE_PMD_NR, true);
return 0;
+check_same:
+ spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_same(pmd, *pmdp)))
+ goto out_unlock;
clear_pmdnuma:
pmd = pmd_mknonnuma(pmd);
set_pmd_at(mm, haddr, pmdp, pmd);
VM_BUG_ON(pmd_numa(*pmdp));
update_mmu_cache_pmd(vma, addr, pmdp);
- if (page_locked)
- unlock_page(page);
-
out_unlock:
spin_unlock(&mm->page_table_lock);
if (current_nid != -1)
- task_numa_fault(current_nid, HPAGE_PMD_NR, migrated);
+ task_numa_fault(current_nid, HPAGE_PMD_NR, false);
return 0;
}
return ret;
}
-static void __split_huge_page_refcount(struct page *page)
+static void __split_huge_page_refcount(struct page *page,
+ struct list_head *list)
{
int i;
struct zone *zone = page_zone(page);
page_tail->mapping = page->mapping;
page_tail->index = page->index + i;
- page_xchg_last_nid(page_tail, page_last_nid(page));
+ page_nid_xchg_last(page_tail, page_nid_last(page));
BUG_ON(!PageAnon(page_tail));
BUG_ON(!PageUptodate(page_tail));
BUG_ON(!PageDirty(page_tail));
BUG_ON(!PageSwapBacked(page_tail));
- lru_add_page_tail(page, page_tail, lruvec);
+ lru_add_page_tail(page, page_tail, lruvec, list);
}
atomic_sub(tail_count, &page->_count);
BUG_ON(atomic_read(&page->_count) <= 0);
/* must be called with anon_vma->root->rwsem held */
static void __split_huge_page(struct page *page,
- struct anon_vma *anon_vma)
+ struct anon_vma *anon_vma,
+ struct list_head *list)
{
int mapcount, mapcount2;
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
mapcount, page_mapcount(page));
BUG_ON(mapcount != page_mapcount(page));
- __split_huge_page_refcount(page);
+ __split_huge_page_refcount(page, list);
mapcount2 = 0;
anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
BUG_ON(mapcount != mapcount2);
}
-int split_huge_page(struct page *page)
+/*
+ * Split a hugepage into normal pages. This doesn't change the position of head
+ * page. If @list is null, tail pages will be added to LRU list, otherwise, to
+ * @list. Both head page and tail pages will inherit mapping, flags, and so on
+ * from the hugepage.
+ * Return 0 if the hugepage is split successfully otherwise return 1.
+ */
+int split_huge_page_to_list(struct page *page, struct list_head *list)
{
struct anon_vma *anon_vma;
int ret = 1;
- BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
+ BUG_ON(is_huge_zero_page(page));
BUG_ON(!PageAnon(page));
/*
goto out_unlock;
BUG_ON(!PageSwapBacked(page));
- __split_huge_page(page, anon_vma);
+ __split_huge_page(page, anon_vma, list);
count_vm_event(THP_SPLIT);
BUG_ON(PageCompound(page));
out_unlock:
- anon_vma_unlock(anon_vma);
+ anon_vma_unlock_write(anon_vma);
put_anon_vma(anon_vma);
out:
return ret;
return 0;
}
-static void __init khugepaged_slab_free(void)
-{
- kmem_cache_destroy(mm_slot_cache);
- mm_slot_cache = NULL;
-}
-
static inline struct mm_slot *alloc_mm_slot(void)
{
if (!mm_slot_cache) /* initialization failed */
kmem_cache_free(mm_slot_cache, mm_slot);
}
-static int __init mm_slots_hash_init(void)
-{
- mm_slots_hash = kzalloc(MM_SLOTS_HASH_HEADS * sizeof(struct hlist_head),
- GFP_KERNEL);
- if (!mm_slots_hash)
- return -ENOMEM;
- return 0;
-}
-
-#if 0
-static void __init mm_slots_hash_free(void)
-{
- kfree(mm_slots_hash);
- mm_slots_hash = NULL;
-}
-#endif
-
static struct mm_slot *get_mm_slot(struct mm_struct *mm)
{
struct mm_slot *mm_slot;
- struct hlist_head *bucket;
- struct hlist_node *node;
- bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct))
- % MM_SLOTS_HASH_HEADS];
- hlist_for_each_entry(mm_slot, node, bucket, hash) {
+ hash_for_each_possible(mm_slots_hash, mm_slot, hash, (unsigned long)mm)
if (mm == mm_slot->mm)
return mm_slot;
- }
+
return NULL;
}
static void insert_to_mm_slots_hash(struct mm_struct *mm,
struct mm_slot *mm_slot)
{
- struct hlist_head *bucket;
-
- bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct))
- % MM_SLOTS_HASH_HEADS];
mm_slot->mm = mm;
- hlist_add_head(&mm_slot->hash, bucket);
+ hash_add(mm_slots_hash, &mm_slot->hash, (long)mm);
}
static inline int khugepaged_test_exit(struct mm_struct *mm)
spin_lock(&khugepaged_mm_lock);
mm_slot = get_mm_slot(mm);
if (mm_slot && khugepaged_scan.mm_slot != mm_slot) {
- hlist_del(&mm_slot->hash);
+ hash_del(&mm_slot->hash);
list_del(&mm_slot->mm_node);
free = 1;
}
BUG_ON(!pmd_none(*pmd));
set_pmd_at(mm, address, pmd, _pmd);
spin_unlock(&mm->page_table_lock);
- anon_vma_unlock(vma->anon_vma);
+ anon_vma_unlock_write(vma->anon_vma);
goto out;
}
* All pages are isolated and locked so anon_vma rmap
* can't run anymore.
*/
- anon_vma_unlock(vma->anon_vma);
+ anon_vma_unlock_write(vma->anon_vma);
__collapse_huge_page_copy(pte, new_page, vma, address, ptl);
pte_unmap(pte);
struct page *page;
unsigned long _address;
spinlock_t *ptl;
- int node = -1;
+ int node = NUMA_NO_NODE;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
* be more sophisticated and look at more pages,
* but isn't for now.
*/
- if (node == -1)
+ if (node == NUMA_NO_NODE)
node = page_to_nid(page);
VM_BUG_ON(PageCompound(page));
if (!PageLRU(page) || PageLocked(page) || !PageAnon(page))
if (khugepaged_test_exit(mm)) {
/* free mm_slot */
- hlist_del(&mm_slot->hash);
+ hash_del(&mm_slot->hash);
list_del(&mm_slot->mm_node);
/*
projects / deliverable / linux.git / blobdiff