#include <linux/mmu_notifier.h>
#include <linux/rmap.h>
#include <linux/swap.h>
+#include <linux/shrinker.h>
#include <linux/mm_inline.h>
#include <linux/kthread.h>
#include <linux/khugepaged.h>
#include <linux/freezer.h>
#include <linux/mman.h>
#include <linux/pagemap.h>
+#include <linux/migrate.h>
+#include <linux/hashtable.h>
+
#include <asm/tlb.h>
#include <asm/pgalloc.h>
#include "internal.h"
(1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)|
#endif
(1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)|
- (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG);
+ (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG)|
+ (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG);
/* default scan 8*512 pte (or vmas) every 30 second */
static unsigned int khugepaged_pages_to_scan __read_mostly = HPAGE_PMD_NR*8;
/* during fragmentation poll the hugepage allocator once every minute */
static unsigned int khugepaged_alloc_sleep_millisecs __read_mostly = 60000;
static struct task_struct *khugepaged_thread __read_mostly;
-static unsigned long huge_zero_pfn __read_mostly;
static DEFINE_MUTEX(khugepaged_mutex);
static DEFINE_SPINLOCK(khugepaged_mm_lock);
static DECLARE_WAIT_QUEUE_HEAD(khugepaged_wait);
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;
return err;
}
-static int init_huge_zero_pfn(void)
+static atomic_t huge_zero_refcount;
+static struct page *huge_zero_page __read_mostly;
+
+static inline bool is_huge_zero_page(struct page *page)
{
- struct page *hpage;
- unsigned long pfn;
+ return ACCESS_ONCE(huge_zero_page) == page;
+}
- hpage = alloc_pages((GFP_TRANSHUGE | __GFP_ZERO) & ~__GFP_MOVABLE,
+static inline bool is_huge_zero_pmd(pmd_t pmd)
+{
+ return is_huge_zero_page(pmd_page(pmd));
+}
+
+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_page);
+
+ zero_page = alloc_pages((GFP_TRANSHUGE | __GFP_ZERO) & ~__GFP_MOVABLE,
HPAGE_PMD_ORDER);
- if (!hpage)
- return -ENOMEM;
- pfn = page_to_pfn(hpage);
- if (cmpxchg(&huge_zero_pfn, 0, pfn))
- __free_page(hpage);
- return 0;
+ if (!zero_page) {
+ count_vm_event(THP_ZERO_PAGE_ALLOC_FAILED);
+ return NULL;
+ }
+ count_vm_event(THP_ZERO_PAGE_ALLOC);
+ preempt_disable();
+ 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_page);
}
-static inline bool is_huge_zero_pfn(unsigned long pfn)
+static void put_huge_zero_page(void)
{
- return huge_zero_pfn && pfn == huge_zero_pfn;
+ /*
+ * Counter should never go to zero here. Only shrinker can put
+ * last reference.
+ */
+ BUG_ON(atomic_dec_and_test(&huge_zero_refcount));
}
-static inline bool is_huge_zero_pmd(pmd_t pmd)
+static int shrink_huge_zero_page(struct shrinker *shrink,
+ struct shrink_control *sc)
{
- return is_huge_zero_pfn(pmd_pfn(pmd));
+ if (!sc->nr_to_scan)
+ /* we can free zero page only if last reference remains */
+ return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0;
+
+ if (atomic_cmpxchg(&huge_zero_refcount, 1, 0) == 1) {
+ struct page *zero_page = xchg(&huge_zero_page, NULL);
+ BUG_ON(zero_page == NULL);
+ __free_page(zero_page);
+ }
+
+ return 0;
}
+static struct shrinker huge_zero_page_shrinker = {
+ .shrink = shrink_huge_zero_page,
+ .seeks = DEFAULT_SEEKS,
+};
+
#ifdef CONFIG_SYSFS
static ssize_t double_flag_show(struct kobject *kobj,
static struct kobj_attribute defrag_attr =
__ATTR(defrag, 0644, defrag_show, defrag_store);
+static ssize_t use_zero_page_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return single_flag_show(kobj, attr, buf,
+ TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG);
+}
+static ssize_t use_zero_page_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ return single_flag_store(kobj, attr, buf, count,
+ TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG);
+}
+static struct kobj_attribute use_zero_page_attr =
+ __ATTR(use_zero_page, 0644, use_zero_page_show, use_zero_page_store);
#ifdef CONFIG_DEBUG_VM
static ssize_t debug_cow_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
static struct attribute *hugepage_attr[] = {
&enabled_attr.attr,
&defrag_attr.attr,
+ &use_zero_page_attr.attr,
#ifdef CONFIG_DEBUG_VM
&debug_cow_attr.attr,
#endif
*hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj);
if (unlikely(!*hugepage_kobj)) {
- printk(KERN_ERR "hugepage: failed kobject create\n");
+ printk(KERN_ERR "hugepage: failed to create transparent hugepage kobject\n");
return -ENOMEM;
}
err = sysfs_create_group(*hugepage_kobj, &hugepage_attr_group);
if (err) {
- printk(KERN_ERR "hugepage: failed register hugeage group\n");
+ printk(KERN_ERR "hugepage: failed to register transparent hugepage group\n");
goto delete_obj;
}
err = sysfs_create_group(*hugepage_kobj, &khugepaged_attr_group);
if (err) {
- printk(KERN_ERR "hugepage: failed register hugeage group\n");
+ printk(KERN_ERR "hugepage: failed to register transparent hugepage group\n");
goto remove_hp_group;
}
if (err)
goto out;
- err = mm_slots_hash_init();
- if (err) {
- khugepaged_slab_free();
- goto out;
- }
+ register_shrinker(&huge_zero_page_shrinker);
/*
* By default disable transparent hugepages on smaller systems,
}
__setup("transparent_hugepage=", setup_transparent_hugepage);
-static inline pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
+pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
{
if (likely(vma->vm_flags & VM_WRITE))
pmd = pmd_mkwrite(pmd);
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);
}
#endif
-static void set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
- struct vm_area_struct *vma, unsigned long haddr, pmd_t *pmd)
+static bool set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
+ struct vm_area_struct *vma, unsigned long haddr, pmd_t *pmd,
+ struct page *zero_page)
{
pmd_t entry;
- entry = pfn_pmd(huge_zero_pfn, vma->vm_page_prot);
+ if (!pmd_none(*pmd))
+ return false;
+ entry = mk_pmd(zero_page, vma->vm_page_prot);
entry = pmd_wrprotect(entry);
entry = pmd_mkhuge(entry);
set_pmd_at(mm, haddr, pmd, entry);
pgtable_trans_huge_deposit(mm, pgtable);
mm->nr_ptes++;
+ return true;
}
int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
return VM_FAULT_OOM;
if (unlikely(khugepaged_enter(vma)))
return VM_FAULT_OOM;
- if (!(flags & FAULT_FLAG_WRITE)) {
+ if (!(flags & FAULT_FLAG_WRITE) &&
+ transparent_hugepage_use_zero_page()) {
pgtable_t pgtable;
- if (unlikely(!huge_zero_pfn && init_huge_zero_pfn())) {
- count_vm_event(THP_FAULT_FALLBACK);
- goto out;
- }
+ struct page *zero_page;
+ bool set;
pgtable = pte_alloc_one(mm, haddr);
if (unlikely(!pgtable))
return VM_FAULT_OOM;
+ 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_huge_zero_page(pgtable, mm, vma, haddr, pmd);
+ set = set_huge_zero_page(pgtable, mm, vma, haddr, pmd,
+ zero_page);
spin_unlock(&mm->page_table_lock);
+ if (!set) {
+ pte_free(mm, pgtable);
+ put_huge_zero_page();
+ }
return 0;
}
page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
* run pte_offset_map on the pmd, if an huge pmd could
* materialize from under us from a different thread.
*/
- if (unlikely(__pte_alloc(mm, vma, pmd, address)))
+ if (unlikely(pmd_none(*pmd)) &&
+ unlikely(__pte_alloc(mm, vma, pmd, address)))
return VM_FAULT_OOM;
/* if an huge pmd materialized from under us just retry later */
if (unlikely(pmd_trans_huge(*pmd)))
* a page table.
*/
if (is_huge_zero_pmd(pmd)) {
- set_huge_zero_page(pgtable, dst_mm, vma, addr, dst_pmd);
+ 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_page = get_huge_zero_page();
+ set = set_huge_zero_page(pgtable, dst_mm, vma, addr, dst_pmd,
+ zero_page);
+ BUG_ON(!set); /* unexpected !pmd_none(dst_pmd) */
ret = 0;
goto out_unlock;
}
static int do_huge_pmd_wp_zero_page_fallback(struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmd, unsigned long haddr)
+ pmd_t *pmd, pmd_t orig_pmd, unsigned long haddr)
{
pgtable_t pgtable;
pmd_t _pmd;
mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_same(*pmd, orig_pmd)))
+ goto out_free_page;
+
pmdp_clear_flush(vma, haddr, pmd);
/* leave pmd empty until pte is filled */
smp_wmb(); /* make pte visible before pmd */
pmd_populate(mm, pmd, pgtable);
spin_unlock(&mm->page_table_lock);
+ put_huge_zero_page();
inc_mm_counter(mm, MM_ANONPAGES);
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
ret |= VM_FAULT_WRITE;
out:
return ret;
+out_free_page:
+ spin_unlock(&mm->page_table_lock);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mem_cgroup_uncharge_page(page);
+ put_page(page);
+ goto out;
}
static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
count_vm_event(THP_FAULT_FALLBACK);
if (is_huge_zero_pmd(orig_pmd)) {
ret = do_huge_pmd_wp_zero_page_fallback(mm, vma,
- address, pmd, haddr);
+ address, pmd, orig_pmd, haddr);
} else {
ret = do_huge_pmd_wp_page_fallback(mm, vma, address,
pmd, orig_pmd, page, haddr);
page_add_new_anon_rmap(new_page, vma, haddr);
set_pmd_at(mm, haddr, pmd, entry);
update_mmu_cache_pmd(vma, address, pmd);
- if (is_huge_zero_pmd(orig_pmd))
+ if (is_huge_zero_pmd(orig_pmd)) {
add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
- else {
+ put_huge_zero_page();
+ } else {
VM_BUG_ON(!PageHead(page));
page_remove_rmap(page);
put_page(page);
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) {
return page;
}
+/* NUMA hinting page fault entry point for trans huge pmds */
+int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, pmd_t pmd, pmd_t *pmdp)
+{
+ struct page *page;
+ unsigned long haddr = addr & HPAGE_PMD_MASK;
+ int target_nid;
+ int current_nid = -1;
+ bool migrated;
+
+ spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_same(pmd, *pmdp)))
+ goto out_unlock;
+
+ page = pmd_page(pmd);
+ get_page(page);
+ current_nid = page_to_nid(page);
+ count_vm_numa_event(NUMA_HINT_FAULTS);
+ if (current_nid == numa_node_id())
+ count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL);
+
+ target_nid = mpol_misplaced(page, vma, haddr);
+ if (target_nid == -1) {
+ put_page(page);
+ goto clear_pmdnuma;
+ }
+
+ /* Acquire the page lock to serialise THP migrations */
+ spin_unlock(&mm->page_table_lock);
+ lock_page(page);
+
+ /* Confirm the PTE did not while locked */
+ spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_same(pmd, *pmdp))) {
+ unlock_page(page);
+ put_page(page);
+ goto out_unlock;
+ }
+ spin_unlock(&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)
+ goto check_same;
+
+ 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);
+out_unlock:
+ spin_unlock(&mm->page_table_lock);
+ if (current_nid != -1)
+ task_numa_fault(current_nid, HPAGE_PMD_NR, false);
+ return 0;
+}
+
int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
pmd_t *pmd, unsigned long addr)
{
if (is_huge_zero_pmd(orig_pmd)) {
tlb->mm->nr_ptes--;
spin_unlock(&tlb->mm->page_table_lock);
+ put_huge_zero_page();
} else {
page = pmd_page(orig_pmd);
page_remove_rmap(page);
}
int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
- unsigned long addr, pgprot_t newprot)
+ unsigned long addr, pgprot_t newprot, int prot_numa)
{
struct mm_struct *mm = vma->vm_mm;
int ret = 0;
if (__pmd_trans_huge_lock(pmd, vma) == 1) {
pmd_t entry;
entry = pmdp_get_and_clear(mm, addr, pmd);
- entry = pmd_modify(entry, newprot);
- BUG_ON(pmd_write(entry));
+ if (!prot_numa) {
+ entry = pmd_modify(entry, newprot);
+ BUG_ON(pmd_write(entry));
+ } else {
+ struct page *page = pmd_page(*pmd);
+
+ /* only check non-shared pages */
+ if (page_mapcount(page) == 1 &&
+ !pmd_numa(*pmd)) {
+ entry = pmd_mknuma(entry);
+ }
+ }
set_pmd_at(mm, addr, pmd, entry);
spin_unlock(&vma->vm_mm->page_table_lock);
ret = 1;
* We can't temporarily set the pmd to null in order
* to split it, the pmd must remain marked huge at all
* times or the VM won't take the pmd_trans_huge paths
- * and it won't wait on the anon_vma->root->mutex to
+ * and it won't wait on the anon_vma->root->rwsem to
* serialize against split_huge_page*.
*/
pmdp_splitting_flush(vma, address, pmd);
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_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);
BUG_ON(page_mapcount(page) != 1);
if (!pmd_young(*pmd))
entry = pte_mkold(entry);
+ if (pmd_numa(*pmd))
+ entry = pte_mknuma(entry);
pte = pte_offset_map(&_pmd, haddr);
BUG_ON(!pte_none(*pte));
set_pte_at(mm, haddr, pte, entry);
return ret;
}
-/* must be called with anon_vma->root->mutex hold */
+/* 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));
- anon_vma = page_lock_anon_vma(page);
+
+ /*
+ * The caller does not necessarily hold an mmap_sem that would prevent
+ * the anon_vma disappearing so we first we take a reference to it
+ * and then lock the anon_vma for write. This is similar to
+ * page_lock_anon_vma_read except the write lock is taken to serialise
+ * against parallel split or collapse operations.
+ */
+ anon_vma = page_get_anon_vma(page);
if (!anon_vma)
goto out;
+ anon_vma_lock_write(anon_vma);
+
ret = 0;
if (!PageCompound(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:
- page_unlock_anon_vma(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;
}
goto out;
vma = find_vma(mm, address);
+ if (!vma)
+ goto out;
hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
hend = vma->vm_end & HPAGE_PMD_MASK;
if (address < hstart || address + HPAGE_PMD_SIZE > hend)
if (pmd_trans_huge(*pmd))
goto out;
- anon_vma_lock(vma->anon_vma);
+ anon_vma_lock_write(vma->anon_vma);
pte = pte_offset_map(pmd, address);
ptl = pte_lockptr(mm, pmd);
pte_unmap(pte);
spin_lock(&mm->page_table_lock);
BUG_ON(!pmd_none(*pmd));
- set_pmd_at(mm, address, pmd, _pmd);
+ /*
+ * We can only use set_pmd_at when establishing
+ * hugepmds and never for establishing regular pmds that
+ * points to regular pagetables. Use pmd_populate for that
+ */
+ pmd_populate(mm, pmd, pmd_pgtable(_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);
/*
}
smp_wmb(); /* make pte visible before pmd */
pmd_populate(mm, pmd, pgtable);
+ put_huge_zero_page();
}
void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
mmun_start = haddr;
mmun_end = haddr + HPAGE_PMD_SIZE;
+again:
mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
spin_lock(&mm->page_table_lock);
if (unlikely(!pmd_trans_huge(*pmd))) {
split_huge_page(page);
put_page(page);
- BUG_ON(pmd_trans_huge(*pmd));
+
+ /*
+ * We don't always have down_write of mmap_sem here: a racing
+ * do_huge_pmd_wp_page() might have copied-on-write to another
+ * huge page before our split_huge_page() got the anon_vma lock.
+ */
+ if (unlikely(pmd_trans_huge(*pmd)))
+ goto again;
}
void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
Code Review / linux-3.10.git / blobdiff