#include <linux/khugepaged.h>
#include <linux/freezer.h>
#include <linux/mman.h>
+#include <linux/pagemap.h>
#include <asm/tlb.h>
#include <asm/pgalloc.h>
#include "internal.h"
unsigned long recommended_min;
extern int min_free_kbytes;
- if (!test_bit(TRANSPARENT_HUGEPAGE_FLAG,
- &transparent_hugepage_flags) &&
- !test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
- &transparent_hugepage_flags))
+ if (!khugepaged_enabled())
return 0;
for_each_populated_zone(zone)
{
int err = 0;
if (khugepaged_enabled()) {
- int wakeup;
- if (unlikely(!mm_slot_cache || !mm_slots_hash)) {
- err = -ENOMEM;
- goto out;
- }
- mutex_lock(&khugepaged_mutex);
if (!khugepaged_thread)
khugepaged_thread = kthread_run(khugepaged, NULL,
"khugepaged");
err = PTR_ERR(khugepaged_thread);
khugepaged_thread = NULL;
}
- wakeup = !list_empty(&khugepaged_scan.mm_head);
- mutex_unlock(&khugepaged_mutex);
- if (wakeup)
+
+ if (!list_empty(&khugepaged_scan.mm_head))
wake_up_interruptible(&khugepaged_wait);
set_recommended_min_free_kbytes();
- } else
- /* wakeup to exit */
- wake_up_interruptible(&khugepaged_wait);
-out:
+ } else if (khugepaged_thread) {
+ kthread_stop(khugepaged_thread);
+ khugepaged_thread = NULL;
+ }
+
return err;
}
TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG);
if (ret > 0) {
- int err = start_khugepaged();
+ int err;
+
+ mutex_lock(&khugepaged_mutex);
+ err = start_khugepaged();
+ mutex_unlock(&khugepaged_mutex);
+
if (err)
ret = err;
}
- if (ret > 0 &&
- (test_bit(TRANSPARENT_HUGEPAGE_FLAG,
- &transparent_hugepage_flags) ||
- test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
- &transparent_hugepage_flags)))
- set_recommended_min_free_kbytes();
-
return ret;
}
static struct kobj_attribute enabled_attr =
start_khugepaged();
- set_recommended_min_free_kbytes();
-
return 0;
out:
hugepage_exit_sysfs(hugepage_kobj);
}
__setup("transparent_hugepage=", setup_transparent_hugepage);
-static void prepare_pmd_huge_pte(pgtable_t pgtable,
- struct mm_struct *mm)
-{
- assert_spin_locked(&mm->page_table_lock);
-
- /* FIFO */
- if (!mm->pmd_huge_pte)
- INIT_LIST_HEAD(&pgtable->lru);
- else
- list_add(&pgtable->lru, &mm->pmd_huge_pte->lru);
- mm->pmd_huge_pte = pgtable;
-}
-
static inline pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
{
if (likely(vma->vm_flags & VM_WRITE))
return pmd;
}
+static inline pmd_t mk_huge_pmd(struct page *page, struct vm_area_struct *vma)
+{
+ pmd_t entry;
+ entry = mk_pmd(page, vma->vm_page_prot);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+ entry = pmd_mkhuge(entry);
+ return entry;
+}
+
static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
struct vm_area_struct *vma,
unsigned long haddr, pmd_t *pmd,
struct page *page)
{
- int ret = 0;
pgtable_t pgtable;
VM_BUG_ON(!PageCompound(page));
pgtable = pte_alloc_one(mm, haddr);
- if (unlikely(!pgtable)) {
- mem_cgroup_uncharge_page(page);
- put_page(page);
+ if (unlikely(!pgtable))
return VM_FAULT_OOM;
- }
clear_huge_page(page, haddr, HPAGE_PMD_NR);
__SetPageUptodate(page);
pte_free(mm, pgtable);
} else {
pmd_t entry;
- entry = mk_pmd(page, vma->vm_page_prot);
- entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
- entry = pmd_mkhuge(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
*/
page_add_new_anon_rmap(page, vma, haddr);
set_pmd_at(mm, haddr, pmd, entry);
- prepare_pmd_huge_pte(pgtable, mm);
+ pgtable_trans_huge_deposit(mm, pgtable);
add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
+ mm->nr_ptes++;
spin_unlock(&mm->page_table_lock);
}
- return ret;
+ return 0;
}
static inline gfp_t alloc_hugepage_gfpmask(int defrag, gfp_t extra_gfp)
put_page(page);
goto out;
}
+ if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd,
+ page))) {
+ mem_cgroup_uncharge_page(page);
+ put_page(page);
+ goto out;
+ }
- return __do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page);
+ return 0;
}
out:
/*
pmdp_set_wrprotect(src_mm, addr, src_pmd);
pmd = pmd_mkold(pmd_wrprotect(pmd));
set_pmd_at(dst_mm, addr, dst_pmd, pmd);
- prepare_pmd_huge_pte(pgtable, dst_mm);
+ pgtable_trans_huge_deposit(dst_mm, pgtable);
+ dst_mm->nr_ptes++;
ret = 0;
out_unlock:
return ret;
}
-/* no "address" argument so destroys page coloring of some arch */
-pgtable_t get_pmd_huge_pte(struct mm_struct *mm)
+void huge_pmd_set_accessed(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long address,
+ pmd_t *pmd, pmd_t orig_pmd,
+ int dirty)
{
- pgtable_t pgtable;
+ pmd_t entry;
+ unsigned long haddr;
- assert_spin_locked(&mm->page_table_lock);
+ spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_same(*pmd, orig_pmd)))
+ goto unlock;
- /* FIFO */
- pgtable = mm->pmd_huge_pte;
- if (list_empty(&pgtable->lru))
- mm->pmd_huge_pte = NULL;
- else {
- mm->pmd_huge_pte = list_entry(pgtable->lru.next,
- struct page, lru);
- list_del(&pgtable->lru);
- }
- return pgtable;
+ entry = pmd_mkyoung(orig_pmd);
+ haddr = address & HPAGE_PMD_MASK;
+ if (pmdp_set_access_flags(vma, haddr, pmd, entry, dirty))
+ update_mmu_cache_pmd(vma, address, pmd);
+
+unlock:
+ spin_unlock(&mm->page_table_lock);
}
static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
pmd_t _pmd;
int ret = 0, i;
struct page **pages;
+ unsigned long mmun_start; /* For mmu_notifiers */
+ unsigned long mmun_end; /* For mmu_notifiers */
pages = kmalloc(sizeof(struct page *) * HPAGE_PMD_NR,
GFP_KERNEL);
cond_resched();
}
+ mmun_start = haddr;
+ mmun_end = haddr + HPAGE_PMD_SIZE;
+ 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_pages;
VM_BUG_ON(!PageHead(page));
- pmdp_clear_flush_notify(vma, haddr, pmd);
+ pmdp_clear_flush(vma, haddr, pmd);
/* leave pmd empty until pte is filled */
- pgtable = get_pmd_huge_pte(mm);
+ pgtable = pgtable_trans_huge_withdraw(mm);
pmd_populate(mm, &_pmd, pgtable);
for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
}
kfree(pages);
- mm->nr_ptes++;
smp_wmb(); /* make pte visible before pmd */
pmd_populate(mm, pmd, pgtable);
page_remove_rmap(page);
spin_unlock(&mm->page_table_lock);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+
ret |= VM_FAULT_WRITE;
put_page(page);
out_free_pages:
spin_unlock(&mm->page_table_lock);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
mem_cgroup_uncharge_start();
for (i = 0; i < HPAGE_PMD_NR; i++) {
mem_cgroup_uncharge_page(pages[i]);
int ret = 0;
struct page *page, *new_page;
unsigned long haddr;
+ unsigned long mmun_start; /* For mmu_notifiers */
+ unsigned long mmun_end; /* For mmu_notifiers */
VM_BUG_ON(!vma->anon_vma);
spin_lock(&mm->page_table_lock);
entry = pmd_mkyoung(orig_pmd);
entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
if (pmdp_set_access_flags(vma, haddr, pmd, entry, 1))
- update_mmu_cache(vma, address, entry);
+ update_mmu_cache_pmd(vma, address, pmd);
ret |= VM_FAULT_WRITE;
goto out_unlock;
}
count_vm_event(THP_FAULT_FALLBACK);
ret = do_huge_pmd_wp_page_fallback(mm, vma, address,
pmd, orig_pmd, page, haddr);
+ if (ret & VM_FAULT_OOM)
+ split_huge_page(page);
put_page(page);
goto out;
}
if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
put_page(new_page);
+ split_huge_page(page);
put_page(page);
ret |= VM_FAULT_OOM;
goto out;
copy_user_huge_page(new_page, page, haddr, vma, HPAGE_PMD_NR);
__SetPageUptodate(new_page);
+ mmun_start = haddr;
+ mmun_end = haddr + HPAGE_PMD_SIZE;
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+
spin_lock(&mm->page_table_lock);
put_page(page);
if (unlikely(!pmd_same(*pmd, orig_pmd))) {
+ spin_unlock(&mm->page_table_lock);
mem_cgroup_uncharge_page(new_page);
put_page(new_page);
+ goto out_mn;
} else {
pmd_t entry;
VM_BUG_ON(!PageHead(page));
- entry = mk_pmd(new_page, vma->vm_page_prot);
- entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
- entry = pmd_mkhuge(entry);
- pmdp_clear_flush_notify(vma, haddr, pmd);
+ entry = mk_huge_pmd(new_page, vma);
+ pmdp_clear_flush(vma, haddr, pmd);
page_add_new_anon_rmap(new_page, vma, haddr);
set_pmd_at(mm, haddr, pmd, entry);
- update_mmu_cache(vma, address, entry);
+ update_mmu_cache_pmd(vma, address, pmd);
page_remove_rmap(page);
put_page(page);
ret |= VM_FAULT_WRITE;
}
-out_unlock:
spin_unlock(&mm->page_table_lock);
+out_mn:
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
out:
return ret;
+out_unlock:
+ spin_unlock(&mm->page_table_lock);
+ return ret;
}
-struct page *follow_trans_huge_pmd(struct mm_struct *mm,
+struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
unsigned long addr,
pmd_t *pmd,
unsigned int flags)
{
+ struct mm_struct *mm = vma->vm_mm;
struct page *page = NULL;
assert_spin_locked(&mm->page_table_lock);
_pmd = pmd_mkyoung(pmd_mkdirty(*pmd));
set_pmd_at(mm, addr & HPAGE_PMD_MASK, pmd, _pmd);
}
+ if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) {
+ if (page->mapping && trylock_page(page)) {
+ lru_add_drain();
+ if (page->mapping)
+ mlock_vma_page(page);
+ unlock_page(page);
+ }
+ }
page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT;
VM_BUG_ON(!PageCompound(page));
if (flags & FOLL_GET)
{
int ret = 0;
- spin_lock(&tlb->mm->page_table_lock);
- if (likely(pmd_trans_huge(*pmd))) {
- if (unlikely(pmd_trans_splitting(*pmd))) {
- spin_unlock(&tlb->mm->page_table_lock);
- wait_split_huge_page(vma->anon_vma,
- pmd);
- } else {
- struct page *page;
- pgtable_t pgtable;
- pgtable = get_pmd_huge_pte(tlb->mm);
- page = pmd_page(*pmd);
- pmd_clear(pmd);
- tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
- page_remove_rmap(page);
- VM_BUG_ON(page_mapcount(page) < 0);
- add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
- VM_BUG_ON(!PageHead(page));
- spin_unlock(&tlb->mm->page_table_lock);
- tlb_remove_page(tlb, page);
- pte_free(tlb->mm, pgtable);
- ret = 1;
- }
- } else
+ if (__pmd_trans_huge_lock(pmd, vma) == 1) {
+ struct page *page;
+ pgtable_t pgtable;
+ pmd_t orig_pmd;
+ pgtable = pgtable_trans_huge_withdraw(tlb->mm);
+ orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd);
+ page = pmd_page(orig_pmd);
+ tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
+ page_remove_rmap(page);
+ VM_BUG_ON(page_mapcount(page) < 0);
+ add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
+ VM_BUG_ON(!PageHead(page));
+ tlb->mm->nr_ptes--;
spin_unlock(&tlb->mm->page_table_lock);
-
+ tlb_remove_page(tlb, page);
+ pte_free(tlb->mm, pgtable);
+ ret = 1;
+ }
return ret;
}
{
int ret = 0;
- spin_lock(&vma->vm_mm->page_table_lock);
- if (likely(pmd_trans_huge(*pmd))) {
- ret = !pmd_trans_splitting(*pmd);
- spin_unlock(&vma->vm_mm->page_table_lock);
- if (unlikely(!ret))
- wait_split_huge_page(vma->anon_vma, pmd);
- else {
- /*
- * All logical pages in the range are present
- * if backed by a huge page.
- */
- memset(vec, 1, (end - addr) >> PAGE_SHIFT);
- }
- } else
+ if (__pmd_trans_huge_lock(pmd, vma) == 1) {
+ /*
+ * All logical pages in the range are present
+ * if backed by a huge page.
+ */
spin_unlock(&vma->vm_mm->page_table_lock);
+ memset(vec, 1, (end - addr) >> PAGE_SHIFT);
+ ret = 1;
+ }
return ret;
}
goto out;
}
- spin_lock(&mm->page_table_lock);
- if (likely(pmd_trans_huge(*old_pmd))) {
- if (pmd_trans_splitting(*old_pmd)) {
- spin_unlock(&mm->page_table_lock);
- wait_split_huge_page(vma->anon_vma, old_pmd);
- ret = -1;
- } else {
- pmd = pmdp_get_and_clear(mm, old_addr, old_pmd);
- VM_BUG_ON(!pmd_none(*new_pmd));
- set_pmd_at(mm, new_addr, new_pmd, pmd);
- spin_unlock(&mm->page_table_lock);
- ret = 1;
- }
- } else {
+ ret = __pmd_trans_huge_lock(old_pmd, vma);
+ if (ret == 1) {
+ pmd = pmdp_get_and_clear(mm, old_addr, old_pmd);
+ VM_BUG_ON(!pmd_none(*new_pmd));
+ set_pmd_at(mm, new_addr, new_pmd, pmd);
spin_unlock(&mm->page_table_lock);
}
out:
struct mm_struct *mm = vma->vm_mm;
int ret = 0;
- spin_lock(&mm->page_table_lock);
+ if (__pmd_trans_huge_lock(pmd, vma) == 1) {
+ pmd_t entry;
+ entry = pmdp_get_and_clear(mm, addr, pmd);
+ entry = pmd_modify(entry, newprot);
+ set_pmd_at(mm, addr, pmd, entry);
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ ret = 1;
+ }
+
+ return ret;
+}
+
+/*
+ * Returns 1 if a given pmd maps a stable (not under splitting) thp.
+ * Returns -1 if it maps a thp under splitting. Returns 0 otherwise.
+ *
+ * Note that if it returns 1, this routine returns without unlocking page
+ * table locks. So callers must unlock them.
+ */
+int __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma)
+{
+ spin_lock(&vma->vm_mm->page_table_lock);
if (likely(pmd_trans_huge(*pmd))) {
if (unlikely(pmd_trans_splitting(*pmd))) {
- spin_unlock(&mm->page_table_lock);
+ spin_unlock(&vma->vm_mm->page_table_lock);
wait_split_huge_page(vma->anon_vma, pmd);
+ return -1;
} else {
- pmd_t entry;
-
- entry = pmdp_get_and_clear(mm, addr, pmd);
- entry = pmd_modify(entry, newprot);
- set_pmd_at(mm, addr, pmd, entry);
- spin_unlock(&vma->vm_mm->page_table_lock);
- ret = 1;
+ /* Thp mapped by 'pmd' is stable, so we can
+ * handle it as it is. */
+ return 1;
}
- } else
- spin_unlock(&vma->vm_mm->page_table_lock);
-
- return ret;
+ }
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ return 0;
}
pmd_t *page_check_address_pmd(struct page *page,
unsigned long address,
enum page_check_address_pmd_flag flag)
{
- pgd_t *pgd;
- pud_t *pud;
pmd_t *pmd, *ret = NULL;
if (address & ~HPAGE_PMD_MASK)
goto out;
- pgd = pgd_offset(mm, address);
- if (!pgd_present(*pgd))
+ pmd = mm_find_pmd(mm, address);
+ if (!pmd)
goto out;
-
- pud = pud_offset(pgd, address);
- if (!pud_present(*pud))
- goto out;
-
- pmd = pmd_offset(pud, address);
if (pmd_none(*pmd))
goto out;
if (pmd_page(*pmd) != page)
struct mm_struct *mm = vma->vm_mm;
pmd_t *pmd;
int ret = 0;
+ /* For mmu_notifiers */
+ const unsigned long mmun_start = address;
+ const unsigned long mmun_end = address + HPAGE_PMD_SIZE;
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
spin_lock(&mm->page_table_lock);
pmd = page_check_address_pmd(page, mm, address,
PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG);
* and it won't wait on the anon_vma->root->mutex to
* serialize against split_huge_page*.
*/
- pmdp_splitting_flush_notify(vma, address, pmd);
+ pmdp_splitting_flush(vma, address, pmd);
ret = 1;
}
spin_unlock(&mm->page_table_lock);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
return ret;
}
{
int i;
struct zone *zone = page_zone(page);
+ struct lruvec *lruvec;
int tail_count = 0;
/* prevent PageLRU to go away from under us, and freeze lru stats */
spin_lock_irq(&zone->lru_lock);
+ lruvec = mem_cgroup_page_lruvec(page, zone);
+
compound_lock(page);
/* complete memcg works before add pages to LRU */
mem_cgroup_split_huge_fixup(page);
BUG_ON(!PageDirty(page_tail));
BUG_ON(!PageSwapBacked(page_tail));
-
- lru_add_page_tail(zone, page, page_tail);
+ lru_add_page_tail(page, page_tail, lruvec);
}
atomic_sub(tail_count, &page->_count);
BUG_ON(atomic_read(&page->_count) <= 0);
- __dec_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
+ __mod_zone_page_state(zone, NR_ANON_TRANSPARENT_HUGEPAGES, -1);
__mod_zone_page_state(zone, NR_ANON_PAGES, HPAGE_PMD_NR);
ClearPageCompound(page);
pmd = page_check_address_pmd(page, mm, address,
PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG);
if (pmd) {
- pgtable = get_pmd_huge_pte(mm);
+ pgtable = pgtable_trans_huge_withdraw(mm);
pmd_populate(mm, &_pmd, pgtable);
- for (i = 0, haddr = address; i < HPAGE_PMD_NR;
- i++, haddr += PAGE_SIZE) {
+ haddr = address;
+ for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
pte_t *pte, entry;
BUG_ON(PageCompound(page+i));
entry = mk_pte(page + i, vma->vm_page_prot);
pte_unmap(pte);
}
- mm->nr_ptes++;
smp_wmb(); /* make pte visible before pmd */
/*
* Up to this point the pmd is present and huge and
* SMP TLB and finally we write the non-huge version
* of the pmd entry with pmd_populate.
*/
- set_pmd_at(mm, address, pmd, pmd_mknotpresent(*pmd));
- flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+ pmdp_invalidate(vma, address, pmd);
pmd_populate(mm, pmd, pgtable);
ret = 1;
}
struct anon_vma *anon_vma)
{
int mapcount, mapcount2;
+ pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
struct anon_vma_chain *avc;
BUG_ON(!PageHead(page));
BUG_ON(PageTail(page));
mapcount = 0;
- list_for_each_entry(avc, &anon_vma->head, same_anon_vma) {
+ anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
struct vm_area_struct *vma = avc->vma;
unsigned long addr = vma_address(page, vma);
BUG_ON(is_vma_temporary_stack(vma));
- if (addr == -EFAULT)
- continue;
mapcount += __split_huge_page_splitting(page, vma, addr);
}
/*
__split_huge_page_refcount(page);
mapcount2 = 0;
- list_for_each_entry(avc, &anon_vma->head, same_anon_vma) {
+ anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
struct vm_area_struct *vma = avc->vma;
unsigned long addr = vma_address(page, vma);
BUG_ON(is_vma_temporary_stack(vma));
- if (addr == -EFAULT)
- continue;
mapcount2 += __split_huge_page_map(page, vma, addr);
}
if (mapcount != mapcount2)
return ret;
}
-#define VM_NO_THP (VM_SPECIAL|VM_INSERTPAGE|VM_MIXEDMAP|VM_SAO| \
- VM_HUGETLB|VM_SHARED|VM_MAYSHARE)
+#define VM_NO_THP (VM_SPECIAL|VM_MIXEDMAP|VM_HUGETLB|VM_SHARED|VM_MAYSHARE)
int hugepage_madvise(struct vm_area_struct *vma,
unsigned long *vm_flags, int advice)
{
+ struct mm_struct *mm = vma->vm_mm;
+
switch (advice) {
case MADV_HUGEPAGE:
/*
*/
if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP))
return -EINVAL;
+ if (mm->def_flags & VM_NOHUGEPAGE)
+ return -EINVAL;
*vm_flags &= ~VM_NOHUGEPAGE;
*vm_flags |= VM_HUGEPAGE;
/*
if (vma->vm_ops)
/* khugepaged not yet working on file or special mappings */
return 0;
- /*
- * If is_pfn_mapping() is true is_learn_pfn_mapping() must be
- * true too, verify it here.
- */
- VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP);
+ VM_BUG_ON(vma->vm_flags & VM_NO_THP);
hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
hend = vma->vm_end & HPAGE_PMD_MASK;
if (hstart < hend)
}
}
-static void release_all_pte_pages(pte_t *pte)
-{
- release_pte_pages(pte, pte + HPAGE_PMD_NR);
-}
-
static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
unsigned long address,
pte_t *pte)
{
struct page *page;
pte_t *_pte;
- int referenced = 0, isolated = 0, none = 0;
+ int referenced = 0, none = 0;
for (_pte = pte; _pte < pte+HPAGE_PMD_NR;
_pte++, address += PAGE_SIZE) {
pte_t pteval = *_pte;
if (pte_none(pteval)) {
if (++none <= khugepaged_max_ptes_none)
continue;
- else {
- release_pte_pages(pte, _pte);
+ else
goto out;
- }
}
- if (!pte_present(pteval) || !pte_write(pteval)) {
- release_pte_pages(pte, _pte);
+ if (!pte_present(pteval) || !pte_write(pteval))
goto out;
- }
page = vm_normal_page(vma, address, pteval);
- if (unlikely(!page)) {
- release_pte_pages(pte, _pte);
+ if (unlikely(!page))
goto out;
- }
+
VM_BUG_ON(PageCompound(page));
BUG_ON(!PageAnon(page));
VM_BUG_ON(!PageSwapBacked(page));
/* cannot use mapcount: can't collapse if there's a gup pin */
- if (page_count(page) != 1) {
- release_pte_pages(pte, _pte);
+ if (page_count(page) != 1)
goto out;
- }
/*
* We can do it before isolate_lru_page because the
* page can't be freed from under us. NOTE: PG_lock
* is needed to serialize against split_huge_page
* when invoked from the VM.
*/
- if (!trylock_page(page)) {
- release_pte_pages(pte, _pte);
+ if (!trylock_page(page))
goto out;
- }
/*
* Isolate the page to avoid collapsing an hugepage
* currently in use by the VM.
*/
if (isolate_lru_page(page)) {
unlock_page(page);
- release_pte_pages(pte, _pte);
goto out;
}
/* 0 stands for page_is_file_cache(page) == false */
mmu_notifier_test_young(vma->vm_mm, address))
referenced = 1;
}
- if (unlikely(!referenced))
- release_all_pte_pages(pte);
- else
- isolated = 1;
+ if (likely(referenced))
+ return 1;
out:
- return isolated;
+ release_pte_pages(pte, _pte);
+ return 0;
}
static void __collapse_huge_page_copy(pte_t *pte, struct page *page,
src_page = pte_page(pteval);
copy_user_highpage(page, src_page, address, vma);
VM_BUG_ON(page_mapcount(src_page) != 1);
- VM_BUG_ON(page_count(src_page) != 2);
release_pte_page(src_page);
/*
* ptl mostly unnecessary, but preempt has to
}
}
-static void collapse_huge_page(struct mm_struct *mm,
- unsigned long address,
- struct page **hpage,
- struct vm_area_struct *vma,
- int node)
+static void khugepaged_alloc_sleep(void)
{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd, _pmd;
- pte_t *pte;
- pgtable_t pgtable;
- struct page *new_page;
- spinlock_t *ptl;
- int isolated;
- unsigned long hstart, hend;
+ wait_event_freezable_timeout(khugepaged_wait, false,
+ msecs_to_jiffies(khugepaged_alloc_sleep_millisecs));
+}
- VM_BUG_ON(address & ~HPAGE_PMD_MASK);
-#ifndef CONFIG_NUMA
- up_read(&mm->mmap_sem);
- VM_BUG_ON(!*hpage);
- new_page = *hpage;
-#else
+#ifdef CONFIG_NUMA
+static bool khugepaged_prealloc_page(struct page **hpage, bool *wait)
+{
+ if (IS_ERR(*hpage)) {
+ if (!*wait)
+ return false;
+
+ *wait = false;
+ *hpage = NULL;
+ khugepaged_alloc_sleep();
+ } else if (*hpage) {
+ put_page(*hpage);
+ *hpage = NULL;
+ }
+
+ return true;
+}
+
+static struct page
+*khugepaged_alloc_page(struct page **hpage, struct mm_struct *mm,
+ struct vm_area_struct *vma, unsigned long address,
+ int node)
+{
VM_BUG_ON(*hpage);
/*
* Allocate the page while the vma is still valid and under
* mmap_sem in read mode is good idea also to allow greater
* scalability.
*/
- new_page = alloc_hugepage_vma(khugepaged_defrag(), vma, address,
+ *hpage = alloc_hugepage_vma(khugepaged_defrag(), vma, address,
node, __GFP_OTHER_NODE);
/*
* preparation for taking it in write mode.
*/
up_read(&mm->mmap_sem);
- if (unlikely(!new_page)) {
+ if (unlikely(!*hpage)) {
count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
*hpage = ERR_PTR(-ENOMEM);
- return;
+ return NULL;
}
-#endif
count_vm_event(THP_COLLAPSE_ALLOC);
- if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
-#ifdef CONFIG_NUMA
- put_page(new_page);
+ return *hpage;
+}
+#else
+static struct page *khugepaged_alloc_hugepage(bool *wait)
+{
+ struct page *hpage;
+
+ do {
+ hpage = alloc_hugepage(khugepaged_defrag());
+ if (!hpage) {
+ count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
+ if (!*wait)
+ return NULL;
+
+ *wait = false;
+ khugepaged_alloc_sleep();
+ } else
+ count_vm_event(THP_COLLAPSE_ALLOC);
+ } while (unlikely(!hpage) && likely(khugepaged_enabled()));
+
+ return hpage;
+}
+
+static bool khugepaged_prealloc_page(struct page **hpage, bool *wait)
+{
+ if (!*hpage)
+ *hpage = khugepaged_alloc_hugepage(wait);
+
+ if (unlikely(!*hpage))
+ return false;
+
+ return true;
+}
+
+static struct page
+*khugepaged_alloc_page(struct page **hpage, struct mm_struct *mm,
+ struct vm_area_struct *vma, unsigned long address,
+ int node)
+{
+ up_read(&mm->mmap_sem);
+ VM_BUG_ON(!*hpage);
+ return *hpage;
+}
#endif
+
+static bool hugepage_vma_check(struct vm_area_struct *vma)
+{
+ if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) ||
+ (vma->vm_flags & VM_NOHUGEPAGE))
+ return false;
+
+ if (!vma->anon_vma || vma->vm_ops)
+ return false;
+ if (is_vma_temporary_stack(vma))
+ return false;
+ VM_BUG_ON(vma->vm_flags & VM_NO_THP);
+ return true;
+}
+
+static void collapse_huge_page(struct mm_struct *mm,
+ unsigned long address,
+ struct page **hpage,
+ struct vm_area_struct *vma,
+ int node)
+{
+ pmd_t *pmd, _pmd;
+ pte_t *pte;
+ pgtable_t pgtable;
+ struct page *new_page;
+ spinlock_t *ptl;
+ int isolated;
+ unsigned long hstart, hend;
+ unsigned long mmun_start; /* For mmu_notifiers */
+ unsigned long mmun_end; /* For mmu_notifiers */
+
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+
+ /* release the mmap_sem read lock. */
+ new_page = khugepaged_alloc_page(hpage, mm, vma, address, node);
+ if (!new_page)
+ return;
+
+ if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL)))
return;
- }
/*
* Prevent all access to pagetables with the exception of
hend = vma->vm_end & HPAGE_PMD_MASK;
if (address < hstart || address + HPAGE_PMD_SIZE > hend)
goto out;
-
- if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) ||
- (vma->vm_flags & VM_NOHUGEPAGE))
+ if (!hugepage_vma_check(vma))
goto out;
-
- if (!vma->anon_vma || vma->vm_ops)
+ pmd = mm_find_pmd(mm, address);
+ if (!pmd)
goto out;
- if (is_vma_temporary_stack(vma))
- goto out;
- /*
- * If is_pfn_mapping() is true is_learn_pfn_mapping() must be
- * true too, verify it here.
- */
- VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP);
-
- pgd = pgd_offset(mm, address);
- if (!pgd_present(*pgd))
- goto out;
-
- pud = pud_offset(pgd, address);
- if (!pud_present(*pud))
- goto out;
-
- pmd = pmd_offset(pud, address);
- /* pmd can't go away or become huge under us */
- if (!pmd_present(*pmd) || pmd_trans_huge(*pmd))
+ if (pmd_trans_huge(*pmd))
goto out;
anon_vma_lock(vma->anon_vma);
pte = pte_offset_map(pmd, address);
ptl = pte_lockptr(mm, pmd);
+ mmun_start = address;
+ mmun_end = address + HPAGE_PMD_SIZE;
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
spin_lock(&mm->page_table_lock); /* probably unnecessary */
/*
* After this gup_fast can't run anymore. This also removes
* huge and small TLB entries for the same virtual address
* to avoid the risk of CPU bugs in that area.
*/
- _pmd = pmdp_clear_flush_notify(vma, address, pmd);
+ _pmd = pmdp_clear_flush(vma, address, pmd);
spin_unlock(&mm->page_table_lock);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
spin_lock(ptl);
isolated = __collapse_huge_page_isolate(vma, address, pte);
pte_unmap(pte);
__SetPageUptodate(new_page);
pgtable = pmd_pgtable(_pmd);
- VM_BUG_ON(page_count(pgtable) != 1);
- VM_BUG_ON(page_mapcount(pgtable) != 0);
- _pmd = mk_pmd(new_page, vma->vm_page_prot);
- _pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma);
- _pmd = pmd_mkhuge(_pmd);
+ _pmd = mk_huge_pmd(new_page, vma);
/*
* spin_lock() below is not the equivalent of smp_wmb(), so
BUG_ON(!pmd_none(*pmd));
page_add_new_anon_rmap(new_page, vma, address);
set_pmd_at(mm, address, pmd, _pmd);
- update_mmu_cache(vma, address, _pmd);
- prepare_pmd_huge_pte(pgtable, mm);
- mm->nr_ptes--;
+ update_mmu_cache_pmd(vma, address, pmd);
+ pgtable_trans_huge_deposit(mm, pgtable);
spin_unlock(&mm->page_table_lock);
-#ifndef CONFIG_NUMA
*hpage = NULL;
-#endif
+
khugepaged_pages_collapsed++;
out_up_write:
up_write(&mm->mmap_sem);
out:
mem_cgroup_uncharge_page(new_page);
-#ifdef CONFIG_NUMA
- put_page(new_page);
-#endif
goto out_up_write;
}
unsigned long address,
struct page **hpage)
{
- pgd_t *pgd;
- pud_t *pud;
pmd_t *pmd;
pte_t *pte, *_pte;
int ret = 0, referenced = 0, none = 0;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
- pgd = pgd_offset(mm, address);
- if (!pgd_present(*pgd))
+ pmd = mm_find_pmd(mm, address);
+ if (!pmd)
goto out;
-
- pud = pud_offset(pgd, address);
- if (!pud_present(*pud))
- goto out;
-
- pmd = pmd_offset(pud, address);
- if (!pmd_present(*pmd) || pmd_trans_huge(*pmd))
+ if (pmd_trans_huge(*pmd))
goto out;
pte = pte_offset_map_lock(mm, pmd, address, &ptl);
progress++;
break;
}
-
- if ((!(vma->vm_flags & VM_HUGEPAGE) &&
- !khugepaged_always()) ||
- (vma->vm_flags & VM_NOHUGEPAGE)) {
- skip:
+ if (!hugepage_vma_check(vma)) {
+skip:
progress++;
continue;
}
- if (!vma->anon_vma || vma->vm_ops)
- goto skip;
- if (is_vma_temporary_stack(vma))
- goto skip;
- /*
- * If is_pfn_mapping() is true is_learn_pfn_mapping()
- * must be true too, verify it here.
- */
- VM_BUG_ON(is_linear_pfn_mapping(vma) ||
- vma->vm_flags & VM_NO_THP);
-
hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
hend = vma->vm_end & HPAGE_PMD_MASK;
if (hstart >= hend)
static int khugepaged_wait_event(void)
{
return !list_empty(&khugepaged_scan.mm_head) ||
- !khugepaged_enabled();
+ kthread_should_stop();
}
-static void khugepaged_do_scan(struct page **hpage)
+static void khugepaged_do_scan(void)
{
+ struct page *hpage = NULL;
unsigned int progress = 0, pass_through_head = 0;
unsigned int pages = khugepaged_pages_to_scan;
+ bool wait = true;
barrier(); /* write khugepaged_pages_to_scan to local stack */
while (progress < pages) {
- cond_resched();
-
-#ifndef CONFIG_NUMA
- if (!*hpage) {
- *hpage = alloc_hugepage(khugepaged_defrag());
- if (unlikely(!*hpage)) {
- count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
- break;
- }
- count_vm_event(THP_COLLAPSE_ALLOC);
- }
-#else
- if (IS_ERR(*hpage))
+ if (!khugepaged_prealloc_page(&hpage, &wait))
break;
-#endif
+
+ cond_resched();
if (unlikely(kthread_should_stop() || freezing(current)))
break;
if (khugepaged_has_work() &&
pass_through_head < 2)
progress += khugepaged_scan_mm_slot(pages - progress,
- hpage);
+ &hpage);
else
progress = pages;
spin_unlock(&khugepaged_mm_lock);
}
-}
-
-static void khugepaged_alloc_sleep(void)
-{
- wait_event_freezable_timeout(khugepaged_wait, false,
- msecs_to_jiffies(khugepaged_alloc_sleep_millisecs));
-}
-
-#ifndef CONFIG_NUMA
-static struct page *khugepaged_alloc_hugepage(void)
-{
- struct page *hpage;
- do {
- hpage = alloc_hugepage(khugepaged_defrag());
- if (!hpage) {
- count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
- khugepaged_alloc_sleep();
- } else
- count_vm_event(THP_COLLAPSE_ALLOC);
- } while (unlikely(!hpage) &&
- likely(khugepaged_enabled()));
- return hpage;
+ if (!IS_ERR_OR_NULL(hpage))
+ put_page(hpage);
}
-#endif
-static void khugepaged_loop(void)
+static void khugepaged_wait_work(void)
{
- struct page *hpage;
+ try_to_freeze();
-#ifdef CONFIG_NUMA
- hpage = NULL;
-#endif
- while (likely(khugepaged_enabled())) {
-#ifndef CONFIG_NUMA
- hpage = khugepaged_alloc_hugepage();
- if (unlikely(!hpage))
- break;
-#else
- if (IS_ERR(hpage)) {
- khugepaged_alloc_sleep();
- hpage = NULL;
- }
-#endif
+ if (khugepaged_has_work()) {
+ if (!khugepaged_scan_sleep_millisecs)
+ return;
- khugepaged_do_scan(&hpage);
-#ifndef CONFIG_NUMA
- if (hpage)
- put_page(hpage);
-#endif
- try_to_freeze();
- if (unlikely(kthread_should_stop()))
- break;
- if (khugepaged_has_work()) {
- if (!khugepaged_scan_sleep_millisecs)
- continue;
- wait_event_freezable_timeout(khugepaged_wait, false,
- msecs_to_jiffies(khugepaged_scan_sleep_millisecs));
- } else if (khugepaged_enabled())
- wait_event_freezable(khugepaged_wait,
- khugepaged_wait_event());
+ wait_event_freezable_timeout(khugepaged_wait,
+ kthread_should_stop(),
+ msecs_to_jiffies(khugepaged_scan_sleep_millisecs));
+ return;
}
+
+ if (khugepaged_enabled())
+ wait_event_freezable(khugepaged_wait, khugepaged_wait_event());
}
static int khugepaged(void *none)
set_freezable();
set_user_nice(current, 19);
- /* serialize with start_khugepaged() */
- mutex_lock(&khugepaged_mutex);
-
- for (;;) {
- mutex_unlock(&khugepaged_mutex);
- VM_BUG_ON(khugepaged_thread != current);
- khugepaged_loop();
- VM_BUG_ON(khugepaged_thread != current);
-
- mutex_lock(&khugepaged_mutex);
- if (!khugepaged_enabled())
- break;
- if (unlikely(kthread_should_stop()))
- break;
+ while (!kthread_should_stop()) {
+ khugepaged_do_scan();
+ khugepaged_wait_work();
}
spin_lock(&khugepaged_mm_lock);
if (mm_slot)
collect_mm_slot(mm_slot);
spin_unlock(&khugepaged_mm_lock);
-
- khugepaged_thread = NULL;
- mutex_unlock(&khugepaged_mutex);
-
return 0;
}
static void split_huge_page_address(struct mm_struct *mm,
unsigned long address)
{
- pgd_t *pgd;
- pud_t *pud;
pmd_t *pmd;
VM_BUG_ON(!(address & ~HPAGE_PMD_MASK));
- pgd = pgd_offset(mm, address);
- if (!pgd_present(*pgd))
- return;
-
- pud = pud_offset(pgd, address);
- if (!pud_present(*pud))
- return;
-
- pmd = pmd_offset(pud, address);
- if (!pmd_present(*pmd))
+ pmd = mm_find_pmd(mm, address);
+ if (!pmd)
return;
/*
* Caller holds the mmap_sem write mode, so a huge pmd cannot