BUG_ON(atomic_dec_and_test(&huge_zero_refcount));
}
-static int shrink_huge_zero_page(struct shrinker *shrink,
- struct shrink_control *sc)
+static unsigned long shrink_huge_zero_page_count(struct shrinker *shrink,
+ struct shrink_control *sc)
{
- 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;
+ /* we can free zero page only if last reference remains */
+ return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0;
+}
+static unsigned long shrink_huge_zero_page_scan(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
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 HPAGE_PMD_NR;
}
return 0;
}
static struct shrinker huge_zero_page_shrinker = {
- .shrink = shrink_huge_zero_page,
+ .count_objects = shrink_huge_zero_page_count,
+ .scan_objects = shrink_huge_zero_page_scan,
.seeks = DEFAULT_SEEKS,
};
unsigned long msecs;
int err;
- err = strict_strtoul(buf, 10, &msecs);
+ err = kstrtoul(buf, 10, &msecs);
if (err || msecs > UINT_MAX)
return -EINVAL;
unsigned long msecs;
int err;
- err = strict_strtoul(buf, 10, &msecs);
+ err = kstrtoul(buf, 10, &msecs);
if (err || msecs > UINT_MAX)
return -EINVAL;
int err;
unsigned long pages;
- err = strict_strtoul(buf, 10, &pages);
+ err = kstrtoul(buf, 10, &pages);
if (err || !pages || pages > UINT_MAX)
return -EINVAL;
int err;
unsigned long max_ptes_none;
- err = strict_strtoul(buf, 10, &max_ptes_none);
+ err = kstrtoul(buf, 10, &max_ptes_none);
if (err || max_ptes_none > HPAGE_PMD_NR-1)
return -EINVAL;
return pmd;
}
-static inline pmd_t mk_huge_pmd(struct page *page, struct vm_area_struct *vma)
+static inline pmd_t mk_huge_pmd(struct page *page, pgprot_t prot)
{
pmd_t entry;
- entry = mk_pmd(page, vma->vm_page_prot);
- entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+ entry = mk_pmd(page, prot);
entry = pmd_mkhuge(entry);
return entry;
}
pte_free(mm, pgtable);
} else {
pmd_t entry;
- entry = mk_huge_pmd(page, vma);
+ entry = mk_huge_pmd(page, vma->vm_page_prot);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
page_add_new_anon_rmap(page, vma, haddr);
pgtable_trans_huge_deposit(mm, pmd, pgtable);
set_pmd_at(mm, haddr, pmd, entry);
{
struct page *page;
unsigned long haddr = address & HPAGE_PMD_MASK;
- pte_t *pte;
- if (haddr >= vma->vm_start && haddr + HPAGE_PMD_SIZE <= vma->vm_end) {
- if (unlikely(anon_vma_prepare(vma)))
- return VM_FAULT_OOM;
- if (unlikely(khugepaged_enter(vma)))
+ if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end)
+ return VM_FAULT_FALLBACK;
+ if (unlikely(anon_vma_prepare(vma)))
+ return VM_FAULT_OOM;
+ if (unlikely(khugepaged_enter(vma)))
+ return VM_FAULT_OOM;
+ if (!(flags & FAULT_FLAG_WRITE) &&
+ transparent_hugepage_use_zero_page()) {
+ pgtable_t pgtable;
+ struct page *zero_page;
+ bool set;
+ pgtable = pte_alloc_one(mm, haddr);
+ if (unlikely(!pgtable))
return VM_FAULT_OOM;
- if (!(flags & FAULT_FLAG_WRITE) &&
- transparent_hugepage_use_zero_page()) {
- pgtable_t pgtable;
- 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 = 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),
- vma, haddr, numa_node_id(), 0);
- if (unlikely(!page)) {
+ zero_page = get_huge_zero_page();
+ if (unlikely(!zero_page)) {
+ pte_free(mm, pgtable);
count_vm_event(THP_FAULT_FALLBACK);
- goto out;
- }
- count_vm_event(THP_FAULT_ALLOC);
- if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) {
- put_page(page);
- goto out;
+ return VM_FAULT_FALLBACK;
}
- if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd,
- page))) {
- mem_cgroup_uncharge_page(page);
- put_page(page);
- goto out;
+ spin_lock(&mm->page_table_lock);
+ 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;
}
-out:
- /*
- * Use __pte_alloc instead of pte_alloc_map, because we can't
- * run pte_offset_map on the pmd, if an huge pmd could
- * materialize from under us from a different thread.
- */
- 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)))
- return 0;
- /*
- * A regular pmd is established and it can't morph into a huge pmd
- * from under us anymore at this point because we hold the mmap_sem
- * read mode and khugepaged takes it in write mode. So now it's
- * safe to run pte_offset_map().
- */
- pte = pte_offset_map(pmd, address);
- return handle_pte_fault(mm, vma, address, pte, pmd, flags);
+ page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
+ vma, haddr, numa_node_id(), 0);
+ if (unlikely(!page)) {
+ count_vm_event(THP_FAULT_FALLBACK);
+ return VM_FAULT_FALLBACK;
+ }
+ if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) {
+ put_page(page);
+ count_vm_event(THP_FAULT_FALLBACK);
+ return VM_FAULT_FALLBACK;
+ }
+ if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page))) {
+ mem_cgroup_uncharge_page(page);
+ put_page(page);
+ count_vm_event(THP_FAULT_FALLBACK);
+ return VM_FAULT_FALLBACK;
+ }
+
+ count_vm_event(THP_FAULT_ALLOC);
+ return 0;
}
int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
new_page = NULL;
if (unlikely(!new_page)) {
- 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, orig_pmd, haddr);
split_huge_page(page);
put_page(page);
}
+ count_vm_event(THP_FAULT_FALLBACK);
goto out;
}
- count_vm_event(THP_FAULT_ALLOC);
if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
put_page(new_page);
split_huge_page(page);
put_page(page);
}
+ count_vm_event(THP_FAULT_FALLBACK);
ret |= VM_FAULT_OOM;
goto out;
}
+ count_vm_event(THP_FAULT_ALLOC);
+
if (is_huge_zero_pmd(orig_pmd))
clear_huge_page(new_page, haddr, HPAGE_PMD_NR);
else
goto out_mn;
} else {
pmd_t entry;
- entry = mk_huge_pmd(new_page, vma);
+ entry = mk_huge_pmd(new_page, vma->vm_page_prot);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
pmdp_clear_flush(vma, haddr, pmd);
page_add_new_anon_rmap(new_page, vma, haddr);
set_pmd_at(mm, haddr, pmd, entry);
BUG_ON(atomic_read(&page->_count) <= 0);
__mod_zone_page_state(zone, NR_ANON_TRANSPARENT_HUGEPAGES, -1);
- __mod_zone_page_state(zone, NR_ANON_PAGES, HPAGE_PMD_NR);
ClearPageCompound(page);
compound_unlock(page);
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)
__SetPageUptodate(new_page);
pgtable = pmd_pgtable(_pmd);
- _pmd = mk_huge_pmd(new_page, vma);
+ _pmd = mk_huge_pmd(new_page, vma->vm_page_prot);
+ _pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma);
/*
* spin_lock() below is not the equivalent of smp_wmb(), so
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,
projects / deliverable / linux.git / blobdiff