src_page = pmd_page(pmd);
VM_BUG_ON_PAGE(!PageHead(src_page), src_page);
+
+ /*
+ * If this page is a potentially pinned page, split and retry the fault
+ * with smaller page size. Normally this should not happen because the
+ * userspace should use MADV_DONTFORK upon pinned regions. This is a
+ * best effort that the pinned pages won't be replaced by another
+ * random page during the coming copy-on-write.
+ */
+ if (unlikely(is_cow_mapping(vma->vm_flags) &&
+ atomic_read(&src_mm->has_pinned) &&
+ page_maybe_dma_pinned(src_page))) {
+ pte_free(dst_mm, pgtable);
+ spin_unlock(src_ptl);
+ spin_unlock(dst_ptl);
+ __split_huge_pmd(vma, src_pmd, addr, false, NULL);
+ return -EAGAIN;
+ }
+
get_page(src_page);
page_dup_rmap(src_page, true);
add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR);
/* No huge zero pud yet */
}
+ /* Please refer to comments in copy_huge_pmd() */
+ if (unlikely(is_cow_mapping(vma->vm_flags) &&
+ atomic_read(&src_mm->has_pinned) &&
+ page_maybe_dma_pinned(pud_page(pud)))) {
+ spin_unlock(src_ptl);
+ spin_unlock(dst_ptl);
+ __split_huge_pud(vma, src_pud, addr);
+ return -EAGAIN;
+ }
+
pudp_set_wrprotect(src_mm, addr, src_pud);
pud = pud_mkold(pud_wrprotect(pud));
set_pud_at(dst_mm, addr, dst_pud, pud);
put_page(page);
add_mm_counter(mm, mm_counter_file(page), -HPAGE_PMD_NR);
return;
- } else if (is_huge_zero_pmd(*pmd)) {
+ } else if (pmd_trans_huge(*pmd) && is_huge_zero_pmd(*pmd)) {
/*
* FIXME: Do we want to invalidate secondary mmu by calling
* mmu_notifier_invalidate_range() see comments below inside
pte = pte_offset_map(&_pmd, addr);
BUG_ON(!pte_none(*pte));
set_pte_at(mm, addr, pte, entry);
- atomic_inc(&page[i]._mapcount);
- pte_unmap(pte);
- }
-
- /*
- * Set PG_double_map before dropping compound_mapcount to avoid
- * false-negative page_mapped().
- */
- if (compound_mapcount(page) > 1 && !TestSetPageDoubleMap(page)) {
- for (i = 0; i < HPAGE_PMD_NR; i++)
+ if (!pmd_migration)
atomic_inc(&page[i]._mapcount);
+ pte_unmap(pte);
}
- lock_page_memcg(page);
- if (atomic_add_negative(-1, compound_mapcount_ptr(page))) {
- /* Last compound_mapcount is gone. */
- __dec_lruvec_page_state(page, NR_ANON_THPS);
- if (TestClearPageDoubleMap(page)) {
- /* No need in mapcount reference anymore */
+ if (!pmd_migration) {
+ /*
+ * Set PG_double_map before dropping compound_mapcount to avoid
+ * false-negative page_mapped().
+ */
+ if (compound_mapcount(page) > 1 &&
+ !TestSetPageDoubleMap(page)) {
for (i = 0; i < HPAGE_PMD_NR; i++)
- atomic_dec(&page[i]._mapcount);
+ atomic_inc(&page[i]._mapcount);
}
+
+ lock_page_memcg(page);
+ if (atomic_add_negative(-1, compound_mapcount_ptr(page))) {
+ /* Last compound_mapcount is gone. */
+ __dec_lruvec_page_state(page, NR_ANON_THPS);
+ if (TestClearPageDoubleMap(page)) {
+ /* No need in mapcount reference anymore */
+ for (i = 0; i < HPAGE_PMD_NR; i++)
+ atomic_dec(&page[i]._mapcount);
+ }
+ }
+ unlock_page_memcg(page);
}
- unlock_page_memcg(page);
smp_wmb(); /* make pte visible before pmd */
pmd_populate(mm, pmd, pgtable);
/*
* If we're also updating the vma->vm_next->vm_start, if the new
- * vm_next->vm_start isn't page aligned and it could previously
+ * vm_next->vm_start isn't hpage aligned and it could previously
* contain an hugepage: check if we need to split an huge pmd.
*/
if (adjust_next > 0) {
struct vm_area_struct *next = vma->vm_next;
unsigned long nstart = next->vm_start;
- nstart += adjust_next << PAGE_SHIFT;
+ nstart += adjust_next;
if (nstart & ~HPAGE_PMD_MASK &&
(nstart & HPAGE_PMD_MASK) >= next->vm_start &&
(nstart & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= next->vm_end)
VM_BUG_ON_PAGE(!unmap_success, page);
}
-static void remap_page(struct page *page)
+static void remap_page(struct page *page, unsigned int nr)
{
int i;
if (PageTransHuge(page)) {
remove_migration_ptes(page, page, true);
} else {
- for (i = 0; i < HPAGE_PMD_NR; i++)
+ for (i = 0; i < nr; i++)
remove_migration_ptes(page + i, page + i, true);
}
}
(1L << PG_workingset) |
(1L << PG_locked) |
(1L << PG_unevictable) |
+#ifdef CONFIG_64BIT
+ (1L << PG_arch_2) |
+#endif
(1L << PG_dirty)));
/* ->mapping in first tail page is compound_mapcount */
struct lruvec *lruvec;
struct address_space *swap_cache = NULL;
unsigned long offset = 0;
+ unsigned int nr = thp_nr_pages(head);
int i;
lruvec = mem_cgroup_page_lruvec(head, pgdat);
xa_lock(&swap_cache->i_pages);
}
- for (i = HPAGE_PMD_NR - 1; i >= 1; i--) {
+ for (i = nr - 1; i >= 1; i--) {
__split_huge_page_tail(head, i, lruvec, list);
/* Some pages can be beyond i_size: drop them from page cache */
if (head[i].index >= end) {
ClearPageCompound(head);
- split_page_owner(head, HPAGE_PMD_ORDER);
+ split_page_owner(head, nr);
/* See comment in __split_huge_page_tail() */
if (PageAnon(head)) {
spin_unlock_irqrestore(&pgdat->lru_lock, flags);
- remap_page(head);
+ remap_page(head, nr);
+
+ if (PageSwapCache(head)) {
+ swp_entry_t entry = { .val = page_private(head) };
+
+ split_swap_cluster(entry);
+ }
- for (i = 0; i < HPAGE_PMD_NR; i++) {
+ for (i = 0; i < nr; i++) {
struct page *subpage = head + i;
if (subpage == page)
continue;
int total_mapcount(struct page *page)
{
- int i, compound, ret;
+ int i, compound, nr, ret;
VM_BUG_ON_PAGE(PageTail(page), page);
return atomic_read(&page->_mapcount) + 1;
compound = compound_mapcount(page);
+ nr = compound_nr(page);
if (PageHuge(page))
return compound;
ret = compound;
- for (i = 0; i < HPAGE_PMD_NR; i++)
+ for (i = 0; i < nr; i++)
ret += atomic_read(&page[i]._mapcount) + 1;
/* File pages has compound_mapcount included in _mapcount */
if (!PageAnon(page))
- return ret - compound * HPAGE_PMD_NR;
+ return ret - compound * nr;
if (PageDoubleMap(page))
- ret -= HPAGE_PMD_NR;
+ ret -= nr;
return ret;
}
page = compound_head(page);
_total_mapcount = ret = 0;
- for (i = 0; i < HPAGE_PMD_NR; i++) {
+ for (i = 0; i < thp_nr_pages(page); i++) {
mapcount = atomic_read(&page[i]._mapcount) + 1;
ret = max(ret, mapcount);
_total_mapcount += mapcount;
}
if (PageDoubleMap(page)) {
ret -= 1;
- _total_mapcount -= HPAGE_PMD_NR;
+ _total_mapcount -= thp_nr_pages(page);
}
mapcount = compound_mapcount(page);
ret += mapcount;
/* Additional pins from page cache */
if (PageAnon(page))
- extra_pins = PageSwapCache(page) ? HPAGE_PMD_NR : 0;
+ extra_pins = PageSwapCache(page) ? thp_nr_pages(page) : 0;
else
- extra_pins = HPAGE_PMD_NR;
+ extra_pins = thp_nr_pages(page);
if (pextra_pins)
*pextra_pins = extra_pins;
return total_mapcount(page) == page_count(page) - extra_pins - 1;
}
__split_huge_page(page, list, end, flags);
- if (PageSwapCache(head)) {
- swp_entry_t entry = { .val = page_private(head) };
-
- ret = split_swap_cluster(entry);
- } else
- ret = 0;
+ ret = 0;
} else {
if (IS_ENABLED(CONFIG_DEBUG_VM) && mapcount) {
pr_alert("total_mapcount: %u, page_count(): %u\n",
fail: if (mapping)
xa_unlock(&mapping->i_pages);
spin_unlock_irqrestore(&pgdata->lru_lock, flags);
- remap_page(head);
+ remap_page(head, thp_nr_pages(head));
ret = -EBUSY;
}
projects / linux-2.6-microblaze.git / blobdiff