#include <linux/hugetlb_cgroup.h>
#include <linux/gfp.h>
#include <linux/balloon_compaction.h>
+#include <linux/mmu_notifier.h>
#include <asm/tlbflush.h>
*/
int migrate_page_move_mapping(struct address_space *mapping,
struct page *newpage, struct page *page,
- struct buffer_head *head, enum migrate_mode mode)
+ struct buffer_head *head, enum migrate_mode mode,
+ int extra_count)
{
- int expected_count = 0;
+ int expected_count = 1 + extra_count;
void **pslot;
if (!mapping) {
/* Anonymous page without mapping */
- if (page_count(page) != 1)
+ if (page_count(page) != expected_count)
return -EAGAIN;
return MIGRATEPAGE_SUCCESS;
}
pslot = radix_tree_lookup_slot(&mapping->page_tree,
page_index(page));
- expected_count = 2 + page_has_private(page);
+ expected_count += 1 + page_has_private(page);
if (page_count(page) != expected_count ||
radix_tree_deref_slot_protected(pslot, &mapping->tree_lock) != page) {
spin_unlock_irq(&mapping->tree_lock);
BUG_ON(PageWriteback(page)); /* Writeback must be complete */
- rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode);
+ rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0);
if (rc != MIGRATEPAGE_SUCCESS)
return rc;
head = page_buffers(page);
- rc = migrate_page_move_mapping(mapping, newpage, page, head, mode);
+ rc = migrate_page_move_mapping(mapping, newpage, page, head, mode, 0);
if (rc != MIGRATEPAGE_SUCCESS)
return rc;
return 1;
}
+bool pmd_trans_migrating(pmd_t pmd)
+{
+ struct page *page = pmd_page(pmd);
+ return PageLocked(page);
+}
+
+void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd)
+{
+ struct page *page = pmd_page(*pmd);
+ wait_on_page_locked(page);
+}
+
/*
* Attempt to migrate a misplaced page to the specified destination
* node. Caller is expected to have an elevated reference count on
struct page *page, int node)
{
spinlock_t *ptl;
- unsigned long haddr = address & HPAGE_PMD_MASK;
pg_data_t *pgdat = NODE_DATA(node);
int isolated = 0;
struct page *new_page = NULL;
struct mem_cgroup *memcg = NULL;
int page_lru = page_is_file_cache(page);
+ unsigned long mmun_start = address & HPAGE_PMD_MASK;
+ unsigned long mmun_end = mmun_start + HPAGE_PMD_SIZE;
+ pmd_t orig_entry;
/*
* Rate-limit the amount of data that is being migrated to a node.
goto out_fail;
}
+ if (mm_tlb_flush_pending(mm))
+ flush_tlb_range(vma, mmun_start, mmun_end);
+
/* Prepare a page as a migration target */
__set_page_locked(new_page);
SetPageSwapBacked(new_page);
WARN_ON(PageLRU(new_page));
/* Recheck the target PMD */
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
ptl = pmd_lock(mm, pmd);
- if (unlikely(!pmd_same(*pmd, entry))) {
+ if (unlikely(!pmd_same(*pmd, entry) || page_count(page) != 2)) {
+fail_putback:
spin_unlock(ptl);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
/* Reverse changes made by migrate_page_copy() */
if (TestClearPageActive(new_page))
putback_lru_page(page);
mod_zone_page_state(page_zone(page),
NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR);
- goto out_fail;
+
+ goto out_unlock;
}
/*
*/
mem_cgroup_prepare_migration(page, new_page, &memcg);
+ orig_entry = *pmd;
entry = mk_pmd(new_page, vma->vm_page_prot);
- entry = pmd_mknonnuma(entry);
- entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
entry = pmd_mkhuge(entry);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
- pmdp_clear_flush(vma, haddr, pmd);
- set_pmd_at(mm, haddr, pmd, entry);
- page_add_new_anon_rmap(new_page, vma, haddr);
+ /*
+ * Clear the old entry under pagetable lock and establish the new PTE.
+ * Any parallel GUP will either observe the old page blocking on the
+ * page lock, block on the page table lock or observe the new page.
+ * The SetPageUptodate on the new page and page_add_new_anon_rmap
+ * guarantee the copy is visible before the pagetable update.
+ */
+ flush_cache_range(vma, mmun_start, mmun_end);
+ page_add_new_anon_rmap(new_page, vma, mmun_start);
+ pmdp_clear_flush(vma, mmun_start, pmd);
+ set_pmd_at(mm, mmun_start, pmd, entry);
+ flush_tlb_range(vma, mmun_start, mmun_end);
update_mmu_cache_pmd(vma, address, &entry);
+
+ if (page_count(page) != 2) {
+ set_pmd_at(mm, mmun_start, pmd, orig_entry);
+ flush_tlb_range(vma, mmun_start, mmun_end);
+ update_mmu_cache_pmd(vma, address, &entry);
+ page_remove_rmap(new_page);
+ goto fail_putback;
+ }
+
page_remove_rmap(page);
+
/*
* Finish the charge transaction under the page table lock to
* prevent split_huge_page() from dividing up the charge
*/
mem_cgroup_end_migration(memcg, page, new_page, true);
spin_unlock(ptl);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
unlock_page(new_page);
unlock_page(page);
out_fail:
count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR);
out_dropref:
- entry = pmd_mknonnuma(entry);
- set_pmd_at(mm, haddr, pmd, entry);
- update_mmu_cache_pmd(vma, address, &entry);
+ ptl = pmd_lock(mm, pmd);
+ if (pmd_same(*pmd, entry)) {
+ entry = pmd_mknonnuma(entry);
+ set_pmd_at(mm, mmun_start, pmd, entry);
+ update_mmu_cache_pmd(vma, address, &entry);
+ }
+ spin_unlock(ptl);
+out_unlock:
unlock_page(page);
put_page(page);
return 0;
git.openpandora.org / pandora-kernel.git / blobdiff