Merge branch 'akpm' (patches from Andrew Morton)

Merge more patches from Andrew Morton:
 "The rest of MM.  Plus one misc cleanup"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits)
  mm/Kconfig: add MMU dependency for MIGRATION.
  kernel: replace strict_strto*() with kstrto*()
  mm, thp: count thp_fault_fallback anytime thp fault fails
  thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page()
  thp: do_huge_pmd_anonymous_page() cleanup
  thp: move maybe_pmd_mkwrite() out of mk_huge_pmd()
  mm: cleanup add_to_page_cache_locked()
  thp: account anon transparent huge pages into NR_ANON_PAGES
  truncate: drop 'oldsize' truncate_pagecache() parameter
  mm: make lru_add_drain_all() selective
  memcg: document cgroup dirty/writeback memory statistics
  memcg: add per cgroup writeback pages accounting
  memcg: check for proper lock held in mem_cgroup_update_page_stat
  memcg: remove MEMCG_NR_FILE_MAPPED
  memcg: reduce function dereference
  memcg: avoid overflow caused by PAGE_ALIGN
  memcg: rename RESOURCE_MAX to RES_COUNTER_MAX
  memcg: correct RESOURCE_MAX to ULLONG_MAX
  mm: memcg: do not trap chargers with full callstack on OOM
  mm: memcg: rework and document OOM waiting and wakeup
  ...

mm/Kconfig

@@ -245,7 +245,7 @@ config COMPACTION
 config MIGRATION
 	bool "Page migration"
 	def_bool y
-	depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA
+	depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU
 	help
 	  Allows the migration of the physical location of pages of processes
 	  while the virtual addresses are not changed. This is useful in
@@ -480,7 +480,7 @@ config FRONTSWAP
 
 config CMA
 	bool "Contiguous Memory Allocator"
-	depends on HAVE_MEMBLOCK
+	depends on HAVE_MEMBLOCK && MMU
 	select MIGRATION
 	select MEMORY_ISOLATION
 	help

mm/filemap.c

@@ -467,32 +467,34 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
 	error = mem_cgroup_cache_charge(page, current->mm,
 					gfp_mask & GFP_RECLAIM_MASK);
 	if (error)
-		goto out;
+		return error;
 
 	error = radix_tree_maybe_preload(gfp_mask & ~__GFP_HIGHMEM);
-	if (error == 0) {
-		page_cache_get(page);
-		page->mapping = mapping;
-		page->index = offset;
-
-		spin_lock_irq(&mapping->tree_lock);
-		error = radix_tree_insert(&mapping->page_tree, offset, page);
-		if (likely(!error)) {
-			mapping->nrpages++;
-			__inc_zone_page_state(page, NR_FILE_PAGES);
-			spin_unlock_irq(&mapping->tree_lock);
-			trace_mm_filemap_add_to_page_cache(page);
-		} else {
-			page->mapping = NULL;
-			/* Leave page->index set: truncation relies upon it */
-			spin_unlock_irq(&mapping->tree_lock);
-			mem_cgroup_uncharge_cache_page(page);
-			page_cache_release(page);
-		}
-		radix_tree_preload_end();
-	} else
+	if (error) {
 		mem_cgroup_uncharge_cache_page(page);
-out:
+		return error;
+	}
+
+	page_cache_get(page);
+	page->mapping = mapping;
+	page->index = offset;
+
+	spin_lock_irq(&mapping->tree_lock);
+	error = radix_tree_insert(&mapping->page_tree, offset, page);
+	radix_tree_preload_end();
+	if (unlikely(error))
+		goto err_insert;
+	mapping->nrpages++;
+	__inc_zone_page_state(page, NR_FILE_PAGES);
+	spin_unlock_irq(&mapping->tree_lock);
+	trace_mm_filemap_add_to_page_cache(page);
+	return 0;
+err_insert:
+	page->mapping = NULL;
+	/* Leave page->index set: truncation relies upon it */
+	spin_unlock_irq(&mapping->tree_lock);
+	mem_cgroup_uncharge_cache_page(page);
+	page_cache_release(page);
 	return error;
 }
 EXPORT_SYMBOL(add_to_page_cache_locked);
@@ -1614,6 +1616,7 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	struct inode *inode = mapping->host;
 	pgoff_t offset = vmf->pgoff;
 	struct page *page;
+	bool memcg_oom;
 	pgoff_t size;
 	int ret = 0;
 
@@ -1622,7 +1625,11 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		return VM_FAULT_SIGBUS;
 
 	/*
-	 * Do we have something in the page cache already?
+	 * Do we have something in the page cache already?  Either
+	 * way, try readahead, but disable the memcg OOM killer for it
+	 * as readahead is optional and no errors are propagated up
+	 * the fault stack.  The OOM killer is enabled while trying to
+	 * instantiate the faulting page individually below.
 	 */
 	page = find_get_page(mapping, offset);
 	if (likely(page) && !(vmf->flags & FAULT_FLAG_TRIED)) {
@@ -1630,10 +1637,14 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		 * We found the page, so try async readahead before
 		 * waiting for the lock.
 		 */
+		memcg_oom = mem_cgroup_toggle_oom(false);
 		do_async_mmap_readahead(vma, ra, file, page, offset);
+		mem_cgroup_toggle_oom(memcg_oom);
 	} else if (!page) {
 		/* No page in the page cache at all */
+		memcg_oom = mem_cgroup_toggle_oom(false);
 		do_sync_mmap_readahead(vma, ra, file, offset);
+		mem_cgroup_toggle_oom(memcg_oom);
 		count_vm_event(PGMAJFAULT);
 		mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);
 		ret = VM_FAULT_MAJOR;

mm/huge_memory.c

@@ -695,11 +695,10 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
 	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;
 }
@@ -732,7 +731,8 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
 		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);
@@ -788,77 +788,57 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
 {
 	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)))
+	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 (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;
-			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;
+			return VM_FAULT_FALLBACK;
 		}
-		count_vm_event(THP_FAULT_ALLOC);
-		if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) {
-			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();
 		}
-		if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd,
-							  page))) {
-			mem_cgroup_uncharge_page(page);
-			put_page(page);
-			goto out;
-		}
-
 		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,
@@ -1170,7 +1150,6 @@ alloc:
 		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);
@@ -1181,9 +1160,9 @@ alloc:
 				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);
@@ -1191,10 +1170,13 @@ alloc:
 			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
@@ -1215,7 +1197,8 @@ alloc:
 		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);
@@ -1666,7 +1649,6 @@ static void __split_huge_page_refcount(struct page *page,
 	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);
@@ -2364,7 +2346,8 @@ static void collapse_huge_page(struct mm_struct *mm,
 	__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

mm/memory.c

@@ -3695,7 +3695,7 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
  * but allow concurrent faults), and pte mapped but not yet locked.
  * We return with mmap_sem still held, but pte unmapped and unlocked.
  */
-int handle_pte_fault(struct mm_struct *mm,
+static int handle_pte_fault(struct mm_struct *mm,
 		     struct vm_area_struct *vma, unsigned long address,
 		     pte_t *pte, pmd_t *pmd, unsigned int flags)
 {
@@ -3754,22 +3754,14 @@ unlock:
 /*
  * By the time we get here, we already hold the mm semaphore
  */
-int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
-		unsigned long address, unsigned int flags)
+static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+			     unsigned long address, unsigned int flags)
 {
 	pgd_t *pgd;
 	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte;
 
-	__set_current_state(TASK_RUNNING);
-
-	count_vm_event(PGFAULT);
-	mem_cgroup_count_vm_event(mm, PGFAULT);
-
-	/* do counter updates before entering really critical section. */
-	check_sync_rss_stat(current);
-
 	if (unlikely(is_vm_hugetlb_page(vma)))
 		return hugetlb_fault(mm, vma, address, flags);
 
@@ -3782,9 +3774,12 @@ retry:
 	if (!pmd)
 		return VM_FAULT_OOM;
 	if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) {
+		int ret = VM_FAULT_FALLBACK;
 		if (!vma->vm_ops)
-			return do_huge_pmd_anonymous_page(mm, vma, address,
-							  pmd, flags);
+			ret = do_huge_pmd_anonymous_page(mm, vma, address,
+					pmd, flags);
+		if (!(ret & VM_FAULT_FALLBACK))
+			return ret;
 	} else {
 		pmd_t orig_pmd = *pmd;
 		int ret;
@@ -3850,6 +3845,37 @@ retry:
 	return handle_pte_fault(mm, vma, address, pte, pmd, flags);
 }
 
+int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+		    unsigned long address, unsigned int flags)
+{
+	int ret;
+
+	__set_current_state(TASK_RUNNING);
+
+	count_vm_event(PGFAULT);
+	mem_cgroup_count_vm_event(mm, PGFAULT);
+
+	/* do counter updates before entering really critical section. */
+	check_sync_rss_stat(current);
+
+	/*
+	 * Enable the memcg OOM handling for faults triggered in user
+	 * space.  Kernel faults are handled more gracefully.
+	 */
+	if (flags & FAULT_FLAG_USER)
+		mem_cgroup_enable_oom();
+
+	ret = __handle_mm_fault(mm, vma, address, flags);
+
+	if (flags & FAULT_FLAG_USER)
+		mem_cgroup_disable_oom();
+
+	if (WARN_ON(task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM)))
+		mem_cgroup_oom_synchronize();
+
+	return ret;
+}
+
 #ifndef __PAGETABLE_PUD_FOLDED
 /*
  * Allocate page upper directory.

mm/oom_kill.c

@@ -678,9 +678,12 @@ out:
  */
 void pagefault_out_of_memory(void)
 {
-	struct zonelist *zonelist = node_zonelist(first_online_node,
-						  GFP_KERNEL);
+	struct zonelist *zonelist;
 
+	if (mem_cgroup_oom_synchronize())
+		return;
+
+	zonelist = node_zonelist(first_online_node, GFP_KERNEL);
 	if (try_set_zonelist_oom(zonelist, GFP_KERNEL)) {
 		out_of_memory(NULL, 0, 0, NULL, false);
 		clear_zonelist_oom(zonelist, GFP_KERNEL);

mm/page-writeback.c

@@ -2143,11 +2143,17 @@ EXPORT_SYMBOL(account_page_dirtied);
 
 /*
  * Helper function for set_page_writeback family.
+ *
+ * The caller must hold mem_cgroup_begin/end_update_page_stat() lock
+ * while calling this function.
+ * See test_set_page_writeback for example.
+ *
  * NOTE: Unlike account_page_dirtied this does not rely on being atomic
  * wrt interrupts.
  */
 void account_page_writeback(struct page *page)
 {
+	mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
 	inc_zone_page_state(page, NR_WRITEBACK);
 }
 EXPORT_SYMBOL(account_page_writeback);
@@ -2364,7 +2370,10 @@ int test_clear_page_writeback(struct page *page)
 {
 	struct address_space *mapping = page_mapping(page);
 	int ret;
+	bool locked;
+	unsigned long memcg_flags;
 
+	mem_cgroup_begin_update_page_stat(page, &locked, &memcg_flags);
 	if (mapping) {
 		struct backing_dev_info *bdi = mapping->backing_dev_info;
 		unsigned long flags;
@@ -2385,9 +2394,11 @@ int test_clear_page_writeback(struct page *page)
 		ret = TestClearPageWriteback(page);
 	}
 	if (ret) {
+		mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
 		dec_zone_page_state(page, NR_WRITEBACK);
 		inc_zone_page_state(page, NR_WRITTEN);
 	}
+	mem_cgroup_end_update_page_stat(page, &locked, &memcg_flags);
 	return ret;
 }
 
@@ -2395,7 +2406,10 @@ int test_set_page_writeback(struct page *page)
 {
 	struct address_space *mapping = page_mapping(page);
 	int ret;
+	bool locked;
+	unsigned long memcg_flags;
 
+	mem_cgroup_begin_update_page_stat(page, &locked, &memcg_flags);
 	if (mapping) {
 		struct backing_dev_info *bdi = mapping->backing_dev_info;
 		unsigned long flags;
@@ -2422,6 +2436,7 @@ int test_set_page_writeback(struct page *page)
 	}
 	if (!ret)
 		account_page_writeback(page);
+	mem_cgroup_end_update_page_stat(page, &locked, &memcg_flags);
 	return ret;
 
 }

mm/rmap.c

@@ -1052,11 +1052,11 @@ void do_page_add_anon_rmap(struct page *page,
 {
 	int first = atomic_inc_and_test(&page->_mapcount);
 	if (first) {
-		if (!PageTransHuge(page))
-			__inc_zone_page_state(page, NR_ANON_PAGES);
-		else
+		if (PageTransHuge(page))
 			__inc_zone_page_state(page,
 					      NR_ANON_TRANSPARENT_HUGEPAGES);
+		__mod_zone_page_state(page_zone(page), NR_ANON_PAGES,
+				hpage_nr_pages(page));
 	}
 	if (unlikely(PageKsm(page)))
 		return;
@@ -1085,10 +1085,10 @@ void page_add_new_anon_rmap(struct page *page,
 	VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
 	SetPageSwapBacked(page);
 	atomic_set(&page->_mapcount, 0); /* increment count (starts at -1) */
-	if (!PageTransHuge(page))
-		__inc_zone_page_state(page, NR_ANON_PAGES);
-	else
+	if (PageTransHuge(page))
 		__inc_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
+	__mod_zone_page_state(page_zone(page), NR_ANON_PAGES,
+			hpage_nr_pages(page));
 	__page_set_anon_rmap(page, vma, address, 1);
 	if (!mlocked_vma_newpage(vma, page)) {
 		SetPageActive(page);
@@ -1111,7 +1111,7 @@ void page_add_file_rmap(struct page *page)
 	mem_cgroup_begin_update_page_stat(page, &locked, &flags);
 	if (atomic_inc_and_test(&page->_mapcount)) {
 		__inc_zone_page_state(page, NR_FILE_MAPPED);
-		mem_cgroup_inc_page_stat(page, MEMCG_NR_FILE_MAPPED);
+		mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED);
 	}
 	mem_cgroup_end_update_page_stat(page, &locked, &flags);
 }
@@ -1148,14 +1148,14 @@ void page_remove_rmap(struct page *page)
 		goto out;
 	if (anon) {
 		mem_cgroup_uncharge_page(page);
-		if (!PageTransHuge(page))
-			__dec_zone_page_state(page, NR_ANON_PAGES);
-		else
+		if (PageTransHuge(page))
 			__dec_zone_page_state(page,
 					      NR_ANON_TRANSPARENT_HUGEPAGES);
+		__mod_zone_page_state(page_zone(page), NR_ANON_PAGES,
+				-hpage_nr_pages(page));
 	} else {
 		__dec_zone_page_state(page, NR_FILE_MAPPED);
-		mem_cgroup_dec_page_stat(page, MEMCG_NR_FILE_MAPPED);
+		mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED);
 		mem_cgroup_end_update_page_stat(page, &locked, &flags);
 	}
 	if (unlikely(PageMlocked(page)))

mm/swap.c

@@ -432,6 +432,11 @@ static void activate_page_drain(int cpu)
 		pagevec_lru_move_fn(pvec, __activate_page, NULL);
 }
 
+static bool need_activate_page_drain(int cpu)
+{
+	return pagevec_count(&per_cpu(activate_page_pvecs, cpu)) != 0;
+}
+
 void activate_page(struct page *page)
 {
 	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
@@ -449,6 +454,11 @@ static inline void activate_page_drain(int cpu)
 {
 }
 
+static bool need_activate_page_drain(int cpu)
+{
+	return false;
+}
+
 void activate_page(struct page *page)
 {
 	struct zone *zone = page_zone(page);
@@ -701,12 +711,36 @@ static void lru_add_drain_per_cpu(struct work_struct *dummy)
 	lru_add_drain();
 }
 
-/*
- * Returns 0 for success
- */
-int lru_add_drain_all(void)
+static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work);
+
+void lru_add_drain_all(void)
 {
-	return schedule_on_each_cpu(lru_add_drain_per_cpu);
+	static DEFINE_MUTEX(lock);
+	static struct cpumask has_work;
+	int cpu;
+
+	mutex_lock(&lock);
+	get_online_cpus();
+	cpumask_clear(&has_work);
+
+	for_each_online_cpu(cpu) {
+		struct work_struct *work = &per_cpu(lru_add_drain_work, cpu);
+
+		if (pagevec_count(&per_cpu(lru_add_pvec, cpu)) ||
+		    pagevec_count(&per_cpu(lru_rotate_pvecs, cpu)) ||
+		    pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) ||
+		    need_activate_page_drain(cpu)) {
+			INIT_WORK(work, lru_add_drain_per_cpu);
+			schedule_work_on(cpu, work);
+			cpumask_set_cpu(cpu, &has_work);
+		}
+	}
+
+	for_each_cpu(cpu, &has_work)
+		flush_work(&per_cpu(lru_add_drain_work, cpu));
+
+	put_online_cpus();
+	mutex_unlock(&lock);
 }
 
 /*

mm/truncate.c

@@ -567,7 +567,6 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages2);
 /**
  * truncate_pagecache - unmap and remove pagecache that has been truncated
  * @inode: inode
- * @oldsize: old file size
  * @newsize: new file size
  *
  * inode's new i_size must already be written before truncate_pagecache
@@ -580,7 +579,7 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages2);
  * situations such as writepage being called for a page that has already
  * had its underlying blocks deallocated.
  */
-void truncate_pagecache(struct inode *inode, loff_t oldsize, loff_t newsize)
+void truncate_pagecache(struct inode *inode, loff_t newsize)
 {
 	struct address_space *mapping = inode->i_mapping;
 	loff_t holebegin = round_up(newsize, PAGE_SIZE);
@@ -614,12 +613,8 @@ EXPORT_SYMBOL(truncate_pagecache);
  */
 void truncate_setsize(struct inode *inode, loff_t newsize)
 {
-	loff_t oldsize;
-
-	oldsize = inode->i_size;
 	i_size_write(inode, newsize);
-
-	truncate_pagecache(inode, oldsize, newsize);
+	truncate_pagecache(inode, newsize);
 }
 EXPORT_SYMBOL(truncate_setsize);
 

mm/vmscan.c

@@ -139,11 +139,23 @@ static bool global_reclaim(struct scan_control *sc)
 {
 	return !sc->target_mem_cgroup;
 }
+
+static bool mem_cgroup_should_soft_reclaim(struct scan_control *sc)
+{
+	struct mem_cgroup *root = sc->target_mem_cgroup;
+	return !mem_cgroup_disabled() &&
+		mem_cgroup_soft_reclaim_eligible(root, root) != SKIP_TREE;
+}
 #else
 static bool global_reclaim(struct scan_control *sc)
 {
 	return true;
 }
+
+static bool mem_cgroup_should_soft_reclaim(struct scan_control *sc)
+{
+	return false;
+}
 #endif
 
 unsigned long zone_reclaimable_pages(struct zone *zone)
@@ -2164,9 +2176,11 @@ static inline bool should_continue_reclaim(struct zone *zone,
 	}
 }
 
-static void shrink_zone(struct zone *zone, struct scan_control *sc)
+static int
+__shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim)
 {
 	unsigned long nr_reclaimed, nr_scanned;
+	int groups_scanned = 0;
 
 	do {
 		struct mem_cgroup *root = sc->target_mem_cgroup;
@@ -2174,15 +2188,17 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc)
 			.zone = zone,
 			.priority = sc->priority,
 		};
-		struct mem_cgroup *memcg;
+		struct mem_cgroup *memcg = NULL;
+		mem_cgroup_iter_filter filter = (soft_reclaim) ?
+			mem_cgroup_soft_reclaim_eligible : NULL;
 
 		nr_reclaimed = sc->nr_reclaimed;
 		nr_scanned = sc->nr_scanned;
 
-		memcg = mem_cgroup_iter(root, NULL, &reclaim);
-		do {
+		while ((memcg = mem_cgroup_iter_cond(root, memcg, &reclaim, filter))) {
 			struct lruvec *lruvec;
 
+			groups_scanned++;
 			lruvec = mem_cgroup_zone_lruvec(zone, memcg);
 
 			shrink_lruvec(lruvec, sc);
@@ -2202,8 +2218,7 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc)
 				mem_cgroup_iter_break(root, memcg);
 				break;
 			}
-			memcg = mem_cgroup_iter(root, memcg, &reclaim);
-		} while (memcg);
+		}
 
 		vmpressure(sc->gfp_mask, sc->target_mem_cgroup,
 			   sc->nr_scanned - nr_scanned,
@@ -2211,6 +2226,37 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc)
 
 	} while (should_continue_reclaim(zone, sc->nr_reclaimed - nr_reclaimed,
 					 sc->nr_scanned - nr_scanned, sc));
+
+	return groups_scanned;
+}
+
+
+static void shrink_zone(struct zone *zone, struct scan_control *sc)
+{
+	bool do_soft_reclaim = mem_cgroup_should_soft_reclaim(sc);
+	unsigned long nr_scanned = sc->nr_scanned;
+	int scanned_groups;
+
+	scanned_groups = __shrink_zone(zone, sc, do_soft_reclaim);
+	/*
+	 * memcg iterator might race with other reclaimer or start from
+	 * a incomplete tree walk so the tree walk in __shrink_zone
+	 * might have missed groups that are above the soft limit. Try
+	 * another loop to catch up with others. Do it just once to
+	 * prevent from reclaim latencies when other reclaimers always
+	 * preempt this one.
+	 */
+	if (do_soft_reclaim && !scanned_groups)
+		__shrink_zone(zone, sc, do_soft_reclaim);
+
+	/*
+	 * No group is over the soft limit or those that are do not have
+	 * pages in the zone we are reclaiming so we have to reclaim everybody
+	 */
+	if (do_soft_reclaim && (sc->nr_scanned == nr_scanned)) {
+		__shrink_zone(zone, sc, false);
+		return;
+	}
 }
 
 /* Returns true if compaction should go ahead for a high-order request */
@@ -2274,8 +2320,6 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
 {
 	struct zoneref *z;
 	struct zone *zone;
-	unsigned long nr_soft_reclaimed;
-	unsigned long nr_soft_scanned;
 	bool aborted_reclaim = false;
 
 	/*
@@ -2315,18 +2359,6 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
 					continue;
 				}
 			}
-			/*
-			 * This steals pages from memory cgroups over softlimit
-			 * and returns the number of reclaimed pages and
-			 * scanned pages. This works for global memory pressure
-			 * and balancing, not for a memcg's limit.
-			 */
-			nr_soft_scanned = 0;
-			nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone,
-						sc->order, sc->gfp_mask,
-						&nr_soft_scanned);
-			sc->nr_reclaimed += nr_soft_reclaimed;
-			sc->nr_scanned += nr_soft_scanned;
 			/* need some check for avoid more shrink_zone() */
 		}
 
@@ -2920,8 +2952,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 {
 	int i;
 	int end_zone = 0;	/* Inclusive.  0 = ZONE_DMA */
-	unsigned long nr_soft_reclaimed;
-	unsigned long nr_soft_scanned;
 	struct scan_control sc = {
 		.gfp_mask = GFP_KERNEL,
 		.priority = DEF_PRIORITY,
@@ -3036,15 +3066,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 
 			sc.nr_scanned = 0;
 
-			nr_soft_scanned = 0;
-			/*
-			 * Call soft limit reclaim before calling shrink_zone.
-			 */
-			nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone,
-							order, sc.gfp_mask,
-							&nr_soft_scanned);
-			sc.nr_reclaimed += nr_soft_reclaimed;
-
 			/*
 			 * There should be no need to raise the scanning
 			 * priority if enough pages are already being scanned