Merge branch 'akpm' (Andrew's patch bomb)

Merge the emailed seties of 19 patches from Andrew Morton

* akpm:
  rapidio/tsi721: fix queue wrapping bug in inbound doorbell handler
  memcg: fix mapcount check in move charge code for anonymous page
  mm: thp: fix BUG on mm->nr_ptes
  alpha: fix 32/64-bit bug in futex support
  memcg: fix GPF when cgroup removal races with last exit
  debugobjects: Fix selftest for static warnings
  floppy/scsi: fix setting of BIO flags
  memcg: fix deadlock by inverting lrucare nesting
  drivers/rtc/rtc-r9701.c: fix crash in r9701_remove()
  c2port: class_create() returns an ERR_PTR
  pps: class_create() returns an ERR_PTR, not NULL
  hung_task: fix the broken rcu_lock_break() logic
  vfork: kill PF_STARTING
  coredump_wait: don't call complete_vfork_done()
  vfork: make it killable
  vfork: introduce complete_vfork_done()
  aio: wake up waiters when freeing unused kiocbs
  kprobes: return proper error code from register_kprobe()
  kmsg_dump: don't run on non-error paths by default

Documentation/kernel-parameters.txt

@@ -2211,6 +2211,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 			default: off.
 
+	printk.always_kmsg_dump=
+			Trigger kmsg_dump for cases other than kernel oops or
+			panics
+			Format: <bool>  (1/Y/y=enable, 0/N/n=disable)
+			default: disabled
+
 	printk.time=	Show timing data prefixed to each printk message line
 			Format: <bool>  (1/Y/y=enable, 0/N/n=disable)
 

arch/alpha/include/asm/futex.h

@@ -108,7 +108,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 	"	lda	$31,3b-2b(%0)\n"
 	"	.previous\n"
 	:	"+r"(ret), "=&r"(prev), "=&r"(cmp)
-	:	"r"(uaddr), "r"((long)oldval), "r"(newval)
+	:	"r"(uaddr), "r"((long)(int)oldval), "r"(newval)
 	:	"memory");
 
 	*uval = prev;

drivers/block/floppy.c

@@ -3832,7 +3832,7 @@ static int __floppy_read_block_0(struct block_device *bdev)
 	bio.bi_size = size;
 	bio.bi_bdev = bdev;
 	bio.bi_sector = 0;
-	bio.bi_flags = BIO_QUIET;
+	bio.bi_flags = (1 << BIO_QUIET);
 	init_completion(&complete);
 	bio.bi_private = &complete;
 	bio.bi_end_io = floppy_rb0_complete;

drivers/misc/c2port/core.c

@@ -984,9 +984,9 @@ static int __init c2port_init(void)
 		" - (C) 2007 Rodolfo Giometti\n");
 
 	c2port_class = class_create(THIS_MODULE, "c2port");
-	if (!c2port_class) {
+	if (IS_ERR(c2port_class)) {
 		printk(KERN_ERR "c2port: failed to allocate class\n");
-		return -ENOMEM;
+		return PTR_ERR(c2port_class);
 	}
 	c2port_class->dev_attrs = c2port_attrs;
 

drivers/pps/pps.c

@@ -369,9 +369,9 @@ static int __init pps_init(void)
 	int err;
 
 	pps_class = class_create(THIS_MODULE, "pps");
-	if (!pps_class) {
+	if (IS_ERR(pps_class)) {
 		pr_err("failed to allocate class\n");
-		return -ENOMEM;
+		return PTR_ERR(pps_class);
 	}
 	pps_class->dev_attrs = pps_attrs;
 

drivers/rapidio/devices/tsi721.c

@@ -410,13 +410,14 @@ static void tsi721_db_dpc(struct work_struct *work)
 	 */
 	mport = priv->mport;
 
-	wr_ptr = ioread32(priv->regs + TSI721_IDQ_WP(IDB_QUEUE));
-	rd_ptr = ioread32(priv->regs + TSI721_IDQ_RP(IDB_QUEUE));
+	wr_ptr = ioread32(priv->regs + TSI721_IDQ_WP(IDB_QUEUE)) % IDB_QSIZE;
+	rd_ptr = ioread32(priv->regs + TSI721_IDQ_RP(IDB_QUEUE)) % IDB_QSIZE;
 
 	while (wr_ptr != rd_ptr) {
 		idb_entry = (u64 *)(priv->idb_base +
 					(TSI721_IDB_ENTRY_SIZE * rd_ptr));
 		rd_ptr++;
+		rd_ptr %= IDB_QSIZE;
 		idb.msg = *idb_entry;
 		*idb_entry = 0;
 

drivers/rtc/rtc-r9701.c

@@ -125,6 +125,13 @@ static int __devinit r9701_probe(struct spi_device *spi)
 	unsigned char tmp;
 	int res;
 
+	tmp = R100CNT;
+	res = read_regs(&spi->dev, &tmp, 1);
+	if (res || tmp != 0x20) {
+		dev_err(&spi->dev, "cannot read RTC register\n");
+		return -ENODEV;
+	}
+
 	rtc = rtc_device_register("r9701",
 				&spi->dev, &r9701_rtc_ops, THIS_MODULE);
 	if (IS_ERR(rtc))
@@ -132,13 +139,6 @@ static int __devinit r9701_probe(struct spi_device *spi)
 
 	dev_set_drvdata(&spi->dev, rtc);
 
-	tmp = R100CNT;
-	res = read_regs(&spi->dev, &tmp, 1);
-	if (res || tmp != 0x20) {
-		rtc_device_unregister(rtc);
-		return res;
-	}
-
 	return 0;
 }
 

drivers/scsi/sd_dif.c

@@ -408,7 +408,7 @@ int sd_dif_prepare(struct request *rq, sector_t hw_sector, unsigned int sector_s
 			kunmap_atomic(sdt, KM_USER0);
 		}
 
-		bio->bi_flags |= BIO_MAPPED_INTEGRITY;
+		bio->bi_flags |= (1 << BIO_MAPPED_INTEGRITY);
 	}
 
 	return 0;

fs/aio.c

@@ -490,6 +490,8 @@ static void kiocb_batch_free(struct kioctx *ctx, struct kiocb_batch *batch)
 		kmem_cache_free(kiocb_cachep, req);
 		ctx->reqs_active--;
 	}
+	if (unlikely(!ctx->reqs_active && ctx->dead))
+		wake_up_all(&ctx->wait);
 	spin_unlock_irq(&ctx->ctx_lock);
 }
 

fs/exec.c

@@ -1915,7 +1915,6 @@ static int coredump_wait(int exit_code, struct core_state *core_state)
 {
 	struct task_struct *tsk = current;
 	struct mm_struct *mm = tsk->mm;
-	struct completion *vfork_done;
 	int core_waiters = -EBUSY;
 
 	init_completion(&core_state->startup);
@@ -1927,22 +1926,9 @@ static int coredump_wait(int exit_code, struct core_state *core_state)
 		core_waiters = zap_threads(tsk, mm, core_state, exit_code);
 	up_write(&mm->mmap_sem);
 
-	if (unlikely(core_waiters < 0))
-		goto fail;
-
-	/*
-	 * Make sure nobody is waiting for us to release the VM,
-	 * otherwise we can deadlock when we wait on each other
-	 */
-	vfork_done = tsk->vfork_done;
-	if (vfork_done) {
-		tsk->vfork_done = NULL;
-		complete(vfork_done);
-	}
-
-	if (core_waiters)
+	if (core_waiters > 0)
 		wait_for_completion(&core_state->startup);
-fail:
+
 	return core_waiters;
 }
 

include/linux/kmsg_dump.h

@@ -15,13 +15,18 @@
 #include <linux/errno.h>
 #include <linux/list.h>
 
+/*
+ * Keep this list arranged in rough order of priority. Anything listed after
+ * KMSG_DUMP_OOPS will not be logged by default unless printk.always_kmsg_dump
+ * is passed to the kernel.
+ */
 enum kmsg_dump_reason {
-	KMSG_DUMP_OOPS,
 	KMSG_DUMP_PANIC,
+	KMSG_DUMP_OOPS,
+	KMSG_DUMP_EMERG,
 	KMSG_DUMP_RESTART,
 	KMSG_DUMP_HALT,
 	KMSG_DUMP_POWEROFF,
-	KMSG_DUMP_EMERG,
 };
 
 /**

include/linux/memcontrol.h

@@ -129,7 +129,6 @@ extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
 extern void mem_cgroup_replace_page_cache(struct page *oldpage,
 					struct page *newpage);
 
-extern void mem_cgroup_reset_owner(struct page *page);
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 extern int do_swap_account;
 #endif
@@ -392,10 +391,6 @@ static inline void mem_cgroup_replace_page_cache(struct page *oldpage,
 				struct page *newpage)
 {
 }
-
-static inline void mem_cgroup_reset_owner(struct page *page)
-{
-}
 #endif /* CONFIG_CGROUP_MEM_CONT */
 
 #if !defined(CONFIG_CGROUP_MEM_RES_CTLR) || !defined(CONFIG_DEBUG_VM)

include/linux/sched.h

@@ -1777,7 +1777,6 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *
 /*
  * Per process flags
  */
-#define PF_STARTING	0x00000002	/* being created */
 #define PF_EXITING	0x00000004	/* getting shut down */
 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
@@ -2371,7 +2370,7 @@ static inline int thread_group_empty(struct task_struct *p)
  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
  * pins the final release of task.io_context.  Also protects ->cpuset and
- * ->cgroup.subsys[].
+ * ->cgroup.subsys[]. And ->vfork_done.
  *
  * Nests both inside and outside of read_lock(&tasklist_lock).
  * It must not be nested with write_lock_irq(&tasklist_lock),

kernel/fork.c

@@ -668,6 +668,38 @@ struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
 	return mm;
 }
 
+static void complete_vfork_done(struct task_struct *tsk)
+{
+	struct completion *vfork;
+
+	task_lock(tsk);
+	vfork = tsk->vfork_done;
+	if (likely(vfork)) {
+		tsk->vfork_done = NULL;
+		complete(vfork);
+	}
+	task_unlock(tsk);
+}
+
+static int wait_for_vfork_done(struct task_struct *child,
+				struct completion *vfork)
+{
+	int killed;
+
+	freezer_do_not_count();
+	killed = wait_for_completion_killable(vfork);
+	freezer_count();
+
+	if (killed) {
+		task_lock(child);
+		child->vfork_done = NULL;
+		task_unlock(child);
+	}
+
+	put_task_struct(child);
+	return killed;
+}
+
 /* Please note the differences between mmput and mm_release.
  * mmput is called whenever we stop holding onto a mm_struct,
  * error success whatever.
@@ -683,8 +715,6 @@ struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
  */
 void mm_release(struct task_struct *tsk, struct mm_struct *mm)
 {
-	struct completion *vfork_done = tsk->vfork_done;
-
 	/* Get rid of any futexes when releasing the mm */
 #ifdef CONFIG_FUTEX
 	if (unlikely(tsk->robust_list)) {
@@ -704,17 +734,15 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
 	/* Get rid of any cached register state */
 	deactivate_mm(tsk, mm);
 
-	/* notify parent sleeping on vfork() */
-	if (vfork_done) {
-		tsk->vfork_done = NULL;
-		complete(vfork_done);
-	}
+	if (tsk->vfork_done)
+		complete_vfork_done(tsk);
 
 	/*
 	 * If we're exiting normally, clear a user-space tid field if
 	 * requested.  We leave this alone when dying by signal, to leave
 	 * the value intact in a core dump, and to save the unnecessary
-	 * trouble otherwise.  Userland only wants this done for a sys_exit.
+	 * trouble, say, a killed vfork parent shouldn't touch this mm.
+	 * Userland only wants this done for a sys_exit.
 	 */
 	if (tsk->clear_child_tid) {
 		if (!(tsk->flags & PF_SIGNALED) &&
@@ -1018,7 +1046,6 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p)
 
 	new_flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER);
 	new_flags |= PF_FORKNOEXEC;
-	new_flags |= PF_STARTING;
 	p->flags = new_flags;
 }
 
@@ -1548,16 +1575,9 @@ long do_fork(unsigned long clone_flags,
 		if (clone_flags & CLONE_VFORK) {
 			p->vfork_done = &vfork;
 			init_completion(&vfork);
+			get_task_struct(p);
 		}
 
-		/*
-		 * We set PF_STARTING at creation in case tracing wants to
-		 * use this to distinguish a fully live task from one that
-		 * hasn't finished SIGSTOP raising yet.  Now we clear it
-		 * and set the child going.
-		 */
-		p->flags &= ~PF_STARTING;
-
 		wake_up_new_task(p);
 
 		/* forking complete and child started to run, tell ptracer */
@@ -1565,10 +1585,8 @@ long do_fork(unsigned long clone_flags,
 			ptrace_event(trace, nr);
 
 		if (clone_flags & CLONE_VFORK) {
-			freezer_do_not_count();
-			wait_for_completion(&vfork);
-			freezer_count();
-			ptrace_event(PTRACE_EVENT_VFORK_DONE, nr);
+			if (!wait_for_vfork_done(p, &vfork))
+				ptrace_event(PTRACE_EVENT_VFORK_DONE, nr);
 		}
 	} else {
 		nr = PTR_ERR(p);

kernel/hung_task.c

@@ -119,15 +119,20 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
  * For preemptible RCU it is sufficient to call rcu_read_unlock in order
  * to exit the grace period. For classic RCU, a reschedule is required.
  */
-static void rcu_lock_break(struct task_struct *g, struct task_struct *t)
+static bool rcu_lock_break(struct task_struct *g, struct task_struct *t)
 {
+	bool can_cont;
+
 	get_task_struct(g);
 	get_task_struct(t);
 	rcu_read_unlock();
 	cond_resched();
 	rcu_read_lock();
+	can_cont = pid_alive(g) && pid_alive(t);
 	put_task_struct(t);
 	put_task_struct(g);
+
+	return can_cont;
 }
 
 /*
@@ -154,9 +159,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout)
 			goto unlock;
 		if (!--batch_count) {
 			batch_count = HUNG_TASK_BATCHING;
-			rcu_lock_break(g, t);
-			/* Exit if t or g was unhashed during refresh. */
-			if (t->state == TASK_DEAD || g->state == TASK_DEAD)
+			if (!rcu_lock_break(g, t))
 				goto unlock;
 		}
 		/* use "==" to skip the TASK_KILLABLE tasks waiting on NFS */

kernel/kprobes.c

@@ -1334,8 +1334,10 @@ int __kprobes register_kprobe(struct kprobe *p)
 	if (!kernel_text_address((unsigned long) p->addr) ||
 	    in_kprobes_functions((unsigned long) p->addr) ||
 	    ftrace_text_reserved(p->addr, p->addr) ||
-	    jump_label_text_reserved(p->addr, p->addr))
-		goto fail_with_jump_label;
+	    jump_label_text_reserved(p->addr, p->addr)) {
+		ret = -EINVAL;
+		goto cannot_probe;
+	}
 
 	/* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */
 	p->flags &= KPROBE_FLAG_DISABLED;
@@ -1352,7 +1354,7 @@ int __kprobes register_kprobe(struct kprobe *p)
 		 * its code to prohibit unexpected unloading.
 		 */
 		if (unlikely(!try_module_get(probed_mod)))
-			goto fail_with_jump_label;
+			goto cannot_probe;
 
 		/*
 		 * If the module freed .init.text, we couldn't insert
@@ -1361,7 +1363,7 @@ int __kprobes register_kprobe(struct kprobe *p)
 		if (within_module_init((unsigned long)p->addr, probed_mod) &&
 		    probed_mod->state != MODULE_STATE_COMING) {
 			module_put(probed_mod);
-			goto fail_with_jump_label;
+			goto cannot_probe;
 		}
 		/* ret will be updated by following code */
 	}
@@ -1409,7 +1411,7 @@ int __kprobes register_kprobe(struct kprobe *p)
 
 	return ret;
 
-fail_with_jump_label:
+cannot_probe:
 	preempt_enable();
 	jump_label_unlock();
 	return ret;

kernel/printk.c

@@ -702,6 +702,9 @@ static bool printk_time = 0;
 #endif
 module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
 
+static bool always_kmsg_dump;
+module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR);
+
 /* Check if we have any console registered that can be called early in boot. */
 static int have_callable_console(void)
 {
@@ -1732,6 +1735,9 @@ void kmsg_dump(enum kmsg_dump_reason reason)
 	unsigned long l1, l2;
 	unsigned long flags;
 
+	if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump)
+		return;
+
 	/* Theoretically, the log could move on after we do this, but
 	   there's not a lot we can do about that. The new messages
 	   will overwrite the start of what we dump. */

lib/debugobjects.c

@@ -818,17 +818,9 @@ static int __init fixup_activate(void *addr, enum debug_obj_state state)
 		if (obj->static_init == 1) {
 			debug_object_init(obj, &descr_type_test);
 			debug_object_activate(obj, &descr_type_test);
-			/*
-			 * Real code should return 0 here ! This is
-			 * not a fixup of some bad behaviour. We
-			 * merily call the debug_init function to keep
-			 * track of the object.
-			 */
-			return 1;
-		} else {
-			/* Real code needs to emit a warning here */
+			return 0;
 		}
-		return 0;
+		return 1;
 
 	case ODEBUG_STATE_ACTIVE:
 		debug_object_deactivate(obj, &descr_type_test);
@@ -967,7 +959,7 @@ static void __init debug_objects_selftest(void)
 
 	obj.static_init = 1;
 	debug_object_activate(&obj, &descr_type_test);
-	if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
+	if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
 		goto out;
 	debug_object_init(&obj, &descr_type_test);
 	if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))

mm/huge_memory.c

@@ -671,6 +671,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
 		set_pmd_at(mm, haddr, pmd, entry);
 		prepare_pmd_huge_pte(pgtable, mm);
 		add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
+		mm->nr_ptes++;
 		spin_unlock(&mm->page_table_lock);
 	}
 
@@ -789,6 +790,7 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	pmd = pmd_mkold(pmd_wrprotect(pmd));
 	set_pmd_at(dst_mm, addr, dst_pmd, pmd);
 	prepare_pmd_huge_pte(pgtable, dst_mm);
+	dst_mm->nr_ptes++;
 
 	ret = 0;
 out_unlock:
@@ -887,7 +889,6 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
 	}
 	kfree(pages);
 
-	mm->nr_ptes++;
 	smp_wmb(); /* make pte visible before pmd */
 	pmd_populate(mm, pmd, pgtable);
 	page_remove_rmap(page);
@@ -1047,6 +1048,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 			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);
@@ -1375,7 +1377,6 @@ static int __split_huge_page_map(struct page *page,
 			pte_unmap(pte);
 		}
 
-		mm->nr_ptes++;
 		smp_wmb(); /* make pte visible before pmd */
 		/*
 		 * Up to this point the pmd is present and huge and
@@ -1988,7 +1989,6 @@ static void collapse_huge_page(struct mm_struct *mm,
 	set_pmd_at(mm, address, pmd, _pmd);
 	update_mmu_cache(vma, address, _pmd);
 	prepare_pmd_huge_pte(pgtable, mm);
-	mm->nr_ptes--;
 	spin_unlock(&mm->page_table_lock);
 
 #ifndef CONFIG_NUMA

mm/ksm.c

@@ -28,7 +28,6 @@
 #include <linux/kthread.h>
 #include <linux/wait.h>
 #include <linux/slab.h>
-#include <linux/memcontrol.h>
 #include <linux/rbtree.h>
 #include <linux/memory.h>
 #include <linux/mmu_notifier.h>
@@ -1572,16 +1571,6 @@ struct page *ksm_does_need_to_copy(struct page *page,
 
 	new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
 	if (new_page) {
-		/*
-		 * The memcg-specific accounting when moving
-		 * pages around the LRU lists relies on the
-		 * page's owner (memcg) to be valid.  Usually,
-		 * pages are assigned to a new owner before
-		 * being put on the LRU list, but since this
-		 * is not the case here, the stale owner from
-		 * a previous allocation cycle must be reset.
-		 */
-		mem_cgroup_reset_owner(new_page);
 		copy_user_highpage(new_page, page, address, vma);
 
 		SetPageDirty(new_page);

mm/memcontrol.c

@@ -1042,6 +1042,19 @@ struct lruvec *mem_cgroup_lru_add_list(struct zone *zone, struct page *page,
 
 	pc = lookup_page_cgroup(page);
 	memcg = pc->mem_cgroup;
+
+	/*
+	 * Surreptitiously switch any uncharged page to root:
+	 * an uncharged page off lru does nothing to secure
+	 * its former mem_cgroup from sudden removal.
+	 *
+	 * Our caller holds lru_lock, and PageCgroupUsed is updated
+	 * under page_cgroup lock: between them, they make all uses
+	 * of pc->mem_cgroup safe.
+	 */
+	if (!PageCgroupUsed(pc) && memcg != root_mem_cgroup)
+		pc->mem_cgroup = memcg = root_mem_cgroup;
+
 	mz = page_cgroup_zoneinfo(memcg, page);
 	/* compound_order() is stabilized through lru_lock */
 	MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
@@ -2408,8 +2421,12 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
 				       struct page *page,
 				       unsigned int nr_pages,
 				       struct page_cgroup *pc,
-				       enum charge_type ctype)
+				       enum charge_type ctype,
+				       bool lrucare)
 {
+	struct zone *uninitialized_var(zone);
+	bool was_on_lru = false;
+
 	lock_page_cgroup(pc);
 	if (unlikely(PageCgroupUsed(pc))) {
 		unlock_page_cgroup(pc);
@@ -2420,6 +2437,21 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
 	 * we don't need page_cgroup_lock about tail pages, becase they are not
 	 * accessed by any other context at this point.
 	 */
+
+	/*
+	 * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
+	 * may already be on some other mem_cgroup's LRU.  Take care of it.
+	 */
+	if (lrucare) {
+		zone = page_zone(page);
+		spin_lock_irq(&zone->lru_lock);
+		if (PageLRU(page)) {
+			ClearPageLRU(page);
+			del_page_from_lru_list(zone, page, page_lru(page));
+			was_on_lru = true;
+		}
+	}
+
 	pc->mem_cgroup = memcg;
 	/*
 	 * We access a page_cgroup asynchronously without lock_page_cgroup().
@@ -2443,9 +2475,18 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
 		break;
 	}
 
+	if (lrucare) {
+		if (was_on_lru) {
+			VM_BUG_ON(PageLRU(page));
+			SetPageLRU(page);
+			add_page_to_lru_list(zone, page, page_lru(page));
+		}
+		spin_unlock_irq(&zone->lru_lock);
+	}
+
 	mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), nr_pages);
 	unlock_page_cgroup(pc);
-	WARN_ON_ONCE(PageLRU(page));
+
 	/*
 	 * "charge_statistics" updated event counter. Then, check it.
 	 * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
@@ -2643,7 +2684,7 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
 	ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
 	if (ret == -ENOMEM)
 		return ret;
-	__mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype);
+	__mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype, false);
 	return 0;
 }
 
@@ -2663,35 +2704,6 @@ static void
 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
 					enum charge_type ctype);
 
-static void
-__mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *memcg,
-					enum charge_type ctype)
-{
-	struct page_cgroup *pc = lookup_page_cgroup(page);
-	struct zone *zone = page_zone(page);
-	unsigned long flags;
-	bool removed = false;
-
-	/*
-	 * In some case, SwapCache, FUSE(splice_buf->radixtree), the page
-	 * is already on LRU. It means the page may on some other page_cgroup's
-	 * LRU. Take care of it.
-	 */
-	spin_lock_irqsave(&zone->lru_lock, flags);
-	if (PageLRU(page)) {
-		del_page_from_lru_list(zone, page, page_lru(page));
-		ClearPageLRU(page);
-		removed = true;
-	}
-	__mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
-	if (removed) {
-		add_page_to_lru_list(zone, page, page_lru(page));
-		SetPageLRU(page);
-	}
-	spin_unlock_irqrestore(&zone->lru_lock, flags);
-	return;
-}
-
 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
 				gfp_t gfp_mask)
 {
@@ -2769,13 +2781,16 @@ static void
 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
 					enum charge_type ctype)
 {
+	struct page_cgroup *pc;
+
 	if (mem_cgroup_disabled())
 		return;
 	if (!memcg)
 		return;
 	cgroup_exclude_rmdir(&memcg->css);
 
-	__mem_cgroup_commit_charge_lrucare(page, memcg, ctype);
+	pc = lookup_page_cgroup(page);
+	__mem_cgroup_commit_charge(memcg, page, 1, pc, ctype, true);
 	/*
 	 * Now swap is on-memory. This means this page may be
 	 * counted both as mem and swap....double count.
@@ -3027,23 +3042,6 @@ void mem_cgroup_uncharge_end(void)
 	batch->memcg = NULL;
 }
 
-/*
- * A function for resetting pc->mem_cgroup for newly allocated pages.
- * This function should be called if the newpage will be added to LRU
- * before start accounting.
- */
-void mem_cgroup_reset_owner(struct page *newpage)
-{
-	struct page_cgroup *pc;
-
-	if (mem_cgroup_disabled())
-		return;
-
-	pc = lookup_page_cgroup(newpage);
-	VM_BUG_ON(PageCgroupUsed(pc));
-	pc->mem_cgroup = root_mem_cgroup;
-}
-
 #ifdef CONFIG_SWAP
 /*
  * called after __delete_from_swap_cache() and drop "page" account.
@@ -3248,7 +3246,7 @@ int mem_cgroup_prepare_migration(struct page *page,
 		ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
 	else
 		ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-	__mem_cgroup_commit_charge(memcg, newpage, 1, pc, ctype);
+	__mem_cgroup_commit_charge(memcg, newpage, 1, pc, ctype, false);
 	return ret;
 }
 
@@ -3332,7 +3330,7 @@ void mem_cgroup_replace_page_cache(struct page *oldpage,
 	 * the newpage may be on LRU(or pagevec for LRU) already. We lock
 	 * LRU while we overwrite pc->mem_cgroup.
 	 */
-	__mem_cgroup_commit_charge_lrucare(newpage, memcg, type);
+	__mem_cgroup_commit_charge(memcg, newpage, 1, pc, type, true);
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -5077,7 +5075,7 @@ static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
 		return NULL;
 	if (PageAnon(page)) {
 		/* we don't move shared anon */
-		if (!move_anon() || page_mapcount(page) > 2)
+		if (!move_anon() || page_mapcount(page) > 1)
 			return NULL;
 	} else if (!move_file())
 		/* we ignore mapcount for file pages */

mm/migrate.c

@@ -839,8 +839,6 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
 	if (!newpage)
 		return -ENOMEM;
 
-	mem_cgroup_reset_owner(newpage);
-
 	if (page_count(page) == 1) {
 		/* page was freed from under us. So we are done. */
 		goto out;

mm/swap.c

@@ -652,7 +652,7 @@ EXPORT_SYMBOL(__pagevec_release);
 void lru_add_page_tail(struct zone* zone,
 		       struct page *page, struct page *page_tail)
 {
-	int active;
+	int uninitialized_var(active);
 	enum lru_list lru;
 	const int file = 0;
 
@@ -672,7 +672,6 @@ void lru_add_page_tail(struct zone* zone,
 			active = 0;
 			lru = LRU_INACTIVE_ANON;
 		}
-		update_page_reclaim_stat(zone, page_tail, file, active);
 	} else {
 		SetPageUnevictable(page_tail);
 		lru = LRU_UNEVICTABLE;
@@ -693,6 +692,9 @@ void lru_add_page_tail(struct zone* zone,
 		list_head = page_tail->lru.prev;
 		list_move_tail(&page_tail->lru, list_head);
 	}
+
+	if (!PageUnevictable(page))
+		update_page_reclaim_stat(zone, page_tail, file, active);
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
@@ -710,8 +712,8 @@ static void __pagevec_lru_add_fn(struct page *page, void *arg)
 	SetPageLRU(page);
 	if (active)
 		SetPageActive(page);
-	update_page_reclaim_stat(zone, page, file, active);
 	add_page_to_lru_list(zone, page, lru);
+	update_page_reclaim_stat(zone, page, file, active);
 }
 
 /*

mm/swap_state.c

@@ -300,16 +300,6 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 			new_page = alloc_page_vma(gfp_mask, vma, addr);
 			if (!new_page)
 				break;		/* Out of memory */
-			/*
-			 * The memcg-specific accounting when moving
-			 * pages around the LRU lists relies on the
-			 * page's owner (memcg) to be valid.  Usually,
-			 * pages are assigned to a new owner before
-			 * being put on the LRU list, but since this
-			 * is not the case here, the stale owner from
-			 * a previous allocation cycle must be reset.
-			 */
-			mem_cgroup_reset_owner(new_page);
 		}
 
 		/*