ARM: PL08x: rename 'desc_list' as 'pend_list'

[mv-sheeva.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9a99cfaf0a19025f6020c106d56e1ce28d6499b4..7a22b41292115f78dc039ebf5e271090dc5a8f9d 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -61,7 +61,14 @@ struct mem_cgroup *root_mem_cgroup __read_mostly;
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
 int do_swap_account __read_mostly;
-static int really_do_swap_account __initdata = 1; /* for remember boot option*/
+
+/* for remember boot option*/
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED
+static int really_do_swap_account __initdata = 1;
+#else
+static int really_do_swap_account __initdata = 0;
+#endif
+
 #else
 #define do_swap_account                (0)
 #endif
@@ -278,13 +285,14 @@ enum move_type {
 
 /* "mc" and its members are protected by cgroup_mutex */
 static struct move_charge_struct {
-       spinlock_t        lock; /* for from, to, moving_task */
+       spinlock_t        lock; /* for from, to */
        struct mem_cgroup *from;
        struct mem_cgroup *to;
        unsigned long precharge;
        unsigned long moved_charge;
        unsigned long moved_swap;
        struct task_struct *moving_task;        /* a task moving charges */
+       struct mm_struct *mm;
        wait_queue_head_t waitq;                /* a waitq for other context */
 } mc = {
        .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
@@ -2152,7 +2160,7 @@ static void __mem_cgroup_move_account(struct page_cgroup *pc,
 {
        VM_BUG_ON(from == to);
        VM_BUG_ON(PageLRU(pc->page));
-       VM_BUG_ON(!PageCgroupLocked(pc));
+       VM_BUG_ON(!page_is_cgroup_locked(pc));
        VM_BUG_ON(!PageCgroupUsed(pc));
        VM_BUG_ON(pc->mem_cgroup != from);
 
@@ -4208,15 +4216,17 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
 
        memset(mem, 0, size);
        mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
-       if (!mem->stat) {
-               if (size < PAGE_SIZE)
-                       kfree(mem);
-               else
-                       vfree(mem);
-               mem = NULL;
-       }
+       if (!mem->stat)
+               goto out_free;
        spin_lock_init(&mem->pcp_counter_lock);
        return mem;
+
+out_free:
+       if (size < PAGE_SIZE)
+               kfree(mem);
+       else
+               vfree(mem);
+       return NULL;
 }
 
 /*
@@ -4629,7 +4639,7 @@ static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
        unsigned long precharge;
        struct vm_area_struct *vma;
 
-       down_read(&mm->mmap_sem);
+       /* We've already held the mmap_sem */
        for (vma = mm->mmap; vma; vma = vma->vm_next) {
                struct mm_walk mem_cgroup_count_precharge_walk = {
                        .pmd_entry = mem_cgroup_count_precharge_pte_range,
@@ -4641,7 +4651,6 @@ static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
                walk_page_range(vma->vm_start, vma->vm_end,
                                        &mem_cgroup_count_precharge_walk);
        }
-       up_read(&mm->mmap_sem);
 
        precharge = mc.precharge;
        mc.precharge = 0;
@@ -4692,11 +4701,16 @@ static void mem_cgroup_clear_mc(void)
 
                mc.moved_swap = 0;
        }
+       if (mc.mm) {
+               up_read(&mc.mm->mmap_sem);
+               mmput(mc.mm);
+       }
        spin_lock(&mc.lock);
        mc.from = NULL;
        mc.to = NULL;
-       mc.moving_task = NULL;
        spin_unlock(&mc.lock);
+       mc.moving_task = NULL;
+       mc.mm = NULL;
        mem_cgroup_end_move(from);
        memcg_oom_recover(from);
        memcg_oom_recover(to);
@@ -4722,12 +4736,21 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
                        return 0;
                /* We move charges only when we move a owner of the mm */
                if (mm->owner == p) {
+                       /*
+                        * We do all the move charge works under one mmap_sem to
+                        * avoid deadlock with down_write(&mmap_sem)
+                        * -> try_charge() -> if (mc.moving_task) -> sleep.
+                        */
+                       down_read(&mm->mmap_sem);
+
                        VM_BUG_ON(mc.from);
                        VM_BUG_ON(mc.to);
                        VM_BUG_ON(mc.precharge);
                        VM_BUG_ON(mc.moved_charge);
                        VM_BUG_ON(mc.moved_swap);
                        VM_BUG_ON(mc.moving_task);
+                       VM_BUG_ON(mc.mm);
+
                        mem_cgroup_start_move(from);
                        spin_lock(&mc.lock);
                        mc.from = from;
@@ -4735,14 +4758,16 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
                        mc.precharge = 0;
                        mc.moved_charge = 0;
                        mc.moved_swap = 0;
-                       mc.moving_task = current;
                        spin_unlock(&mc.lock);
+                       mc.moving_task = current;
+                       mc.mm = mm;
 
                        ret = mem_cgroup_precharge_mc(mm);
                        if (ret)
                                mem_cgroup_clear_mc();
-               }
-               mmput(mm);
+                       /* We call up_read() and mmput() in clear_mc(). */
+               } else
+                       mmput(mm);
        }
        return ret;
 }
@@ -4830,7 +4855,7 @@ static void mem_cgroup_move_charge(struct mm_struct *mm)
        struct vm_area_struct *vma;
 
        lru_add_drain_all();
-       down_read(&mm->mmap_sem);
+       /* We've already held the mmap_sem */
        for (vma = mm->mmap; vma; vma = vma->vm_next) {
                int ret;
                struct mm_walk mem_cgroup_move_charge_walk = {
@@ -4849,7 +4874,6 @@ static void mem_cgroup_move_charge(struct mm_struct *mm)
                         */
                        break;
        }
-       up_read(&mm->mmap_sem);
 }
 
 static void mem_cgroup_move_task(struct cgroup_subsys *ss,
@@ -4858,17 +4882,11 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss,
                                struct task_struct *p,
                                bool threadgroup)
 {
-       struct mm_struct *mm;
-
-       if (!mc.to)
+       if (!mc.mm)
                /* no need to move charge */
                return;
 
-       mm = get_task_mm(p);
-       if (mm) {
-               mem_cgroup_move_charge(mm);
-               mmput(mm);
-       }
+       mem_cgroup_move_charge(mc.mm);
        mem_cgroup_clear_mc();
 }
 #else  /* !CONFIG_MMU */
@@ -4909,10 +4927,20 @@ struct cgroup_subsys mem_cgroup_subsys = {
 };
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+static int __init enable_swap_account(char *s)
+{
+       /* consider enabled if no parameter or 1 is given */
+       if (!s || !strcmp(s, "1"))
+               really_do_swap_account = 1;
+       else if (!strcmp(s, "0"))
+               really_do_swap_account = 0;
+       return 1;
+}
+__setup("swapaccount", enable_swap_account);
 
 static int __init disable_swap_account(char *s)
 {
-       really_do_swap_account = 0;
+       enable_swap_account("0");
        return 1;
 }
 __setup("noswapaccount", disable_swap_account);