Merge branch 'akpm-current/current'

[karo-tx-linux.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 34cd0df82a8b57ac47e2916964384af01d162385..48735e7c617b3d9454b35ac5ea6a4f9ff5ef472c 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -435,7 +435,7 @@ struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page)
 
        memcg = page->mem_cgroup;
 
-       if (!memcg || !cgroup_on_dfl(memcg->css.cgroup))
+       if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
                memcg = root_mem_cgroup;
 
        rcu_read_unlock();
@@ -2892,7 +2892,7 @@ static int memcg_activate_kmem(struct mem_cgroup *memcg,
         * of course permitted.
         */
        mutex_lock(&memcg_create_mutex);
-       if (cgroup_has_tasks(memcg->css.cgroup) ||
+       if (cgroup_is_populated(memcg->css.cgroup) ||
            (memcg->use_hierarchy && memcg_has_children(memcg)))
                err = -EBUSY;
        mutex_unlock(&memcg_create_mutex);
@@ -3707,44 +3707,43 @@ struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
 /**
  * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
  * @wb: bdi_writeback in question
- * @pavail: out parameter for number of available pages
+ * @pfilepages: out parameter for number of file pages
+ * @pheadroom: out parameter for number of allocatable pages according to memcg
  * @pdirty: out parameter for number of dirty pages
  * @pwriteback: out parameter for number of pages under writeback
  *
- * Determine the numbers of available, dirty, and writeback pages in @wb's
- * memcg.  Dirty and writeback are self-explanatory.  Available is a bit
- * more involved.
+ * Determine the numbers of file, headroom, dirty, and writeback pages in
+ * @wb's memcg.  File, dirty and writeback are self-explanatory.  Headroom
+ * is a bit more involved.
  *
- * A memcg's headroom is "min(max, high) - used".  The available memory is
- * calculated as the lowest headroom of itself and the ancestors plus the
- * number of pages already being used for file pages.  Note that this
- * doesn't consider the actual amount of available memory in the system.
- * The caller should further cap *@pavail accordingly.
+ * A memcg's headroom is "min(max, high) - used".  In the hierarchy, the
+ * headroom is calculated as the lowest headroom of itself and the
+ * ancestors.  Note that this doesn't consider the actual amount of
+ * available memory in the system.  The caller should further cap
+ * *@pheadroom accordingly.
  */
-void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pavail,
-                        unsigned long *pdirty, unsigned long *pwriteback)
+void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
+                        unsigned long *pheadroom, unsigned long *pdirty,
+                        unsigned long *pwriteback)
 {
        struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
        struct mem_cgroup *parent;
-       unsigned long head_room = PAGE_COUNTER_MAX;
-       unsigned long file_pages;
 
        *pdirty = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_DIRTY);
 
        /* this should eventually include NR_UNSTABLE_NFS */
        *pwriteback = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK);
+       *pfilepages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) |
+                                                    (1 << LRU_ACTIVE_FILE));
+       *pheadroom = PAGE_COUNTER_MAX;
 
-       file_pages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) |
-                                                   (1 << LRU_ACTIVE_FILE));
        while ((parent = parent_mem_cgroup(memcg))) {
                unsigned long ceiling = min(memcg->memory.limit, memcg->high);
                unsigned long used = page_counter_read(&memcg->memory);
 
-               head_room = min(head_room, ceiling - min(ceiling, used));
+               *pheadroom = min(*pheadroom, ceiling - min(ceiling, used));
                memcg = parent;
        }
-
-       *pavail = file_pages + head_room;
 }
 
 #else  /* CONFIG_CGROUP_WRITEBACK */
@@ -4033,8 +4032,7 @@ static struct cftype mem_cgroup_legacy_files[] = {
        {
                .name = "cgroup.event_control",         /* XXX: for compat */
                .write = memcg_write_event_control,
-               .flags = CFTYPE_NO_PREFIX,
-               .mode = S_IWUGO,
+               .flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE,
        },
        {
                .name = "swappiness",
@@ -4780,7 +4778,7 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
 {
        struct mem_cgroup *memcg = mem_cgroup_from_css(css);
        struct mem_cgroup *from;
-       struct task_struct *p;
+       struct task_struct *leader, *p;
        struct mm_struct *mm;
        unsigned long move_flags;
        int ret = 0;
@@ -4794,7 +4792,20 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
        if (!move_flags)
                return 0;
 
-       p = cgroup_taskset_first(tset);
+       /*
+        * Multi-process migrations only happen on the default hierarchy
+        * where charge immigration is not used.  Perform charge
+        * immigration if @tset contains a leader and whine if there are
+        * multiple.
+        */
+       p = NULL;
+       cgroup_taskset_for_each_leader(leader, tset) {
+               WARN_ON_ONCE(p);
+               p = leader;
+       }
+       if (!p)
+               return 0;
+
        from = mem_cgroup_from_task(p);
 
        VM_BUG_ON(from == memcg);
@@ -5001,7 +5012,7 @@ static void mem_cgroup_bind(struct cgroup_subsys_state *root_css)
         * guarantees that @root doesn't have any children, so turning it
         * on for the root memcg is enough.
         */
-       if (cgroup_on_dfl(root_css->cgroup))
+       if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
                root_mem_cgroup->use_hierarchy = true;
        else
                root_mem_cgroup->use_hierarchy = false;
@@ -5146,6 +5157,7 @@ static struct cftype memory_files[] = {
        {
                .name = "events",
                .flags = CFTYPE_NOT_ON_ROOT,
+               .file_offset = offsetof(struct mem_cgroup, events_file),
                .seq_show = memory_events_show,
        },
        { }     /* terminate */