mm: memcg: switch to css_tryget() in get_mem_cgroup_from_mm()

[linux-2.6-microblaze.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3631065..46ad252 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -484,7 +484,7 @@ ino_t page_cgroup_ino(struct page *page)
        unsigned long ino = 0;
 
        rcu_read_lock();
-       if (PageHead(page) && PageSlab(page))
+       if (PageSlab(page) && !PageTail(page))
                memcg = memcg_from_slab_page(page);
        else
                memcg = READ_ONCE(page->mem_cgroup);
@@ -960,7 +960,7 @@ struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
                        if (unlikely(!memcg))
                                memcg = root_mem_cgroup;
                }
-       } while (!css_tryget_online(&memcg->css));
+       } while (!css_tryget(&memcg->css));
        rcu_read_unlock();
        return memcg;
 }
@@ -2534,6 +2534,15 @@ retry:
                goto retry;
        }
 
+       /*
+        * Memcg doesn't have a dedicated reserve for atomic
+        * allocations. But like the global atomic pool, we need to
+        * put the burden of reclaim on regular allocation requests
+        * and let these go through as privileged allocations.
+        */
+       if (gfp_mask & __GFP_ATOMIC)
+               goto force;
+
        /*
         * Unlike in global OOM situations, memcg is not in a physical
         * memory shortage.  Allow dying and OOM-killed tasks to
@@ -5014,12 +5023,6 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
 {
        int node;
 
-       /*
-        * Flush percpu vmstats and vmevents to guarantee the value correctness
-        * on parent's and all ancestor levels.
-        */
-       memcg_flush_percpu_vmstats(memcg, false);
-       memcg_flush_percpu_vmevents(memcg);
        for_each_node(node)
                free_mem_cgroup_per_node_info(memcg, node);
        free_percpu(memcg->vmstats_percpu);
@@ -5030,6 +5033,12 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
 static void mem_cgroup_free(struct mem_cgroup *memcg)
 {
        memcg_wb_domain_exit(memcg);
+       /*
+        * Flush percpu vmstats and vmevents to guarantee the value correctness
+        * on parent's and all ancestor levels.
+        */
+       memcg_flush_percpu_vmstats(memcg, false);
+       memcg_flush_percpu_vmevents(memcg);
        __mem_cgroup_free(memcg);
 }