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Diffstat (limited to 'mm/memcontrol.c')
-rw-r--r--mm/memcontrol.c22
1 files changed, 20 insertions, 2 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 960371788687..f29157288b7d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3386,11 +3386,28 @@ static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg)
#define MEM_CGROUP_ID_MAX ((1UL << MEM_CGROUP_ID_SHIFT) - 1)
static DEFINE_IDR(mem_cgroup_idr);
+static DEFINE_SPINLOCK(memcg_idr_lock);
+
+static int mem_cgroup_alloc_id(void)
+{
+ int ret;
+
+ idr_preload(GFP_KERNEL);
+ spin_lock(&memcg_idr_lock);
+ ret = idr_alloc(&mem_cgroup_idr, NULL, 1, MEM_CGROUP_ID_MAX + 1,
+ GFP_NOWAIT);
+ spin_unlock(&memcg_idr_lock);
+ idr_preload_end();
+ return ret;
+}
static void mem_cgroup_id_remove(struct mem_cgroup *memcg)
{
if (memcg->id.id > 0) {
+ spin_lock(&memcg_idr_lock);
idr_remove(&mem_cgroup_idr, memcg->id.id);
+ spin_unlock(&memcg_idr_lock);
+
memcg->id.id = 0;
}
}
@@ -3524,8 +3541,7 @@ static struct mem_cgroup *mem_cgroup_alloc(struct mem_cgroup *parent)
if (!memcg)
return ERR_PTR(error);
- memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL,
- 1, MEM_CGROUP_ID_MAX + 1, GFP_KERNEL);
+ memcg->id.id = mem_cgroup_alloc_id();
if (memcg->id.id < 0) {
error = memcg->id.id;
goto fail;
@@ -3667,7 +3683,9 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css)
* publish it here at the end of onlining. This matches the
* regular ID destruction during offlining.
*/
+ spin_lock(&memcg_idr_lock);
idr_replace(&mem_cgroup_idr, memcg, memcg->id.id);
+ spin_unlock(&memcg_idr_lock);
return 0;
offline_kmem: