memcg: remove pcp_counter_lock

Commit 733a572e66d2 ("memcg: make mem_cgroup_read_{stat|event}() iterate
possible cpus instead of online") removed the last use of the per memcg
pcp_counter_lock but forgot to remove the variable.

Kill the vestigial variable.

Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index ad800e62cb7a603fdd5f7fb1a752edb03417dbb4..6452ff4c463fd8715edc9a5043bc812521a18d6a 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -242,7 +242,6 @@ struct mem_cgroup {
         * percpu counter.
         */
        struct mem_cgroup_stat_cpu __percpu *stat;
-       spinlock_t pcp_counter_lock;
 
 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
        struct cg_proto tcp_mem;

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 03cc0a742ff1ee25c2812afdff3334a48e86e654..1fedbde68f595c2b83d5aa84962a667c1ada120a 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4185,7 +4185,6 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
        if (memcg_wb_domain_init(memcg, GFP_KERNEL))
                goto out_free_stat;
 
-       spin_lock_init(&memcg->pcp_counter_lock);
        return memcg;
 
 out_free_stat: