perf cgroup: Clean up perf_cgroup_create()

- Use kzalloc() to replace kmalloc() + memset().

- Remove redundant initialization, since alloc_percpu() returns
  zero-filled percpu memory.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4D6F347E.2010806@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 10 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index b00209544d57..193b1900e64f 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -7346,26 +7346,17 @@ static struct cgroup_subsys_state *perf_cgroup_create(
         struct cgroup_subsys *ss, struct cgroup *cont)
 {
         struct perf_cgroup *jc;
-        struct perf_cgroup_info *t;
-        int c;
 
-        jc = kmalloc(sizeof(*jc), GFP_KERNEL);
+        jc = kzalloc(sizeof(*jc), GFP_KERNEL);
         if (!jc)
                 return ERR_PTR(-ENOMEM);
 
-        memset(jc, 0, sizeof(*jc));
-
         jc->info = alloc_percpu(struct perf_cgroup_info);
         if (!jc->info) {
                 kfree(jc);
                 return ERR_PTR(-ENOMEM);
         }
 
-        for_each_possible_cpu(c) {
-                t = per_cpu_ptr(jc->info, c);
-                t->time = 0;
-                t->timestamp = 0;
-        }
         return &jc->css;
 }