sched/accounting: Fix user/system tick double accounting

Now that we're  pointing cpuacct's root cgroup to cpustat and accounting
through task_group_account_field(), we should not access cpustat directly.
Since it is done anyway inside the acessor function, we end up accounting
it twice, which is wrong.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1322863119-14225-2-git-send-email-glommer@parallels.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3e078f26cb6772ab9cab833c18b42082053ec568..6e860100d11c6b34953acef8c76aa4dd5bd0bbe5 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2601,8 +2601,6 @@ static inline void task_group_account_field(struct task_struct *p,
 void account_user_time(struct task_struct *p, cputime_t cputime,
                       cputime_t cputime_scaled)
 {
-       u64 *cpustat = kcpustat_this_cpu->cpustat;
-       u64 tmp;
        int index;
 
        /* Add user time to process. */
@@ -2610,13 +2608,11 @@ void account_user_time(struct task_struct *p, cputime_t cputime,
        p->utimescaled = cputime_add(p->utimescaled, cputime_scaled);
        account_group_user_time(p, cputime);
 
-       /* Add user time to cpustat. */
-       tmp = cputime_to_cputime64(cputime);
-
        index = (TASK_NICE(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
-       cpustat[index] += tmp;
 
+       /* Add user time to cpustat. */
        task_group_account_field(p, index, cputime);
+
        /* Account for user time used */
        acct_update_integrals(p);
 }
@@ -2662,16 +2658,12 @@ static inline
 void __account_system_time(struct task_struct *p, cputime_t cputime,
                        cputime_t cputime_scaled, int index)
 {
-       u64 tmp = cputime_to_cputime64(cputime);
-       u64 *cpustat = kcpustat_this_cpu->cpustat;
-
        /* Add system time to process. */
        p->stime = cputime_add(p->stime, cputime);
        p->stimescaled = cputime_add(p->stimescaled, cputime_scaled);
        account_group_system_time(p, cputime);
 
        /* Add system time to cpustat. */
-       cpustat[index] += tmp;
        task_group_account_field(p, index, cputime);
 
        /* Account for system time used */