[PATCH v4 1/4] account guest time per-cgroup as well.

[Glauber Costa <glommer@parallels.com>]

We already track multiple tick statistics per-cgroup, using
the task_group_account_field facility. This patch accounts
guest_time in that manner as well.

Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Paul Turner <pjt@google.com>
---
 kernel/sched/core.c |   10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 39eb601..220d416 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2717,8 +2717,6 @@ void account_user_time(struct task_struct *p, cputime_t cputime,
 static void account_guest_time(struct task_struct *p, cputime_t cputime,
 			       cputime_t cputime_scaled)
 {
-	u64 *cpustat = kcpustat_this_cpu->cpustat;
-
 	/* Add guest time to process. */
 	p->utime += cputime;
 	p->utimescaled += cputime_scaled;
@@ -2727,11 +2725,11 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime,
 
 	/* Add guest time to cpustat. */
 	if (TASK_NICE(p) > 0) {
-		cpustat[CPUTIME_NICE] += (__force u64) cputime;
-		cpustat[CPUTIME_GUEST_NICE] += (__force u64) cputime;
+		task_group_account_field(p, CPUTIME_NICE, (__force u64) cputime);
+		task_group_account_field(p, CPUTIME_GUEST, (__force u64) cputime);
 	} else {
-		cpustat[CPUTIME_USER] += (__force u64) cputime;
-		cpustat[CPUTIME_GUEST] += (__force u64) cputime;
+		task_group_account_field(p, CPUTIME_USER, (__force u64) cputime);
+		task_group_account_field(p, CPUTIME_GUEST, (__force u64) cputime);
 	}
 }
 
-- 
1.7.10.2