alinux: sched/cputime: Fix guest cputime of cpuacct.proc_stat

to #26424323

For container only cases, since guest cputime is always 0, we don't
calculate it and return 0 directly before.

Howerver, when running vm inside a cgroup, we expect the cgroup to
maintain guest cputime correctly.
Tested-by: NYihao Wu <wuyihao@linux.alibaba.com>
Signed-off-by: NShanpei Chen <shanpeic@linux.alibaba.com>
Reviewed-by: NShanpei Chen <shanpeic@linux.alibaba.com>
Signed-off-by: NYihao Wu <wuyihao@linux.alibaba.com>

kernel/sched/cpuacct.c

@@ -360,7 +360,8 @@ static void __cpuacct_get_usage_result(struct cpuacct *ca, int cpu,
 		res->steal = se->statistics.wait_sum;
 	else
 		res->steal = 0;
-	res->guest = res->guest_nice = 0; /* currently always 0 */
+	res->guest = kcpustat->cpustat[CPUTIME_GUEST];
+	res->guest_nice = kcpustat->cpustat[CPUTIME_GUEST_NICE];
 }
 
 static int cpuacct_proc_stats_show(struct seq_file *sf, void *v)
@@ -392,6 +393,7 @@ static int cpuacct_proc_stats_show(struct seq_file *sf, void *v)
 			softirq += res.softirq;
 			steal += res.steal;
 			guest += res.guest;
+			guest += res.guest_nice;
 			iowait += res.iowait;
 			idle += res.idle;
 		}
@@ -406,6 +408,7 @@ static int cpuacct_proc_stats_show(struct seq_file *sf, void *v)
 			irq += kcpustat->cpustat[CPUTIME_IRQ];
 			softirq += kcpustat->cpustat[CPUTIME_SOFTIRQ];
 			guest += kcpustat->cpustat[CPUTIME_GUEST];
+			guest += kcpustat->cpustat[CPUTIME_GUEST_NICE];
 			idle += get_idle_time(cpu);
 			iowait += get_iowait_time(cpu);
 			steal += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];

kernel/sched/cputime.c

@@ -137,8 +137,6 @@ void account_user_time(struct task_struct *p, u64 cputime)
  */
 void account_guest_time(struct task_struct *p, u64 cputime)
 {
-	u64 *cpustat = kcpustat_this_cpu->cpustat;
-
 	/* Add guest time to process. */
 	p->utime += cputime;
 	account_group_user_time(p, cputime);
@@ -146,11 +144,11 @@ void account_guest_time(struct task_struct *p, u64 cputime)
 
 	/* Add guest time to cpustat. */
 	if (task_nice(p) > 0) {
-		cpustat[CPUTIME_NICE] += cputime;
-		cpustat[CPUTIME_GUEST_NICE] += cputime;
+		task_group_account_field(p, CPUTIME_NICE, cputime);
+		task_group_account_field(p, CPUTIME_GUEST_NICE, cputime);
 	} else {
-		cpustat[CPUTIME_USER] += cputime;
-		cpustat[CPUTIME_GUEST] += cputime;
+		task_group_account_field(p, CPUTIME_USER, cputime);
+		task_group_account_field(p, CPUTIME_GUEST, cputime);
 	}
 }