sched/cpuacct: Add cpuacct_acount_field()

So we can remove open-coded cpuacct code in cputime.c.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/51553692.9060008@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 48b5e9184dcc..72bd971ea377 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -218,6 +218,29 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime)
         rcu_read_unlock();
 }
 
+/*
+ * Add user/system time to cpuacct.
+ *
+ * Note: it's the caller that updates the account of the root cgroup.
+ */
+void cpuacct_account_field(struct task_struct *p, int index, u64 val)
+{
+        struct kernel_cpustat *kcpustat;
+        struct cpuacct *ca;
+
+        if (unlikely(!cpuacct_subsys.active))
+                return;
+
+        rcu_read_lock();
+        ca = task_ca(p);
+        while (ca && (ca != &root_cpuacct)) {
+                kcpustat = this_cpu_ptr(ca->cpustat);
+                kcpustat->cpustat[index] += val;
+                ca = parent_ca(ca);
+        }
+        rcu_read_unlock();
+}
+
 void __init cpuacct_init(void)
 {
         root_cpuacct.cpustat = &kernel_cpustat;