cputime: Move thread_group_cputime() to sched code

thread_group_cputime() is a general cputime API that is not only
used by posix cpu timer. Let's move this helper to sched code.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 8d859dae5bed..e56f138a23c7 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -288,6 +288,34 @@ static __always_inline bool steal_account_process_tick(void)
         return false;
 }
 
+/*
+ * Accumulate raw cputime values of dead tasks (sig->[us]time) and live
+ * tasks (sum on group iteration) belonging to @tsk's group.
+ */
+void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
+{
+        struct signal_struct *sig = tsk->signal;
+        struct task_struct *t;
+
+        times->utime = sig->utime;
+        times->stime = sig->stime;
+        times->sum_exec_runtime = sig->sum_sched_runtime;
+
+        rcu_read_lock();
+        /* make sure we can trust tsk->thread_group list */
+        if (!likely(pid_alive(tsk)))
+                goto out;
+
+        t = tsk;
+        do {
+                times->utime += t->utime;
+                times->stime += t->stime;
+                times->sum_exec_runtime += task_sched_runtime(t);
+        } while_each_thread(tsk, t);
+out:
+        rcu_read_unlock();
+}
+
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
 
 #ifdef CONFIG_IRQ_TIME_ACCOUNTING