cputime: Use accessors to read task cputime stats

This is in preparation for the full dynticks feature. While
remotely reading the cputime of a task running in a full
dynticks CPU, we'll need to do some extra-computation. This
way we can account the time it spent tickless in userspace
since its last cputime snapshot.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 8 insertions, 4 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 372771e948c2..776a45a3661b 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1638,6 +1638,7 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
         unsigned long flags;
         struct sighand_struct *psig;
         bool autoreap = false;
+        cputime_t utime, stime;
 
         BUG_ON(sig == -1);
 
@@ -1675,8 +1676,9 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
                                        task_uid(tsk));
         rcu_read_unlock();
 
-        info.si_utime = cputime_to_clock_t(tsk->utime + tsk->signal->utime);
-        info.si_stime = cputime_to_clock_t(tsk->stime + tsk->signal->stime);
+        task_cputime(tsk, &utime, &stime);
+        info.si_utime = cputime_to_clock_t(utime + tsk->signal->utime);
+        info.si_stime = cputime_to_clock_t(stime + tsk->signal->stime);
 
         info.si_status = tsk->exit_code & 0x7f;
         if (tsk->exit_code & 0x80)
@@ -1740,6 +1742,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
         unsigned long flags;
         struct task_struct *parent;
         struct sighand_struct *sighand;
+        cputime_t utime, stime;
 
         if (for_ptracer) {
                 parent = tsk->parent;
@@ -1758,8 +1761,9 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
         info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk));
         rcu_read_unlock();
 
-        info.si_utime = cputime_to_clock_t(tsk->utime);
-        info.si_stime = cputime_to_clock_t(tsk->stime);
+        task_cputime(tsk, &utime, &stime);
+        info.si_utime = cputime_to_clock_t(utime);
+        info.si_stime = cputime_to_clock_t(stime);
 
         info.si_code = why;
         switch (why) {