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, 5 insertions, 2 deletions

diff --git a/kernel/delayacct.c b/kernel/delayacct.c
index 418b3f7053aa..d473988c1d0b 100644
--- a/kernel/delayacct.c
+++ b/kernel/delayacct.c
@@ -106,6 +106,7 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
         unsigned long long t2, t3;
         unsigned long flags;
         struct timespec ts;
+        cputime_t utime, stime, stimescaled, utimescaled;
 
         /* Though tsk->delays accessed later, early exit avoids
          * unnecessary returning of other data
@@ -114,12 +115,14 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
                 goto done;
 
         tmp = (s64)d->cpu_run_real_total;
-        cputime_to_timespec(tsk->utime + tsk->stime, &ts);
+        task_cputime(tsk, &utime, &stime);
+        cputime_to_timespec(utime + stime, &ts);
         tmp += timespec_to_ns(&ts);
         d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
 
         tmp = (s64)d->cpu_scaled_run_real_total;
-        cputime_to_timespec(tsk->utimescaled + tsk->stimescaled, &ts);
+        task_cputime_scaled(tsk, &utimescaled, &stimescaled);
+        cputime_to_timespec(utimescaled + stimescaled, &ts);
         tmp += timespec_to_ns(&ts);
         d->cpu_scaled_run_real_total =
                 (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp;