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, 3 insertions, 1 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 3046a503242c..e5d5e8e1e030 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -224,11 +224,13 @@ void clear_tasks_mm_cpumask(int cpu)
 static inline void check_for_tasks(int cpu)
 {
         struct task_struct *p;
+        cputime_t utime, stime;
 
         write_lock_irq(&tasklist_lock);
         for_each_process(p) {
+                task_cputime(p, &utime, &stime);
                 if (task_cpu(p) == cpu && p->state == TASK_RUNNING &&
-                    (p->utime || p->stime))
+                    (utime || stime))
                         printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d "
                                 "(state = %ld, flags = %x)\n",
                                 p->comm, task_pid_nr(p), cpu,