sched: Change thread_group_cputime() to use for_each_thread()

Change thread_group_cputime() to use for_each_thread() instead of
buggy while_each_thread(). This also makes the pid_alive() check
unnecessary.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Frank Mayhar <fmayhar@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sanjay Rao <srao@redhat.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140813192000.GA19327@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 72fdf06..3e52836 100644 (file)
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -294,18 +294,12 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
        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 {
+       for_each_thread(tsk, t) {
                task_cputime(t, &utime, &stime);
                times->utime += utime;
                times->stime += stime;
                times->sum_exec_runtime += task_sched_runtime(t);
-       } while_each_thread(tsk, t);
-out:
+       }
        rcu_read_unlock();
 }