sched/core: Add missing update_rq_clock() call in set_user_nice()

Address this rq-clock update bug:

  WARNING: CPU: 30 PID: 195 at ../kernel/sched/sched.h:797 set_next_entity()
  rq->clock_update_flags < RQCF_ACT_SKIP

  Call Trace:
    dump_stack()
    __warn()
    warn_slowpath_fmt()
    set_next_entity()
    ? _raw_spin_lock()
    set_curr_task_fair()
    set_user_nice.part.85()
    set_user_nice()
    create_worker()
    worker_thread()
    kthread()
    ret_from_fork()

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b7f7f215b51ba1371c44065036a968423d007e14..d2338927773aae4152d5017b35f3626fb64af664 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3752,6 +3752,8 @@ void set_user_nice(struct task_struct *p, long nice)
         * the task might be in the middle of scheduling on another CPU.
         */
        rq = task_rq_lock(p, &rf);
+       update_rq_clock(rq);
+
        /*
         * The RT priorities are set via sched_setscheduler(), but we still
         * allow the 'normal' nice value to be set - but as expected