rq_clock() is called from sched_info_{depart,arrive}() after resetting
RQCF_ACT_SKIP but prior to a call to update_rq_clock().

In preparation for pending patches that check whether the rq clock has
been updated inside of a pin context before rq_clock() is called, move
the reset of rq->clock_skip_update immediately before unpinning the rq
lock.

This will avoid the new warnings which check if update_rq_clock() is
being actively skipped.

Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Mike Galbraith <umgwanakikb...@gmail.com>
Cc: Mel Gorman <mgor...@techsingularity.net>
Signed-off-by: Matt Fleming <m...@codeblueprint.co.uk>
---
 kernel/sched/core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 7950c372fca0..1254629c9f2f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2871,6 +2871,9 @@ context_switch(struct rq *rq, struct task_struct *prev,
                prev->active_mm = NULL;
                rq->prev_mm = oldmm;
        }
+
+       rq->clock_skip_update = 0;
+
        /*
         * Since the runqueue lock will be released by the next
         * task (which is an invalid locking op but in the case
@@ -3387,7 +3390,6 @@ static void __sched notrace __schedule(bool preempt)
        next = pick_next_task(rq, prev, &rf);
        clear_tsk_need_resched(prev);
        clear_preempt_need_resched();
-       rq->clock_skip_update = 0;
 
        if (likely(prev != next)) {
                rq->nr_switches++;
@@ -3397,6 +3399,7 @@ static void __sched notrace __schedule(bool preempt)
                trace_sched_switch(preempt, prev, next);
                rq = context_switch(rq, prev, next, &rf); /* unlocks the rq */
        } else {
+               rq->clock_skip_update = 0;
                rq_unpin_lock(rq, &rf);
                raw_spin_unlock_irq(&rq->lock);
        }
-- 
2.9.3

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