sched/core: Simplify helpers for rq clock update skip requests

By renaming the functions we can get rid of the skip parameter
and have better code redability. It makes zero sense to have
things such as:

  rq_clock_skip_update(rq, false)

When the skip request is in fact not going to happen. Ever. Rename
things such that we end up with:

  rq_clock_skip_update(rq)
  rq_clock_cancel_skipupdate(rq)

Signed-off-by: Davidlohr Bueso <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/20180404161539.nhadkff2aats74jh@linux-n805
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 28b68995a4172b4459b162b1544c06cd9fae36c2..550a07f648b66c8902ac3cbd213f342d1bd47ddf 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -874,7 +874,7 @@ void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
         * this case, we can save a useless back to back clock update.
         */
        if (task_on_rq_queued(rq->curr) && test_tsk_need_resched(rq->curr))
-               rq_clock_skip_update(rq, true);
+               rq_clock_skip_update(rq);
 }
 
 #ifdef CONFIG_SMP

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index d1c7bf7c7e5b954d673e1aa46f5ad5413b943c5d..e7b3008b85bb022076efec9a14cc6bc139da424a 100644 (file)
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1560,7 +1560,7 @@ static void yield_task_dl(struct rq *rq)
         * so we don't do microscopic update in schedule()
         * and double the fastpath cost.
         */
-       rq_clock_skip_update(rq, true);
+       rq_clock_skip_update(rq);
 }
 
 #ifdef CONFIG_SMP

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0951d1c58d2f5ffa6e19df144aa99ed876d14252..54dc31e7ab9b2b56bc24932740a18a49a9666065 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7089,7 +7089,7 @@ static void yield_task_fair(struct rq *rq)
                 * so we don't do microscopic update in schedule()
                 * and double the fastpath cost.
                 */
-               rq_clock_skip_update(rq, true);
+               rq_clock_skip_update(rq);
        }
 
        set_skip_buddy(se);

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index ad13e6242481d9acf7319d831a01f2b005a67e39..7aef6b4e885a5e058ce75bdbc4f5bf756a2783b2 100644 (file)
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -861,7 +861,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
                                 * 'runtime'.
                                 */
                                if (rt_rq->rt_nr_running && rq->curr == rq->idle)
-                                       rq_clock_skip_update(rq, false);
+                                       rq_clock_cancel_skipupdate(rq);
                        }
                        if (rt_rq->rt_time || rt_rq->rt_nr_running)
                                idle = 0;

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index c3deaee7a7a2f36c55cec7e9ece0157a44989359..15750c222ca2ad4c7e7e20806de1dd143a099f87 100644 (file)
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -976,13 +976,20 @@ static inline u64 rq_clock_task(struct rq *rq)
        return rq->clock_task;
 }
 
-static inline void rq_clock_skip_update(struct rq *rq, bool skip)
+static inline void rq_clock_skip_update(struct rq *rq)
 {
        lockdep_assert_held(&rq->lock);
-       if (skip)
-               rq->clock_update_flags |= RQCF_REQ_SKIP;
-       else
-               rq->clock_update_flags &= ~RQCF_REQ_SKIP;
+       rq->clock_update_flags |= RQCF_REQ_SKIP;
+}
+
+/*
+ * See rt task throttoling, which is the only time a skip
+ * request is cancelled.
+ */
+static inline void rq_clock_cancel_skipupdate(struct rq *rq)
+{
+       lockdep_assert_held(&rq->lock);
+       rq->clock_update_flags &= ~RQCF_REQ_SKIP;
 }
 
 struct rq_flags {