sched/deadline: Split cpudl_set() into cpudl_set() and cpudl_clear()

These 2 exercise independent code paths and need different arguments.

After this change, you call:

  cpudl_clear(cp, cpu);
  cpudl_set(cp, cpu, dl);

instead of:

  cpudl_set(cp, cpu, 0 /* dl */, 0 /* is_valid */);
  cpudl_set(cp, cpu, dl, 1 /* is_valid */);

Signed-off-by: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Luca Abeni <luca.abeni@unitn.it>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-dl@retis.sssup.it
Link: http://lkml.kernel.org/r/1471184828-12644-4-git-send-email-tommaso.cucinotta@sssup.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>

3 files changed, 40 insertions, 22 deletions

diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 0ace75a7a87b..e73119013c53 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -145,16 +145,15 @@ out:
 }
 
 /*
- * cpudl_set - update the cpudl max-heap
+ * cpudl_clear - remove a cpu from the cpudl max-heap
  * @cp: the cpudl max-heap context
  * @cpu: the target cpu
- * @dl: the new earliest deadline for this cpu
  *
  * Notes: assumes cpu_rq(cpu)->lock is locked
  *
  * Returns: (void)
  */
-void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
+void cpudl_clear(struct cpudl *cp, int cpu)
 {
         int old_idx, new_cpu;
         unsigned long flags;
@@ -162,17 +161,15 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
         WARN_ON(!cpu_present(cpu));
 
         raw_spin_lock_irqsave(&cp->lock, flags);
+
         old_idx = cp->elements[cpu].idx;
-        if (!is_valid) {
-                /* remove item */
-                if (old_idx == IDX_INVALID) {
-                        /*
-                         * Nothing to remove if old_idx was invalid.
-                         * This could happen if a rq_offline_dl is
-                         * called for a CPU without -dl tasks running.
-                         */
-                        goto out;
-                }
+        if (old_idx == IDX_INVALID) {
+                /*
+                 * Nothing to remove if old_idx was invalid.
+                 * This could happen if a rq_offline_dl is
+                 * called for a CPU without -dl tasks running.
+                 */
+        } else {
                 new_cpu = cp->elements[cp->size - 1].cpu;
                 cp->elements[old_idx].dl = cp->elements[cp->size - 1].dl;
                 cp->elements[old_idx].cpu = new_cpu;
@@ -180,11 +177,32 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
                 cp->elements[new_cpu].idx = old_idx;
                 cp->elements[cpu].idx = IDX_INVALID;
                 cpudl_heapify(cp, old_idx);
-                cpumask_set_cpu(cpu, cp->free_cpus);
 
-                goto out;
+                cpumask_set_cpu(cpu, cp->free_cpus);
         }
+        raw_spin_unlock_irqrestore(&cp->lock, flags);
+}
+
+/*
+ * cpudl_set - update the cpudl max-heap
+ * @cp: the cpudl max-heap context
+ * @cpu: the target cpu
+ * @dl: the new earliest deadline for this cpu
+ *
+ * Notes: assumes cpu_rq(cpu)->lock is locked
+ *
+ * Returns: (void)
+ */
+void cpudl_set(struct cpudl *cp, int cpu, u64 dl)
+{
+        int old_idx;
+        unsigned long flags;
+
+        WARN_ON(!cpu_present(cpu));
 
+        raw_spin_lock_irqsave(&cp->lock, flags);
+
+        old_idx = cp->elements[cpu].idx;
         if (old_idx == IDX_INVALID) {
                 int new_idx = cp->size++;
                 cp->elements[new_idx].dl = dl;
@@ -197,7 +215,6 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
                 cpudl_heapify(cp, old_idx);
         }
 
-out:
         raw_spin_unlock_irqrestore(&cp->lock, flags);
 }
 
diff --git a/kernel/sched/cpudeadline.h b/kernel/sched/cpudeadline.h
index fcbdf83fed7e..f7da8c55bba0 100644
--- a/kernel/sched/cpudeadline.h
+++ b/kernel/sched/cpudeadline.h
@@ -23,7 +23,8 @@ struct cpudl {
 #ifdef CONFIG_SMP
 int cpudl_find(struct cpudl *cp, struct task_struct *p,
                struct cpumask *later_mask);
-void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid);
+void cpudl_set(struct cpudl *cp, int cpu, u64 dl);
+void cpudl_clear(struct cpudl *cp, int cpu);
 int cpudl_init(struct cpudl *cp);
 void cpudl_set_freecpu(struct cpudl *cp, int cpu);
 void cpudl_clear_freecpu(struct cpudl *cp, int cpu);
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index d091f4a95416..18fb0b8fc911 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -798,7 +798,7 @@ static void inc_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
         if (dl_rq->earliest_dl.curr == 0 ||
             dl_time_before(deadline, dl_rq->earliest_dl.curr)) {
                 dl_rq->earliest_dl.curr = deadline;
-                cpudl_set(&rq->rd->cpudl, rq->cpu, deadline, 1);
+                cpudl_set(&rq->rd->cpudl, rq->cpu, deadline);
         }
 }
 
@@ -813,14 +813,14 @@ static void dec_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
         if (!dl_rq->dl_nr_running) {
                 dl_rq->earliest_dl.curr = 0;
                 dl_rq->earliest_dl.next = 0;
-                cpudl_set(&rq->rd->cpudl, rq->cpu, 0, 0);
+                cpudl_clear(&rq->rd->cpudl, rq->cpu);
         } else {
                 struct rb_node *leftmost = dl_rq->rb_leftmost;
                 struct sched_dl_entity *entry;
 
                 entry = rb_entry(leftmost, struct sched_dl_entity, rb_node);
                 dl_rq->earliest_dl.curr = entry->deadline;
-                cpudl_set(&rq->rd->cpudl, rq->cpu, entry->deadline, 1);
+                cpudl_set(&rq->rd->cpudl, rq->cpu, entry->deadline);
         }
 }
 
@@ -1671,7 +1671,7 @@ static void rq_online_dl(struct rq *rq)
 
         cpudl_set_freecpu(&rq->rd->cpudl, rq->cpu);
         if (rq->dl.dl_nr_running > 0)
-                cpudl_set(&rq->rd->cpudl, rq->cpu, rq->dl.earliest_dl.curr, 1);
+                cpudl_set(&rq->rd->cpudl, rq->cpu, rq->dl.earliest_dl.curr);
 }
 
 /* Assumes rq->lock is held */
@@ -1680,7 +1680,7 @@ static void rq_offline_dl(struct rq *rq)
         if (rq->dl.overloaded)
                 dl_clear_overload(rq);
 
-        cpudl_set(&rq->rd->cpudl, rq->cpu, 0, 0);
+        cpudl_clear(&rq->rd->cpudl, rq->cpu);
         cpudl_clear_freecpu(&rq->rd->cpudl, rq->cpu);
 }