sched/core: Make policy-testing consistent

Most of the policy-tests are done via the <class>_policy() helpers with
the notable exception of idle. A new wrapper for valid_policy() has also
been added to improve readability  in set_load_weight().

This commit does not change the logical behavior of the scheduler core.

Signed-off-by: Henrik Austad <henrik@austad.us>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1441810841-4756-1-git-send-email-henrik@austad.us
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 12 insertions, 6 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6ab415aa15c4..1b30b5b24a4a 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -817,7 +817,7 @@ static void set_load_weight(struct task_struct *p)
         /*
          * SCHED_IDLE tasks get minimal weight:
          */
-        if (p->policy == SCHED_IDLE) {
+        if (idle_policy(p->policy)) {
                 load->weight = scale_load(WEIGHT_IDLEPRIO);
                 load->inv_weight = WMULT_IDLEPRIO;
                 return;
@@ -3733,10 +3733,7 @@ recheck:
         } else {
                 reset_on_fork = !!(attr->sched_flags & SCHED_FLAG_RESET_ON_FORK);
 
-                if (policy != SCHED_DEADLINE &&
-                                policy != SCHED_FIFO && policy != SCHED_RR &&
-                                policy != SCHED_NORMAL && policy != SCHED_BATCH &&
-                                policy != SCHED_IDLE)
+                if (!valid_policy(policy))
                         return -EINVAL;
         }
 
@@ -3792,7 +3789,7 @@ recheck:
                  * Treat SCHED_IDLE as nice 20. Only allow a switch to
                  * SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
                  */
-                if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) {
+                if (idle_policy(p->policy) && !idle_policy(policy)) {
                         if (!can_nice(p, task_nice(p)))
                                 return -EPERM;
                 }
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 167ab4844ee6..3845a711c65e 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -84,6 +84,10 @@ static inline void update_cpu_load_active(struct rq *this_rq) { }
  */
 #define RUNTIME_INF     ((u64)~0ULL)
 
+static inline int idle_policy(int policy)
+{
+        return policy == SCHED_IDLE;
+}
 static inline int fair_policy(int policy)
 {
         return policy == SCHED_NORMAL || policy == SCHED_BATCH;
@@ -98,6 +102,11 @@ static inline int dl_policy(int policy)
 {
         return policy == SCHED_DEADLINE;
 }
+static inline bool valid_policy(int policy)
+{
+        return idle_policy(policy) || fair_policy(policy) ||
+                rt_policy(policy) || dl_policy(policy);
+}
 
 static inline int task_has_rt_policy(struct task_struct *p)
 {