sched: Remove ASYM_GRAN feature

This features has been enabled for quite a while, after testing showed that
easing preemption for light tasks was harmful to high priority threads.

Remove the feature flag.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1268301675.6785.44.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 11 insertions, 17 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 1d99535b0928..9357ecdb7f6b 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1583,24 +1583,18 @@ wakeup_gran(struct sched_entity *curr, struct sched_entity *se)
         /*
          * Since its curr running now, convert the gran from real-time
          * to virtual-time in his units.
+         *
+         * By using 'se' instead of 'curr' we penalize light tasks, so
+         * they get preempted easier. That is, if 'se' < 'curr' then
+         * the resulting gran will be larger, therefore penalizing the
+         * lighter, if otoh 'se' > 'curr' then the resulting gran will
+         * be smaller, again penalizing the lighter task.
+         *
+         * This is especially important for buddies when the leftmost
+         * task is higher priority than the buddy.
          */
-        if (sched_feat(ASYM_GRAN)) {
-                /*
-                 * By using 'se' instead of 'curr' we penalize light tasks, so
-                 * they get preempted easier. That is, if 'se' < 'curr' then
-                 * the resulting gran will be larger, therefore penalizing the
-                 * lighter, if otoh 'se' > 'curr' then the resulting gran will
-                 * be smaller, again penalizing the lighter task.
-                 *
-                 * This is especially important for buddies when the leftmost
-                 * task is higher priority than the buddy.
-                 */
-                if (unlikely(se->load.weight != NICE_0_LOAD))
-                        gran = calc_delta_fair(gran, se);
-        } else {
-                if (unlikely(curr->load.weight != NICE_0_LOAD))
-                        gran = calc_delta_fair(gran, curr);
-        }
+        if (unlikely(se->load.weight != NICE_0_LOAD))
+                gran = calc_delta_fair(gran, se);
 
         return gran;
 }