X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fsched_features.h;h=83c66e8ad3ee314704456e14dfc23607d00c5f0d;hb=1f522509c77a5dea8dc384b735314f03908a6415;hp=afa549166d8dd7abcb752bd6baa39d29b476ceee;hpb=a7be37ac8e1565e00880531f4e2aff421a21c803;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index afa5491..83c66e8 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -1,9 +1,63 @@
-SCHED_FEAT(NEW_FAIR_SLEEPERS, 1)
-SCHED_FEAT(NORMALIZED_SLEEPER, 1)
-SCHED_FEAT(WAKEUP_PREEMPT, 1)
+/*
+ * Only give sleepers 50% of their service deficit. This allows
+ * them to run sooner, but does not allow tons of sleepers to
+ * rip the spread apart.
+ */
+SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1)
+
+/*
+ * Place new tasks ahead so that they do not starve already running
+ * tasks
+ */
 SCHED_FEAT(START_DEBIT, 1)
+
+/*
+ * Should wakeups try to preempt running tasks.
+ */
+SCHED_FEAT(WAKEUP_PREEMPT, 1)
+
+/*
+ * Based on load and program behaviour, see if it makes sense to place
+ * a newly woken task on the same cpu as the task that woke it --
+ * improve cache locality. Typically used with SYNC wakeups as
+ * generated by pipes and the like, see also SYNC_WAKEUPS.
+ */
 SCHED_FEAT(AFFINE_WAKEUPS, 1)
+
+/*
+ * Prefer to schedule the task we woke last (assuming it failed
+ * wakeup-preemption), since its likely going to consume data we
+ * touched, increases cache locality.
+ */
+SCHED_FEAT(NEXT_BUDDY, 0)
+
+/*
+ * Prefer to schedule the task that ran last (when we did
+ * wake-preempt) as that likely will touch the same data, increases
+ * cache locality.
+ */
+SCHED_FEAT(LAST_BUDDY, 1)
+
+/*
+ * Consider buddies to be cache hot, decreases the likelyness of a
+ * cache buddy being migrated away, increases cache locality.
+ */
 SCHED_FEAT(CACHE_HOT_BUDDY, 1)
-SCHED_FEAT(SYNC_WAKEUPS, 1)
-SCHED_FEAT(HRTICK, 1)
+
+/*
+ * Use arch dependent cpu power functions
+ */
+SCHED_FEAT(ARCH_POWER, 0)
+
+SCHED_FEAT(HRTICK, 0)
 SCHED_FEAT(DOUBLE_TICK, 0)
+SCHED_FEAT(LB_BIAS, 1)
+SCHED_FEAT(LB_SHARES_UPDATE, 1)
+SCHED_FEAT(ASYM_EFF_LOAD, 1)
+
+/*
+ * Spin-wait on mutex acquisition when the mutex owner is running on
+ * another cpu -- assumes that when the owner is running, it will soon
+ * release the lock. Decreases scheduling overhead.
+ */
+SCHED_FEAT(OWNER_SPIN, 1)