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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2011-11-15 20:14:39 +0400
committerIngo Molnar <mingo@elte.hu>2011-11-17 15:20:22 +0400
commit391e43da797a96aeb65410281891f6d0b0e9611c (patch)
tree0ce6784525a5a8f75b377170cf1a7d60abccea29 /kernel/sched/features.h
parent029632fbb7b7c9d85063cc9eb470de6c54873df3 (diff)
downloadlinux-391e43da797a96aeb65410281891f6d0b0e9611c.tar.xz
sched: Move all scheduler bits into kernel/sched/
There's too many sched*.[ch] files in kernel/, give them their own directory. (No code changed, other than Makefile glue added.) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched/features.h')
-rw-r--r--kernel/sched/features.h70
1 files changed, 70 insertions, 0 deletions
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
new file mode 100644
index 000000000000..84802245abd2
--- /dev/null
+++ b/kernel/sched/features.h
@@ -0,0 +1,70 @@
+/*
+ * 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)
+
+/*
+ * 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)
+
+/*
+ * 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)
+
+/*
+ * 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)
+
+/*
+ * Decrement CPU power based on time not spent running tasks
+ */
+SCHED_FEAT(NONTASK_POWER, 1)
+
+/*
+ * Queue remote wakeups on the target CPU and process them
+ * using the scheduler IPI. Reduces rq->lock contention/bounces.
+ */
+SCHED_FEAT(TTWU_QUEUE, 1)
+
+SCHED_FEAT(FORCE_SD_OVERLAP, 0)
+SCHED_FEAT(RT_RUNTIME_SHARE, 1)