[net-next-2.6.git] / kernel / sched_features.h

/*
 * 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)

/*
 * 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)

/*
 * Decrement CPU power based on irq activity
 */
SCHED_FEAT(NONIRQ_POWER, 1)
Commit	Line	Data
51e0304c IM	1	/*
	2	* Only give sleepers 50% of their service deficit. This allows
	3	* them to run sooner, but does not allow tons of sleepers to
	4	* rip the spread apart.
	5	*/
	6	SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1)
e26af0e8	7
e26af0e8 PZ	8	/*
	9	* Place new tasks ahead so that they do not starve already running
	10	* tasks
	11	*/
f00b45c1	12	SCHED_FEAT(START_DEBIT, 1)
e26af0e8 PZ	13
	14	/*
	15	* Should wakeups try to preempt running tasks.
	16	*/
	17	SCHED_FEAT(WAKEUP_PREEMPT, 1)
	18
e26af0e8 PZ	19	/*
	20	* Based on load and program behaviour, see if it makes sense to place
	21	* a newly woken task on the same cpu as the task that woke it --
	22	* improve cache locality. Typically used with SYNC wakeups as
	23	* generated by pipes and the like, see also SYNC_WAKEUPS.
	24	*/
f00b45c1	25	SCHED_FEAT(AFFINE_WAKEUPS, 1)
e26af0e8 PZ	26
	27	/*
	28	* Prefer to schedule the task we woke last (assuming it failed
	29	* wakeup-preemption), since its likely going to consume data we
	30	* touched, increases cache locality.
	31	*/
0ec9fab3	32	SCHED_FEAT(NEXT_BUDDY, 0)
e26af0e8 PZ	33
	34	/*
	35	* Prefer to schedule the task that ran last (when we did
	36	* wake-preempt) as that likely will touch the same data, increases
	37	* cache locality.
	38	*/
	39	SCHED_FEAT(LAST_BUDDY, 1)
	40
	41	/*
	42	* Consider buddies to be cache hot, decreases the likelyness of a
	43	* cache buddy being migrated away, increases cache locality.
	44	*/
f00b45c1	45	SCHED_FEAT(CACHE_HOT_BUDDY, 1)
e26af0e8	46
8e6598af PZ	47	/*
	48	* Use arch dependent cpu power functions
	49	*/
	50	SCHED_FEAT(ARCH_POWER, 0)
	51
0c4b83da	52	SCHED_FEAT(HRTICK, 0)
f00b45c1	53	SCHED_FEAT(DOUBLE_TICK, 0)
efc2dead	54	SCHED_FEAT(LB_BIAS, 1)
3b640894	55	SCHED_FEAT(LB_SHARES_UPDATE, 1)
f5bfb7d9	56	SCHED_FEAT(ASYM_EFF_LOAD, 1)
e26af0e8 PZ	57
	58	/*
	59	* Spin-wait on mutex acquisition when the mutex owner is running on
	60	* another cpu -- assumes that when the owner is running, it will soon
	61	* release the lock. Decreases scheduling overhead.
	62	*/
0d66bf6d	63	SCHED_FEAT(OWNER_SPIN, 1)
aa483808 VP	64
	65	/*
	66	* Decrement CPU power based on irq activity
	67	*/
	68	SCHED_FEAT(NONIRQ_POWER, 1)