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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-09-10 14:36:49 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-09-10 14:36:49 -0700
commit53f7b9bccd332bba39be78f9085ac1a26fa387fc (patch)
tree841d4de4cdb5ce5ccf4b197c0cda570fc17a49df
parent3c038f97e4b14c322b49f13578e0714e1a2ece53 (diff)
parent1169783085adb9ac969d21103a6885e8435f7ed3 (diff)
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Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched: sched: fix ideal_runtime calculations for reniced tasks sched: improve prev_sum_exec_runtime setting sched: simplify __check_preempt_curr_fair() sched: fix xtensa build warning sched: debug: fix sum_exec_runtime clearing sched: debug: fix cfs_rq->wait_runtime accounting sched: fix niced_granularity() shift sched: fix MC/HT scheduler optimization, without breaking the FUZZ logic.
-rw-r--r--kernel/sched.c15
-rw-r--r--kernel/sched_debug.c1
-rw-r--r--kernel/sched_fair.c59
3 files changed, 38 insertions, 37 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index b533d6db78aa..deeb1f8e0c30 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -668,7 +668,7 @@ static u64 div64_likely32(u64 divident, unsigned long divisor)
/*
* Shift right and round:
*/
-#define RSR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))
+#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))
static unsigned long
calc_delta_mine(unsigned long delta_exec, unsigned long weight,
@@ -684,10 +684,10 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
* Check whether we'd overflow the 64-bit multiplication:
*/
if (unlikely(tmp > WMULT_CONST))
- tmp = RSR(RSR(tmp, WMULT_SHIFT/2) * lw->inv_weight,
+ tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight,
WMULT_SHIFT/2);
else
- tmp = RSR(tmp * lw->inv_weight, WMULT_SHIFT);
+ tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT);
return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
}
@@ -858,7 +858,6 @@ static void dec_nr_running(struct task_struct *p, struct rq *rq)
static void set_load_weight(struct task_struct *p)
{
- task_rq(p)->cfs.wait_runtime -= p->se.wait_runtime;
p->se.wait_runtime = 0;
if (task_has_rt_policy(p)) {
@@ -2512,7 +2511,7 @@ group_next:
* a think about bumping its value to force at least one task to be
* moved
*/
- if (*imbalance + SCHED_LOAD_SCALE_FUZZ < busiest_load_per_task) {
+ if (*imbalance < busiest_load_per_task) {
unsigned long tmp, pwr_now, pwr_move;
unsigned int imbn;
@@ -2564,10 +2563,8 @@ small_imbalance:
pwr_move /= SCHED_LOAD_SCALE;
/* Move if we gain throughput */
- if (pwr_move <= pwr_now)
- goto out_balanced;
-
- *imbalance = busiest_load_per_task;
+ if (pwr_move > pwr_now)
+ *imbalance = busiest_load_per_task;
}
return busiest;
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index ab18f45f2ab2..c3ee38bd3426 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -283,4 +283,5 @@ void proc_sched_set_task(struct task_struct *p)
p->se.wait_runtime_overruns = p->se.wait_runtime_underruns = 0;
#endif
p->se.sum_exec_runtime = 0;
+ p->se.prev_sum_exec_runtime = 0;
}
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index ce39282d9c0d..892616bf2c77 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -194,6 +194,8 @@ __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
update_load_add(&cfs_rq->load, se->load.weight);
cfs_rq->nr_running++;
se->on_rq = 1;
+
+ schedstat_add(cfs_rq, wait_runtime, se->wait_runtime);
}
static inline void
@@ -205,6 +207,8 @@ __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
update_load_sub(&cfs_rq->load, se->load.weight);
cfs_rq->nr_running--;
se->on_rq = 0;
+
+ schedstat_add(cfs_rq, wait_runtime, -se->wait_runtime);
}
static inline struct rb_node *first_fair(struct cfs_rq *cfs_rq)
@@ -291,7 +295,7 @@ niced_granularity(struct sched_entity *curr, unsigned long granularity)
/*
* It will always fit into 'long':
*/
- return (long) (tmp >> WMULT_SHIFT);
+ return (long) (tmp >> (WMULT_SHIFT-NICE_0_SHIFT));
}
static inline void
@@ -574,7 +578,6 @@ static void __enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
prev_runtime = se->wait_runtime;
__add_wait_runtime(cfs_rq, se, delta_fair);
- schedstat_add(cfs_rq, wait_runtime, se->wait_runtime);
delta_fair = se->wait_runtime - prev_runtime;
/*
@@ -662,7 +665,6 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
if (tsk->state & TASK_UNINTERRUPTIBLE)
se->block_start = rq_of(cfs_rq)->clock;
}
- cfs_rq->wait_runtime -= se->wait_runtime;
#endif
}
__dequeue_entity(cfs_rq, se);
@@ -671,22 +673,39 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
/*
* Preempt the current task with a newly woken task if needed:
*/
-static int
+static void
__check_preempt_curr_fair(struct cfs_rq *cfs_rq, struct sched_entity *se,
struct sched_entity *curr, unsigned long granularity)
{
s64 __delta = curr->fair_key - se->fair_key;
+ unsigned long ideal_runtime, delta_exec;
+
+ /*
+ * ideal_runtime is compared against sum_exec_runtime, which is
+ * walltime, hence do not scale.
+ */
+ ideal_runtime = max(sysctl_sched_latency / cfs_rq->nr_running,
+ (unsigned long)sysctl_sched_min_granularity);
+
+ /*
+ * If we executed more than what the latency constraint suggests,
+ * reduce the rescheduling granularity. This way the total latency
+ * of how much a task is not scheduled converges to
+ * sysctl_sched_latency:
+ */
+ delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
+ if (delta_exec > ideal_runtime)
+ granularity = 0;
/*
* Take scheduling granularity into account - do not
* preempt the current task unless the best task has
* a larger than sched_granularity fairness advantage:
+ *
+ * scale granularity as key space is in fair_clock.
*/
- if (__delta > niced_granularity(curr, granularity)) {
+ if (__delta > niced_granularity(curr, granularity))
resched_task(rq_of(cfs_rq)->curr);
- return 1;
- }
- return 0;
}
static inline void
@@ -702,6 +721,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
update_stats_wait_end(cfs_rq, se);
update_stats_curr_start(cfs_rq, se);
set_cfs_rq_curr(cfs_rq, se);
+ se->prev_sum_exec_runtime = se->sum_exec_runtime;
}
static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
@@ -731,7 +751,6 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
{
- unsigned long gran, ideal_runtime, delta_exec;
struct sched_entity *next;
/*
@@ -748,22 +767,8 @@ static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
if (next == curr)
return;
- gran = sched_granularity(cfs_rq);
- ideal_runtime = niced_granularity(curr,
- max(sysctl_sched_latency / cfs_rq->nr_running,
- (unsigned long)sysctl_sched_min_granularity));
- /*
- * If we executed more than what the latency constraint suggests,
- * reduce the rescheduling granularity. This way the total latency
- * of how much a task is not scheduled converges to
- * sysctl_sched_latency:
- */
- delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
- if (delta_exec > ideal_runtime)
- gran = 0;
-
- if (__check_preempt_curr_fair(cfs_rq, next, curr, gran))
- curr->prev_sum_exec_runtime = curr->sum_exec_runtime;
+ __check_preempt_curr_fair(cfs_rq, next, curr,
+ sched_granularity(cfs_rq));
}
/**************************************************
@@ -1121,10 +1126,8 @@ static void task_new_fair(struct rq *rq, struct task_struct *p)
* The statistical average of wait_runtime is about
* -granularity/2, so initialize the task with that:
*/
- if (sysctl_sched_features & SCHED_FEAT_START_DEBIT) {
+ if (sysctl_sched_features & SCHED_FEAT_START_DEBIT)
se->wait_runtime = -(sched_granularity(cfs_rq) / 2);
- schedstat_add(cfs_rq, wait_runtime, se->wait_runtime);
- }
__enqueue_entity(cfs_rq, se);
}