On Thu, 6 Mar 2003, Andrew Morton wrote:
> Overall, yep, good patch and we should run with it. [...]
great - here it is -A5 which is -A4 in a cleaned up form:
- make SMART_WAKE_CHILD and SYNC_WAKEUPS unconditional.
- remove a mis-merge of a TASK_ZOMBIE assert.
(without the last_run rename the patch becomes even smaller, do a
':s/last_run/sleep_timestamp/g' on it in vi.)
Ingo
--- linux/include/linux/sched.h.orig
+++ linux/include/linux/sched.h
@@ -328,7 +328,7 @@ struct task_struct {
prio_array_t *array;
unsigned long sleep_avg;
- unsigned long sleep_timestamp;
+ unsigned long last_run;
unsigned long policy;
unsigned long cpus_allowed;
--- linux/kernel/sched.c.orig
+++ linux/kernel/sched.c
@@ -54,20 +54,19 @@
/*
* These are the 'tuning knobs' of the scheduler:
*
- * Minimum timeslice is 10 msecs, default timeslice is 150 msecs,
- * maximum timeslice is 300 msecs. Timeslices get refilled after
+ * Minimum timeslice is 10 msecs, default timeslice is 100 msecs,
+ * maximum timeslice is 200 msecs. Timeslices get refilled after
* they expire.
*/
#define MIN_TIMESLICE ( 10 * HZ / 1000)
-#define MAX_TIMESLICE (300 * HZ / 1000)
-#define CHILD_PENALTY 95
+#define MAX_TIMESLICE (200 * HZ / 1000)
+#define CHILD_PENALTY 50
#define PARENT_PENALTY 100
#define EXIT_WEIGHT 3
#define PRIO_BONUS_RATIO 25
#define INTERACTIVE_DELTA 2
-#define MAX_SLEEP_AVG (2*HZ)
-#define STARVATION_LIMIT (2*HZ)
-#define NODE_THRESHOLD 125
+#define MAX_SLEEP_AVG (10*HZ)
+#define STARVATION_LIMIT (10*HZ)
/*
* If a task is 'interactive' then we reinsert it in the active
@@ -323,16 +322,21 @@ static inline int effective_prio(task_t
* Also update all the scheduling statistics stuff. (sleep average
* calculation, priority modifiers, etc.)
*/
+static inline void __activate_task(task_t *p, runqueue_t *rq)
+{
+ enqueue_task(p, rq->active);
+ rq->nr_running++;
+}
+
static inline void activate_task(task_t *p, runqueue_t *rq)
{
- unsigned long sleep_time = jiffies - p->sleep_timestamp;
- prio_array_t *array = rq->active;
+ unsigned long sleep_time = jiffies - p->last_run;
if (!rt_task(p) && sleep_time) {
/*
* This code gives a bonus to interactive tasks. We update
* an 'average sleep time' value here, based on
- * sleep_timestamp. The more time a task spends sleeping,
+ * ->last_run. The more time a task spends sleeping,
* the higher the average gets - and the higher the priority
* boost gets as well.
*/
@@ -341,8 +345,7 @@ static inline void activate_task(task_t
p->sleep_avg = MAX_SLEEP_AVG;
p->prio = effective_prio(p);
}
- enqueue_task(p, array);
- nr_running_inc(rq);
+ __activate_task(p, rq);
}
/*
@@ -479,10 +482,13 @@ repeat_lock_task:
}
if (old_state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible--;
- activate_task(p, rq);
-
- if (p->prio < rq->curr->prio)
- resched_task(rq->curr);
+ if (sync)
+ __activate_task(p, rq);
+ else {
+ activate_task(p, rq);
+ if (p->prio < rq->curr->prio)
+ resched_task(rq->curr);
+ }
success = 1;
}
p->state = TASK_RUNNING;
@@ -525,8 +531,16 @@ void wake_up_forked_process(task_t * p)
p->prio = effective_prio(p);
}
set_task_cpu(p, smp_processor_id());
- activate_task(p, rq);
+ if (unlikely(!current->array))
+ __activate_task(p, rq);
+ else {
+ p->prio = current->prio;
+ list_add_tail(&p->run_list, ¤t->run_list);
+ p->array = current->array;
+ p->array->nr_active++;
+ rq->nr_running++;
+ }
task_rq_unlock(rq, &flags);
}
@@ -953,6 +967,11 @@ static inline void pull_task(runqueue_t
*/
if (p->prio < this_rq->curr->prio)
set_need_resched();
+ else {
+ if (p->prio == this_rq->curr->prio &&
+ p->time_slice > this_rq->curr->time_slice)
+ set_need_resched();
+ }
}
/*
@@ -1016,7 +1035,7 @@ skip_queue:
*/
#define CAN_MIGRATE_TASK(p,rq,this_cpu) \
- ((jiffies - (p)->sleep_timestamp > cache_decay_ticks) && \
+ ((jiffies - (p)->last_run > cache_decay_ticks) && \
!task_running(rq, p) && \
((p)->cpus_allowed & (1UL << (this_cpu))))
@@ -1076,9 +1095,9 @@ DEFINE_PER_CPU(struct kernel_stat, kstat
* increasing number of running tasks:
*/
#define EXPIRED_STARVING(rq) \
- ((rq)->expired_timestamp && \
+ (STARVATION_LIMIT && ((rq)->expired_timestamp && \
(jiffies - (rq)->expired_timestamp >= \
- STARVATION_LIMIT * ((rq)->nr_running) + 1))
+ STARVATION_LIMIT * ((rq)->nr_running) + 1)))
/*
* This function gets called by the timer code, with HZ frequency.
@@ -1201,7 +1220,7 @@ need_resched:
rq = this_rq();
release_kernel_lock(prev);
- prev->sleep_timestamp = jiffies;
+ prev->last_run = jiffies;
spin_lock_irq(&rq->lock);
/*
@@ -1701,7 +1720,7 @@ static int setscheduler(pid_t pid, int p
else
p->prio = p->static_prio;
if (array)
- activate_task(p, task_rq(p));
+ __activate_task(p, task_rq(p));
out_unlock:
task_rq_unlock(rq, &flags);
--- linux/kernel/fork.c.orig
+++ linux/kernel/fork.c
@@ -916,7 +916,7 @@ static struct task_struct *copy_process(
*/
p->first_time_slice = 1;
current->time_slice >>= 1;
- p->sleep_timestamp = jiffies;
+ p->last_run = jiffies;
if (!current->time_slice) {
/*
* This case is rare, it happens when the parent has only
-
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This archive was generated by hypermail 2b29 : Fri Mar 07 2003 - 22:00:31 EST