From: Con Kolivas <kernel@kolivas.org>
Small error in the just interactive logic has been corrected.
Idle tasks get one higher priority than just interactive so they don't get
swamped under heavy load.
Cosmetic cleanup.
kernel/sched.c | 31 +++++++++++++++----------------
1 files changed, 15 insertions(+), 16 deletions(-)
diff -puN kernel/sched.c~o19int kernel/sched.c
--- 25/kernel/sched.c~o19int 2003-08-30 16:01:59.000000000 -0700
+++ 25-akpm/kernel/sched.c 2003-08-30 16:01:59.000000000 -0700
@@ -64,8 +64,8 @@
/*
* Some helpers for converting nanosecond timing to jiffy resolution
*/
-#define NS_TO_JIFFIES(TIME) (TIME / (1000000000 / HZ))
-#define JIFFIES_TO_NS(TIME) (TIME * (1000000000 / HZ))
+#define NS_TO_JIFFIES(TIME) ((TIME) / (1000000000 / HZ))
+#define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ))
/*
* These are the 'tuning knobs' of the scheduler:
@@ -132,7 +132,8 @@
((p)->prio <= (p)->static_prio - DELTA(p))
#define JUST_INTERACTIVE_SLEEP(p) \
- (MAX_SLEEP_AVG - (DELTA(p) * AVG_TIMESLICE))
+ (JIFFIES_TO_NS(MAX_SLEEP_AVG * \
+ (MAX_BONUS / 2 + DELTA((p)) + 1) / MAX_BONUS - 1))
#define HIGH_CREDIT(p) \
((p)->interactive_credit > MAX_SLEEP_AVG)
@@ -382,10 +383,8 @@ static void recalc_task_prio(task_t *p,
* prevent them suddenly becoming cpu hogs and starving
* other processes.
*/
- if (p->mm && sleep_time >
- JIFFIES_TO_NS(JUST_INTERACTIVE_SLEEP(p)))
- p->sleep_avg =
- JIFFIES_TO_NS(JUST_INTERACTIVE_SLEEP(p));
+ if (p->mm && sleep_time >JUST_INTERACTIVE_SLEEP(p))
+ p->sleep_avg = JUST_INTERACTIVE_SLEEP(p) + 1;
else {
/*
* The lower the sleep avg a task has the more
@@ -405,16 +404,15 @@ static void recalc_task_prio(task_t *p,
/*
* Non high_credit tasks waking from uninterruptible
* sleep are limited in their sleep_avg rise as they
- * are likely to be waiting on I/O
+ * are likely to be cpu hogs waiting on I/O
*/
if (p->activated == -1 && !HIGH_CREDIT(p) && p->mm){
- if (p->sleep_avg >=
- JIFFIES_TO_NS(JUST_INTERACTIVE_SLEEP(p)))
- sleep_time = 0;
+ if (p->sleep_avg >= JUST_INTERACTIVE_SLEEP(p))
+ sleep_time = 0;
else if (p->sleep_avg + sleep_time >=
- JIFFIES_TO_NS(JUST_INTERACTIVE_SLEEP(p))){
+ JUST_INTERACTIVE_SLEEP(p)){
p->sleep_avg =
- JIFFIES_TO_NS(JUST_INTERACTIVE_SLEEP(p));
+ JUST_INTERACTIVE_SLEEP(p);
sleep_time = 0;
}
}
@@ -431,7 +429,8 @@ static void recalc_task_prio(task_t *p,
if (p->sleep_avg > NS_MAX_SLEEP_AVG){
p->sleep_avg = NS_MAX_SLEEP_AVG;
- p->interactive_credit += !(HIGH_CREDIT(p));
+ if (!HIGH_CREDIT(p))
+ p->interactive_credit++;
}
}
}
@@ -1548,8 +1547,8 @@ switch_tasks:
prev->sleep_avg -= run_time;
if ((long)prev->sleep_avg <= 0){
prev->sleep_avg = 0;
- prev->interactive_credit -=
- !(HIGH_CREDIT(prev) || LOW_CREDIT(prev));
+ if (!(HIGH_CREDIT(prev) || LOW_CREDIT(prev)))
+ prev->interactive_credit--;
}
prev->timestamp = now;
_