On Sun, 6 Jan 2002, Jens Axboe wrote:
> On Sat, Jan 05 2002, Davide Libenzi wrote:
> > > > (*) 100MHz 486DX4, 28MB ram, no L2 cache, two old and slow IDE disks,
> > > > small custom no-nonsense RedHat 7.2, kernels compiled with gcc 2.95.3.
> > >
> > > Is this ISA (maybe it has something to do with ISA bouncing)? Mine is:
> > >
> > > 486 DX/2 ISA, Adaptec 1542, two slow scsi disks and a self-made
> > > slackware-based system.
> > >
> > > Can you also backout the scheduler changes to verify this? I have a
> > > backout patch for 2.5.2-pre6, if you don't want to do this for yourself.
> >
> > There should be some part of the kernel that assume a certain scheduler
> > behavior. There was a guy that reported a bad hdparm performance and i
> > tried it. By running hdparm -t my system has a context switch of 20-30
> > and an irq load of about 100-110.
> > The scheduler itself, even if you code it in visual basic, cannot make
> > this with such loads.
> > Did you try to profile the kernel ?
>
> Davide,
>
> If this is caused by ISA bounce problems, then you should be able to
> reproduce by doing something ala
>
> [ drivers/ide/ide-dma.c ]
>
> ide_toggle_bounce()
> {
> ...
>
> + addr = BLK_BOUNCE_ISA;
> blk_queue_bounce_limit(&drive->queue, addr);
> }
>
> pseudo-diff, just add the addr = line. Now compare performance with and
> without your scheduler changes.
I fail to understand where the scheduler code can influence this.
There's basically nothing inside blk_queue_bounce_limit()
I made this patch for Andrea and it's the scheduler code for 2.4.18-pre1
Could someone give it a try on old 486s
- Davide
diff -Nru linux-2.4.18-pre1.vanilla/arch/alpha/kernel/process.c linux-2.4.18-pre1.tsss/arch/alpha/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/alpha/kernel/process.c Sun Sep 30 12:26:08 2001
+++ linux-2.4.18-pre1.tsss/arch/alpha/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -75,7 +75,6 @@
{
/* An endless idle loop with no priority at all. */
current->nice = 20;
- current->counter = -100;
while (1) {
/* FIXME -- EV6 and LCA45 know how to power down
diff -Nru linux-2.4.18-pre1.vanilla/arch/arm/kernel/process.c linux-2.4.18-pre1.tsss/arch/arm/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/arm/kernel/process.c Sun Sep 30 12:26:08 2001
+++ linux-2.4.18-pre1.tsss/arch/arm/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -85,7 +85,6 @@
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
- current->counter = -100;
while (1) {
void (*idle)(void) = pm_idle;
diff -Nru linux-2.4.18-pre1.vanilla/arch/cris/kernel/process.c linux-2.4.18-pre1.tsss/arch/cris/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/cris/kernel/process.c Fri Nov 9 13:58:02 2001
+++ linux-2.4.18-pre1.tsss/arch/cris/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -119,7 +119,6 @@
int cpu_idle(void *unused)
{
while(1) {
- current->counter = -100;
schedule();
}
}
diff -Nru linux-2.4.18-pre1.vanilla/arch/i386/kernel/process.c linux-2.4.18-pre1.tsss/arch/i386/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/i386/kernel/process.c Thu Oct 4 18:42:54 2001
+++ linux-2.4.18-pre1.tsss/arch/i386/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -125,7 +125,6 @@
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
- current->counter = -100;
while (1) {
void (*idle)(void) = pm_idle;
diff -Nru linux-2.4.18-pre1.vanilla/arch/ia64/kernel/process.c linux-2.4.18-pre1.tsss/arch/ia64/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/ia64/kernel/process.c Fri Nov 9 14:26:17 2001
+++ linux-2.4.18-pre1.tsss/arch/ia64/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -114,8 +114,6 @@
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
- current->counter = -100;
-
while (1) {
#ifdef CONFIG_SMP
diff -Nru linux-2.4.18-pre1.vanilla/arch/m68k/kernel/process.c linux-2.4.18-pre1.tsss/arch/m68k/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/m68k/kernel/process.c Sun Sep 30 12:26:08 2001
+++ linux-2.4.18-pre1.tsss/arch/m68k/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -81,7 +81,6 @@
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
- current->counter = -100;
idle();
}
diff -Nru linux-2.4.18-pre1.vanilla/arch/mips/kernel/process.c linux-2.4.18-pre1.tsss/arch/mips/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/mips/kernel/process.c Sun Sep 9 10:43:01 2001
+++ linux-2.4.18-pre1.tsss/arch/mips/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -36,7 +36,6 @@
{
/* endless idle loop with no priority at all */
current->nice = 20;
- current->counter = -100;
init_idle();
while (1) {
diff -Nru linux-2.4.18-pre1.vanilla/arch/mips64/kernel/process.c linux-2.4.18-pre1.tsss/arch/mips64/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/mips64/kernel/process.c Fri Feb 9 11:29:44 2001
+++ linux-2.4.18-pre1.tsss/arch/mips64/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -34,7 +34,6 @@
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
- current->counter = -100;
while (1) {
while (!current->need_resched)
if (wait_available)
diff -Nru linux-2.4.18-pre1.vanilla/arch/parisc/kernel/process.c linux-2.4.18-pre1.tsss/arch/parisc/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/parisc/kernel/process.c Fri Feb 9 11:29:44 2001
+++ linux-2.4.18-pre1.tsss/arch/parisc/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -71,7 +71,6 @@
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
- current->counter = -100;
while (1) {
while (!current->need_resched) {
diff -Nru linux-2.4.18-pre1.vanilla/arch/ppc/8260_io/uart.c linux-2.4.18-pre1.tsss/arch/ppc/8260_io/uart.c
--- linux-2.4.18-pre1.vanilla/arch/ppc/8260_io/uart.c Sat Jan 5 19:34:50 2002
+++ linux-2.4.18-pre1.tsss/arch/ppc/8260_io/uart.c Sat Jan 5 19:38:57 2002
@@ -1732,7 +1732,7 @@
printk("lsr = %d (jiff=%lu)...", lsr, jiffies);
#endif
current->state = TASK_INTERRUPTIBLE;
-/* current->counter = 0; make us low-priority */
+/* current->dyn_prio = 0; make us low-priority */
schedule_timeout(char_time);
if (signal_pending(current))
break;
diff -Nru linux-2.4.18-pre1.vanilla/arch/ppc/8xx_io/uart.c linux-2.4.18-pre1.tsss/arch/ppc/8xx_io/uart.c
--- linux-2.4.18-pre1.vanilla/arch/ppc/8xx_io/uart.c Sat Jan 5 19:34:50 2002
+++ linux-2.4.18-pre1.tsss/arch/ppc/8xx_io/uart.c Sat Jan 5 19:38:57 2002
@@ -1798,7 +1798,7 @@
printk("lsr = %d (jiff=%lu)...", lsr, jiffies);
#endif
current->state = TASK_INTERRUPTIBLE;
-/* current->counter = 0; make us low-priority */
+/* current->dyn_prio = 0; make us low-priority */
schedule_timeout(char_time);
if (signal_pending(current))
break;
diff -Nru linux-2.4.18-pre1.vanilla/arch/ppc/kernel/idle.c linux-2.4.18-pre1.tsss/arch/ppc/kernel/idle.c
--- linux-2.4.18-pre1.vanilla/arch/ppc/kernel/idle.c Sat Jan 5 19:34:50 2002
+++ linux-2.4.18-pre1.tsss/arch/ppc/kernel/idle.c Sat Jan 5 19:38:57 2002
@@ -54,7 +54,6 @@
/* endless loop with no priority at all */
current->nice = 20;
- current->counter = -100;
init_idle();
for (;;) {
#ifdef CONFIG_SMP
diff -Nru linux-2.4.18-pre1.vanilla/arch/s390/kernel/process.c linux-2.4.18-pre1.tsss/arch/s390/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/s390/kernel/process.c Sat Jan 5 19:34:51 2002
+++ linux-2.4.18-pre1.tsss/arch/s390/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -57,7 +57,6 @@
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
- current->counter = -100;
wait_psw.mask = _WAIT_PSW_MASK;
wait_psw.addr = (unsigned long) &&idle_wakeup | 0x80000000L;
while(1) {
diff -Nru linux-2.4.18-pre1.vanilla/arch/s390x/kernel/process.c linux-2.4.18-pre1.tsss/arch/s390x/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/s390x/kernel/process.c Sat Jan 5 19:34:51 2002
+++ linux-2.4.18-pre1.tsss/arch/s390x/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -57,7 +57,6 @@
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
- current->counter = -100;
wait_psw.mask = _WAIT_PSW_MASK;
wait_psw.addr = (unsigned long) &&idle_wakeup;
while(1) {
diff -Nru linux-2.4.18-pre1.vanilla/arch/sh/kernel/process.c linux-2.4.18-pre1.tsss/arch/sh/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/sh/kernel/process.c Mon Oct 15 13:36:48 2001
+++ linux-2.4.18-pre1.tsss/arch/sh/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -41,7 +41,6 @@
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
- current->counter = -100;
while (1) {
if (hlt_counter) {
diff -Nru linux-2.4.18-pre1.vanilla/arch/sparc/kernel/process.c linux-2.4.18-pre1.tsss/arch/sparc/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/sparc/kernel/process.c Fri Dec 21 09:41:53 2001
+++ linux-2.4.18-pre1.tsss/arch/sparc/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -61,7 +61,6 @@
/* endless idle loop with no priority at all */
current->nice = 20;
- current->counter = -100;
init_idle();
for (;;) {
@@ -110,7 +109,6 @@
{
/* endless idle loop with no priority at all */
current->nice = 20;
- current->counter = -100;
init_idle();
while(1) {
diff -Nru linux-2.4.18-pre1.vanilla/arch/sparc64/kernel/process.c linux-2.4.18-pre1.tsss/arch/sparc64/kernel/process.c
--- linux-2.4.18-pre1.vanilla/arch/sparc64/kernel/process.c Fri Dec 21 09:41:53 2001
+++ linux-2.4.18-pre1.tsss/arch/sparc64/kernel/process.c Sat Jan 5 19:38:57 2002
@@ -54,7 +54,6 @@
/* endless idle loop with no priority at all */
current->nice = 20;
- current->counter = -100;
init_idle();
for (;;) {
@@ -84,7 +83,6 @@
int cpu_idle(void)
{
current->nice = 20;
- current->counter = -100;
init_idle();
while(1) {
diff -Nru linux-2.4.18-pre1.vanilla/drivers/net/slip.c linux-2.4.18-pre1.tsss/drivers/net/slip.c
--- linux-2.4.18-pre1.vanilla/drivers/net/slip.c Sun Sep 30 12:26:07 2001
+++ linux-2.4.18-pre1.tsss/drivers/net/slip.c Sat Jan 5 19:38:57 2002
@@ -1394,7 +1394,7 @@
*/
do {
if (busy) {
- current->counter = 0;
+ current->time_slice = 0;
schedule();
}
diff -Nru linux-2.4.18-pre1.vanilla/fs/proc/array.c linux-2.4.18-pre1.tsss/fs/proc/array.c
--- linux-2.4.18-pre1.vanilla/fs/proc/array.c Thu Oct 11 09:00:01 2001
+++ linux-2.4.18-pre1.tsss/fs/proc/array.c Sat Jan 5 19:38:57 2002
@@ -335,8 +335,7 @@
/* scale priority and nice values from timeslices to -20..20 */
/* to make it look like a "normal" Unix priority/nice value */
- priority = task->counter;
- priority = 20 - (priority * 10 + DEF_COUNTER / 2) / DEF_COUNTER;
+ priority = task->dyn_prio;
nice = task->nice;
read_lock(&tasklist_lock);
diff -Nru linux-2.4.18-pre1.vanilla/include/linux/sched.h linux-2.4.18-pre1.tsss/include/linux/sched.h
--- linux-2.4.18-pre1.vanilla/include/linux/sched.h Fri Dec 21 09:42:03 2001
+++ linux-2.4.18-pre1.tsss/include/linux/sched.h Sat Jan 5 19:56:14 2002
@@ -150,6 +150,7 @@
extern void update_process_times(int user);
extern void update_one_process(struct task_struct *p, unsigned long user,
unsigned long system, int cpu);
+extern void expire_task(struct task_struct *p);
#define MAX_SCHEDULE_TIMEOUT LONG_MAX
extern signed long FASTCALL(schedule_timeout(signed long timeout));
@@ -300,7 +301,7 @@
* all fields in a single cacheline that are needed for
* the goodness() loop in schedule().
*/
- long counter;
+ unsigned long dyn_prio;
long nice;
unsigned long policy;
struct mm_struct *mm;
@@ -319,7 +320,9 @@
* that's just fine.)
*/
struct list_head run_list;
- unsigned long sleep_time;
+ long time_slice;
+ /* recalculation loop checkpoint */
+ unsigned long rcl_last;
struct task_struct *next_task, *prev_task;
struct mm_struct *active_mm;
@@ -446,8 +449,9 @@
*/
#define _STK_LIM (8*1024*1024)
-#define DEF_COUNTER (10*HZ/100) /* 100 ms time slice */
-#define MAX_COUNTER (20*HZ/100)
+#define MAX_DYNPRIO 40
+#define DEF_TSLICE (5 * HZ / 100)
+#define MAX_TSLICE (20 * HZ / 100)
#define DEF_NICE (0)
@@ -468,14 +472,16 @@
addr_limit: KERNEL_DS, \
exec_domain: &default_exec_domain, \
lock_depth: -1, \
- counter: DEF_COUNTER, \
+ dyn_prio: 0, \
nice: DEF_NICE, \
policy: SCHED_OTHER, \
mm: NULL, \
active_mm: &init_mm, \
cpus_runnable: -1, \
cpus_allowed: -1, \
- run_list: LIST_HEAD_INIT(tsk.run_list), \
+ run_list: { NULL, NULL }, \
+ rcl_last: 0, \
+ time_slice: DEF_TSLICE, \
next_task: &tsk, \
prev_task: &tsk, \
p_opptr: &tsk, \
@@ -876,7 +882,6 @@
static inline void del_from_runqueue(struct task_struct * p)
{
nr_running--;
- p->sleep_time = jiffies;
list_del(&p->run_list);
p->run_list.next = NULL;
}
diff -Nru linux-2.4.18-pre1.vanilla/kernel/exit.c linux-2.4.18-pre1.tsss/kernel/exit.c
--- linux-2.4.18-pre1.vanilla/kernel/exit.c Sat Jan 5 19:34:51 2002
+++ linux-2.4.18-pre1.tsss/kernel/exit.c Sat Jan 5 19:38:57 2002
@@ -62,9 +62,9 @@
* timeslices, because any timeslice recovered here
* was given away by the parent in the first place.)
*/
- current->counter += p->counter;
- if (current->counter >= MAX_COUNTER)
- current->counter = MAX_COUNTER;
+ current->time_slice += p->time_slice;
+ if (current->time_slice > MAX_TSLICE)
+ current->time_slice = MAX_TSLICE;
p->pid = 0;
free_task_struct(p);
} else {
diff -Nru linux-2.4.18-pre1.vanilla/kernel/fork.c linux-2.4.18-pre1.tsss/kernel/fork.c
--- linux-2.4.18-pre1.vanilla/kernel/fork.c Wed Nov 21 10:18:42 2001
+++ linux-2.4.18-pre1.tsss/kernel/fork.c Sat Jan 5 19:38:57 2002
@@ -682,9 +682,9 @@
* more scheduling fairness. This is only important in the first
* timeslice, on the long run the scheduling behaviour is unchanged.
*/
- p->counter = (current->counter + 1) >> 1;
- current->counter >>= 1;
- if (!current->counter)
+ p->time_slice = (current->time_slice + 1) >> 1;
+ current->time_slice >>= 1;
+ if (!current->time_slice)
current->need_resched = 1;
/*
diff -Nru linux-2.4.18-pre1.vanilla/kernel/sched.c linux-2.4.18-pre1.tsss/kernel/sched.c
--- linux-2.4.18-pre1.vanilla/kernel/sched.c Fri Dec 21 09:42:04 2001
+++ linux-2.4.18-pre1.tsss/kernel/sched.c Sat Jan 5 19:52:29 2002
@@ -51,24 +51,16 @@
* NOTE! The unix "nice" value influences how long a process
* gets. The nice value ranges from -20 to +19, where a -20
* is a "high-priority" task, and a "+10" is a low-priority
- * task.
- *
- * We want the time-slice to be around 50ms or so, so this
- * calculation depends on the value of HZ.
+ * task. The default time slice for zero-nice tasks will be 37ms.
*/
-#if HZ < 200
-#define TICK_SCALE(x) ((x) >> 2)
-#elif HZ < 400
-#define TICK_SCALE(x) ((x) >> 1)
-#elif HZ < 800
-#define TICK_SCALE(x) (x)
-#elif HZ < 1600
-#define TICK_SCALE(x) ((x) << 1)
-#else
-#define TICK_SCALE(x) ((x) << 2)
-#endif
+#define NICE_RANGE 40
+#define MIN_NICE_TSLICE 10000
+#define MAX_NICE_TSLICE 90000
+#define TASK_TIMESLICE(p) ((int) ts_table[19 - (p)->nice])
+
+static unsigned char ts_table[NICE_RANGE];
-#define NICE_TO_TICKS(nice) (TICK_SCALE(20-(nice))+1)
+#define MM_AFFINITY_BONUS 1
/*
@@ -94,6 +86,8 @@
static LIST_HEAD(runqueue_head);
+static unsigned long rcl_curr = 0;
+
/*
* We align per-CPU scheduling data on cacheline boundaries,
* to prevent cacheline ping-pong.
@@ -165,10 +159,11 @@
* Don't do any other calculations if the time slice is
* over..
*/
- weight = p->counter;
- if (!weight)
- goto out;
-
+ if (!p->time_slice)
+ return 0;
+
+ weight = p->dyn_prio + 1;
+
#ifdef CONFIG_SMP
/* Give a largish advantage to the same processor... */
/* (this is equivalent to penalizing other processors) */
@@ -178,7 +173,7 @@
/* .. and a slight advantage to the current MM */
if (p->mm == this_mm || !p->mm)
- weight += 1;
+ weight += MM_AFFINITY_BONUS;
weight += 20 - p->nice;
goto out;
}
@@ -324,6 +319,9 @@
*/
static inline void add_to_runqueue(struct task_struct * p)
{
+ p->dyn_prio += rcl_curr - p->rcl_last;
+ p->rcl_last = rcl_curr;
+ if (p->dyn_prio > MAX_DYNPRIO) p->dyn_prio = MAX_DYNPRIO;
list_add(&p->run_list, &runqueue_head);
nr_running++;
}
@@ -536,6 +534,19 @@
__schedule_tail(prev);
}
+void expire_task(struct task_struct *p)
+{
+ if (unlikely(!p->time_slice))
+ goto need_resched;
+
+ if (!--p->time_slice) {
+ if (p->dyn_prio)
+ p->dyn_prio--;
+ need_resched:
+ p->need_resched = 1;
+ }
+}
+
/*
* 'schedule()' is the scheduler function. It's a very simple and nice
* scheduler: it's not perfect, but certainly works for most things.
@@ -578,20 +589,20 @@
/* move an exhausted RR process to be last.. */
if (unlikely(prev->policy == SCHED_RR))
- if (!prev->counter) {
- prev->counter = NICE_TO_TICKS(prev->nice);
+ if (!prev->time_slice) {
+ prev->time_slice = TASK_TIMESLICE(prev);
move_last_runqueue(prev);
}
switch (prev->state) {
- case TASK_INTERRUPTIBLE:
- if (signal_pending(prev)) {
- prev->state = TASK_RUNNING;
- break;
- }
- default:
- del_from_runqueue(prev);
- case TASK_RUNNING:;
+ case TASK_INTERRUPTIBLE:
+ if (signal_pending(prev)) {
+ prev->state = TASK_RUNNING;
+ break;
+ }
+ default:
+ del_from_runqueue(prev);
+ case TASK_RUNNING:;
}
prev->need_resched = 0;
@@ -616,14 +627,12 @@
/* Do we need to re-calculate counters? */
if (unlikely(!c)) {
- struct task_struct *p;
-
- spin_unlock_irq(&runqueue_lock);
- read_lock(&tasklist_lock);
- for_each_task(p)
- p->counter = (p->counter >> 1) + NICE_TO_TICKS(p->nice);
- read_unlock(&tasklist_lock);
- spin_lock_irq(&runqueue_lock);
+ ++rcl_curr;
+ list_for_each(tmp, &runqueue_head) {
+ p = list_entry(tmp, struct task_struct, run_list);
+ p->time_slice = TASK_TIMESLICE(p);
+ p->rcl_last = rcl_curr;
+ }
goto repeat_schedule;
}
@@ -1056,17 +1065,17 @@
nr_pending--;
#endif
if (nr_pending) {
+ struct task_struct *ctsk = current;
/*
* This process can only be rescheduled by us,
* so this is safe without any locking.
*/
- if (current->policy == SCHED_OTHER)
- current->policy |= SCHED_YIELD;
- current->need_resched = 1;
-
- spin_lock_irq(&runqueue_lock);
- move_last_runqueue(current);
- spin_unlock_irq(&runqueue_lock);
+ if (ctsk->policy == SCHED_OTHER)
+ ctsk->policy |= SCHED_YIELD;
+ ctsk->need_resched = 1;
+
+ ctsk->time_slice = 0;
+ ++ctsk->dyn_prio;
}
return 0;
}
@@ -1115,7 +1124,7 @@
read_lock(&tasklist_lock);
p = find_process_by_pid(pid);
if (p)
- jiffies_to_timespec(p->policy & SCHED_FIFO ? 0 : NICE_TO_TICKS(p->nice),
+ jiffies_to_timespec(p->policy & SCHED_FIFO ? 0 : TASK_TIMESLICE(p),
&t);
read_unlock(&tasklist_lock);
if (p)
@@ -1306,9 +1315,10 @@
if (current != &init_task && task_on_runqueue(current)) {
printk("UGH! (%d:%d) was on the runqueue, removing.\n",
- smp_processor_id(), current->pid);
+ smp_processor_id(), current->pid);
del_from_runqueue(current);
}
+ current->dyn_prio = 0;
sched_data->curr = current;
sched_data->last_schedule = get_cycles();
clear_bit(current->processor, &wait_init_idle);
@@ -1316,6 +1326,18 @@
extern void init_timervecs (void);
+static void fill_tslice_map(void)
+{
+ int i;
+
+ for (i = 0; i < NICE_RANGE; i++) {
+ ts_table[i] = ((MIN_NICE_TSLICE +
+ ((MAX_NICE_TSLICE -
+ MIN_NICE_TSLICE) / (NICE_RANGE - 1)) * i) * HZ) / 1000000;
+ if (!ts_table[i]) ts_table[i] = 1;
+ }
+}
+
void __init sched_init(void)
{
/*
@@ -1329,6 +1351,8 @@
for(nr = 0; nr < PIDHASH_SZ; nr++)
pidhash[nr] = NULL;
+
+ fill_tslice_map();
init_timervecs();
diff -Nru linux-2.4.18-pre1.vanilla/kernel/timer.c linux-2.4.18-pre1.tsss/kernel/timer.c
--- linux-2.4.18-pre1.vanilla/kernel/timer.c Mon Oct 8 10:41:41 2001
+++ linux-2.4.18-pre1.tsss/kernel/timer.c Sat Jan 5 19:38:57 2002
@@ -583,10 +583,7 @@
update_one_process(p, user_tick, system, cpu);
if (p->pid) {
- if (--p->counter <= 0) {
- p->counter = 0;
- p->need_resched = 1;
- }
+ expire_task(p);
if (p->nice > 0)
kstat.per_cpu_nice[cpu] += user_tick;
else
diff -Nru linux-2.4.18-pre1.vanilla/mm/oom_kill.c linux-2.4.18-pre1.tsss/mm/oom_kill.c
--- linux-2.4.18-pre1.vanilla/mm/oom_kill.c Sat Nov 3 17:05:25 2001
+++ linux-2.4.18-pre1.tsss/mm/oom_kill.c Sat Jan 5 19:38:57 2002
@@ -149,7 +149,8 @@
* all the memory it needs. That way it should be able to
* exit() and clear out its resources quickly...
*/
- p->counter = 5 * HZ;
+ p->time_slice = 2 * MAX_TSLICE;
+ p->dyn_prio = MAX_DYNPRIO + 1;
p->flags |= PF_MEMALLOC | PF_MEMDIE;
/* This process has hardware access, be more careful. */
-
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