On Tue, Apr 17, 2007 at 02:57:49AM -0700, William Lee Irwin III wrote:
> Interesting! That's what vdls did, except its fundamental data structure
> was more like a circular buffer data structure (resembling Davide
> Libenzi's timer ring in concept, but with all the details different).
> I'm not entirely sure how that would've turned out performancewise if
> I'd done any tuning at all. I was mostly interested in doing something
> like what I heard Bob Mullens did in 1976 for basic pedagogical value
> about schedulers to prepare for writing patches for gang scheduling as
> opposed to creating a viable replacement for the mainline scheduler.
Con helped me dredge up the vdls bits, so here is the last version I
before I got tired of toying with the idea. It's not all that clean,
with a fair amount of debug code floating around and a number of
idiocies (it seems there was a plot to use a heap somewhere I forgot
about entirely, never mind other cruft), but I thought I should at least
say something more provable than "there was a patch I never posted."
Enjoy!
-- wli
diff -prauN linux-2.6.0-test11/fs/proc/array.c sched-2.6.0-test11-5/fs/proc/array.c
--- linux-2.6.0-test11/fs/proc/array.c 2003-11-26 12:44:26.000000000 -0800
+++ sched-2.6.0-test11-5/fs/proc/array.c 2003-12-17 07:37:11.000000000 -0800
@@ -162,7 +162,7 @@ static inline char * task_state(struct t
"Uid:\t%d\t%d\t%d\t%d\n"
"Gid:\t%d\t%d\t%d\t%d\n",
get_task_state(p),
- (p->sleep_avg/1024)*100/(1000000000/1024),
+ 0UL, /* was ->sleep_avg */
p->tgid,
p->pid, p->pid ? p->real_parent->pid : 0,
p->pid && p->ptrace ? p->parent->pid : 0,
@@ -345,7 +345,7 @@ int proc_pid_stat(struct task_struct *ta
read_unlock(&tasklist_lock);
res = sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \
%lu %lu %lu %lu %lu %ld %ld %ld %ld %d %ld %llu %lu %ld %lu %lu %lu %lu %lu \
-%lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu\n",
+%lu %lu %lu %lu %lu %lu %lu %lu %d %d %d %d\n",
task->pid,
task->comm,
state,
@@ -390,8 +390,8 @@ int proc_pid_stat(struct task_struct *ta
task->cnswap,
task->exit_signal,
task_cpu(task),
- task->rt_priority,
- task->policy);
+ task_prio(task),
+ task_sched_policy(task));
if(mm)
mmput(mm);
return res;
diff -prauN linux-2.6.0-test11/include/asm-i386/thread_info.h sched-2.6.0-test11-5/include/asm-i386/thread_info.h
--- linux-2.6.0-test11/include/asm-i386/thread_info.h 2003-11-26 12:43:06.000000000 -0800
+++ sched-2.6.0-test11-5/include/asm-i386/thread_info.h 2003-12-17 04:55:22.000000000 -0800
@@ -114,6 +114,8 @@ static inline struct thread_info *curren
#define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
#define TIF_IRET 5 /* return with iret */
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
+#define TIF_QUEUED 17
+#define TIF_PREEMPT 18
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
diff -prauN linux-2.6.0-test11/include/linux/binomial.h sched-2.6.0-test11-5/include/linux/binomial.h
--- linux-2.6.0-test11/include/linux/binomial.h 1969-12-31 16:00:00.000000000 -0800
+++ sched-2.6.0-test11-5/include/linux/binomial.h 2003-12-20 15:53:33.000000000 -0800
@@ -0,0 +1,16 @@
+/*
+ * Simple binomial heaps.
+ */
+
+struct binomial {
+ unsigned priority, degree;
+ struct binomial *parent, *child, *sibling;
+};
+
+
+struct binomial *binomial_minimum(struct binomial **);
+void binomial_union(struct binomial **, struct binomial **, struct binomial **);
+void binomial_insert(struct binomial **, struct binomial *);
+struct binomial *binomial_extract_min(struct binomial **);
+void binomial_decrease(struct binomial **, struct binomial *, unsigned);
+void binomial_delete(struct binomial **, struct binomial *);
diff -prauN linux-2.6.0-test11/include/linux/init_task.h sched-2.6.0-test11-5/include/linux/init_task.h
--- linux-2.6.0-test11/include/linux/init_task.h 2003-11-26 12:42:58.000000000 -0800
+++ sched-2.6.0-test11-5/include/linux/init_task.h 2003-12-18 05:51:16.000000000 -0800
@@ -56,6 +56,12 @@
.siglock = SPIN_LOCK_UNLOCKED, \
}
+#define INIT_SCHED_INFO(info) \
+{ \
+ .run_list = LIST_HEAD_INIT((info).run_list), \
+ .policy = 1 /* SCHED_POLICY_TS */, \
+}
+
/*
* INIT_TASK is used to set up the first task table, touch at
* your own risk!. Base=0, limit=0x1fffff (=2MB)
@@ -67,14 +73,10 @@
.usage = ATOMIC_INIT(2), \
.flags = 0, \
.lock_depth = -1, \
- .prio = MAX_PRIO-20, \
- .static_prio = MAX_PRIO-20, \
- .policy = SCHED_NORMAL, \
+ .sched_info = INIT_SCHED_INFO(tsk.sched_info), \
.cpus_allowed = CPU_MASK_ALL, \
.mm = NULL, \
.active_mm = &init_mm, \
- .run_list = LIST_HEAD_INIT(tsk.run_list), \
- .time_slice = HZ, \
.tasks = LIST_HEAD_INIT(tsk.tasks), \
.ptrace_children= LIST_HEAD_INIT(tsk.ptrace_children), \
.ptrace_list = LIST_HEAD_INIT(tsk.ptrace_list), \
diff -prauN linux-2.6.0-test11/include/linux/sched.h sched-2.6.0-test11-5/include/linux/sched.h
--- linux-2.6.0-test11/include/linux/sched.h 2003-11-26 12:42:58.000000000 -0800
+++ sched-2.6.0-test11-5/include/linux/sched.h 2003-12-23 03:47:45.000000000 -0800
@@ -126,6 +126,8 @@ extern unsigned long nr_iowait(void);
#define SCHED_NORMAL 0
#define SCHED_FIFO 1
#define SCHED_RR 2
+#define SCHED_BATCH 3
+#define SCHED_IDLE 4
struct sched_param {
int sched_priority;
@@ -281,10 +283,14 @@ struct signal_struct {
#define MAX_USER_RT_PRIO 100
#define MAX_RT_PRIO MAX_USER_RT_PRIO
-
-#define MAX_PRIO (MAX_RT_PRIO + 40)
-
-#define rt_task(p) ((p)->prio < MAX_RT_PRIO)
+#define NICE_QLEN 128
+#define MIN_TS_PRIO MAX_RT_PRIO
+#define MAX_TS_PRIO (40*NICE_QLEN)
+#define MIN_BATCH_PRIO (MAX_RT_PRIO + MAX_TS_PRIO)
+#define MAX_BATCH_PRIO 100
+#define MAX_PRIO (MIN_BATCH_PRIO + MAX_BATCH_PRIO)
+#define USER_PRIO(prio) ((prio) - MAX_RT_PRIO)
+#define MAX_USER_PRIO USER_PRIO(MAX_PRIO)
/*
* Some day this will be a full-fledged user tracking system..
@@ -330,6 +336,36 @@ struct k_itimer {
struct io_context; /* See blkdev.h */
void exit_io_context(void);
+struct rt_data {
+ int prio, rt_policy;
+ unsigned long quantum, ticks;
+};
+
+/* XXX: do %cpu estimation for ts wakeup levels */
+struct ts_data {
+ int nice;
+ unsigned long ticks, frac_cpu;
+ unsigned long sample_start, sample_ticks;
+};
+
+struct bt_data {
+ int prio;
+ unsigned long ticks;
+};
+
+union class_data {
+ struct rt_data rt;
+ struct ts_data ts;
+ struct bt_data bt;
+};
+
+struct sched_info {
+ int idx; /* queue index, used by all classes */
+ unsigned long policy; /* scheduling policy */
+ struct list_head run_list; /* list links for priority queues */
+ union class_data cl_data; /* class-specific data */
+};
+
struct task_struct {
volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
struct thread_info *thread_info;
@@ -339,18 +375,9 @@ struct task_struct {
int lock_depth; /* Lock depth */
- int prio, static_prio;
- struct list_head run_list;
- prio_array_t *array;
-
- unsigned long sleep_avg;
- long interactive_credit;
- unsigned long long timestamp;
- int activated;
+ struct sched_info sched_info;
- unsigned long policy;
cpumask_t cpus_allowed;
- unsigned int time_slice, first_time_slice;
struct list_head tasks;
struct list_head ptrace_children;
@@ -391,7 +418,6 @@ struct task_struct {
int __user *set_child_tid; /* CLONE_CHILD_SETTID */
int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
- unsigned long rt_priority;
unsigned long it_real_value, it_prof_value, it_virt_value;
unsigned long it_real_incr, it_prof_incr, it_virt_incr;
struct timer_list real_timer;
@@ -520,12 +546,14 @@ extern void node_nr_running_init(void);
#define node_nr_running_init() {}
#endif
-extern void set_user_nice(task_t *p, long nice);
-extern int task_prio(task_t *p);
-extern int task_nice(task_t *p);
-extern int task_curr(task_t *p);
-extern int idle_cpu(int cpu);
-
+void set_user_nice(task_t *task, long nice);
+int task_prio(task_t *task);
+int task_nice(task_t *task);
+int task_sched_policy(task_t *task);
+void set_task_sched_policy(task_t *task, int policy);
+int rt_task(task_t *task);
+int task_curr(task_t *task);
+int idle_cpu(int cpu);
void yield(void);
/*
@@ -844,6 +872,21 @@ static inline int need_resched(void)
return unlikely(test_thread_flag(TIF_NEED_RESCHED));
}
+static inline void set_task_queued(task_t *task)
+{
+ set_tsk_thread_flag(task, TIF_QUEUED);
+}
+
+static inline void clear_task_queued(task_t *task)
+{
+ clear_tsk_thread_flag(task, TIF_QUEUED);
+}
+
+static inline int task_queued(task_t *task)
+{
+ return test_tsk_thread_flag(task, TIF_QUEUED);
+}
+
extern void __cond_resched(void);
static inline void cond_resched(void)
{
diff -prauN linux-2.6.0-test11/kernel/Makefile sched-2.6.0-test11-5/kernel/Makefile
--- linux-2.6.0-test11/kernel/Makefile 2003-11-26 12:43:24.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/Makefile 2003-12-17 03:30:08.000000000 -0800
@@ -6,7 +6,7 @@ obj-y = sched.o fork.o exec_domain.o
exit.o itimer.o time.o softirq.o resource.o \
sysctl.o capability.o ptrace.o timer.o user.o \
signal.o sys.o kmod.o workqueue.o pid.o \
- rcupdate.o intermodule.o extable.o params.o posix-timers.o
+ rcupdate.o intermodule.o extable.o params.o posix-timers.o sched/
obj-$(CONFIG_FUTEX) += futex.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
diff -prauN linux-2.6.0-test11/kernel/exit.c sched-2.6.0-test11-5/kernel/exit.c
--- linux-2.6.0-test11/kernel/exit.c 2003-11-26 12:45:29.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/exit.c 2003-12-17 07:04:02.000000000 -0800
@@ -225,7 +225,7 @@ void reparent_to_init(void)
/* Set the exit signal to SIGCHLD so we signal init on exit */
current->exit_signal = SIGCHLD;
- if ((current->policy == SCHED_NORMAL) && (task_nice(current) < 0))
+ if (task_nice(current) < 0)
set_user_nice(current, 0);
/* cpus_allowed? */
/* rt_priority? */
diff -prauN linux-2.6.0-test11/kernel/fork.c sched-2.6.0-test11-5/kernel/fork.c
--- linux-2.6.0-test11/kernel/fork.c 2003-11-26 12:42:58.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/fork.c 2003-12-23 06:22:59.000000000 -0800
@@ -836,6 +836,9 @@ struct task_struct *copy_process(unsigne
atomic_inc(&p->user->__count);
atomic_inc(&p->user->processes);
+ clear_tsk_thread_flag(p, TIF_SIGPENDING);
+ clear_tsk_thread_flag(p, TIF_QUEUED);
+
/*
* If multiple threads are within copy_process(), then this check
* triggers too late. This doesn't hurt, the check is only there
@@ -861,13 +864,21 @@ struct task_struct *copy_process(unsigne
p->state = TASK_UNINTERRUPTIBLE;
copy_flags(clone_flags, p);
- if (clone_flags & CLONE_IDLETASK)
+ if (clone_flags & CLONE_IDLETASK) {
p->pid = 0;
- else {
+ set_task_sched_policy(p, SCHED_IDLE);
+ } else {
+ if (task_sched_policy(p) == SCHED_IDLE) {
+ memset(&p->sched_info, 0, sizeof(struct sched_info));
+ set_task_sched_policy(p, SCHED_NORMAL);
+ set_user_nice(p, 0);
+ }
p->pid = alloc_pidmap();
if (p->pid == -1)
goto bad_fork_cleanup;
}
+ if (p->pid == 1)
+ BUG_ON(task_nice(p));
retval = -EFAULT;
if (clone_flags & CLONE_PARENT_SETTID)
if (put_user(p->pid, parent_tidptr))
@@ -875,8 +886,7 @@ struct task_struct *copy_process(unsigne
p->proc_dentry = NULL;
- INIT_LIST_HEAD(&p->run_list);
-
+ INIT_LIST_HEAD(&p->sched_info.run_list);
INIT_LIST_HEAD(&p->children);
INIT_LIST_HEAD(&p->sibling);
INIT_LIST_HEAD(&p->posix_timers);
@@ -885,8 +895,6 @@ struct task_struct *copy_process(unsigne
spin_lock_init(&p->alloc_lock);
spin_lock_init(&p->switch_lock);
spin_lock_init(&p->proc_lock);
-
- clear_tsk_thread_flag(p, TIF_SIGPENDING);
init_sigpending(&p->pending);
p->it_real_value = p->it_virt_value = p->it_prof_value = 0;
@@ -898,7 +906,6 @@ struct task_struct *copy_process(unsigne
p->tty_old_pgrp = 0;
p->utime = p->stime = 0;
p->cutime = p->cstime = 0;
- p->array = NULL;
p->lock_depth = -1; /* -1 = no lock */
p->start_time = get_jiffies_64();
p->security = NULL;
@@ -948,33 +955,6 @@ struct task_struct *copy_process(unsigne
p->pdeath_signal = 0;
/*
- * Share the timeslice between parent and child, thus the
- * total amount of pending timeslices in the system doesn't change,
- * resulting in more scheduling fairness.
- */
- local_irq_disable();
- p->time_slice = (current->time_slice + 1) >> 1;
- /*
- * The remainder of the first timeslice might be recovered by
- * the parent if the child exits early enough.
- */
- p->first_time_slice = 1;
- current->time_slice >>= 1;
- p->timestamp = sched_clock();
- if (!current->time_slice) {
- /*
- * This case is rare, it happens when the parent has only
- * a single jiffy left from its timeslice. Taking the
- * runqueue lock is not a problem.
- */
- current->time_slice = 1;
- preempt_disable();
- scheduler_tick(0, 0);
- local_irq_enable();
- preempt_enable();
- } else
- local_irq_enable();
- /*
* Ok, add it to the run-queues and make it
* visible to the rest of the system.
*
diff -prauN linux-2.6.0-test11/kernel/sched/Makefile sched-2.6.0-test11-5/kernel/sched/Makefile
--- linux-2.6.0-test11/kernel/sched/Makefile 1969-12-31 16:00:00.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/sched/Makefile 2003-12-17 03:32:21.000000000 -0800
@@ -0,0 +1 @@
+obj-y = util.o ts.o idle.o rt.o batch.o
diff -prauN linux-2.6.0-test11/kernel/sched/batch.c sched-2.6.0-test11-5/kernel/sched/batch.c
--- linux-2.6.0-test11/kernel/sched/batch.c 1969-12-31 16:00:00.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/sched/batch.c 2003-12-19 21:32:49.000000000 -0800
@@ -0,0 +1,190 @@
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/percpu.h>
+#include <linux/kernel_stat.h>
+#include <asm/page.h>
+#include "queue.h"
+
+struct batch_queue {
+ int base, tasks;
+ task_t *curr;
+ unsigned long bitmap[BITS_TO_LONGS(MAX_BATCH_PRIO)];
+ struct list_head queue[MAX_BATCH_PRIO];
+};
+
+static int batch_quantum = 1024;
+static DEFINE_PER_CPU(struct batch_queue, batch_queues);
+
+static int batch_init(struct policy *policy, int cpu)
+{
+ int k;
+ struct batch_queue *queue = &per_cpu(batch_queues, cpu);
+
+ policy->queue = (struct queue *)queue;
+ for (k = 0; k < MAX_BATCH_PRIO; ++k)
+ INIT_LIST_HEAD(&queue->queue[k]);
+ return 0;
+}
+
+static int batch_tick(struct queue *__queue, task_t *task, int user_ticks, int sys_ticks)
+{
+ struct batch_queue *queue = (struct batch_queue *)__queue;
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+
+ cpustat->nice += user_ticks;
+ cpustat->system += sys_ticks;
+
+ task->sched_info.cl_data.bt.ticks--;
+ if (!task->sched_info.cl_data.bt.ticks) {
+ int new_idx;
+
+ task->sched_info.cl_data.bt.ticks = batch_quantum;
+ new_idx = (task->sched_info.idx + task->sched_info.cl_data.bt.prio)
+ % MAX_BATCH_PRIO;
+ if (!test_bit(new_idx, queue->bitmap))
+ __set_bit(new_idx, queue->bitmap);
+ list_move_tail(&task->sched_info.run_list,
+ &queue->queue[new_idx]);
+ if (list_empty(&queue->queue[task->sched_info.idx]))
+ __clear_bit(task->sched_info.idx, queue->bitmap);
+ task->sched_info.idx = new_idx;
+ queue->base = find_first_circular_bit(queue->bitmap,
+ queue->base,
+ MAX_BATCH_PRIO);
+ set_need_resched();
+ }
+ return 0;
+}
+
+static void batch_yield(struct queue *__queue, task_t *task)
+{
+ int new_idx;
+ struct batch_queue *queue = (struct batch_queue *)__queue;
+
+ new_idx = (queue->base + MAX_BATCH_PRIO - 1) % MAX_BATCH_PRIO;
+ if (!test_bit(new_idx, queue->bitmap))
+ __set_bit(new_idx, queue->bitmap);
+ list_move_tail(&task->sched_info.run_list, &queue->queue[new_idx]);
+ if (list_empty(&queue->queue[task->sched_info.idx]))
+ __clear_bit(task->sched_info.idx, queue->bitmap);
+ task->sched_info.idx = new_idx;
+ queue->base = find_first_circular_bit(queue->bitmap,
+ queue->base,
+ MAX_BATCH_PRIO);
+ set_need_resched();
+}
+
+static task_t *batch_curr(struct queue *__queue)
+{
+ struct batch_queue *queue = (struct batch_queue *)__queue;
+ return queue->curr;
+}
+
+static void batch_set_curr(struct queue *__queue, task_t *task)
+{
+ struct batch_queue *queue = (struct batch_queue *)__queue;
+ queue->curr = task;
+}
+
+static task_t *batch_best(struct queue *__queue)
+{
+ int idx;
+ struct batch_queue *queue = (struct batch_queue *)__queue;
+
+ idx = find_first_circular_bit(queue->bitmap,
+ queue->base,
+ MAX_BATCH_PRIO);
+ BUG_ON(idx >= MAX_BATCH_PRIO);
+ BUG_ON(list_empty(&queue->queue[idx]));
+ return list_entry(queue->queue[idx].next, task_t, sched_info.run_list);
+}
+
+static void batch_enqueue(struct queue *__queue, task_t *task)
+{
+ int idx;
+ struct batch_queue *queue = (struct batch_queue *)__queue;
+
+ idx = (queue->base + task->sched_info.cl_data.bt.prio) % MAX_BATCH_PRIO;
+ if (!test_bit(idx, queue->bitmap))
+ __set_bit(idx, queue->bitmap);
+ list_add_tail(&task->sched_info.run_list, &queue->queue[idx]);
+ task->sched_info.idx = idx;
+ task->sched_info.cl_data.bt.ticks = batch_quantum;
+ queue->tasks++;
+ if (!queue->curr)
+ queue->curr = task;
+}
+
+static void batch_dequeue(struct queue *__queue, task_t *task)
+{
+ struct batch_queue *queue = (struct batch_queue *)__queue;
+ list_del(&task->sched_info.run_list);
+ if (list_empty(&queue->queue[task->sched_info.idx]))
+ __clear_bit(task->sched_info.idx, queue->bitmap);
+ queue->tasks--;
+ if (!queue->tasks)
+ queue->curr = NULL;
+ else if (task == queue->curr)
+ queue->curr = batch_best(__queue);
+}
+
+static int batch_preempt(struct queue *__queue, task_t *task)
+{
+ struct batch_queue *queue = (struct batch_queue *)__queue;
+ if (!queue->curr)
+ return 1;
+ else
+ return task->sched_info.cl_data.bt.prio
+ < queue->curr->sched_info.cl_data.bt.prio;
+}
+
+static int batch_tasks(struct queue *__queue)
+{
+ struct batch_queue *queue = (struct batch_queue *)__queue;
+ return queue->tasks;
+}
+
+static int batch_nice(struct queue *queue, task_t *task)
+{
+ return 20;
+}
+
+static int batch_prio(task_t *task)
+{
+ return USER_PRIO(task->sched_info.cl_data.bt.prio + MIN_BATCH_PRIO);
+}
+
+static void batch_setprio(task_t *task, int prio)
+{
+ BUG_ON(prio < 0);
+ BUG_ON(prio >= MAX_BATCH_PRIO);
+ task->sched_info.cl_data.bt.prio = prio;
+}
+
+struct queue_ops batch_ops = {
+ .init = batch_init,
+ .fini = nop_fini,
+ .tick = batch_tick,
+ .yield = batch_yield,
+ .curr = batch_curr,
+ .set_curr = batch_set_curr,
+ .tasks = batch_tasks,
+ .best = batch_best,
+ .enqueue = batch_enqueue,
+ .dequeue = batch_dequeue,
+ .start_wait = queue_nop,
+ .stop_wait = queue_nop,
+ .sleep = queue_nop,
+ .wake = queue_nop,
+ .preempt = batch_preempt,
+ .nice = batch_nice,
+ .renice = nop_renice,
+ .prio = batch_prio,
+ .setprio = batch_setprio,
+ .timeslice = nop_timeslice,
+ .set_timeslice = nop_set_timeslice,
+};
+
+struct policy batch_policy = {
+ .ops = &batch_ops,
+};
diff -prauN linux-2.6.0-test11/kernel/sched/idle.c sched-2.6.0-test11-5/kernel/sched/idle.c
--- linux-2.6.0-test11/kernel/sched/idle.c 1969-12-31 16:00:00.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/sched/idle.c 2003-12-19 17:31:39.000000000 -0800
@@ -0,0 +1,99 @@
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/percpu.h>
+#include <linux/kernel_stat.h>
+#include <asm/page.h>
+#include "queue.h"
+
+static DEFINE_PER_CPU(task_t *, idle_tasks) = NULL;
+
+static int idle_nice(struct queue *queue, task_t *task)
+{
+ return 20;
+}
+
+static int idle_tasks(struct queue *queue)
+{
+ task_t **idle = (task_t **)queue;
+ return !!(*idle);
+}
+
+static task_t *idle_task(struct queue *queue)
+{
+ return *((task_t **)queue);
+}
+
+static void idle_yield(struct queue *queue, task_t *task)
+{
+ set_need_resched();
+}
+
+static void idle_enqueue(struct queue *queue, task_t *task)
+{
+ task_t **idle = (task_t **)queue;
+ *idle = task;
+}
+
+static void idle_dequeue(struct queue *queue, task_t *task)
+{
+}
+
+static int idle_preempt(struct queue *queue, task_t *task)
+{
+ return 0;
+}
+
+static int idle_tick(struct queue *queue, task_t *task, int user_ticks, int sys_ticks)
+{
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+ runqueue_t *rq = &per_cpu(runqueues, smp_processor_id());
+
+ if (atomic_read(&rq->nr_iowait) > 0)
+ cpustat->iowait += sys_ticks;
+ else
+ cpustat->idle += sys_ticks;
+ return 1;
+}
+
+static int idle_init(struct policy *policy, int cpu)
+{
+ policy->queue = (struct queue *)&per_cpu(idle_tasks, cpu);
+ return 0;
+}
+
+static int idle_prio(task_t *task)
+{
+ return MAX_USER_PRIO;
+}
+
+static void idle_setprio(task_t *task, int prio)
+{
+}
+
+static struct queue_ops idle_ops = {
+ .init = idle_init,
+ .fini = nop_fini,
+ .tick = idle_tick,
+ .yield = idle_yield,
+ .curr = idle_task,
+ .set_curr = queue_nop,
+ .tasks = idle_tasks,
+ .best = idle_task,
+ .enqueue = idle_enqueue,
+ .dequeue = idle_dequeue,
+ .start_wait = queue_nop,
+ .stop_wait = queue_nop,
+ .sleep = queue_nop,
+ .wake = queue_nop,
+ .preempt = idle_preempt,
+ .nice = idle_nice,
+ .renice = nop_renice,
+ .prio = idle_prio,
+ .setprio = idle_setprio,
+ .timeslice = nop_timeslice,
+ .set_timeslice = nop_set_timeslice,
+};
+
+struct policy idle_policy = {
+ .ops = &idle_ops,
+};
diff -prauN linux-2.6.0-test11/kernel/sched/queue.h sched-2.6.0-test11-5/kernel/sched/queue.h
--- linux-2.6.0-test11/kernel/sched/queue.h 1969-12-31 16:00:00.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/sched/queue.h 2003-12-23 03:58:02.000000000 -0800
@@ -0,0 +1,104 @@
+#define SCHED_POLICY_RT 0
+#define SCHED_POLICY_TS 1
+#define SCHED_POLICY_BATCH 2
+#define SCHED_POLICY_IDLE 3
+
+#define RT_POLICY_FIFO 0
+#define RT_POLICY_RR 1
+
+#define NODE_THRESHOLD 125
+
+struct queue;
+struct queue_ops;
+
+struct policy {
+ struct queue *queue;
+ struct queue_ops *ops;
+};
+
+extern struct policy rt_policy, ts_policy, batch_policy, idle_policy;
+
+struct runqueue {
+ spinlock_t lock;
+ int curr;
+ task_t *__curr;
+ unsigned long policy_bitmap;
+ struct policy *policies[BITS_PER_LONG];
+ unsigned long nr_running, nr_switches, nr_uninterruptible;
+ struct mm_struct *prev_mm;
+ int prev_cpu_load[NR_CPUS];
+#ifdef CONFIG_NUMA
+ atomic_t *node_nr_running;
+ int prev_node_load[MAX_NUMNODES];
+#endif
+ task_t *migration_thread;
+ struct list_head migration_queue;
+
+ atomic_t nr_iowait;
+};
+
+typedef struct runqueue runqueue_t;
+
+struct queue_ops {
+ int (*init)(struct policy *, int);
+ void (*fini)(struct policy *, int);
+ task_t *(*curr)(struct queue *);
+ void (*set_curr)(struct queue *, task_t *);
+ task_t *(*best)(struct queue *);
+ int (*tick)(struct queue *, task_t *, int, int);
+ int (*tasks)(struct queue *);
+ void (*enqueue)(struct queue *, task_t *);
+ void (*dequeue)(struct queue *, task_t *);
+ void (*start_wait)(struct queue *, task_t *);
+ void (*stop_wait)(struct queue *, task_t *);
+ void (*sleep)(struct queue *, task_t *);
+ void (*wake)(struct queue *, task_t *);
+ int (*preempt)(struct queue *, task_t *);
+ void (*yield)(struct queue *, task_t *);
+ int (*prio)(task_t *);
+ void (*setprio)(task_t *, int);
+ int (*nice)(struct queue *, task_t *);
+ void (*renice)(struct queue *, task_t *, int);
+ unsigned long (*timeslice)(struct queue *, task_t *);
+ void (*set_timeslice)(struct queue *, task_t *, unsigned long);
+};
+
+DECLARE_PER_CPU(runqueue_t, runqueues);
+
+int find_first_circular_bit(unsigned long *, int, int);
+void queue_nop(struct queue *, task_t *);
+void nop_renice(struct queue *, task_t *, int);
+void nop_fini(struct policy *, int);
+unsigned long nop_timeslice(struct queue *, task_t *);
+void nop_set_timeslice(struct queue *, task_t *, unsigned long);
+
+/* #define DEBUG_SCHED */
+
+#ifdef DEBUG_SCHED
+#define __check_task_policy(idx) \
+do { \
+ unsigned long __idx__ = (idx); \
+ if (__idx__ > SCHED_POLICY_IDLE) { \
+ printk("invalid policy 0x%lx\n", __idx__); \
+ BUG(); \
+ } \
+} while (0)
+
+#define check_task_policy(task) \
+do { \
+ __check_task_policy((task)->sched_info.policy); \
+} while (0)
+
+#define check_policy(policy) \
+do { \
+ BUG_ON((policy) != &rt_policy && \
+ (policy) != &ts_policy && \
+ (policy) != &batch_policy && \
+ (policy) != &idle_policy); \
+} while (0)
+
+#else /* !DEBUG_SCHED */
+#define __check_task_policy(idx) do { } while (0)
+#define check_task_policy(task) do { } while (0)
+#define check_policy(policy) do { } while (0)
+#endif /* !DEBUG_SCHED */
diff -prauN linux-2.6.0-test11/kernel/sched/rt.c sched-2.6.0-test11-5/kernel/sched/rt.c
--- linux-2.6.0-test11/kernel/sched/rt.c 1969-12-31 16:00:00.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/sched/rt.c 2003-12-19 18:16:07.000000000 -0800
@@ -0,0 +1,208 @@
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/percpu.h>
+#include <linux/kernel_stat.h>
+#include <asm/page.h>
+#include "queue.h"
+
+#ifdef DEBUG_SCHED
+#define check_rt_policy(task) \
+do { \
+ BUG_ON((task)->sched_info.policy != SCHED_POLICY_RT); \
+ BUG_ON((task)->sched_info.cl_data.rt.rt_policy != RT_POLICY_RR \
+ && \
+ (task)->sched_info.cl_data.rt.rt_policy!=RT_POLICY_FIFO); \
+ BUG_ON((task)->sched_info.cl_data.rt.prio < 0); \
+ BUG_ON((task)->sched_info.cl_data.rt.prio >= MAX_RT_PRIO); \
+} while (0)
+#else
+#define check_rt_policy(task) do { } while (0)
+#endif
+
+struct rt_queue {
+ unsigned long bitmap[BITS_TO_LONGS(MAX_RT_PRIO)];
+ struct list_head queue[MAX_RT_PRIO];
+ task_t *curr;
+ int tasks;
+};
+
+static DEFINE_PER_CPU(struct rt_queue, rt_queues);
+
+static int rt_init(struct policy *policy, int cpu)
+{
+ int k;
+ struct rt_queue *queue = &per_cpu(rt_queues, cpu);
+
+ policy->queue = (struct queue *)queue;
+ for (k = 0; k < MAX_RT_PRIO; ++k)
+ INIT_LIST_HEAD(&queue->queue[k]);
+ return 0;
+}
+
+static void rt_yield(struct queue *__queue, task_t *task)
+{
+ struct rt_queue *queue = (struct rt_queue *)__queue;
+ check_rt_policy(task);
+ list_del(&task->sched_info.run_list);
+ if (list_empty(&queue->queue[task->sched_info.cl_data.rt.prio]))
+ set_need_resched();
+ list_add_tail(&task->sched_info.run_list,
+ &queue->queue[task->sched_info.cl_data.rt.prio]);
+ check_rt_policy(task);
+}
+
+static int rt_tick(struct queue *queue, task_t *task, int user_ticks, int sys_ticks)
+{
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+ check_rt_policy(task);
+ cpustat->user += user_ticks;
+ cpustat->system += sys_ticks;
+ if (task->sched_info.cl_data.rt.rt_policy == RT_POLICY_RR) {
+ task->sched_info.cl_data.rt.ticks--;
+ if (!task->sched_info.cl_data.rt.ticks) {
+ task->sched_info.cl_data.rt.ticks =
+ task->sched_info.cl_data.rt.quantum;
+ rt_yield(queue, task);
+ }
+ }
+ check_rt_policy(task);
+ return 0;
+}
+
+static task_t *rt_curr(struct queue *__queue)
+{
+ struct rt_queue *queue = (struct rt_queue *)__queue;
+ task_t *task = queue->curr;
+ check_rt_policy(task);
+ return task;
+}
+
+static void rt_set_curr(struct queue *__queue, task_t *task)
+{
+ struct rt_queue *queue = (struct rt_queue *)__queue;
+ queue->curr = task;
+ check_rt_policy(task);
+}
+
+static task_t *rt_best(struct queue *__queue)
+{
+ struct rt_queue *queue = (struct rt_queue *)__queue;
+ task_t *task;
+ int idx;
+ idx = find_first_bit(queue->bitmap, MAX_RT_PRIO);
+ BUG_ON(idx >= MAX_RT_PRIO);
+ task = list_entry(queue->queue[idx].next, task_t, sched_info.run_list);
+ check_rt_policy(task);
+ return task;
+}
+
+static void rt_enqueue(struct queue *__queue, task_t *task)
+{
+ struct rt_queue *queue = (struct rt_queue *)__queue;
+ check_rt_policy(task);
+ if (!test_bit(task->sched_info.cl_data.rt.prio, queue->bitmap))
+ __set_bit(task->sched_info.cl_data.rt.prio, queue->bitmap);
+ list_add_tail(&task->sched_info.run_list,
+ &queue->queue[task->sched_info.cl_data.rt.prio]);
+ check_rt_policy(task);
+ queue->tasks++;
+ if (!queue->curr)
+ queue->curr = task;
+}
+
+static void rt_dequeue(struct queue *__queue, task_t *task)
+{
+ struct rt_queue *queue = (struct rt_queue *)__queue;
+ check_rt_policy(task);
+ list_del(&task->sched_info.run_list);
+ if (list_empty(&queue->queue[task->sched_info.cl_data.rt.prio]))
+ __clear_bit(task->sched_info.cl_data.rt.prio, queue->bitmap);
+ queue->tasks--;
+ check_rt_policy(task);
+ if (!queue->tasks)
+ queue->curr = NULL;
+ else if (task == queue->curr)
+ queue->curr = rt_best(__queue);
+}
+
+static int rt_preempt(struct queue *__queue, task_t *task)
+{
+ struct rt_queue *queue = (struct rt_queue *)__queue;
+ check_rt_policy(task);
+ if (!queue->curr)
+ return 1;
+ check_rt_policy(queue->curr);
+ return task->sched_info.cl_data.rt.prio
+ < queue->curr->sched_info.cl_data.rt.prio;
+}
+
+static int rt_tasks(struct queue *__queue)
+{
+ struct rt_queue *queue = (struct rt_queue *)__queue;
+ return queue->tasks;
+}
+
+static int rt_nice(struct queue *queue, task_t *task)
+{
+ check_rt_policy(task);
+ return -20;
+}
+
+static unsigned long rt_timeslice(struct queue *queue, task_t *task)
+{
+ check_rt_policy(task);
+ if (task->sched_info.cl_data.rt.rt_policy != RT_POLICY_RR)
+ return 0;
+ else
+ return task->sched_info.cl_data.rt.quantum;
+}
+
+static void rt_set_timeslice(struct queue *queue, task_t *task, unsigned long n)
+{
+ check_rt_policy(task);
+ if (task->sched_info.cl_data.rt.rt_policy == RT_POLICY_RR)
+ task->sched_info.cl_data.rt.quantum = n;
+ check_rt_policy(task);
+}
+
+static void rt_setprio(task_t *task, int prio)
+{
+ check_rt_policy(task);
+ BUG_ON(prio < 0);
+ BUG_ON(prio >= MAX_RT_PRIO);
+ task->sched_info.cl_data.rt.prio = prio;
+}
+
+static int rt_prio(task_t *task)
+{
+ check_rt_policy(task);
+ return USER_PRIO(task->sched_info.cl_data.rt.prio);
+}
+
+static struct queue_ops rt_ops = {
+ .init = rt_init,
+ .fini = nop_fini,
+ .tick = rt_tick,
+ .yield = rt_yield,
+ .curr = rt_curr,
+ .set_curr = rt_set_curr,
+ .tasks = rt_tasks,
+ .best = rt_best,
+ .enqueue = rt_enqueue,
+ .dequeue = rt_dequeue,
+ .start_wait = queue_nop,
+ .stop_wait = queue_nop,
+ .sleep = queue_nop,
+ .wake = queue_nop,
+ .preempt = rt_preempt,
+ .nice = rt_nice,
+ .renice = nop_renice,
+ .prio = rt_prio,
+ .setprio = rt_setprio,
+ .timeslice = rt_timeslice,
+ .set_timeslice = rt_set_timeslice,
+};
+
+struct policy rt_policy = {
+ .ops = &rt_ops,
+};
diff -prauN linux-2.6.0-test11/kernel/sched/ts.c sched-2.6.0-test11-5/kernel/sched/ts.c
--- linux-2.6.0-test11/kernel/sched/ts.c 1969-12-31 16:00:00.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/sched/ts.c 2003-12-23 08:24:55.000000000 -0800
@@ -0,0 +1,841 @@
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/percpu.h>
+#include <linux/kernel_stat.h>
+#include <asm/page.h>
+#include "queue.h"
+
+#ifdef DEBUG_SCHED
+#define check_ts_policy(task) \
+do { \
+ BUG_ON((task)->sched_info.policy != SCHED_POLICY_TS); \
+} while (0)
+
+#define check_nice(__queue__) \
+({ \
+ int __k__, __count__ = 0; \
+ if ((__queue__)->tasks < 0) { \
+ printk("negative nice task count %d\n", \
+ (__queue__)->tasks); \
+ BUG(); \
+ } \
+ for (__k__ = 0; __k__ < NICE_QLEN; ++__k__) { \
+ task_t *__task__; \
+ if (list_empty(&(__queue__)->queue[__k__])) { \
+ if (test_bit(__k__, (__queue__)->bitmap)) { \
+ printk("wrong nice bit set\n"); \
+ BUG(); \
+ } \
+ } else { \
+ if (!test_bit(__k__, (__queue__)->bitmap)) { \
+ printk("wrong nice bit clear\n"); \
+ BUG(); \
+ } \
+ } \
+ list_for_each_entry(__task__, \
+ &(__queue__)->queue[__k__], \
+ sched_info.run_list) { \
+ check_ts_policy(__task__); \
+ if (__task__->sched_info.idx != __k__) { \
+ printk("nice index mismatch\n"); \
+ BUG(); \
+ } \
+ ++__count__; \
+ } \
+ } \
+ if ((__queue__)->tasks != __count__) { \
+ printk("wrong nice task count\n"); \
+ printk("expected %d, got %d\n", \
+ (__queue__)->tasks, \
+ __count__); \
+ BUG(); \
+ } \
+ __count__; \
+})
+
+#define check_queue(__queue) \
+do { \
+ int __k, __count = 0; \
+ if ((__queue)->tasks < 0) { \
+ printk("negative queue task count %d\n", \
+ (__queue)->tasks); \
+ BUG(); \
+ } \
+ for (__k = 0; __k < 40; ++__k) { \
+ struct nice_queue *__nice; \
+ if (list_empty(&(__queue)->nices[__k])) { \
+ if (test_bit(__k, (__queue)->bitmap)) { \
+ printk("wrong queue bit set\n"); \
+ BUG(); \
+ } \
+ } else { \
+ if (!test_bit(__k, (__queue)->bitmap)) { \
+ printk("wrong queue bit clear\n"); \
+ BUG(); \
+ } \
+ } \
+ list_for_each_entry(__nice, \
+ &(__queue)->nices[__k], \
+ list) { \
+ __count += check_nice(__nice); \
+ if (__nice->idx != __k) { \
+ printk("queue index mismatch\n"); \
+ BUG(); \
+ } \
+ } \
+ } \
+ if ((__queue)->tasks != __count) { \
+ printk("wrong queue task count\n"); \
+ printk("expected %d, got %d\n", \
+ (__queue)->tasks, \
+ __count); \
+ BUG(); \
+ } \
+} while (0)
+
+#else /* !DEBUG_SCHED */
+#define check_ts_policy(task) do { } while (0)
+#define check_nice(nice) do { } while (0)
+#define check_queue(queue) do { } while (0)
+#endif
+
+/*
+ * Hybrid deadline/multilevel scheduling. Cpu utilization
+ * -dependent deadlines at wake. Queue rotation every 50ms or when
+ * demotions empty the highest level, setting demoted deadlines
+ * relative to the new highest level. Intra-level RR quantum at 10ms.
+ */
+struct nice_queue {
+ int idx, nice, base, tasks, level_quantum, expired;
+ unsigned long bitmap[BITS_TO_LONGS(NICE_QLEN)];
+ struct list_head list, queue[NICE_QLEN];
+ task_t *curr;
+};
+
+/*
+ * Deadline schedule nice levels with priority-dependent deadlines,
+ * default quantum of 100ms. Queue rotates at demotions emptying the
+ * highest level, setting the demoted deadline relative to the new
+ * highest level.
+ */
+struct ts_queue {
+ struct nice_queue nice_levels[40];
+ struct list_head nices[40];
+ int base, quantum, tasks;
+ unsigned long bitmap[BITS_TO_LONGS(40)];
+ struct nice_queue *curr;
+};
+
+/*
+ * Make these sysctl-tunable.
+ */
+static int nice_quantum = 100;
+static int rr_quantum = 10;
+static int level_quantum = 50;
+static int sample_interval = HZ;
+
+static DEFINE_PER_CPU(struct ts_queue, ts_queues);
+
+static task_t *nice_best(struct nice_queue *);
+static struct nice_queue *ts_best_nice(struct ts_queue *);
+
+static void nice_init(struct nice_queue *queue)
+{
+ int k;
+
+ INIT_LIST_HEAD(&queue->list);
+ for (k = 0; k < NICE_QLEN; ++k) {
+ INIT_LIST_HEAD(&queue->queue[k]);
+ }
+}
+
+static int ts_init(struct policy *policy, int cpu)
+{
+ int k;
+ struct ts_queue *queue = &per_cpu(ts_queues, cpu);
+
+ policy->queue = (struct queue *)queue;
+ queue->quantum = nice_quantum;
+
+ for (k = 0; k < 40; ++k) {
+ nice_init(&queue->nice_levels[k]);
+ queue->nice_levels[k].nice = k;
+ INIT_LIST_HEAD(&queue->nices[k]);
+ }
+ return 0;
+}
+
+static int task_deadline(task_t *task)
+{
+ u64 frac_cpu = task->sched_info.cl_data.ts.frac_cpu;
+ frac_cpu *= (u64)NICE_QLEN;
+ frac_cpu >>= 32;
+ return (int)min((u32)(NICE_QLEN - 1), (u32)frac_cpu);
+}
+
+static void nice_rotate_queue(struct nice_queue *queue)
+{
+ int idx, new_idx, deadline, idxdiff;
+ task_t *task = queue->curr;
+
+ check_nice(queue);
+
+ /* shit what if idxdiff == NICE_QLEN - 1?? */
+ idx = queue->curr->sched_info.idx;
+ idxdiff = (idx - queue->base + NICE_QLEN) % NICE_QLEN;
+ deadline = min(1 + task_deadline(task), NICE_QLEN - idxdiff - 1);
+ new_idx = (idx + deadline) % NICE_QLEN;
+#if 0
+ if (idx == new_idx) {
+ /*
+ * buggy; it sets queue->base = idx because in this case
+ * we have task_deadline(task) == 0
+ */
+ new_idx = (idx - task_deadline(task) + NICE_QLEN) % NICE_QLEN;
+ if (queue->base != new_idx)
+ queue->base = new_idx;
+ return;
+ }
+ BUG_ON(!deadline);
+ BUG_ON(queue->base <= new_idx && new_idx <= idx);
+ BUG_ON(idx < queue->base && queue->base <= new_idx);
+ BUG_ON(new_idx <= idx && idx < queue->base);
+ if (0 && idx == new_idx) {
+ printk("FUCKUP: pid = %d, tdl = %d, dl = %d, idx = %d, "
+ "base = %d, diff = %d, fcpu = 0x%lx\n",
+ queue->curr->pid,
+ task_deadline(queue->curr),
+ deadline,
+ idx,
+ queue->base,
+ idxdiff,
+ task->sched_info.cl_data.ts.frac_cpu);
+ BUG();
+ }
+#else
+ /*
+ * RR in the last deadline
+ * special-cased so as not to trip BUG_ON()'s below
+ */
+ if (idx == new_idx) {
+ /* if we got here these two things must hold */
+ BUG_ON(idxdiff != NICE_QLEN - 1);
+ BUG_ON(deadline);
+ list_move_tail(&task->sched_info.run_list, &queue->queue[idx]);
+ if (queue->expired) {
+ queue->level_quantum = level_quantum;
+ queue->expired = 0;
+ }
+ return;
+ }
+#endif
+ task->sched_info.idx = new_idx;
+ if (!test_bit(new_idx, queue->bitmap)) {
+ BUG_ON(!list_empty(&queue->queue[new_idx]));
+ __set_bit(new_idx, queue->bitmap);
+ }
+ list_move_tail(&task->sched_info.run_list,
+ &queue->queue[new_idx]);
+
+ /* expired until list drains */
+ if (!list_empty(&queue->queue[idx]))
+ queue->expired = 1;
+ else {
+ int k, w, m = NICE_QLEN % BITS_PER_LONG;
+ BUG_ON(!test_bit(idx, queue->bitmap));
+ __clear_bit(idx, queue->bitmap);
+
+ for (w = 0, k = 0; k < NICE_QLEN/BITS_PER_LONG; ++k)
+ w += hweight_long(queue->bitmap[k]);
+ if (NICE_QLEN % BITS_PER_LONG)
+ w += hweight_long(queue->bitmap[k] & ((1UL << m) - 1));
+ if (w > 1)
+ queue->base = (queue->base + 1) % NICE_QLEN;
+ queue->level_quantum = level_quantum;
+ queue->expired = 0;
+ }
+ check_nice(queue);
+}
+
+static void nice_tick(struct nice_queue *queue, task_t *task)
+{
+ int idx = task->sched_info.idx;
+ BUG_ON(!task_queued(task));
+ BUG_ON(task != queue->curr);
+ BUG_ON(!test_bit(idx, queue->bitmap));
+ BUG_ON(list_empty(&queue->queue[idx]));
+ check_ts_policy(task);
+ check_nice(queue);
+
+ if (task->sched_info.cl_data.ts.ticks)
+ task->sched_info.cl_data.ts.ticks--;
+
+ if (queue->level_quantum > level_quantum) {
+ WARN_ON(1);
+ queue->level_quantum = 1;
+ }
+
+ if (!queue->expired) {
+ if (queue->level_quantum)
+ queue->level_quantum--;
+ } else if (0 && queue->queue[idx].prev != &task->sched_info.run_list) {
+ int queued = 0, new_idx = (queue->base + 1) % NICE_QLEN;
+ task_t *curr, *sav;
+ task_t *victim = list_entry(queue->queue[idx].prev,
+ task_t,
+ sched_info.run_list);
+ victim->sched_info.idx = new_idx;
+ if (!test_bit(new_idx, queue->bitmap))
+ __set_bit(new_idx, queue->bitmap);
+#if 1
+ list_for_each_entry_safe(curr, sav, &queue->queue[new_idx], sched_info.run_list) {
+ if (victim->sched_info.cl_data.ts.frac_cpu
+ < curr->sched_info.cl_data.ts.frac_cpu) {
+ queued = 1;
+ list_move(&victim->sched_info.run_list,
+ curr->sched_info.run_list.prev);
+ break;
+ }
+ }
+ if (!queued)
+ list_move_tail(&victim->sched_info.run_list,
+ &queue->queue[new_idx]);
+#else
+ list_move(&victim->sched_info.run_list, &queue->queue[new_idx]);
+#endif
+ BUG_ON(list_empty(&queue->queue[idx]));
+ }
+
+ if (!queue->level_quantum && !queue->expired) {
+ check_nice(queue);
+ nice_rotate_queue(queue);
+ check_nice(queue);
+ set_need_resched();
+ } else if (!task->sched_info.cl_data.ts.ticks) {
+ int idxdiff = (idx - queue->base + NICE_QLEN) % NICE_QLEN;
+ check_nice(queue);
+ task->sched_info.cl_data.ts.ticks = rr_quantum;
+ BUG_ON(!test_bit(idx, queue->bitmap));
+ BUG_ON(list_empty(&queue->queue[idx]));
+ if (queue->expired)
+ nice_rotate_queue(queue);
+ else if (idxdiff == NICE_QLEN - 1)
+ list_move_tail(&task->sched_info.run_list,
+ &queue->queue[idx]);
+ else {
+ int new_idx = (idx + 1) % NICE_QLEN;
+ list_del(&task->sched_info.run_list);
+ if (list_empty(&queue->queue[idx])) {
+ BUG_ON(!test_bit(idx, queue->bitmap));
+ __clear_bit(idx, queue->bitmap);
+ }
+ if (!test_bit(new_idx, queue->bitmap)) {
+ BUG_ON(!list_empty(&queue->queue[new_idx]));
+ __set_bit(new_idx, queue->bitmap);
+ }
+ task->sched_info.idx = new_idx;
+ list_add(&task->sched_info.run_list,
+ &queue->queue[new_idx]);
+ }
+ check_nice(queue);
+ set_need_resched();
+ }
+ check_nice(queue);
+ check_ts_policy(task);
+}
+
+static void ts_rotate_queue(struct ts_queue *queue)
+{
+ int idx, new_idx, idxdiff, off, deadline;
+
+ queue->base = find_first_circular_bit(queue->bitmap, queue->base, 40);
+
+ /* shit what if idxdiff == 39?? */
+ check_queue(queue);
+ idx = queue->curr->idx;
+ idxdiff = (idx - queue->base + 40) % 40;
+ off = (int)(queue->curr - queue->nice_levels);
+ deadline = min(1 + off, 40 - idxdiff - 1);
+ new_idx = (idx + deadline) % 40;
+ if (idx == new_idx) {
+ new_idx = (idx - off + 40) % 40;
+ if (queue->base != new_idx)
+ queue->base = new_idx;
+ return;
+ }
+ BUG_ON(!deadline);
+ BUG_ON(queue->base <= new_idx && new_idx <= idx);
+ BUG_ON(idx < queue->base && queue->base <= new_idx);
+ BUG_ON(new_idx <= idx && idx < queue->base);
+ if (!test_bit(new_idx, queue->bitmap)) {
+ BUG_ON(!list_empty(&queue->nices[new_idx]));
+ __set_bit(new_idx, queue->bitmap);
+ }
+ list_move_tail(&queue->curr->list, &queue->nices[new_idx]);
+ queue->curr->idx = new_idx;
+
+ if (list_empty(&queue->nices[idx])) {
+ BUG_ON(!test_bit(idx, queue->bitmap));
+ __clear_bit(idx, queue->bitmap);
+ queue->base = (queue->base + 1) % 40;
+ }
+ check_queue(queue);
+}
+
+static int ts_tick(struct queue *__queue, task_t *task, int user_ticks, int sys_ticks)
+{
+ struct ts_queue *queue = (struct ts_queue *)__queue;
+ struct nice_queue *nice = queue->curr;
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+ int nice_idx = (int)(queue->curr - queue->nice_levels);
+ unsigned long sample_end, delta;
+
+ check_queue(queue);
+ check_ts_policy(task);
+ BUG_ON(!nice);
+ BUG_ON(nice_idx != task->sched_info.cl_data.ts.nice);
+ BUG_ON(!test_bit(nice->idx, queue->bitmap));
+ BUG_ON(list_empty(&queue->nices[nice->idx]));
+
+ sample_end = jiffies;
+ delta = sample_end - task->sched_info.cl_data.ts.sample_start;
+ if (delta)
+ task->sched_info.cl_data.ts.sample_ticks++;
+ else {
+ task->sched_info.cl_data.ts.sample_start = jiffies;
+ task->sched_info.cl_data.ts.sample_ticks = 1;
+ }
+
+ if (delta >= sample_interval) {
+ u64 frac_cpu;
+ frac_cpu = (u64)task->sched_info.cl_data.ts.sample_ticks << 32;
+ do_div(frac_cpu, delta);
+ frac_cpu = 2*frac_cpu + task->sched_info.cl_data.ts.frac_cpu;
+ do_div(frac_cpu, 3);
+ frac_cpu = min(frac_cpu, (1ULL << 32) - 1);
+ task->sched_info.cl_data.ts.frac_cpu = (unsigned long)frac_cpu;
+ task->sched_info.cl_data.ts.sample_start = sample_end;
+ task->sched_info.cl_data.ts.sample_ticks = 0;
+ }
+
+ cpustat->user += user_ticks;
+ cpustat->system += sys_ticks;
+ nice_tick(nice, task);
+ if (queue->quantum > nice_quantum) {
+ queue->quantum = 0;
+ WARN_ON(1);
+ } else if (queue->quantum)
+ queue->quantum--;
+ if (!queue->quantum) {
+ queue->quantum = nice_quantum;
+ ts_rotate_queue(queue);
+ set_need_resched();
+ }
+ check_queue(queue);
+ check_ts_policy(task);
+ return 0;
+}
+
+static void nice_yield(struct nice_queue *queue, task_t *task)
+{
+ int idx, new_idx = (queue->base + NICE_QLEN - 1) % NICE_QLEN;
+
+ check_nice(queue);
+ check_ts_policy(task);
+ if (!test_bit(new_idx, queue->bitmap)) {
+ BUG_ON(!list_empty(&queue->queue[new_idx]));
+ __set_bit(new_idx, queue->bitmap);
+ }
+ list_move_tail(&task->sched_info.run_list, &queue->queue[new_idx]);
+ idx = task->sched_info.idx;
+ task->sched_info.idx = new_idx;
+ set_need_resched();
+
+ if (list_empty(&queue->queue[idx])) {
+ BUG_ON(!test_bit(idx, queue->bitmap));
+ __clear_bit(idx, queue->bitmap);
+ }
+ queue->curr = nice_best(queue);
+#if 0
+ if (queue->curr->sched_info.idx != queue->base)
+ queue->base = queue->curr->sched_info.idx;
+#endif
+ check_nice(queue);
+ check_ts_policy(task);
+}
+
+/*
+ * This is somewhat problematic; nice_yield() only parks tasks on
+ * the end of their current nice levels.
+ */
+static void ts_yield(struct queue *__queue, task_t *task)
+{
+ struct ts_queue *queue = (struct ts_queue *)__queue;
+ struct nice_queue *nice = queue->curr;
+
+ check_queue(queue);
+ check_ts_policy(task);
+ nice_yield(nice, task);
+
+ /*
+ * If there's no one to yield to, move the whole nice level.
+ * If this is problematic, setting nice-dependent deadlines
+ * on a single unified queue may be in order.
+ */
+ if (nice->tasks == 1) {
+ int idx, new_idx = (queue->base + 40 - 1) % 40;
+ idx = nice->idx;
+ if (!test_bit(new_idx, queue->bitmap)) {
+ BUG_ON(!list_empty(&queue->nices[new_idx]));
+ __set_bit(new_idx, queue->bitmap);
+ }
+ list_move_tail(&nice->list, &queue->nices[new_idx]);
+ if (list_empty(&queue->nices[idx])) {
+ BUG_ON(!test_bit(idx, queue->bitmap));
+ __clear_bit(idx, queue->bitmap);
+ }
+ nice->idx = new_idx;
+ queue->base = find_first_circular_bit(queue->bitmap,
+ queue->base,
+ 40);
+ BUG_ON(queue->base >= 40);
+ BUG_ON(!test_bit(queue->base, queue->bitmap));
+ queue->curr = ts_best_nice(queue);
+ }
+ check_queue(queue);
+ check_ts_policy(task);
+}
+
+static task_t *ts_curr(struct queue *__queue)
+{
+ struct ts_queue *queue = (struct ts_queue *)__queue;
+ task_t *task = queue->curr->curr;
+ check_queue(queue);
+ if (task)
+ check_ts_policy(task);
+ return task;
+}
+
+static void ts_set_curr(struct queue *__queue, task_t *task)
+{
+ struct ts_queue *queue = (struct ts_queue *)__queue;
+ struct nice_queue *nice;
+ check_queue(queue);
+ check_ts_policy(task);
+ nice = &queue->nice_levels[task->sched_info.cl_data.ts.nice];
+ queue->curr = nice;
+ nice->curr = task;
+ check_queue(queue);
+ check_ts_policy(task);
+}
+
+static task_t *nice_best(struct nice_queue *queue)
+{
+ task_t *task;
+ int idx = find_first_circular_bit(queue->bitmap,
+ queue->base,
+ NICE_QLEN);
+ check_nice(queue);
+ if (idx >= NICE_QLEN)
+ return NULL;
+ BUG_ON(list_empty(&queue->queue[idx]));
+ BUG_ON(!test_bit(idx, queue->bitmap));
+ task = list_entry(queue->queue[idx].next, task_t, sched_info.run_list);
+ check_nice(queue);
+ check_ts_policy(task);
+ return task;
+}
+
+static struct nice_queue *ts_best_nice(struct ts_queue *queue)
+{
+ int idx = find_first_circular_bit(queue->bitmap, queue->base, 40);
+ check_queue(queue);
+ if (idx >= 40)
+ return NULL;
+ BUG_ON(list_empty(&queue->nices[idx]));
+ BUG_ON(!test_bit(idx, queue->bitmap));
+ return list_entry(queue->nices[idx].next, struct nice_queue, list);
+}
+
+static task_t *ts_best(struct queue *__queue)
+{
+ struct ts_queue *queue = (struct ts_queue *)__queue;
+ struct nice_queue *nice = ts_best_nice(queue);
+ return nice ? nice_best(nice) : NULL;
+}
+
+static void nice_enqueue(struct nice_queue *queue, task_t *task)
+{
+ task_t *curr, *sav;
+ int queued = 0, idx, deadline, base, idxdiff;
+ check_nice(queue);
+ check_ts_policy(task);
+
+ /* don't livelock when queue->expired */
+ deadline = min(!!queue->expired + task_deadline(task), NICE_QLEN - 1);
+ idx = (queue->base + deadline) % NICE_QLEN;
+
+ if (!test_bit(idx, queue->bitmap)) {
+ BUG_ON(!list_empty(&queue->queue[idx]));
+ __set_bit(idx, queue->bitmap);
+ }
+
+#if 1
+ /* keep nice level's queue sorted -- use binomial heaps here soon */
+ list_for_each_entry_safe(curr, sav, &queue->queue[idx], sched_info.run_list) {
+ if (task->sched_info.cl_data.ts.frac_cpu
+ >= curr->sched_info.cl_data.ts.frac_cpu) {
+ list_add(&task->sched_info.run_list,
+ curr->sched_info.run_list.prev);
+ queued = 1;
+ break;
+ }
+ }
+ if (!queued)
+ list_add_tail(&task->sched_info.run_list, &queue->queue[idx]);
+#else
+ list_add_tail(&task->sched_info.run_list, &queue->queue[idx]);
+#endif
+ task->sched_info.idx = idx;
+ /* if (!task->sched_info.cl_data.ts.ticks) */
+ task->sched_info.cl_data.ts.ticks = rr_quantum;
+
+ if (queue->tasks)
+ BUG_ON(!queue->curr);
+ else {
+ BUG_ON(queue->curr);
+ queue->curr = task;
+ }
+ queue->tasks++;
+ check_nice(queue);
+ check_ts_policy(task);
+}
+
+static void ts_enqueue(struct queue *__queue, task_t *task)
+{
+ struct ts_queue *queue = (struct ts_queue *)__queue;
+ struct nice_queue *nice;
+
+ check_queue(queue);
+ check_ts_policy(task);
+ nice = &queue->nice_levels[task->sched_info.cl_data.ts.nice];
+ if (!nice->tasks) {
+ int idx = (queue->base + task->sched_info.cl_data.ts.nice) % 40;
+ if (!test_bit(idx, queue->bitmap)) {
+ BUG_ON(!list_empty(&queue->nices[idx]));
+ __set_bit(idx, queue->bitmap);
+ }
+ list_add_tail(&nice->list, &queue->nices[idx]);
+ nice->idx = idx;
+ if (!queue->curr)
+ queue->curr = nice;
+ }
+ nice_enqueue(nice, task);
+ queue->tasks++;
+ queue->base = find_first_circular_bit(queue->bitmap, queue->base, 40);
+ check_queue(queue);
+ check_ts_policy(task);
+}
+
+static void nice_dequeue(struct nice_queue *queue, task_t *task)
+{
+ check_nice(queue);
+ check_ts_policy(task);
+ list_del(&task->sched_info.run_list);
+ if (list_empty(&queue->queue[task->sched_info.idx])) {
+ BUG_ON(!test_bit(task->sched_info.idx, queue->bitmap));
+ __clear_bit(task->sched_info.idx, queue->bitmap);
+ }
+ queue->tasks--;
+ if (task == queue->curr) {
+ queue->curr = nice_best(queue);
+#if 0
+ if (queue->curr)
+ queue->base = queue->curr->sched_info.idx;
+#endif
+ }
+ check_nice(queue);
+ check_ts_policy(task);
+}
+
+static void ts_dequeue(struct queue *__queue, task_t *task)
+{
+ struct ts_queue *queue = (struct ts_queue *)__queue;
+ struct nice_queue *nice;
+
+ BUG_ON(!queue->tasks);
+ check_queue(queue);
+ check_ts_policy(task);
+ nice = &queue->nice_levels[task->sched_info.cl_data.ts.nice];
+
+ nice_dequeue(nice, task);
+ queue->tasks--;
+ if (!nice->tasks) {
+ list_del_init(&nice->list);
+ if (list_empty(&queue->nices[nice->idx])) {
+ BUG_ON(!test_bit(nice->idx, queue->bitmap));
+ __clear_bit(nice->idx, queue->bitmap);
+ }
+ if (nice == queue->curr)
+ queue->curr = ts_best_nice(queue);
+ }
+ queue->base = find_first_circular_bit(queue->bitmap, queue->base, 40);
+ if (queue->base >= 40)
+ queue->base = 0;
+ check_queue(queue);
+ check_ts_policy(task);
+}
+
+static int ts_tasks(struct queue *__queue)
+{
+ struct ts_queue *queue = (struct ts_queue *)__queue;
+ check_queue(queue);
+ return queue->tasks;
+}
+
+static int ts_nice(struct queue *__queue, task_t *task)
+{
+ int nice = task->sched_info.cl_data.ts.nice - 20;
+ check_ts_policy(task);
+ BUG_ON(nice < -20);
+ BUG_ON(nice >= 20);
+ return nice;
+}
+
+static void ts_renice(struct queue *queue, task_t *task, int nice)
+{
+ check_queue((struct ts_queue *)queue);
+ check_ts_policy(task);
+ BUG_ON(nice < -20);
+ BUG_ON(nice >= 20);
+ task->sched_info.cl_data.ts.nice = nice + 20;
+ check_queue((struct ts_queue *)queue);
+}
+
+static int nice_task_prio(struct nice_queue *nice, task_t *task)
+{
+ if (!task_queued(task))
+ return task_deadline(task);
+ else {
+ int prio = task->sched_info.idx - nice->base;
+ return prio < 0 ? prio + NICE_QLEN : prio;
+ }
+}
+
+static int ts_nice_prio(struct ts_queue *ts, struct nice_queue *nice)
+{
+ if (list_empty(&nice->list))
+ return (int)(nice - ts->nice_levels);
+ else {
+ int prio = nice->idx - ts->base;
+ return prio < 0 ? prio + 40 : prio;
+ }
+}
+
+/* 100% fake priority to report heuristics and the like */
+static int ts_prio(task_t *task)
+{
+ int policy_idx;
+ struct policy *policy;
+ struct ts_queue *ts;
+ struct nice_queue *nice;
+
+ policy_idx = task->sched_info.policy;
+ policy = per_cpu(runqueues, task_cpu(task)).policies[policy_idx];
+ ts = (struct ts_queue *)policy->queue;
+ nice = &ts->nice_levels[task->sched_info.cl_data.ts.nice];
+ return 40*ts_nice_prio(ts, nice) + nice_task_prio(nice, task);
+}
+
+static void ts_setprio(task_t *task, int prio)
+{
+}
+
+static void ts_start_wait(struct queue *__queue, task_t *task)
+{
+}
+
+static void ts_stop_wait(struct queue *__queue, task_t *task)
+{
+}
+
+static void ts_sleep(struct queue *__queue, task_t *task)
+{
+}
+
+static void ts_wake(struct queue *__queue, task_t *task)
+{
+}
+
+static int nice_preempt(struct nice_queue *queue, task_t *task)
+{
+ check_nice(queue);
+ check_ts_policy(task);
+ /* assume FB style preemption at wakeup */
+ if (!task_queued(task) || !queue->curr)
+ return 1;
+ else {
+ int delta_t, delta_q;
+ delta_t = (task->sched_info.idx - queue->base + NICE_QLEN)
+ % NICE_QLEN;
+ delta_q = (queue->curr->sched_info.idx - queue->base
+ + NICE_QLEN)
+ % NICE_QLEN;
+ if (delta_t < delta_q)
+ return 1;
+ else if (task->sched_info.cl_data.ts.frac_cpu
+ < queue->curr->sched_info.cl_data.ts.frac_cpu)
+ return 1;
+ else
+ return 0;
+ }
+ check_nice(queue);
+}
+
+static int ts_preempt(struct queue *__queue, task_t *task)
+{
+ int curr_nice;
+ struct ts_queue *queue = (struct ts_queue *)__queue;
+ struct nice_queue *nice = queue->curr;
+
+ check_queue(queue);
+ check_ts_policy(task);
+ if (!queue->curr)
+ return 1;
+
+ curr_nice = (int)(nice - queue->nice_levels);
+
+ /* preempt when nice number is lower, or the above for matches */
+ if (task->sched_info.cl_data.ts.nice != curr_nice)
+ return task->sched_info.cl_data.ts.nice < curr_nice;
+ else
+ return nice_preempt(nice, task);
+}
+
+static struct queue_ops ts_ops = {
+ .init = ts_init,
+ .fini = nop_fini,
+ .tick = ts_tick,
+ .yield = ts_yield,
+ .curr = ts_curr,
+ .set_curr = ts_set_curr,
+ .tasks = ts_tasks,
+ .best = ts_best,
+ .enqueue = ts_enqueue,
+ .dequeue = ts_dequeue,
+ .start_wait = ts_start_wait,
+ .stop_wait = ts_stop_wait,
+ .sleep = ts_sleep,
+ .wake = ts_wake,
+ .preempt = ts_preempt,
+ .nice = ts_nice,
+ .renice = ts_renice,
+ .prio = ts_prio,
+ .setprio = ts_setprio,
+ .timeslice = nop_timeslice,
+ .set_timeslice = nop_set_timeslice,
+};
+
+struct policy ts_policy = {
+ .ops = &ts_ops,
+};
diff -prauN linux-2.6.0-test11/kernel/sched/util.c sched-2.6.0-test11-5/kernel/sched/util.c
--- linux-2.6.0-test11/kernel/sched/util.c 1969-12-31 16:00:00.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/sched/util.c 2003-12-19 08:43:20.000000000 -0800
@@ -0,0 +1,37 @@
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/percpu.h>
+#include <asm/page.h>
+#include "queue.h"
+
+int find_first_circular_bit(unsigned long *addr, int start, int end)
+{
+ int bit = find_next_bit(addr, end, start);
+ if (bit < end)
+ return bit;
+ bit = find_first_bit(addr, start);
+ if (bit < start)
+ return bit;
+ return end;
+}
+
+void queue_nop(struct queue *queue, task_t *task)
+{
+}
+
+void nop_renice(struct queue *queue, task_t *task, int nice)
+{
+}
+
+void nop_fini(struct policy *policy, int cpu)
+{
+}
+
+unsigned long nop_timeslice(struct queue *queue, task_t *task)
+{
+ return 0;
+}
+
+void nop_set_timeslice(struct queue *queue, task_t *task, unsigned long n)
+{
+}
diff -prauN linux-2.6.0-test11/kernel/sched.c sched-2.6.0-test11-5/kernel/sched.c
--- linux-2.6.0-test11/kernel/sched.c 2003-11-26 12:45:17.000000000 -0800
+++ sched-2.6.0-test11-5/kernel/sched.c 2003-12-21 06:06:32.000000000 -0800
@@ -15,6 +15,8 @@
* and per-CPU runqueues. Cleanups and useful suggestions
* by Davide Libenzi, preemptible kernel bits by Robert Love.
* 2003-09-03 Interactivity tuning by Con Kolivas.
+ * 2003-12-17 Total rewrite and generalized scheduler policies
+ * by William Irwin.
*/
#include <linux/mm.h>
@@ -38,6 +40,8 @@
#include <linux/cpu.h>
#include <linux/percpu.h>
+#include "sched/queue.h"
+
#ifdef CONFIG_NUMA
#define cpu_to_node_mask(cpu) node_to_cpumask(cpu_to_node(cpu))
#else
@@ -45,181 +49,79 @@
#endif
/*
- * Convert user-nice values [ -20 ... 0 ... 19 ]
- * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
- * and back.
- */
-#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
-#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
-#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
-
-/*
- * 'User priority' is the nice value converted to something we
- * can work with better when scaling various scheduler parameters,
- * it's a [ 0 ... 39 ] range.
- */
-#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
-#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
-#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
-#define AVG_TIMESLICE (MIN_TIMESLICE + ((MAX_TIMESLICE - MIN_TIMESLICE) *\
- (MAX_PRIO-1-NICE_TO_PRIO(0))/(MAX_USER_PRIO - 1)))
-
-/*
- * 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))
-
-/*
- * These are the 'tuning knobs' of the scheduler:
- *
- * 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 (200 * HZ / 1000)
-#define ON_RUNQUEUE_WEIGHT 30
-#define CHILD_PENALTY 95
-#define PARENT_PENALTY 100
-#define EXIT_WEIGHT 3
-#define PRIO_BONUS_RATIO 25
-#define MAX_BONUS (MAX_USER_PRIO * PRIO_BONUS_RATIO / 100)
-#define INTERACTIVE_DELTA 2
-#define MAX_SLEEP_AVG (AVG_TIMESLICE * MAX_BONUS)
-#define STARVATION_LIMIT (MAX_SLEEP_AVG)
-#define NS_MAX_SLEEP_AVG (JIFFIES_TO_NS(MAX_SLEEP_AVG))
-#define NODE_THRESHOLD 125
-#define CREDIT_LIMIT 100
-
-/*
- * If a task is 'interactive' then we reinsert it in the active
- * array after it has expired its current timeslice. (it will not
- * continue to run immediately, it will still roundrobin with
- * other interactive tasks.)
- *
- * This part scales the interactivity limit depending on niceness.
- *
- * We scale it linearly, offset by the INTERACTIVE_DELTA delta.
- * Here are a few examples of different nice levels:
- *
- * TASK_INTERACTIVE(-20): [1,1,1,1,1,1,1,1,1,0,0]
- * TASK_INTERACTIVE(-10): [1,1,1,1,1,1,1,0,0,0,0]
- * TASK_INTERACTIVE( 0): [1,1,1,1,0,0,0,0,0,0,0]
- * TASK_INTERACTIVE( 10): [1,1,0,0,0,0,0,0,0,0,0]
- * TASK_INTERACTIVE( 19): [0,0,0,0,0,0,0,0,0,0,0]
- *
- * (the X axis represents the possible -5 ... 0 ... +5 dynamic
- * priority range a task can explore, a value of '1' means the
- * task is rated interactive.)
- *
- * Ie. nice +19 tasks can never get 'interactive' enough to be
- * reinserted into the active array. And only heavily CPU-hog nice -20
- * tasks will be expired. Default nice 0 tasks are somewhere between,
- * it takes some effort for them to get interactive, but it's not
- * too hard.
- */
-
-#define CURRENT_BONUS(p) \
- (NS_TO_JIFFIES((p)->sleep_avg) * MAX_BONUS / \
- MAX_SLEEP_AVG)
-
-#ifdef CONFIG_SMP
-#define TIMESLICE_GRANULARITY(p) (MIN_TIMESLICE * \
- (1 << (((MAX_BONUS - CURRENT_BONUS(p)) ? : 1) - 1)) * \
- num_online_cpus())
-#else
-#define TIMESLICE_GRANULARITY(p) (MIN_TIMESLICE * \
- (1 << (((MAX_BONUS - CURRENT_BONUS(p)) ? : 1) - 1)))
-#endif
-
-#define SCALE(v1,v1_max,v2_max) \
- (v1) * (v2_max) / (v1_max)
-
-#define DELTA(p) \
- (SCALE(TASK_NICE(p), 40, MAX_USER_PRIO*PRIO_BONUS_RATIO/100) + \
- INTERACTIVE_DELTA)
-
-#define TASK_INTERACTIVE(p) \
- ((p)->prio <= (p)->static_prio - DELTA(p))
-
-#define JUST_INTERACTIVE_SLEEP(p) \
- (JIFFIES_TO_NS(MAX_SLEEP_AVG * \
- (MAX_BONUS / 2 + DELTA((p)) + 1) / MAX_BONUS - 1))
-
-#define HIGH_CREDIT(p) \
- ((p)->interactive_credit > CREDIT_LIMIT)
-
-#define LOW_CREDIT(p) \
- ((p)->interactive_credit < -CREDIT_LIMIT)
-
-#define TASK_PREEMPTS_CURR(p, rq) \
- ((p)->prio < (rq)->curr->prio)
-
-/*
- * BASE_TIMESLICE scales user-nice values [ -20 ... 19 ]
- * to time slice values.
- *
- * The higher a thread's priority, the bigger timeslices
- * it gets during one round of execution. But even the lowest
- * priority thread gets MIN_TIMESLICE worth of execution time.
- *
- * task_timeslice() is the interface that is used by the scheduler.
- */
-
-#define BASE_TIMESLICE(p) (MIN_TIMESLICE + \
- ((MAX_TIMESLICE - MIN_TIMESLICE) * (MAX_PRIO-1-(p)->static_prio)/(MAX_USER_PRIO - 1)))
-
-static inline unsigned int task_timeslice(task_t *p)
-{
- return BASE_TIMESLICE(p);
-}
-
-/*
- * These are the runqueue data structures:
- */
-
-#define BITMAP_SIZE ((((MAX_PRIO+1+7)/8)+sizeof(long)-1)/sizeof(long))
-
-typedef struct runqueue runqueue_t;
-
-struct prio_array {
- int nr_active;
- unsigned long bitmap[BITMAP_SIZE];
- struct list_head queue[MAX_PRIO];
-};
-
-/*
* This is the main, per-CPU runqueue data structure.
*
* Locking rule: those places that want to lock multiple runqueues
* (such as the load balancing or the thread migration code), lock
* acquire operations must be ordered by ascending &runqueue.
*/
-struct runqueue {
- spinlock_t lock;
- unsigned long nr_running, nr_switches, expired_timestamp,
- nr_uninterruptible;
- task_t *curr, *idle;
- struct mm_struct *prev_mm;
- prio_array_t *active, *expired, arrays[2];
- int prev_cpu_load[NR_CPUS];
-#ifdef CONFIG_NUMA
- atomic_t *node_nr_running;
- int prev_node_load[MAX_NUMNODES];
-#endif
- task_t *migration_thread;
- struct list_head migration_queue;
+DEFINE_PER_CPU(struct runqueue, runqueues);
- atomic_t nr_iowait;
+struct policy *policies[] = {
+ &rt_policy,
+ &ts_policy,
+ &batch_policy,
+ &idle_policy,
+ NULL,
};
-static DEFINE_PER_CPU(struct runqueue, runqueues);
-
#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
#define this_rq() (&__get_cpu_var(runqueues))
#define task_rq(p) cpu_rq(task_cpu(p))
-#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
+#define rq_curr(rq) (rq)->__curr
+#define cpu_curr(cpu) rq_curr(cpu_rq(cpu))
+
+static inline struct policy *task_policy(task_t *task)
+{
+ unsigned long idx;
+ struct policy *policy;
+ idx = task->sched_info.policy;
+ __check_task_policy(idx);
+ policy = task_rq(task)->policies[idx];
+ check_policy(policy);
+ return policy;
+}
+
+static inline struct policy *rq_policy(runqueue_t *rq)
+{
+ unsigned long idx;
+ task_t *task;
+ struct policy *policy;
+
+ task = rq_curr(rq);
+ BUG_ON(!task);
+ BUG_ON((unsigned long)task < PAGE_OFFSET);
+ idx = task->sched_info.policy;
+ __check_task_policy(idx);
+ policy = rq->policies[idx];
+ check_policy(policy);
+ return policy;
+}
+
+static int __task_nice(task_t *task)
+{
+ struct policy *policy = task_policy(task);
+ return policy->ops->nice(policy->queue, task);
+}
+
+static inline void set_rq_curr(runqueue_t *rq, task_t *task)
+{
+ rq->curr = task->sched_info.policy;
+ __check_task_policy(rq->curr);
+ rq->__curr = task;
+}
+
+static inline int task_preempts_curr(task_t *task, runqueue_t *rq)
+{
+ check_task_policy(rq_curr(rq));
+ check_task_policy(task);
+ if (rq_curr(rq)->sched_info.policy != task->sched_info.policy)
+ return task->sched_info.policy < rq_curr(rq)->sched_info.policy;
+ else {
+ struct policy *policy = rq_policy(rq);
+ return policy->ops->preempt(policy->queue, task);
+ }
+}
/*
* Default context-switch locking:
@@ -227,7 +129,7 @@ static DEFINE_PER_CPU(struct runqueue, r
#ifndef prepare_arch_switch
# define prepare_arch_switch(rq, next) do { } while(0)
# define finish_arch_switch(rq, next) spin_unlock_irq(&(rq)->lock)
-# define task_running(rq, p) ((rq)->curr == (p))
+# define task_running(rq, p) (rq_curr(rq) == (p))
#endif
#ifdef CONFIG_NUMA
@@ -320,53 +222,32 @@ static inline void rq_unlock(runqueue_t
}
/*
- * Adding/removing a task to/from a priority array:
+ * Adding/removing a task to/from a policy's queue.
+ * We dare not BUG_ON() a wrong task_queued() as boot-time
+ * calls may trip it.
*/
-static inline void dequeue_task(struct task_struct *p, prio_array_t *array)
+static inline void dequeue_task(task_t *task, runqueue_t *rq)
{
- array->nr_active--;
- list_del(&p->run_list);
- if (list_empty(array->queue + p->prio))
- __clear_bit(p->prio, array->bitmap);
+ struct policy *policy = task_policy(task);
+ BUG_ON(!task_queued(task));
+ policy->ops->dequeue(policy->queue, task);
+ if (!policy->ops->tasks(policy->queue)) {
+ BUG_ON(!test_bit(task->sched_info.policy, &rq->policy_bitmap));
+ __clear_bit(task->sched_info.policy, &rq->policy_bitmap);
+ }
+ clear_task_queued(task);
}
-static inline void enqueue_task(struct task_struct *p, prio_array_t *array)
+static inline void enqueue_task(task_t *task, runqueue_t *rq)
{
- list_add_tail(&p->run_list, array->queue + p->prio);
- __set_bit(p->prio, array->bitmap);
- array->nr_active++;
- p->array = array;
-}
-
-/*
- * effective_prio - return the priority that is based on the static
- * priority but is modified by bonuses/penalties.
- *
- * We scale the actual sleep average [0 .... MAX_SLEEP_AVG]
- * into the -5 ... 0 ... +5 bonus/penalty range.
- *
- * We use 25% of the full 0...39 priority range so that:
- *
- * 1) nice +19 interactive tasks do not preempt nice 0 CPU hogs.
- * 2) nice -20 CPU hogs do not get preempted by nice 0 tasks.
- *
- * Both properties are important to certain workloads.
- */
-static int effective_prio(task_t *p)
-{
- int bonus, prio;
-
- if (rt_task(p))
- return p->prio;
-
- bonus = CURRENT_BONUS(p) - MAX_BONUS / 2;
-
- prio = p->static_prio - bonus;
- if (prio < MAX_RT_PRIO)
- prio = MAX_RT_PRIO;
- if (prio > MAX_PRIO-1)
- prio = MAX_PRIO-1;
- return prio;
+ struct policy *policy = task_policy(task);
+ BUG_ON(task_queued(task));
+ if (!policy->ops->tasks(policy->queue)) {
+ BUG_ON(test_bit(task->sched_info.policy, &rq->policy_bitmap));
+ __set_bit(task->sched_info.policy, &rq->policy_bitmap);
+ }
+ policy->ops->enqueue(policy->queue, task);
+ set_task_queued(task);
}
/*
@@ -374,134 +255,34 @@ static int effective_prio(task_t *p)
*/
static inline void __activate_task(task_t *p, runqueue_t *rq)
{
- enqueue_task(p, rq->active);
+ enqueue_task(p, rq);
nr_running_inc(rq);
}
-static void recalc_task_prio(task_t *p, unsigned long long now)
-{
- unsigned long long __sleep_time = now - p->timestamp;
- unsigned long sleep_time;
-
- if (__sleep_time > NS_MAX_SLEEP_AVG)
- sleep_time = NS_MAX_SLEEP_AVG;
- else
- sleep_time = (unsigned long)__sleep_time;
-
- if (likely(sleep_time > 0)) {
- /*
- * User tasks that sleep a long time are categorised as
- * idle and will get just interactive status to stay active &
- * prevent them suddenly becoming cpu hogs and starving
- * other processes.
- */
- if (p->mm && p->activated != -1 &&
- sleep_time > JUST_INTERACTIVE_SLEEP(p)){
- p->sleep_avg = JIFFIES_TO_NS(MAX_SLEEP_AVG -
- AVG_TIMESLICE);
- if (!HIGH_CREDIT(p))
- p->interactive_credit++;
- } else {
- /*
- * The lower the sleep avg a task has the more
- * rapidly it will rise with sleep time.
- */
- sleep_time *= (MAX_BONUS - CURRENT_BONUS(p)) ? : 1;
-
- /*
- * Tasks with low interactive_credit are limited to
- * one timeslice worth of sleep avg bonus.
- */
- if (LOW_CREDIT(p) &&
- sleep_time > JIFFIES_TO_NS(task_timeslice(p)))
- sleep_time =
- JIFFIES_TO_NS(task_timeslice(p));
-
- /*
- * Non high_credit tasks waking from uninterruptible
- * sleep are limited in their sleep_avg rise as they
- * are likely to be cpu hogs waiting on I/O
- */
- if (p->activated == -1 && !HIGH_CREDIT(p) && p->mm){
- if (p->sleep_avg >= JUST_INTERACTIVE_SLEEP(p))
- sleep_time = 0;
- else if (p->sleep_avg + sleep_time >=
- JUST_INTERACTIVE_SLEEP(p)){
- p->sleep_avg =
- JUST_INTERACTIVE_SLEEP(p);
- sleep_time = 0;
- }
- }
-
- /*
- * This code gives a bonus to interactive tasks.
- *
- * The boost works by updating the 'average sleep time'
- * value here, based on ->timestamp. The more time a task
- * spends sleeping, the higher the average gets - and the
- * higher the priority boost gets as well.
- */
- p->sleep_avg += sleep_time;
-
- if (p->sleep_avg > NS_MAX_SLEEP_AVG){
- p->sleep_avg = NS_MAX_SLEEP_AVG;
- if (!HIGH_CREDIT(p))
- p->interactive_credit++;
- }
- }
- }
-
- p->prio = effective_prio(p);
-}
-
/*
* activate_task - move a task to the runqueue and do priority recalculation
*
* Update all the scheduling statistics stuff. (sleep average
* calculation, priority modifiers, etc.)
*/
-static inline void activate_task(task_t *p, runqueue_t *rq)
+static inline void activate_task(task_t *task, runqueue_t *rq)
{
- unsigned long long now = sched_clock();
-
- recalc_task_prio(p, now);
-
- /*
- * This checks to make sure it's not an uninterruptible task
- * that is now waking up.
- */
- if (!p->activated){
- /*
- * Tasks which were woken up by interrupts (ie. hw events)
- * are most likely of interactive nature. So we give them
- * the credit of extending their sleep time to the period
- * of time they spend on the runqueue, waiting for execution
- * on a CPU, first time around:
- */
- if (in_interrupt())
- p->activated = 2;
- else
- /*
- * Normal first-time wakeups get a credit too for on-runqueue
- * time, but it will be weighted down:
- */
- p->activated = 1;
- }
- p->timestamp = now;
-
- __activate_task(p, rq);
+ struct policy *policy = task_policy(task);
+ policy->ops->wake(policy->queue, task);
+ __activate_task(task, rq);
}
/*
* deactivate_task - remove a task from the runqueue.
*/
-static inline void deactivate_task(struct task_struct *p, runqueue_t *rq)
+static inline void deactivate_task(task_t *task, runqueue_t *rq)
{
+ struct policy *policy = task_policy(task);
nr_running_dec(rq);
- if (p->state == TASK_UNINTERRUPTIBLE)
+ if (task->state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible++;
- dequeue_task(p, p->array);
- p->array = NULL;
+ policy->ops->sleep(policy->queue, task);
+ dequeue_task(task, rq);
}
/*
@@ -625,7 +406,7 @@ repeat_lock_task:
rq = task_rq_lock(p, &flags);
old_state = p->state;
if (old_state & state) {
- if (!p->array) {
+ if (!task_queued(p)) {
/*
* Fast-migrate the task if it's not running or runnable
* currently. Do not violate hard affinity.
@@ -644,14 +425,13 @@ repeat_lock_task:
* Tasks on involuntary sleep don't earn
* sleep_avg beyond just interactive state.
*/
- p->activated = -1;
}
if (sync)
__activate_task(p, rq);
else {
activate_task(p, rq);
- if (TASK_PREEMPTS_CURR(p, rq))
- resched_task(rq->curr);
+ if (task_preempts_curr(p, rq))
+ resched_task(rq_curr(rq));
}
success = 1;
}
@@ -679,68 +459,26 @@ int wake_up_state(task_t *p, unsigned in
* This function will do some initial scheduler statistics housekeeping
* that must be done for every newly created process.
*/
-void wake_up_forked_process(task_t * p)
+void wake_up_forked_process(task_t *task)
{
unsigned long flags;
runqueue_t *rq = task_rq_lock(current, &flags);
- p->state = TASK_RUNNING;
- /*
- * We decrease the sleep average of forking parents
- * and children as well, to keep max-interactive tasks
- * from forking tasks that are max-interactive.
- */
- current->sleep_avg = JIFFIES_TO_NS(CURRENT_BONUS(current) *
- PARENT_PENALTY / 100 * MAX_SLEEP_AVG / MAX_BONUS);
-
- p->sleep_avg = JIFFIES_TO_NS(CURRENT_BONUS(p) *
- CHILD_PENALTY / 100 * MAX_SLEEP_AVG / MAX_BONUS);
-
- p->interactive_credit = 0;
-
- p->prio = effective_prio(p);
- set_task_cpu(p, smp_processor_id());
-
- 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++;
- nr_running_inc(rq);
- }
+ task->state = TASK_RUNNING;
+ set_task_cpu(task, smp_processor_id());
+ if (unlikely(!task_queued(current)))
+ __activate_task(task, rq);
+ else
+ activate_task(task, rq);
task_rq_unlock(rq, &flags);
}
/*
- * Potentially available exiting-child timeslices are
- * retrieved here - this way the parent does not get
- * penalized for creating too many threads.
- *
- * (this cannot be used to 'generate' timeslices
- * artificially, because any timeslice recovered here
- * was given away by the parent in the first place.)
+ * Policies that depend on trapping fork() and exit() may need to
+ * put a hook here.
*/
-void sched_exit(task_t * p)
+void sched_exit(task_t *task)
{
- unsigned long flags;
-
- local_irq_save(flags);
- if (p->first_time_slice) {
- p->parent->time_slice += p->time_slice;
- if (unlikely(p->parent->time_slice > MAX_TIMESLICE))
- p->parent->time_slice = MAX_TIMESLICE;
- }
- local_irq_restore(flags);
- /*
- * If the child was a (relative-) CPU hog then decrease
- * the sleep_avg of the parent as well.
- */
- if (p->sleep_avg < p->parent->sleep_avg)
- p->parent->sleep_avg = p->parent->sleep_avg /
- (EXIT_WEIGHT + 1) * EXIT_WEIGHT + p->sleep_avg /
- (EXIT_WEIGHT + 1);
}
/**
@@ -1128,18 +866,18 @@ out:
* pull_task - move a task from a remote runqueue to the local runqueue.
* Both runqueues must be locked.
*/
-static inline void pull_task(runqueue_t *src_rq, prio_array_t *src_array, task_t *p, runqueue_t *this_rq, int this_cpu)
+static inline void pull_task(runqueue_t *src_rq, task_t *p, runqueue_t *this_rq, int this_cpu)
{
- dequeue_task(p, src_array);
+ dequeue_task(p, src_rq);
nr_running_dec(src_rq);
set_task_cpu(p, this_cpu);
nr_running_inc(this_rq);
- enqueue_task(p, this_rq->active);
+ enqueue_task(p, this_rq);
/*
* Note that idle threads have a prio of MAX_PRIO, for this test
* to be always true for them.
*/
- if (TASK_PREEMPTS_CURR(p, this_rq))
+ if (task_preempts_curr(p, this_rq))
set_need_resched();
}
@@ -1150,14 +888,14 @@ static inline void pull_task(runqueue_t
* ((!idle || (NS_TO_JIFFIES(now - (p)->timestamp) > \
* cache_decay_ticks)) && !task_running(rq, p) && \
* cpu_isset(this_cpu, (p)->cpus_allowed))
+ *
+ * Since there isn't a timestamp anymore, this needs adjustment.
*/
static inline int
can_migrate_task(task_t *tsk, runqueue_t *rq, int this_cpu, int idle)
{
- unsigned long delta = sched_clock() - tsk->timestamp;
-
- if (!idle && (delta <= JIFFIES_TO_NS(cache_decay_ticks)))
+ if (!idle)
return 0;
if (task_running(rq, tsk))
return 0;
@@ -1176,11 +914,8 @@ can_migrate_task(task_t *tsk, runqueue_t
*/
static void load_balance(runqueue_t *this_rq, int idle, cpumask_t cpumask)
{
- int imbalance, idx, this_cpu = smp_processor_id();
+ int imbalance, this_cpu = smp_processor_id();
runqueue_t *busiest;
- prio_array_t *array;
- struct list_head *head, *curr;
- task_t *tmp;
busiest = find_busiest_queue(this_rq, this_cpu, idle, &imbalance, cpumask);
if (!busiest)
@@ -1192,37 +927,6 @@ static void load_balance(runqueue_t *thi
*/
imbalance /= 2;
- /*
- * We first consider expired tasks. Those will likely not be
- * executed in the near future, and they are most likely to
- * be cache-cold, thus switching CPUs has the least effect
- * on them.
- */
- if (busiest->expired->nr_active)
- array = busiest->expired;
- else
- array = busiest->active;
-
-new_array:
- /* Start searching at priority 0: */
- idx = 0;
-skip_bitmap:
- if (!idx)
- idx = sched_find_first_bit(array->bitmap);
- else
- idx = find_next_bit(array->bitmap, MAX_PRIO, idx);
- if (idx >= MAX_PRIO) {
- if (array == busiest->expired) {
- array = busiest->active;
- goto new_array;
- }
- goto out_unlock;
- }
-
- head = array->queue + idx;
- curr = head->prev;
-skip_queue:
- tmp = list_entry(curr, task_t, run_list);
/*
* We do not migrate tasks that are:
@@ -1231,21 +935,19 @@ skip_queue:
* 3) are cache-hot on their current CPU.
*/
- curr = curr->prev;
+ do {
+ struct policy *policy;
+ task_t *task;
+
+ policy = rq_migrate_policy(busiest);
+ if (!policy)
+ break;
+ task = policy->migrate(policy->queue);
+ if (!task)
+ break;
+ pull_task(busiest, task, this_rq, this_cpu);
+ } while (!idle && --imbalance);
- if (!can_migrate_task(tmp, busiest, this_cpu, idle)) {
- if (curr != head)
- goto skip_queue;
- idx++;
- goto skip_bitmap;
- }
- pull_task(busiest, array, tmp, this_rq, this_cpu);
- if (!idle && --imbalance) {
- if (curr != head)
- goto skip_queue;
- idx++;
- goto skip_bitmap;
- }
out_unlock:
spin_unlock(&busiest->lock);
out:
@@ -1356,10 +1058,10 @@ EXPORT_PER_CPU_SYMBOL(kstat);
*/
void scheduler_tick(int user_ticks, int sys_ticks)
{
- int cpu = smp_processor_id();
+ int idle, cpu = smp_processor_id();
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+ struct policy *policy;
runqueue_t *rq = this_rq();
- task_t *p = current;
if (rcu_pending(cpu))
rcu_check_callbacks(cpu, user_ticks);
@@ -1373,98 +1075,28 @@ void scheduler_tick(int user_ticks, int
sys_ticks = 0;
}
- if (p == rq->idle) {
- if (atomic_read(&rq->nr_iowait) > 0)
- cpustat->iowait += sys_ticks;
- else
- cpustat->idle += sys_ticks;
- rebalance_tick(rq, 1);
- return;
- }
- if (TASK_NICE(p) > 0)
- cpustat->nice += user_ticks;
- else
- cpustat->user += user_ticks;
- cpustat->system += sys_ticks;
-
- /* Task might have expired already, but not scheduled off yet */
- if (p->array != rq->active) {
- set_tsk_need_resched(p);
- goto out;
- }
spin_lock(&rq->lock);
- /*
- * The task was running during this tick - update the
- * time slice counter. Note: we do not update a thread's
- * priority until it either goes to sleep or uses up its
- * timeslice. This makes it possible for interactive tasks
- * to use up their timeslices at their highest priority levels.
- */
- if (unlikely(rt_task(p))) {
- /*
- * RR tasks need a special form of timeslice management.
- * FIFO tasks have no timeslices.
- */
- if ((p->policy == SCHED_RR) && !--p->time_slice) {
- p->time_slice = task_timeslice(p);
- p->first_time_slice = 0;
- set_tsk_need_resched(p);
-
- /* put it at the end of the queue: */
- dequeue_task(p, rq->active);
- enqueue_task(p, rq->active);
- }
- goto out_unlock;
- }
- if (!--p->time_slice) {
- dequeue_task(p, rq->active);
- set_tsk_need_resched(p);
- p->prio = effective_prio(p);
- p->time_slice = task_timeslice(p);
- p->first_time_slice = 0;
-
- if (!rq->expired_timestamp)
- rq->expired_timestamp = jiffies;
- if (!TASK_INTERACTIVE(p) || EXPIRED_STARVING(rq)) {
- enqueue_task(p, rq->expired);
- } else
- enqueue_task(p, rq->active);
- } else {
- /*
- * Prevent a too long timeslice allowing a task to monopolize
- * the CPU. We do this by splitting up the timeslice into
- * smaller pieces.
- *
- * Note: this does not mean the task's timeslices expire or
- * get lost in any way, they just might be preempted by
- * another task of equal priority. (one with higher
- * priority would have preempted this task already.) We
- * requeue this task to the end of the list on this priority
- * level, which is in essence a round-robin of tasks with
- * equal priority.
- *
- * This only applies to tasks in the interactive
- * delta range with at least TIMESLICE_GRANULARITY to requeue.
- */
- if (TASK_INTERACTIVE(p) && !((task_timeslice(p) -
- p->time_slice) % TIMESLICE_GRANULARITY(p)) &&
- (p->time_slice >= TIMESLICE_GRANULARITY(p)) &&
- (p->array == rq->active)) {
-
- dequeue_task(p, rq->active);
- set_tsk_need_resched(p);
- p->prio = effective_prio(p);
- enqueue_task(p, rq->active);
- }
- }
-out_unlock:
+ policy = rq_policy(rq);
+ idle = policy->ops->tick(policy->queue, current, user_ticks, sys_ticks);
spin_unlock(&rq->lock);
-out:
- rebalance_tick(rq, 0);
+ rebalance_tick(rq, idle);
}
void scheduling_functions_start_here(void) { }
+static inline task_t *find_best_task(runqueue_t *rq)
+{
+ int idx;
+ struct policy *policy;
+
+ BUG_ON(!rq->policy_bitmap);
+ idx = __ffs(rq->policy_bitmap);
+ __check_task_policy(idx);
+ policy = rq->policies[idx];
+ check_policy(policy);
+ return policy->ops->best(policy->queue);
+}
+
/*
* schedule() is the main scheduler function.
*/
@@ -1472,11 +1104,7 @@ asmlinkage void schedule(void)
{
task_t *prev, *next;
runqueue_t *rq;
- prio_array_t *array;
- struct list_head *queue;
- unsigned long long now;
- unsigned long run_time;
- int idx;
+ struct policy *policy;
/*
* Test if we are atomic. Since do_exit() needs to call into
@@ -1494,22 +1122,9 @@ need_resched:
preempt_disable();
prev = current;
rq = this_rq();
+ policy = rq_policy(rq);
release_kernel_lock(prev);
- now = sched_clock();
- if (likely(now - prev->timestamp < NS_MAX_SLEEP_AVG))
- run_time = now - prev->timestamp;
- else
- run_time = NS_MAX_SLEEP_AVG;
-
- /*
- * Tasks with interactive credits get charged less run_time
- * at high sleep_avg to delay them losing their interactive
- * status
- */
- if (HIGH_CREDIT(prev))
- run_time /= (CURRENT_BONUS(prev) ? : 1);
-
spin_lock_irq(&rq->lock);
/*
@@ -1530,66 +1145,27 @@ need_resched:
prev->nvcsw++;
break;
case TASK_RUNNING:
+ policy->ops->start_wait(policy->queue, prev);
prev->nivcsw++;
}
+
pick_next_task:
- if (unlikely(!rq->nr_running)) {
#ifdef CONFIG_SMP
+ if (unlikely(!rq->nr_running))
load_balance(rq, 1, cpu_to_node_mask(smp_processor_id()));
- if (rq->nr_running)
- goto pick_next_task;
#endif
- next = rq->idle;
- rq->expired_timestamp = 0;
- goto switch_tasks;
- }
-
- array = rq->active;
- if (unlikely(!array->nr_active)) {
- /*
- * Switch the active and expired arrays.
- */
- rq->active = rq->expired;
- rq->expired = array;
- array = rq->active;
- rq->expired_timestamp = 0;
- }
-
- idx = sched_find_first_bit(array->bitmap);
- queue = array->queue + idx;
- next = list_entry(queue->next, task_t, run_list);
-
- if (next->activated > 0) {
- unsigned long long delta = now - next->timestamp;
-
- if (next->activated == 1)
- delta = delta * (ON_RUNQUEUE_WEIGHT * 128 / 100) / 128;
-
- array = next->array;
- dequeue_task(next, array);
- recalc_task_prio(next, next->timestamp + delta);
- enqueue_task(next, array);
- }
- next->activated = 0;
-switch_tasks:
+ next = find_best_task(rq);
+ BUG_ON(!next);
prefetch(next);
clear_tsk_need_resched(prev);
RCU_qsctr(task_cpu(prev))++;
- prev->sleep_avg -= run_time;
- if ((long)prev->sleep_avg <= 0){
- prev->sleep_avg = 0;
- if (!(HIGH_CREDIT(prev) || LOW_CREDIT(prev)))
- prev->interactive_credit--;
- }
- prev->timestamp = now;
-
if (likely(prev != next)) {
- next->timestamp = now;
rq->nr_switches++;
- rq->curr = next;
-
prepare_arch_switch(rq, next);
+ policy = task_policy(next);
+ policy->ops->set_curr(policy->queue, next);
+ set_rq_curr(rq, next);
prev = context_switch(rq, prev, next);
barrier();
@@ -1845,45 +1421,46 @@ void scheduling_functions_end_here(void)
void set_user_nice(task_t *p, long nice)
{
unsigned long flags;
- prio_array_t *array;
runqueue_t *rq;
- int old_prio, new_prio, delta;
+ struct policy *policy;
+ int delta, queued;
- if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
+ if (nice < -20 || nice > 19)
return;
/*
* We have to be careful, if called from sys_setpriority(),
* the task might be in the middle of scheduling on another CPU.
*/
rq = task_rq_lock(p, &flags);
+ delta = nice - __task_nice(p);
+ if (!delta) {
+ if (p->pid == 0 || p->pid == 1)
+ printk("no change in nice, set_user_nice() nops!\n");
+ goto out_unlock;
+ }
+
+ policy = task_policy(p);
+
/*
* The RT priorities are set via setscheduler(), but we still
* allow the 'normal' nice value to be set - but as expected
* it wont have any effect on scheduling until the task is
* not SCHED_NORMAL:
*/
- if (rt_task(p)) {
- p->static_prio = NICE_TO_PRIO(nice);
- goto out_unlock;
- }
- array = p->array;
- if (array)
- dequeue_task(p, array);
-
- old_prio = p->prio;
- new_prio = NICE_TO_PRIO(nice);
- delta = new_prio - old_prio;
- p->static_prio = NICE_TO_PRIO(nice);
- p->prio += delta;
+ queued = task_queued(p);
+ if (queued)
+ dequeue_task(p, rq);
+
+ policy->ops->renice(policy->queue, p, nice);
- if (array) {
- enqueue_task(p, array);
+ if (queued) {
+ enqueue_task(p, rq);
/*
* If the task increased its priority or is running and
* lowered its priority, then reschedule its CPU:
*/
if (delta < 0 || (delta > 0 && task_running(rq, p)))
- resched_task(rq->curr);
+ resched_task(rq_curr(rq));
}
out_unlock:
task_rq_unlock(rq, &flags);
@@ -1919,7 +1496,7 @@ asmlinkage long sys_nice(int increment)
if (increment > 40)
increment = 40;
- nice = PRIO_TO_NICE(current->static_prio) + increment;
+ nice = task_nice(current) + increment;
if (nice < -20)
nice = -20;
if (nice > 19)
@@ -1935,6 +1512,12 @@ asmlinkage long sys_nice(int increment)
#endif
+static int __task_prio(task_t *task)
+{
+ struct policy *policy = task_policy(task);
+ return policy->ops->prio(task);
+}
+
/**
* task_prio - return the priority value of a given task.
* @p: the task in question.
@@ -1943,29 +1526,111 @@ asmlinkage long sys_nice(int increment)
* RT tasks are offset by -200. Normal tasks are centered
* around 0, value goes from -16 to +15.
*/
-int task_prio(task_t *p)
+int task_prio(task_t *task)
{
- return p->prio - MAX_RT_PRIO;
+ int prio;
+ unsigned long flags;
+ runqueue_t *rq;
+
+ rq = task_rq_lock(task, &flags);
+ prio = __task_prio(task);
+ task_rq_unlock(rq, &flags);
+ return prio;
}
/**
* task_nice - return the nice value of a given task.
* @p: the task in question.
*/
-int task_nice(task_t *p)
+int task_nice(task_t *task)
{
- return TASK_NICE(p);
+ int nice;
+ unsigned long flags;
+ runqueue_t *rq;
+
+
+ rq = task_rq_lock(task, &flags);
+ nice = __task_nice(task);
+ task_rq_unlock(rq, &flags);
+ return nice;
}
EXPORT_SYMBOL(task_nice);
+int task_sched_policy(task_t *task)
+{
+ check_task_policy(task);
+ switch (task->sched_info.policy) {
+ case SCHED_POLICY_RT:
+ if (task->sched_info.cl_data.rt.rt_policy
+ == RT_POLICY_RR)
+ return SCHED_RR;
+ else
+ return SCHED_FIFO;
+ case SCHED_POLICY_TS:
+ return SCHED_NORMAL;
+ case SCHED_POLICY_BATCH:
+ return SCHED_BATCH;
+ case SCHED_POLICY_IDLE:
+ return SCHED_IDLE;
+ default:
+ BUG();
+ return -1;
+ }
+}
+EXPORT_SYMBOL(task_sched_policy);
+
+void set_task_sched_policy(task_t *task, int policy)
+{
+ check_task_policy(task);
+ BUG_ON(task_queued(task));
+ switch (policy) {
+ case SCHED_FIFO:
+ task->sched_info.policy = SCHED_POLICY_RT;
+ task->sched_info.cl_data.rt.rt_policy = RT_POLICY_FIFO;
+ break;
+ case SCHED_RR:
+ task->sched_info.policy = SCHED_POLICY_RT;
+ task->sched_info.cl_data.rt.rt_policy = RT_POLICY_RR;
+ break;
+ case SCHED_NORMAL:
+ task->sched_info.policy = SCHED_POLICY_TS;
+ break;
+ case SCHED_BATCH:
+ task->sched_info.policy = SCHED_POLICY_BATCH;
+ break;
+ case SCHED_IDLE:
+ task->sched_info.policy = SCHED_POLICY_IDLE;
+ break;
+ default:
+ BUG();
+ break;
+ }
+ check_task_policy(task);
+}
+EXPORT_SYMBOL(set_task_sched_policy);
+
+int rt_task(task_t *task)
+{
+ check_task_policy(task);
+ return !!(task->sched_info.policy == SCHED_POLICY_RT);
+}
+EXPORT_SYMBOL(rt_task);
+
/**
* idle_cpu - is a given cpu idle currently?
* @cpu: the processor in question.
*/
int idle_cpu(int cpu)
{
- return cpu_curr(cpu) == cpu_rq(cpu)->idle;
+ int idle;
+ unsigned long flags;
+ runqueue_t *rq = cpu_rq(cpu);
+
+ spin_lock_irqsave(&rq->lock, flags);
+ idle = !!(rq->curr == SCHED_POLICY_IDLE);
+ spin_unlock_irqrestore(&rq->lock, flags);
+ return idle;
}
EXPORT_SYMBOL_GPL(idle_cpu);
@@ -1985,11 +1650,10 @@ static inline task_t *find_process_by_pi
static int setscheduler(pid_t pid, int policy, struct sched_param __user *param)
{
struct sched_param lp;
- int retval = -EINVAL;
- int oldprio;
- prio_array_t *array;
+ int queued, retval = -EINVAL;
unsigned long flags;
runqueue_t *rq;
+ struct policy *rq_policy;
task_t *p;
if (!param || pid < 0)
@@ -2017,7 +1681,7 @@ static int setscheduler(pid_t pid, int p
rq = task_rq_lock(p, &flags);
if (policy < 0)
- policy = p->policy;
+ policy = task_sched_policy(p);
else {
retval = -EINVAL;
if (policy != SCHED_FIFO && policy != SCHED_RR &&
@@ -2047,29 +1711,23 @@ static int setscheduler(pid_t pid, int p
if (retval)
goto out_unlock;
- array = p->array;
- if (array)
+ queued = task_queued(p);
+ if (queued)
deactivate_task(p, task_rq(p));
retval = 0;
- p->policy = policy;
- p->rt_priority = lp.sched_priority;
- oldprio = p->prio;
- if (policy != SCHED_NORMAL)
- p->prio = MAX_USER_RT_PRIO-1 - p->rt_priority;
- else
- p->prio = p->static_prio;
- if (array) {
+ set_task_sched_policy(p, policy);
+ check_task_policy(p);
+ rq_policy = rq->policies[p->sched_info.policy];
+ check_policy(rq_policy);
+ rq_policy->ops->setprio(p, lp.sched_priority);
+ if (queued) {
__activate_task(p, task_rq(p));
/*
* Reschedule if we are currently running on this runqueue and
* our priority decreased, or if we are not currently running on
* this runqueue and our priority is higher than the current's
*/
- if (rq->curr == p) {
- if (p->prio > oldprio)
- resched_task(rq->curr);
- } else if (p->prio < rq->curr->prio)
- resched_task(rq->curr);
+ resched_task(rq_curr(rq));
}
out_unlock:
@@ -2121,7 +1779,7 @@ asmlinkage long sys_sched_getscheduler(p
if (p) {
retval = security_task_getscheduler(p);
if (!retval)
- retval = p->policy;
+ retval = task_sched_policy(p);
}
read_unlock(&tasklist_lock);
@@ -2153,7 +1811,7 @@ asmlinkage long sys_sched_getparam(pid_t
if (retval)
goto out_unlock;
- lp.sched_priority = p->rt_priority;
+ lp.sched_priority = task_prio(p);
read_unlock(&tasklist_lock);
/*
@@ -2262,32 +1920,13 @@ out_unlock:
*/
asmlinkage long sys_sched_yield(void)
{
+ struct policy *policy;
runqueue_t *rq = this_rq_lock();
- prio_array_t *array = current->array;
-
- /*
- * We implement yielding by moving the task into the expired
- * queue.
- *
- * (special rule: RT tasks will just roundrobin in the active
- * array.)
- */
- if (likely(!rt_task(current))) {
- dequeue_task(current, array);
- enqueue_task(current, rq->expired);
- } else {
- list_del(¤t->run_list);
- list_add_tail(¤t->run_list, array->queue + current->prio);
- }
- /*
- * Since we are going to call schedule() anyway, there's
- * no need to preempt:
- */
+ policy = rq_policy(rq);
+ policy->ops->yield(policy->queue, current);
_raw_spin_unlock(&rq->lock);
preempt_enable_no_resched();
-
schedule();
-
return 0;
}
@@ -2387,6 +2026,19 @@ asmlinkage long sys_sched_get_priority_m
return ret;
}
+static inline unsigned long task_timeslice(task_t *task)
+{
+ unsigned long flags, timeslice;
+ struct policy *policy;
+ runqueue_t *rq;
+
+ rq = task_rq_lock(task, &flags);
+ policy = task_policy(task);
+ timeslice = policy->ops->timeslice(policy->queue, task);
+ task_rq_unlock(rq, &flags);
+ return timeslice;
+}
+
/**
* sys_sched_rr_get_interval - return the default timeslice of a process.
* @pid: pid of the process.
@@ -2414,8 +2066,7 @@ asmlinkage long sys_sched_rr_get_interva
if (retval)
goto out_unlock;
- jiffies_to_timespec(p->policy & SCHED_FIFO ?
- 0 : task_timeslice(p), &t);
+ jiffies_to_timespec(task_timeslice(p), &t);
read_unlock(&tasklist_lock);
retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
out_nounlock:
@@ -2523,17 +2174,22 @@ void show_state(void)
void __init init_idle(task_t *idle, int cpu)
{
runqueue_t *idle_rq = cpu_rq(cpu), *rq = cpu_rq(task_cpu(idle));
+ struct policy *policy;
unsigned long flags;
local_irq_save(flags);
double_rq_lock(idle_rq, rq);
-
- idle_rq->curr = idle_rq->idle = idle;
+ policy = rq_policy(rq);
+ BUG_ON(policy != task_policy(idle));
+ printk("deactivating, have %d tasks\n",
+ policy->ops->tasks(policy->queue));
deactivate_task(idle, rq);
- idle->array = NULL;
- idle->prio = MAX_PRIO;
+ set_task_sched_policy(idle, SCHED_IDLE);
idle->state = TASK_RUNNING;
set_task_cpu(idle, cpu);
+ activate_task(idle, rq);
+ nr_running_dec(rq);
+ set_rq_curr(rq, idle);
double_rq_unlock(idle_rq, rq);
set_tsk_need_resched(idle);
local_irq_restore(flags);
@@ -2804,38 +2460,27 @@ __init static void init_kstat(void) {
void __init sched_init(void)
{
runqueue_t *rq;
- int i, j, k;
+ int i, j;
/* Init the kstat counters */
init_kstat();
for (i = 0; i < NR_CPUS; i++) {
- prio_array_t *array;
-
rq = cpu_rq(i);
- rq->active = rq->arrays;
- rq->expired = rq->arrays + 1;
spin_lock_init(&rq->lock);
INIT_LIST_HEAD(&rq->migration_queue);
atomic_set(&rq->nr_iowait, 0);
nr_running_init(rq);
-
- for (j = 0; j < 2; j++) {
- array = rq->arrays + j;
- for (k = 0; k < MAX_PRIO; k++) {
- INIT_LIST_HEAD(array->queue + k);
- __clear_bit(k, array->bitmap);
- }
- // delimiter for bitsearch
- __set_bit(MAX_PRIO, array->bitmap);
- }
+ memcpy(rq->policies, policies, sizeof(policies));
+ for (j = 0; j < BITS_PER_LONG && rq->policies[j]; ++j)
+ rq->policies[j]->ops->init(rq->policies[j], i);
}
/*
* We have to do a little magic to get the first
* thread right in SMP mode.
*/
rq = this_rq();
- rq->curr = current;
- rq->idle = current;
+ set_task_sched_policy(current, SCHED_NORMAL);
+ set_rq_curr(rq, current);
set_task_cpu(current, smp_processor_id());
wake_up_forked_process(current);
diff -prauN linux-2.6.0-test11/lib/Makefile sched-2.6.0-test11-5/lib/Makefile
--- linux-2.6.0-test11/lib/Makefile 2003-11-26 12:42:55.000000000 -0800
+++ sched-2.6.0-test11-5/lib/Makefile 2003-12-20 15:09:16.000000000 -0800
@@ -5,7 +5,7 @@
lib-y := errno.o ctype.o string.o vsprintf.o cmdline.o \
bust_spinlocks.o rbtree.o radix-tree.o dump_stack.o \
- kobject.o idr.o div64.o parser.o
+ kobject.o idr.o div64.o parser.o binomial.o
lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
diff -prauN linux-2.6.0-test11/lib/binomial.c sched-2.6.0-test11-5/lib/binomial.c
--- linux-2.6.0-test11/lib/binomial.c 1969-12-31 16:00:00.000000000 -0800
+++ sched-2.6.0-test11-5/lib/binomial.c 2003-12-20 17:32:09.000000000 -0800
@@ -0,0 +1,138 @@
+#include <linux/kernel.h>
+#include <linux/binomial.h>
+
+struct binomial *binomial_minimum(struct binomial **heap)
+{
+ struct binomial *minimum, *tmp;
+
+ for (minimum = NULL, tmp = *heap; tmp; tmp = tmp->sibling) {
+ if (!minimum || minimum->priority > tmp->priority)
+ minimum = tmp;
+ }
+ return minimum;
+}
+
+static void binomial_link(struct binomial *left, struct binomial *right)
+{
+ left->parent = right;
+ left->sibling = right->child;
+ right->child = left;
+ right->degree++;
+}
+
+static void binomial_merge(struct binomial **both, struct binomial **left,
+ struct binomial **right)
+{
+ while (*left && *right) {
+ if ((*left)->degree < (*right)->degree) {
+ *both = *left;
+ left = &(*left)->sibling;
+ } else {
+ *both = *right;
+ right = &(*right)->sibling;
+ }
+ both = &(*both)->sibling;
+ }
+ /*
+ * for more safety:
+ * *left = *right = NULL;
+ */
+}
+
+void binomial_union(struct binomial **both, struct binomial **left,
+ struct binomial **right)
+{
+ struct binomial *prev, *tmp, *next;
+
+ binomial_merge(both, left, right);
+ if (!(tmp = *both))
+ return;
+
+ for (prev = NULL, next = tmp->sibling; next; next = tmp->sibling) {
+ if ((next->sibling && next->sibling->degree == tmp->degree)
+ || tmp->degree != next->degree) {
+ prev = tmp;
+ tmp = next;
+ } else if (tmp->priority <= next->priority) {
+ tmp->sibling = next->sibling;
+ binomial_link(next, tmp);
+ } else {
+ if (!prev)
+ *both = next;
+ else
+ prev->sibling = next;
+ binomial_link(tmp, next);
+ tmp = next;
+ }
+ }
+}
+
+void binomial_insert(struct binomial **heap, struct binomial *element)
+{
+ element->parent = NULL;
+ element->child = NULL;
+ element->sibling = NULL;
+ element->degree = 0;
+ binomial_union(heap, heap, &element);
+}
+
+static void binomial_reverse(struct binomial **in, struct binomial **out)
+{
+ while (*in) {
+ struct binomial *tmp = *in;
+ *in = (*in)->sibling;
+ tmp->sibling = *out;
+ *out = tmp;
+ }
+}
+
+struct binomial *binomial_extract_min(struct binomial **heap)
+{
+ struct binomial *tmp, *minimum, *last, *min_last, *new_heap;
+
+ minimum = last = min_last = new_heap = NULL;
+ for (tmp = *heap; tmp; last = tmp, tmp = tmp->sibling) {
+ if (!minimum || tmp->priority < minimum->priority) {
+ minimum = tmp;
+ min_last = last;
+ }
+ }
+ if (min_last && minimum)
+ min_last->sibling = minimum->sibling;
+ else if (minimum)
+ (*heap)->sibling = minimum->sibling;
+ else
+ return NULL;
+ binomial_reverse(&minimum->child, &new_heap);
+ binomial_union(heap, heap, &new_heap);
+ return minimum;
+}
+
+void binomial_decrease(struct binomial **heap, struct binomial *element,
+ unsigned increment)
+{
+ struct binomial *tmp, *last = NULL;
+
+ element->priority -= min(element->priority, increment);
+ last = element;
+ tmp = last->parent;
+ while (tmp && last->priority < tmp->priority) {
+ unsigned tmp_prio = tmp->priority;
+ tmp->priority = last->priority;
+ last->priority = tmp_prio;
+ last = tmp;
+ tmp = tmp->parent;
+ }
+}
+
+void binomial_delete(struct binomial **heap, struct binomial *element)
+{
+ struct binomial *tmp, *last = element;
+ for (tmp = last->parent; tmp; last = tmp, tmp = tmp->parent) {
+ unsigned tmp_prio = tmp->priority;
+ tmp->priority = last->priority;
+ last->priority = tmp_prio;
+ }
+ binomial_reverse(&last->child, &tmp);
+ binomial_union(heap, heap, &tmp);
+}
diff -prauN linux-2.6.0-test11/mm/oom_kill.c sched-2.6.0-test11-5/mm/oom_kill.c
--- linux-2.6.0-test11/mm/oom_kill.c 2003-11-26 12:44:16.000000000 -0800
+++ sched-2.6.0-test11-5/mm/oom_kill.c 2003-12-17 07:07:53.000000000 -0800
@@ -158,7 +158,6 @@ static void __oom_kill_task(task_t *p)
* all the memory it needs. That way it should be able to
* exit() and clear out its resources quickly...
*/
- p->time_slice = HZ;
p->flags |= PF_MEMALLOC | PF_MEMDIE;
/* This process has hardware access, be more careful. */
-
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