/*
* kernel/sched_pfair.c
*
* Implementation of the (global) Pfair scheduling algorithm.
*
*/
#include <asm/div64.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/percpu.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <litmus/litmus.h>
#include <litmus/jobs.h>
#include <litmus/rt_domain.h>
#include <litmus/sched_plugin.h>
#include <litmus/sched_trace.h>
#include <litmus/bheap.h>
struct subtask {
/* measured in quanta relative to job release */
quanta_t release;
quanta_t deadline;
quanta_t overlap; /* called "b bit" by PD^2 */
quanta_t group_deadline;
};
struct pfair_param {
quanta_t quanta; /* number of subtasks */
quanta_t cur; /* index of current subtask */
quanta_t release; /* in quanta */
quanta_t period; /* in quanta */
quanta_t last_quantum; /* when scheduled last */
int last_cpu; /* where scheduled last */
unsigned int sporadic_release; /* On wakeup, new sporadic release? */
struct subtask subtasks[0]; /* allocate together with pfair_param */
};
#define tsk_pfair(tsk) ((tsk)->rt_param.pfair)
struct pfair_state {
int cpu;
volatile quanta_t cur_tick; /* updated by the CPU that is advancing
* the time */
volatile quanta_t local_tick; /* What tick is the local CPU currently
* executing? Updated only by the local
* CPU. In QEMU, this may lag behind the
* current tick. In a real system, with
* proper timers and aligned quanta,
* that should only be the
* case for a very short time after the
* time advanced. With staggered quanta,
* it will lag for the duration of the
* offset.
*/
struct task_struct* linked; /* the task that should be executing */
struct task_struct* local; /* the local copy of linked */
struct task_struct* scheduled; /* what is actually scheduled */
unsigned long missed_quanta;
lt_t offset; /* stagger offset */
};
/* Currently, we limit the maximum period of any task to 2000 quanta.
* The reason is that it makes the implementation easier since we do not
* need to reallocate the release wheel on task arrivals.
* In the future
*/
#define PFAIR_MAX_PERIOD 2000
/* This is the release queue wheel. It is indexed by pfair_time %
* PFAIR_MAX_PERIOD. Each heap is ordered by PFAIR priority, so that it can be
* merged with the ready queue.
*/
static struct bheap release_queue[PFAIR_MAX_PERIOD];
DEFINE_PER_CPU(struct pfair_state, pfair_state);
struct pfair_state* *pstate; /* short cut */
static quanta_t pfair_time = 0; /* the "official" PFAIR clock */
static quanta_t merge_time = 0; /* Updated after the release queue has been
* merged. Used by drop_all_references().
*/
static rt_domain_t pfair;
/* The pfair_lock is used to serialize all scheduling events.
*/
#define pfair_lock pfair.ready_lock
/* Enable for lots of trace info.
* #define PFAIR_DEBUG
*/
#ifdef PFAIR_DEBUG
#define PTRACE_TASK(t, f, args...) TRACE_TASK(t, f, ## args)
#define PTRACE(f, args...) TRACE(f, ## args)
#else
#define PTRACE_TASK(t, f, args...)
#define PTRACE(f, args...)
#endif
/* gcc will inline all of these accessor functions... */
static struct subtask* cur_subtask(struct task_struct* t)
{
return tsk_pfair(t)->subtasks + tsk_pfair(t)->cur;
}
static quanta_t cur_deadline(struct task_struct* t)
{
return cur_subtask(t)->deadline + tsk_pfair(t)->release;
}
static quanta_t cur_sub_release(struct task_struct* t)
{
return cur_subtask(t)->release + tsk_pfair(t)->release;
}
static quanta_t cur_release(struct task_struct* t)
{
#ifdef EARLY_RELEASE
/* only the release of the first subtask counts when we early
* release */
return tsk_pfair(t)->release;
#else
return cur_sub_release(t);
#endif
}
static quanta_t cur_overlap(struct task_struct* t)
{
return cur_subtask(t)->overlap;
}
static quanta_t cur_group_deadline(struct task_struct* t)
{
quanta_t gdl = cur_subtask(t)->group_deadline;
if (gdl)
return gdl + tsk_pfair(t)->release;
else
return gdl;
}
static int pfair_higher_prio(struct task_struct* first,
struct task_struct* second)
{
return /* first task must exist */
first && (
/* Does the second task exist and is it a real-time task? If
* not, the first task (which is a RT task) has higher
* priority.
*/
!second || !is_realtime(second) ||
/* Is the (subtask) deadline of the first task earlier?
* Then it has higher priority.
*/
time_before(cur_deadline(first), cur_deadline(second)) ||
/* Do we have a deadline tie?
* Then break by B-bit.
*/
(cur_deadline(first) == cur_deadline(second) &&
(cur_overlap(first) > cur_overlap(second) ||
/* Do we have a B-bit tie?
* Then break by group deadline.
*/
(cur_overlap(first) == cur_overlap(second) &&
(time_after(cur_group_deadline(first),
cur_group_deadline(second)) ||
/* Do we have a group deadline tie?
* Then break by PID, which are unique.
*/
(cur_group_deadline(first) ==
cur_group_deadline(second) &&
first->pid < second->pid))))));
}
int pfair_ready_order(struct bheap_node* a, struct bheap_node* b)
{
return pfair_higher_prio(bheap2task(a), bheap2task(b));
}
/* return the proper release queue for time t */
static struct bheap* relq(quanta_t t)
{
struct bheap* rq = &release_queue[t % PFAIR_MAX_PERIOD];
return rq;
}
static void prepare_release(struct task_struct* t, quanta_t at)
{
tsk_pfair(t)->release = at;
tsk_pfair(t)->cur = 0;
}
static void __pfair_add_release(struct task_struct* t, struct bheap* queue)
{
bheap_insert(pfair_ready_order, queue,
tsk_rt(t)->heap_node);
}
static void pfair_add_release(struct task_struct* t)
{
BUG_ON(bheap_node_in_heap(tsk_rt(t)->heap_node));
__pfair_add_release(t, relq(cur_release(t)));
}
/* pull released tasks from the release queue */
static void poll_releases(quanta_t time)
{
__merge_ready(&pfair, relq(time));
merge_time = time;
}
static void check_preempt(struct task_struct* t)
{
int cpu = NO_CPU;
if (tsk_rt(t)->linked_on != tsk_rt(t)->scheduled_on &&
tsk_rt(t)->present) {
/* the task can be scheduled and
* is not scheduled where it ought to be scheduled
*/
cpu = tsk_rt(t)->linked_on != NO_CPU ?
tsk_rt(t)->linked_on :
tsk_rt(t)->scheduled_on;
PTRACE_TASK(t, "linked_on:%d, scheduled_on:%d\n",
tsk_rt(t)->linked_on, tsk_rt(t)->scheduled_on);
/* preempt */
if (cpu == smp_processor_id())
set_tsk_need_resched(current);
else {
smp_send_reschedule(cpu);
}
}
}
/* caller must hold pfair_lock */
static void drop_all_references(struct task_struct *t)
{
int cpu;
struct pfair_state* s;
struct bheap* q;
if (bheap_node_in_heap(tsk_rt(t)->heap_node)) {
/* figure out what queue the node is in */
if (time_before_eq(cur_release(t), merge_time))
q = &pfair.ready_queue;
else
q = relq(cur_release(t));
bheap_delete(pfair_ready_order, q,
tsk_rt(t)->heap_node);
}
for (cpu = 0; cpu < num_online_cpus(); cpu++) {
s = &per_cpu(pfair_state, cpu);
if (s->linked == t)
s->linked = NULL;
if (s->local == t)
s->local = NULL;
if (s->scheduled == t)
s->scheduled = NULL;
}
}
/* returns 1 if the task needs to go the release queue */
static int advance_subtask(quanta_t time, struct task_struct* t, int cpu)
{
struct pfair_param* p = tsk_pfair(t);
int to_relq;
p->cur = (p->cur + 1) % p->quanta;
if (!p->cur) {
sched_trace_task_completion(t, 1);
if (tsk_rt(t)->present) {
/* we start a new job */
prepare_for_next_period(t);
sched_trace_task_release(t);
get_rt_flags(t) = RT_F_RUNNING;
p->release += p->period;
} else {
/* remove task from system until it wakes */
drop_all_references(t);
tsk_pfair(t)->sporadic_release = 1;
TRACE_TASK(t, "on %d advanced to subtask %lu (not present)\n",
cpu, p->cur);
return 0;
}
}
to_relq = time_after(cur_release(t), time);
TRACE_TASK(t, "on %d advanced to subtask %lu -> to_relq=%d\n",
cpu, p->cur, to_relq);
return to_relq;
}
static void advance_subtasks(quanta_t time)
{
int cpu, missed;
struct task_struct* l;
struct pfair_param* p;
for_each_online_cpu(cpu) {
l = pstate[cpu]->linked;
missed = pstate[cpu]->linked != pstate[cpu]->local;
if (l) {
p = tsk_pfair(l);
p->last_quantum = time;
p->last_cpu = cpu;
if (advance_subtask(time, l, cpu)) {
pstate[cpu]->linked = NULL;
pfair_add_release(l);
}
}
}
}
static int target_cpu(quanta_t time, struct task_struct* t, int default_cpu)
{
int cpu;
if (tsk_rt(t)->scheduled_on != NO_CPU) {
/* always observe scheduled_on linkage */
default_cpu = tsk_rt(t)->scheduled_on;
} else if (tsk_pfair(t)->last_quantum == time - 1) {
/* back2back quanta */
/* Only observe last_quantum if no scheduled_on is in the way.
* This should only kick in if a CPU missed quanta, and that
* *should* only happen in QEMU.
*/
cpu = tsk_pfair(t)->last_cpu;
if (!pstate[cpu]->linked ||
tsk_rt(pstate[cpu]->linked)->scheduled_on != cpu) {
default_cpu = cpu;
}
}
return default_cpu;
}
/* returns one if linking was redirected */
static int pfair_link(quanta_t time, int cpu,
struct task_struct* t)
{
int target = target_cpu(time, t, cpu);
struct task_struct* prev = pstate[cpu]->linked;
struct task_struct* other;
if (target != cpu) {
other = pstate[target]->linked;
pstate[target]->linked = t;
tsk_rt(t)->linked_on = target;
if (!other)
/* linked ok, but reschedule this CPU */
return 1;
if (target < cpu) {
/* link other to cpu instead */
tsk_rt(other)->linked_on = cpu;
pstate[cpu]->linked = other;
if (prev) {
/* prev got pushed back into the ready queue */
tsk_rt(prev)->linked_on = NO_CPU;
__add_ready(&pfair, prev);
}
/* we are done with this cpu */
return 0;
} else {
/* re-add other, it's original CPU was not considered yet */
tsk_rt(other)->linked_on = NO_CPU;
__add_ready(&pfair, other);
/* reschedule this CPU */
return 1;
}
} else {
pstate[cpu]->linked = t;
tsk_rt(t)->linked_on = cpu;
if (prev) {
/* prev got pushed back into the ready queue */
tsk_rt(prev)->linked_on = NO_CPU;
__add_ready(&pfair, prev);
}
/* we are done with this CPU */
return 0;
}
}
static void schedule_subtasks(quanta_t time)
{
int cpu, retry;
for_each_online_cpu(cpu) {
retry = 1;
while (retry) {
if (pfair_higher_prio(__peek_ready(&pfair),
pstate[cpu]->linked))
retry = pfair_link(time, cpu,
__take_ready(&pfair));
else
retry = 0;
}
}
}
static void schedule_next_quantum(quanta_t time)
{
int cpu;
/* called with interrupts disabled */
PTRACE("--- Q %lu at %llu PRE-SPIN\n",
time, litmus_clock());
spin_lock(&pfair_lock);
PTRACE("<<< Q %lu at %llu\n",
time, litmus_clock());
sched_trace_quantum_boundary();
advance_subtasks(time);
poll_releases(time);
schedule_subtasks(time);
for (cpu = 0; cpu < num_online_cpus(); cpu++)
if (pstate[cpu]->linked)
PTRACE_TASK(pstate[cpu]->linked,
" linked on %d.\n", cpu);
else
PTRACE("(null) linked on %d.\n", cpu);
/* We are done. Advance time. */
mb();
for (cpu = 0; cpu < num_online_cpus(); cpu++) {
if (pstate[cpu]->local_tick != pstate[cpu]->cur_tick) {
TRACE("BAD Quantum not acked on %d "
"(l:%lu c:%lu p:%lu)\n",
cpu,
pstate[cpu]->local_tick,
pstate[cpu]->cur_tick,
pfair_time);
pstate[cpu]->missed_quanta++;
}
pstate[cpu]->cur_tick = time;
}
PTRACE(">>> Q %lu at %llu\n",
time, litmus_clock());
spin_unlock(&pfair_lock);
}
static noinline void wait_for_quantum(quanta_t q, struct pfair_state* state)
{
quanta_t loc;
goto first; /* skip mb() on first iteration */
do {
cpu_relax();
mb();
first: loc = state->cur_tick;
/* FIXME: what if loc > cur? */
} while (time_before(loc, q));
PTRACE("observed cur_tick:%lu >= q:%lu\n",
loc, q);
}
static quanta_t current_quantum(struct pfair_state* state)
{
lt_t t = litmus_clock() - state->offset;
return time2quanta(t, FLOOR);
}
static void catchup_quanta(quanta_t from, quanta_t target,
struct pfair_state* state)
{
quanta_t cur = from, time;
TRACE("+++< BAD catching up quanta from %lu to %lu\n",
from, target);
while (time_before(cur, target)) {
wait_for_quantum(cur, state);
cur++;
time = cmpxchg(&pfair_time,
cur - 1, /* expected */
cur /* next */
);
if (time == cur - 1)
schedule_next_quantum(cur);
}
TRACE("+++> catching up done\n");
}
/* pfair_tick - this function is called for every local timer
* interrupt.
*/
static void pfair_tick(struct task_struct* t)
{
struct pfair_state* state = &__get_cpu_var(pfair_state);
quanta_t time, cur;
int retry = 10;
do {
cur = current_quantum(state);
PTRACE("q %lu at %llu\n", cur, litmus_clock());
/* Attempt to advance time. First CPU to get here
* will prepare the next quantum.
*/
time = cmpxchg(&pfair_time,
cur - 1, /* expected */
cur /* next */
);
if (time == cur - 1) {
/* exchange succeeded */
wait_for_quantum(cur - 1, state);
schedule_next_quantum(cur);
retry = 0;
} else if (time_before(time, cur - 1)) {
/* the whole system missed a tick !? */
catchup_quanta(time, cur, state);
retry--;
} else if (time_after(time, cur)) {
/* our timer lagging behind!? */
TRACE("BAD pfair_time:%lu > cur:%lu\n", time, cur);
retry--;
} else {
/* Some other CPU already started scheduling
* this quantum. Let it do its job and then update.
*/
retry = 0;
}
} while (retry);
/* Spin locally until time advances. */
wait_for_quantum(cur, state);
/* copy assignment */
/* FIXME: what if we race with a future update? Corrupted state? */
state->local = state->linked;
/* signal that we are done */
mb();
state->local_tick = state->cur_tick;
if (state->local != current
&& (is_realtime(current) || is_present(state->local)))
set_tsk_need_resched(current);
}
static int safe_to_schedule(struct task_struct* t, int cpu)
{
int where = tsk_rt(t)->scheduled_on;
if (where != NO_CPU && where != cpu) {
TRACE_TASK(t, "BAD: can't be scheduled on %d, "
"scheduled already on %d.\n", cpu, where);
return 0;
} else
return tsk_rt(t)->present && get_rt_flags(t) == RT_F_RUNNING;
}
static struct task_struct* pfair_schedule(struct task_struct * prev)
{
struct pfair_state* state = &__get_cpu_var(pfair_state);
int blocks;
struct task_struct* next = NULL;
spin_lock(&pfair_lock);
blocks = is_realtime(prev) && !is_running(prev);
if (state->local && safe_to_schedule(state->local, state->cpu))
next = state->local;
if (prev != next) {
tsk_rt(prev)->scheduled_on = NO_CPU;
if (next)
tsk_rt(next)->scheduled_on = state->cpu;
}
spin_unlock(&pfair_lock);
if (next)
TRACE_TASK(next, "scheduled rel=%lu at %lu (%llu)\n",
tsk_pfair(next)->release, pfair_time, litmus_clock());
else if (is_realtime(prev))
TRACE("Becomes idle at %lu (%llu)\n", pfair_time, litmus_clock());
return next;
}
static void pfair_task_new(struct task_struct * t, int on_rq, int running)
{
unsigned long flags;
TRACE("pfair: task new %d state:%d\n", t->pid, t->state);
spin_lock_irqsave(&pfair_lock, flags);
if (running)
t->rt_param.scheduled_on = task_cpu(t);
else
t->rt_param.scheduled_on = NO_CPU;
prepare_release(t, pfair_time + 1);
tsk_pfair(t)->sporadic_release = 0;
pfair_add_release(t);
check_preempt(t);
spin_unlock_irqrestore(&pfair_lock, flags);
}
static void pfair_task_wake_up(struct task_struct *t)
{
unsigned long flags;
lt_t now;
TRACE_TASK(t, "wakes at %llu, release=%lu, pfair_time:%lu\n",
litmus_clock(), cur_release(t), pfair_time);
spin_lock_irqsave(&pfair_lock, flags);
/* It is a little unclear how to deal with Pfair
* tasks that block for a while and then wake. For now,
* if a task blocks and wakes before its next job release,
* then it may resume if it is currently linked somewhere
* (as if it never blocked at all). Otherwise, we have a
* new sporadic job release.
*/
if (tsk_pfair(t)->sporadic_release) {
now = litmus_clock();
release_at(t, now);
prepare_release(t, time2quanta(now, CEIL));
sched_trace_task_release(t);
/* FIXME: race with pfair_time advancing */
pfair_add_release(t);
tsk_pfair(t)->sporadic_release = 0;
}
check_preempt(t);
spin_unlock_irqrestore(&pfair_lock, flags);
TRACE_TASK(t, "wake up done at %llu\n", litmus_clock());
}
static void pfair_task_block(struct task_struct *t)
{
BUG_ON(!is_realtime(t));
TRACE_TASK(t, "blocks at %llu, state:%d\n",
litmus_clock(), t->state);
}
static void pfair_task_exit(struct task_struct * t)
{
unsigned long flags;
BUG_ON(!is_realtime(t));
/* Remote task from release or ready queue, and ensure
* that it is not the scheduled task for ANY CPU. We
* do this blanket check because occassionally when
* tasks exit while blocked, the task_cpu of the task
* might not be the same as the CPU that the PFAIR scheduler
* has chosen for it.
*/
spin_lock_irqsave(&pfair_lock, flags);
TRACE_TASK(t, "RIP, state:%d\n", t->state);
drop_all_references(t);
spin_unlock_irqrestore(&pfair_lock, flags);
kfree(t->rt_param.pfair);
t->rt_param.pfair = NULL;
}
static void pfair_release_at(struct task_struct* task, lt_t start)
{
unsigned long flags;
quanta_t release;
BUG_ON(!is_realtime(task));
spin_lock_irqsave(&pfair_lock, flags);
release_at(task, start);
release = time2quanta(start, CEIL);
if (release - pfair_time >= PFAIR_MAX_PERIOD)
release = pfair_time + PFAIR_MAX_PERIOD;
TRACE_TASK(task, "sys release at %lu\n", release);
drop_all_references(task);
prepare_release(task, release);
pfair_add_release(task);
/* Clear sporadic release flag, since this release subsumes any
* sporadic release on wake.
*/
tsk_pfair(task)->sporadic_release = 0;
spin_unlock_irqrestore(&pfair_lock, flags);
}
static void init_subtask(struct subtask* sub, unsigned long i,
lt_t quanta, lt_t period)
{
/* since i is zero-based, the formulas are shifted by one */
lt_t tmp;
/* release */
tmp = period * i;
do_div(tmp, quanta); /* floor */
sub->release = (quanta_t) tmp;
/* deadline */
tmp = period * (i + 1);
if (do_div(tmp, quanta)) /* ceil */
tmp++;
sub->deadline = (quanta_t) tmp;
/* next release */
tmp = period * (i + 1);
do_div(tmp, quanta); /* floor */
sub->overlap = sub->deadline - (quanta_t) tmp;
/* Group deadline.
* Based on the formula given in Uma's thesis.
*/
if (2 * quanta >= period) {
/* heavy */
tmp = (sub->deadline - (i + 1)) * period;
if (period > quanta &&
do_div(tmp, (period - quanta))) /* ceil */
tmp++;
sub->group_deadline = (quanta_t) tmp;
} else
sub->group_deadline = 0;
}
static void dump_subtasks(struct task_struct* t)
{
unsigned long i;
for (i = 0; i < t->rt_param.pfair->quanta; i++)
TRACE_TASK(t, "SUBTASK %lu: rel=%lu dl=%lu bbit:%lu gdl:%lu\n",
i + 1,
t->rt_param.pfair->subtasks[i].release,
t->rt_param.pfair->subtasks[i].deadline,
t->rt_param.pfair->subtasks[i].overlap,
t->rt_param.pfair->subtasks[i].group_deadline);
}
static long pfair_admit_task(struct task_struct* t)
{
lt_t quanta;
lt_t period;
s64 quantum_length = ktime_to_ns(tick_period);
struct pfair_param* param;
unsigned long i;
/* Pfair is a tick-based method, so the time
* of interest is jiffies. Calculate tick-based
* times for everything.
* (Ceiling of exec cost, floor of period.)
*/
quanta = get_exec_cost(t);
period = get_rt_period(t);
quanta = time2quanta(get_exec_cost(t), CEIL);
if (do_div(period, quantum_length))
printk(KERN_WARNING
"The period of %s/%d is not a multiple of %llu.\n",
t->comm, t->pid, (unsigned long long) quantum_length);
if (period >= PFAIR_MAX_PERIOD) {
printk(KERN_WARNING
"PFAIR: Rejecting task %s/%d; its period is too long.\n",
t->comm, t->pid);
return -EINVAL;
}
if (quanta == period) {
/* special case: task has weight 1.0 */
printk(KERN_INFO
"Admitting weight 1.0 task. (%s/%d, %llu, %llu).\n",
t->comm, t->pid, quanta, period);
quanta = 1;
period = 1;
}
param = kmalloc(sizeof(*param) +
quanta * sizeof(struct subtask), GFP_ATOMIC);
if (!param)
return -ENOMEM;
param->quanta = quanta;
param->cur = 0;
param->release = 0;
param->period = period;
for (i = 0; i < quanta; i++)
init_subtask(param->subtasks + i, i, quanta, period);
if (t->rt_param.pfair)
/* get rid of stale allocation */
kfree(t->rt_param.pfair);
t->rt_param.pfair = param;
/* spew out some debug info */
dump_subtasks(t);
return 0;
}
static long pfair_activate_plugin(void)
{
int cpu;
struct pfair_state* state;
state = &__get_cpu_var(pfair_state);
pfair_time = current_quantum(state);
TRACE("Activating PFAIR at q=%lu\n", pfair_time);
for (cpu = 0; cpu < num_online_cpus(); cpu++) {
state = &per_cpu(pfair_state, cpu);
state->cur_tick = pfair_time;
state->local_tick = pfair_time;
state->missed_quanta = 0;
state->offset = cpu_stagger_offset(cpu);
}
return 0;
}
/* Plugin object */
static struct sched_plugin pfair_plugin __cacheline_aligned_in_smp = {
.plugin_name = "PFAIR",
.tick = pfair_tick,
.task_new = pfair_task_new,
.task_exit = pfair_task_exit,
.schedule = pfair_schedule,
.task_wake_up = pfair_task_wake_up,
.task_block = pfair_task_block,
.admit_task = pfair_admit_task,
.release_at = pfair_release_at,
.complete_job = complete_job,
.activate_plugin = pfair_activate_plugin,
};
static int __init init_pfair(void)
{
int cpu, i;
struct pfair_state *state;
/*
* initialize short_cut for per-cpu pfair state;
* there may be a problem here if someone removes a cpu
* while we are doing this initialization... and if cpus
* are added / removed later... is it a _real_ problem?
*/
pstate = kmalloc(sizeof(struct pfair_state*) * num_online_cpus(), GFP_KERNEL);
/* initialize release queue */
for (i = 0; i < PFAIR_MAX_PERIOD; i++)
bheap_init(&release_queue[i]);
/* initialize CPU state */
for (cpu = 0; cpu < num_online_cpus(); cpu++) {
state = &per_cpu(pfair_state, cpu);
state->cpu = cpu;
state->cur_tick = 0;
state->local_tick = 0;
state->linked = NULL;
state->local = NULL;
state->scheduled = NULL;
state->missed_quanta = 0;
state->offset = cpu_stagger_offset(cpu);
pstate[cpu] = state;
}
rt_domain_init(&pfair, pfair_ready_order, NULL, NULL);
return register_sched_plugin(&pfair_plugin);
}
static void __exit clean_pfair(void)
{
kfree(pstate);
}
module_init(init_pfair);
module_exit(clean_pfair);
