From 0e9d376bde25a42b15705dc4cb3f746a60e106c9 Mon Sep 17 00:00:00 2001
From: Armin Luntzer <armin.luntzer@univie.ac.at>
Date: Mon, 14 Oct 2019 13:26:56 +0200
Subject: [PATCH] EDF threads need fixed assignments...
---
arch/sparc/include/asm/spinlock.h | 6 +-
arch/sparc/kernel/setup.c | 2 +-
arch/sparc/kernel/thread.c | 4 +-
include/kernel/sched.h | 3 +-
init/Kconfig | 10 +++
init/main.c | 43 +++++++-----
kernel/kthread.c | 6 +-
kernel/sched/core.c | 6 +-
kernel/sched/edf.c | 111 ++++++++++++++++++------------
kernel/sched/rr.c | 19 +++--
10 files changed, 128 insertions(+), 82 deletions(-)
diff --git a/arch/sparc/include/asm/spinlock.h b/arch/sparc/include/asm/spinlock.h
index a5ed587..05a642a 100644
--- a/arch/sparc/include/asm/spinlock.h
+++ b/arch/sparc/include/asm/spinlock.h
@@ -141,11 +141,12 @@ static void spin_lock(struct spinlock *lock)
__attribute__((unused))
static void spin_lock_raw(struct spinlock *lock)
{
+#if 0
if (unlikely(lock->lock_recursion))
return;
lock->lock_recursion = 1;
-
+#endif
__asm__ __volatile__(
"1: \n\t"
"ldstub [%0], %%g2 \n\t"
@@ -155,8 +156,9 @@ static void spin_lock_raw(struct spinlock *lock)
:
: "r" (&lock->lock)
: "g2", "memory", "cc");
-
+#if 0
lock->lock_recursion = 0;
+#endif
}
/**
diff --git a/arch/sparc/kernel/setup.c b/arch/sparc/kernel/setup.c
index dc5096d..d1f045e 100644
--- a/arch/sparc/kernel/setup.c
+++ b/arch/sparc/kernel/setup.c
@@ -132,7 +132,7 @@ void smp_cpu_entry(void)
iowrite32be(0x3, &cpu1_ready);
while (ioread32be(&cpu1_ready) != 0x4);
while(1) {
- // printk("x");
+ //printk(".");
// cpu_relax();
}
// printk("1\n");
diff --git a/arch/sparc/kernel/thread.c b/arch/sparc/kernel/thread.c
index 73cef27..2bff101 100644
--- a/arch/sparc/kernel/thread.c
+++ b/arch/sparc/kernel/thread.c
@@ -112,9 +112,9 @@ void arch_promote_to_task(struct task_struct *task)
task->data = NULL;
- printk(MSG "kernel stack %x %x\n", leon_get_fp(), leon_get_sp());
+ pr_debug(MSG "kernel stack %x %x\n", leon_get_fp(), leon_get_sp());
- printk(MSG "is next at %p stack %p\n", &task->thread_info, task->stack);
+ pr_debug(MSG "is next at %p stack %p\n", &task->thread_info, task->stack);
/* and set the new thread as current */
diff --git a/include/kernel/sched.h b/include/kernel/sched.h
index c080b62..ed0d287 100644
--- a/include/kernel/sched.h
+++ b/include/kernel/sched.h
@@ -6,6 +6,7 @@
#ifndef _KERNEL_SCHED_H_
#define _KERNEL_SCHED_H_
+#include <generated/autoconf.h> /*XXX */
@@ -46,7 +47,7 @@ struct rq {
struct task_queue {
struct list_head new;
- struct list_head run;
+ struct list_head run[CONFIG_SMP_CPUS_MAX];
struct list_head wake;
struct list_head dead;
};
diff --git a/init/Kconfig b/init/Kconfig
index ddc0eeb..9f9165e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -10,6 +10,16 @@ config KERNELVERSION
menu "General Setup"
+config SMP_CPUS_MAX
+ int "Number of supported CPUs"
+ default 2
+ range 0 16
+ help
+ Set maximum number of CPUs supported at runtime. Note that this
+ configures the upper limit, if the number of CPUs present in a system
+ is smaller or larger than this number, either the former or the latter
+ will determine the actual number of CPUs used at runtime.
+
config KALLSYMS
bool "Generate a kernel symbol table"
default y
diff --git a/init/main.c b/init/main.c
index 05778b6..a0025a9 100644
--- a/init/main.c
+++ b/init/main.c
@@ -131,7 +131,7 @@ int task0(void *data)
printk("%d %d %d %llu irq: %s %d per sec; sched %llu us %llu per call, calls %d cpu %d\n", a, b, c, ktime_get(), buf1, (curr -last), ktime_to_us(sched_last_time), sched_last_time /sched_ev, sched_ev - last_call, leon3_cpuid());
last = curr;
last_call = sched_ev;
-// sched_yield();
+ sched_yield();
}
}
@@ -278,50 +278,54 @@ int kernel_main(void)
attr.wcet = ms_to_ktime(200);
sched_set_attr(t, &attr);
kthread_wake_up(t);
+#endif
#if 1
- t = kthread_create(task3, NULL, KTHREAD_CPU_AFFINITY_NONE, "print2");
+
+ t = kthread_create(task0, NULL, 0, "res");
sched_get_attr(t, &attr);
attr.policy = SCHED_EDF;
- attr.period = ms_to_ktime(800);
- attr.deadline_rel = ms_to_ktime(700);
- attr.wcet = ms_to_ktime(200);
+ attr.period = ms_to_ktime(1000);
+ attr.deadline_rel = ms_to_ktime(900);
+ attr.wcet = ms_to_ktime(800);
sched_set_attr(t, &attr);
kthread_wake_up(t);
#endif
#if 1
- t = kthread_create(task1, NULL, KTHREAD_CPU_AFFINITY_NONE, "print3");
+ t = kthread_create(task1, NULL, 0, "task1");
sched_get_attr(t, &attr);
attr.policy = SCHED_EDF;
- attr.period = ms_to_ktime(400);
- attr.deadline_rel = ms_to_ktime(200);
- attr.wcet = ms_to_ktime(100);
+ attr.period = ms_to_ktime(500);
+ attr.deadline_rel = ms_to_ktime(300);
+ attr.wcet = ms_to_ktime(200);
sched_set_attr(t, &attr);
kthread_wake_up(t);
#endif
-#endif
#if 1
-
- t = kthread_create(task0, NULL, 0, "res");
+ t = kthread_create(task2, NULL, 1, "task2");
sched_get_attr(t, &attr);
attr.policy = SCHED_EDF;
- attr.period = ms_to_ktime(1000);
- attr.deadline_rel = ms_to_ktime(900);
- attr.wcet = ms_to_ktime(800);
+ attr.period = ms_to_ktime(400);
+ attr.deadline_rel = ms_to_ktime(200);
+ attr.wcet = ms_to_ktime(100);
sched_set_attr(t, &attr);
kthread_wake_up(t);
#endif
+
#if 1
- t = kthread_create(task1, NULL, 1, "print3");
+ t = kthread_create(task3, NULL, 1, "task3");
sched_get_attr(t, &attr);
attr.policy = SCHED_EDF;
- attr.period = ms_to_ktime(500);
- attr.deadline_rel = ms_to_ktime(300);
+ attr.period = ms_to_ktime(800);
+ attr.deadline_rel = ms_to_ktime(700);
attr.wcet = ms_to_ktime(200);
sched_set_attr(t, &attr);
kthread_wake_up(t);
#endif
+
+
+
#endif
@@ -333,6 +337,7 @@ int kernel_main(void)
while (ioread32be(&cpu1_ready) != 0x3);
iowrite32be(0x4, &cpu1_ready);
while(1) {
+// printk("o");
#if 0
int val = inc;
static ktime last;
@@ -375,7 +380,7 @@ int kernel_main(void)
// sched_yield();
// printk("cpu1\n");
-// cpu_relax();
+ cpu_relax();
}
//printk("%lld\n", buf[i]);
diff --git a/kernel/kthread.c b/kernel/kthread.c
index ae16357..c75b680 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -19,6 +19,8 @@
#include <kernel/tick.h>
+#include <generated/autoconf.h> /* XXX need common CPU include */
+
#define MSG "KTHREAD: "
@@ -41,7 +43,7 @@ static struct spinlock kthread_spinlock;
#include <asm/processor.h>
-struct thread_info *current_set[2]; /* XXX */
+struct thread_info *current_set[CONFIG_SMP_CPUS_MAX]; /* XXX */
/**
@@ -50,7 +52,7 @@ struct thread_info *current_set[2]; /* XXX */
void kthread_lock(void)
{
- spin_lock(&kthread_spinlock);
+ spin_lock_raw(&kthread_spinlock);
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 093d17f..65ab90c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -61,7 +61,6 @@ void schedule(void)
arch_local_irq_disable();
// if (leon3_cpuid() != 0)
// printk("cpu %d\n", leon3_cpuid());
-kthread_lock();
/* get the current task for this CPU */
/* XXX leon3_cpuid() should be smp_cpu_id() arch call*/
@@ -92,8 +91,10 @@ retry:
/* XXX: for now, try to wake up any threads not running
* this is a waste of cycles and instruction space; should be
* done in the scheduler's code (somewhere) */
+ kthread_lock();
list_for_each_entry(sched, &kernel_schedulers, node)
sched->wake_next_task(&sched->tq, now);
+ kthread_unlock();
/* XXX need sorted list: highest->lowest scheduler priority, e.g.:
@@ -108,7 +109,6 @@ retry:
/* if one of the schedulers have a task which needs to run now,
* next is non-NULL
*/
-retry2:
next = sched->pick_next_task(&sched->tq, now);
#if 0
@@ -174,7 +174,6 @@ retry2:
if (!next) {
/* there is absolutely nothing nothing to do, check again later */
tick_set_next_ns(wake_ns);
- kthread_unlock();
goto exit;
}
@@ -209,7 +208,6 @@ retry2:
sched_ev++;
sched_last_time = ktime_add(sched_last_time, ktime_delta(ktime_get(), now));
#endif
- kthread_unlock();
prepare_arch_switch(1);
switch_to(next);
diff --git a/kernel/sched/edf.c b/kernel/sched/edf.c
index 89c6788..74c0350 100644
--- a/kernel/sched/edf.c
+++ b/kernel/sched/edf.c
@@ -11,7 +11,8 @@
#include <kernel/string.h>
#include <kernel/tick.h>
-
+#include <generated/autoconf.h> /* XXX need common CPU include */
+#include <asm/processor.h>
void sched_print_edf_list_internal(struct task_queue *tq, ktime now)
{
@@ -23,6 +24,8 @@ void sched_print_edf_list_internal(struct task_queue *tq, ktime now)
struct task_struct *tsk;
struct task_struct *tmp;
+ int cpu = leon3_cpuid();
+
ktime prev = 0;
ktime prevd = 0;
@@ -30,7 +33,7 @@ void sched_print_edf_list_internal(struct task_queue *tq, ktime now)
printk("\nktime: %lld\n", ktime_to_us(now));
printk("S\tDeadline\tWakeup\t\tdelta W\tdelta P\tt_rem\ttotal\tslices\tName\twcet\tavg\n");
printk("---------------------------------------------------------------------------------------------------------------------------------\n");
- list_for_each_entry_safe(tsk, tmp, &tq->run, node) {
+ list_for_each_entry_safe(tsk, tmp, &tq->run[cpu], node) {
if (tsk->attr.policy == SCHED_RR)
continue;
@@ -194,6 +197,18 @@ static inline void schedule_edf_reinit_task(struct task_struct *tsk, ktime now)
*
* -> need hyperperiod factor H = 2
*
+ *
+ * ####
+ *
+ * Note: EDF in SMP configurations is not an optimal algorithm, and deadlines
+ * cannot be guaranteed even for utilisation values just above 1.0
+ * (Dhall's effect). In order to mitigate this for EDF tasks with no
+ * CPU affinity set (KTHREAD_CPU_AFFINITY_NONE), we search the per-cpu
+ * queues until we find one which is below the utilisation limit and
+ * force the affinity of the task to that particular CPU
+ *
+ *
+ * XXX function needs adaptation
*/
static int edf_schedulable(struct task_queue *tq, const struct task_struct *task)
@@ -201,36 +216,46 @@ static int edf_schedulable(struct task_queue *tq, const struct task_struct *task
struct task_struct *tsk = NULL;
struct task_struct *tmp;
+ int cpu;
+
double u = 0.0; /* utilisation */
/* add all in new */
if (!list_empty(&tq->new)) {
- list_for_each_entry_safe(tsk, tmp, &tq->new, node)
+ list_for_each_entry_safe(tsk, tmp, &tq->new, node) {
+
u += (double) (int32_t) tsk->attr.wcet / (double) (int32_t) tsk->attr.period;
+
+ }
}
/* add all in wakeup */
if (!list_empty(&tq->wake)) {
- list_for_each_entry_safe(tsk, tmp, &tq->wake, node)
- u += (double) (int32_t) tsk->attr.wcet / (double) (int32_t) tsk->attr.period;
+ list_for_each_entry_safe(tsk, tmp, &tq->wake, node) {
+ u += (double) (int32_t) tsk->attr.wcet / (double) (int32_t) tsk->attr.period;
+ }
+
}
/* add all running */
- if (!list_empty(&tq->run)) {
- list_for_each_entry_safe(tsk, tmp, &tq->run, node)
- u += (double) (int32_t) tsk->attr.wcet / (double) (int32_t) tsk->attr.period;
+
+ for (cpu = 0; cpu < 2; cpu++) {
+ if (!list_empty(&tq->run[cpu])) {
+ list_for_each_entry_safe(tsk, tmp, &tq->run[cpu], node)
+ u += (double) (int32_t) tsk->attr.wcet / (double) (int32_t) tsk->attr.period;
+ }
}
- if (u > 1.9) {
+ if (u >= 1.9) {
printk("I am NOT schedul-ableh: %f ", u);
BUG();
return -EINVAL;
@@ -252,6 +277,7 @@ static struct task_struct *edf_pick_next(struct task_queue *tq, ktime now)
{
int64_t delta;
+ int cpu = leon3_cpuid();
struct task_struct *tsk;
struct task_struct *tmp;
@@ -259,10 +285,10 @@ static struct task_struct *edf_pick_next(struct task_queue *tq, ktime now)
static int cnt;
- if (list_empty(&tq->run))
+ if (list_empty(&tq->run[cpu]))
return NULL;
- list_for_each_entry_safe(tsk, tmp, &tq->run, node) {
+ list_for_each_entry_safe(tsk, tmp, &tq->run[cpu], node) {
/* time to wake up yet? */
delta = ktime_delta(tsk->wakeup, now);
@@ -292,7 +318,7 @@ static struct task_struct *edf_pick_next(struct task_queue *tq, ktime now)
schedule_edf_reinit_task(tsk, now);
/* always queue it up at the tail */
- list_move_tail(&tsk->node, &tq->run);
+ list_move_tail(&tsk->node, &tq->run[cpu]);
}
@@ -300,17 +326,14 @@ static struct task_struct *edf_pick_next(struct task_queue *tq, ktime now)
* head of the list, we become the new head
*/
- first = list_first_entry(&tq->run, struct task_struct, node);
+ first = list_first_entry(&tq->run[cpu], struct task_struct, node);
- if (tsk->on_cpu == KTHREAD_CPU_AFFINITY_NONE
- || tsk->on_cpu == leon3_cpuid()) {
if (ktime_before (tsk->wakeup, now)) {
if (ktime_before (tsk->deadline - tsk->runtime, first->deadline)) {
tsk->state = TASK_RUN;
- list_move(&tsk->node, &tq->run);
+ list_move(&tsk->node, &tq->run[cpu]);
}
}
- }
continue;
}
@@ -324,36 +347,25 @@ static struct task_struct *edf_pick_next(struct task_queue *tq, ktime now)
/* if our deadline is earlier than the deadline at the
* head of the list, move us to top */
- if (tsk->on_cpu == KTHREAD_CPU_AFFINITY_NONE
- || tsk->on_cpu == leon3_cpuid()) {
- first = list_first_entry(&tq->run, struct task_struct, node);
+ first = list_first_entry(&tq->run[cpu], struct task_struct, node);
- if (first->on_cpu != KTHREAD_CPU_AFFINITY_NONE
- || tsk->on_cpu != leon3_cpuid()) {
- list_move(&tsk->node, &tq->run);
- }
+ list_move(&tsk->node, &tq->run[cpu]);
if (ktime_before (tsk->deadline - tsk->runtime, first->deadline))
- list_move(&tsk->node, &tq->run);
- }
+ list_move(&tsk->node, &tq->run[cpu]);
continue;
}
}
-/* XXX argh, need cpu affinity run lists */
- list_for_each_entry_safe(tsk, tmp, &tq->run, node) {
+ /* XXX argh, need cpu affinity run lists */
+ list_for_each_entry_safe(tsk, tmp, &tq->run[cpu], node) {
if (tsk->state == TASK_RUN) {
- if (tsk->on_cpu == KTHREAD_CPU_AFFINITY_NONE
- || tsk->on_cpu == leon3_cpuid()) {
- tsk->state = TASK_BUSY;
- return tsk;
- } else {
- continue;
- }
+ tsk->state = TASK_BUSY;
+ return tsk;
}
}
@@ -376,6 +388,8 @@ static struct task_struct *edf_pick_next(struct task_queue *tq, ktime now)
static void edf_wake_next(struct task_queue *tq, ktime now)
{
+ int cpu = leon3_cpuid();
+
ktime last;
struct task_struct *tmp;
@@ -403,17 +417,21 @@ static void edf_wake_next(struct task_queue *tq, ktime now)
task = list_entry(tq->wake.next, struct task_struct, node);
- list_for_each_entry_safe(t, tmp, &tq->run, node) {
+ BUG_ON(task->on_cpu == KTHREAD_CPU_AFFINITY_NONE);
+
+ cpu = task->on_cpu;
- first = list_first_entry(&tq->run, struct task_struct, node);
+ list_for_each_entry_safe(t, tmp, &tq->run[cpu], node) {
+
+ first = list_first_entry(&tq->run[cpu], struct task_struct, node);
if (ktime_before (t->wakeup, now)) {
if (ktime_before (t->deadline - t->runtime, first->deadline)) {
- list_move(&t->node, &tq->run);
+ list_move(&t->node, &tq->run[cpu]);
}
}
}
- list_for_each_entry_safe(t, tmp, &tq->run, node) {
+ list_for_each_entry_safe(t, tmp, &tq->run[cpu], node) {
/* if the relative deadline of task-to-wake can fit in between the unused
* timeslice of this running task, insert after the next wakeup
@@ -446,7 +464,7 @@ static void edf_wake_next(struct task_queue *tq, ktime now)
task->first_dead = task->deadline;
- list_move_tail(&task->node, &tq->run);
+ list_move_tail(&task->node, &tq->run[cpu]);
}
@@ -539,6 +557,8 @@ ktime edf_task_ready_ns(struct task_queue *tq, ktime now)
{
int64_t delta;
+ int cpu = leon3_cpuid();
+
struct task_struct *first;
struct task_struct *tsk;
struct task_struct *tmp;
@@ -547,7 +567,7 @@ ktime edf_task_ready_ns(struct task_queue *tq, ktime now)
- list_for_each_entry_safe(first, tmp, &tq->run, node) {
+ list_for_each_entry_safe(first, tmp, &tq->run[cpu], node) {
if (first->state != TASK_RUN)
continue;
@@ -555,7 +575,7 @@ ktime edf_task_ready_ns(struct task_queue *tq, ktime now)
break;
}
- list_for_each_entry_safe(tsk, tmp, &tq->run, node) {
+ list_for_each_entry_safe(tsk, tmp, &tq->run[cpu], node) {
#if 0
if (tsk->state == TASK_BUSY)
continue; /*meh */
@@ -593,12 +613,15 @@ static struct scheduler sched_edf = {
static int sched_edf_init(void)
{
- /* XXX */
+ int i;
+
INIT_LIST_HEAD(&sched_edf.tq.new);
- INIT_LIST_HEAD(&sched_edf.tq.run);
INIT_LIST_HEAD(&sched_edf.tq.wake);
INIT_LIST_HEAD(&sched_edf.tq.dead);
+ for (i = 0; i < CONFIG_SMP_CPUS_MAX; i++)
+ INIT_LIST_HEAD(&sched_edf.tq.run[i]);
+
sched_register(&sched_edf);
return 0;
diff --git a/kernel/sched/rr.c b/kernel/sched/rr.c
index 9cd49de..4268be1 100644
--- a/kernel/sched/rr.c
+++ b/kernel/sched/rr.c
@@ -19,10 +19,10 @@ static struct task_struct *rr_pick_next(struct task_queue *tq, ktime now)
struct task_struct *tmp;
- if (list_empty(&tq->run))
+ if (list_empty(&tq->run[leon3_cpuid()]))
return NULL;
- list_for_each_entry_safe(next, tmp, &tq->run, node) {
+ list_for_each_entry_safe(next, tmp, &tq->run[leon3_cpuid()], node) {
if (next->on_cpu == KTHREAD_CPU_AFFINITY_NONE
@@ -33,7 +33,7 @@ static struct task_struct *rr_pick_next(struct task_queue *tq, ktime now)
* following a scheduling event. for now, just force
* round robin
*/
- list_move_tail(&next->node, &tq->run);
+ list_move_tail(&next->node, &tq->run[leon3_cpuid()]);
/* reset runtime */
next->runtime = (next->attr.priority * tick_get_period_min_ns());
@@ -43,7 +43,7 @@ static struct task_struct *rr_pick_next(struct task_queue *tq, ktime now)
}
if (next->state == TASK_IDLE)
- list_move_tail(&next->node, &tq->run);
+ list_move_tail(&next->node, &tq->run[leon3_cpuid()]);
if (next->state == TASK_DEAD)
list_move_tail(&next->node, &tq->dead);
@@ -81,7 +81,7 @@ static void rr_wake_next(struct task_queue *tq, ktime now)
BUG_ON(task->attr.policy != SCHED_RR);
/** XXX NO LOCKS */
task->state = TASK_RUN;
- list_move(&task->node, &tq->run);
+ list_move(&task->node, &tq->run[leon3_cpuid()]);
}
@@ -91,7 +91,7 @@ static void rr_enqueue(struct task_queue *tq, struct task_struct *task)
task->runtime = (task->attr.priority * tick_get_period_min_ns());
/** XXX **/
if (task->state == TASK_RUN)
- list_add_tail(&task->node, &tq->run);
+ list_add_tail(&task->node, &tq->run[leon3_cpuid()]);
else
list_add_tail(&task->node, &tq->wake);
}
@@ -168,12 +168,17 @@ static struct scheduler sched_rr = {
static int sched_rr_init(void)
{
+ int i;
+
/* XXX */
INIT_LIST_HEAD(&sched_rr.tq.new);
- INIT_LIST_HEAD(&sched_rr.tq.run);
INIT_LIST_HEAD(&sched_rr.tq.wake);
INIT_LIST_HEAD(&sched_rr.tq.dead);
+ for (i = 0; i < CONFIG_SMP_CPUS_MAX; i++)
+ INIT_LIST_HEAD(&sched_rr.tq.run[i]);
+
+
sched_register(&sched_rr);
return 0;
--
GitLab