Contributors: 14
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Juri Lelli |
750 |
57.52% |
3 |
12.50% |
| Tommaso Cucinotta |
284 |
21.78% |
4 |
16.67% |
| Luca Abeni |
96 |
7.36% |
2 |
8.33% |
| Peter Zijlstra |
88 |
6.75% |
3 |
12.50% |
| Byungchul Park |
20 |
1.53% |
1 |
4.17% |
| Dario Faggioli |
17 |
1.30% |
1 |
4.17% |
| Xunlei Pang |
16 |
1.23% |
1 |
4.17% |
| Boris Ostrovsky |
12 |
0.92% |
1 |
4.17% |
| Li Zefan |
7 |
0.54% |
1 |
4.17% |
| Ingo Molnar |
7 |
0.54% |
3 |
12.50% |
| Fengguang Wu |
3 |
0.23% |
1 |
4.17% |
| Dietmar Eggemann |
2 |
0.15% |
1 |
4.17% |
| Thomas Gleixner |
1 |
0.08% |
1 |
4.17% |
| Vincent Guittot |
1 |
0.08% |
1 |
4.17% |
| Total |
1304 |
|
24 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* kernel/sched/cpudeadline.c
*
* Global CPU deadline management
*
* Author: Juri Lelli <j.lelli@sssup.it>
*/
static inline int parent(int i)
{
return (i - 1) >> 1;
}
static inline int left_child(int i)
{
return (i << 1) + 1;
}
static inline int right_child(int i)
{
return (i << 1) + 2;
}
static void cpudl_heapify_down(struct cpudl *cp, int idx)
{
int l, r, largest;
int orig_cpu = cp->elements[idx].cpu;
u64 orig_dl = cp->elements[idx].dl;
if (left_child(idx) >= cp->size)
return;
/* adapted from lib/prio_heap.c */
while (1) {
u64 largest_dl;
l = left_child(idx);
r = right_child(idx);
largest = idx;
largest_dl = orig_dl;
if ((l < cp->size) && dl_time_before(orig_dl,
cp->elements[l].dl)) {
largest = l;
largest_dl = cp->elements[l].dl;
}
if ((r < cp->size) && dl_time_before(largest_dl,
cp->elements[r].dl))
largest = r;
if (largest == idx)
break;
/* pull largest child onto idx */
cp->elements[idx].cpu = cp->elements[largest].cpu;
cp->elements[idx].dl = cp->elements[largest].dl;
cp->elements[cp->elements[idx].cpu].idx = idx;
idx = largest;
}
/* actual push down of saved original values orig_* */
cp->elements[idx].cpu = orig_cpu;
cp->elements[idx].dl = orig_dl;
cp->elements[cp->elements[idx].cpu].idx = idx;
}
static void cpudl_heapify_up(struct cpudl *cp, int idx)
{
int p;
int orig_cpu = cp->elements[idx].cpu;
u64 orig_dl = cp->elements[idx].dl;
if (idx == 0)
return;
do {
p = parent(idx);
if (dl_time_before(orig_dl, cp->elements[p].dl))
break;
/* pull parent onto idx */
cp->elements[idx].cpu = cp->elements[p].cpu;
cp->elements[idx].dl = cp->elements[p].dl;
cp->elements[cp->elements[idx].cpu].idx = idx;
idx = p;
} while (idx != 0);
/* actual push up of saved original values orig_* */
cp->elements[idx].cpu = orig_cpu;
cp->elements[idx].dl = orig_dl;
cp->elements[cp->elements[idx].cpu].idx = idx;
}
static void cpudl_heapify(struct cpudl *cp, int idx)
{
if (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
cp->elements[idx].dl))
cpudl_heapify_up(cp, idx);
else
cpudl_heapify_down(cp, idx);
}
static inline int cpudl_maximum(struct cpudl *cp)
{
return cp->elements[0].cpu;
}
/*
* cpudl_find - find the best (later-dl) CPU in the system
* @cp: the cpudl max-heap context
* @p: the task
* @later_mask: a mask to fill in with the selected CPUs (or NULL)
*
* Returns: int - CPUs were found
*/
int cpudl_find(struct cpudl *cp, struct task_struct *p,
struct cpumask *later_mask)
{
const struct sched_dl_entity *dl_se = &p->dl;
if (later_mask &&
cpumask_and(later_mask, cp->free_cpus, &p->cpus_mask)) {
unsigned long cap, max_cap = 0;
int cpu, max_cpu = -1;
if (!sched_asym_cpucap_active())
return 1;
/* Ensure the capacity of the CPUs fits the task. */
for_each_cpu(cpu, later_mask) {
if (!dl_task_fits_capacity(p, cpu)) {
cpumask_clear_cpu(cpu, later_mask);
cap = arch_scale_cpu_capacity(cpu);
if (cap > max_cap ||
(cpu == task_cpu(p) && cap == max_cap)) {
max_cap = cap;
max_cpu = cpu;
}
}
}
if (cpumask_empty(later_mask))
cpumask_set_cpu(max_cpu, later_mask);
return 1;
} else {
int best_cpu = cpudl_maximum(cp);
WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
if (cpumask_test_cpu(best_cpu, &p->cpus_mask) &&
dl_time_before(dl_se->deadline, cp->elements[0].dl)) {
if (later_mask)
cpumask_set_cpu(best_cpu, later_mask);
return 1;
}
}
return 0;
}
/*
* cpudl_clear - remove a CPU from the cpudl max-heap
* @cp: the cpudl max-heap context
* @cpu: the target CPU
*
* Notes: assumes cpu_rq(cpu)->lock is locked
*
* Returns: (void)
*/
void cpudl_clear(struct cpudl *cp, int cpu)
{
int old_idx, new_cpu;
unsigned long flags;
WARN_ON(!cpu_present(cpu));
raw_spin_lock_irqsave(&cp->lock, flags);
old_idx = cp->elements[cpu].idx;
if (old_idx == IDX_INVALID) {
/*
* Nothing to remove if old_idx was invalid.
* This could happen if a rq_offline_dl is
* called for a CPU without -dl tasks running.
*/
} else {
new_cpu = cp->elements[cp->size - 1].cpu;
cp->elements[old_idx].dl = cp->elements[cp->size - 1].dl;
cp->elements[old_idx].cpu = new_cpu;
cp->size--;
cp->elements[new_cpu].idx = old_idx;
cp->elements[cpu].idx = IDX_INVALID;
cpudl_heapify(cp, old_idx);
cpumask_set_cpu(cpu, cp->free_cpus);
}
raw_spin_unlock_irqrestore(&cp->lock, flags);
}
/*
* cpudl_set - update the cpudl max-heap
* @cp: the cpudl max-heap context
* @cpu: the target CPU
* @dl: the new earliest deadline for this CPU
*
* Notes: assumes cpu_rq(cpu)->lock is locked
*
* Returns: (void)
*/
void cpudl_set(struct cpudl *cp, int cpu, u64 dl)
{
int old_idx;
unsigned long flags;
WARN_ON(!cpu_present(cpu));
raw_spin_lock_irqsave(&cp->lock, flags);
old_idx = cp->elements[cpu].idx;
if (old_idx == IDX_INVALID) {
int new_idx = cp->size++;
cp->elements[new_idx].dl = dl;
cp->elements[new_idx].cpu = cpu;
cp->elements[cpu].idx = new_idx;
cpudl_heapify_up(cp, new_idx);
cpumask_clear_cpu(cpu, cp->free_cpus);
} else {
cp->elements[old_idx].dl = dl;
cpudl_heapify(cp, old_idx);
}
raw_spin_unlock_irqrestore(&cp->lock, flags);
}
/*
* cpudl_set_freecpu - Set the cpudl.free_cpus
* @cp: the cpudl max-heap context
* @cpu: rd attached CPU
*/
void cpudl_set_freecpu(struct cpudl *cp, int cpu)
{
cpumask_set_cpu(cpu, cp->free_cpus);
}
/*
* cpudl_clear_freecpu - Clear the cpudl.free_cpus
* @cp: the cpudl max-heap context
* @cpu: rd attached CPU
*/
void cpudl_clear_freecpu(struct cpudl *cp, int cpu)
{
cpumask_clear_cpu(cpu, cp->free_cpus);
}
/*
* cpudl_init - initialize the cpudl structure
* @cp: the cpudl max-heap context
*/
int cpudl_init(struct cpudl *cp)
{
int i;
raw_spin_lock_init(&cp->lock);
cp->size = 0;
cp->elements = kcalloc(nr_cpu_ids,
sizeof(struct cpudl_item),
GFP_KERNEL);
if (!cp->elements)
return -ENOMEM;
if (!zalloc_cpumask_var(&cp->free_cpus, GFP_KERNEL)) {
kfree(cp->elements);
return -ENOMEM;
}
for_each_possible_cpu(i)
cp->elements[i].idx = IDX_INVALID;
return 0;
}
/*
* cpudl_cleanup - clean up the cpudl structure
* @cp: the cpudl max-heap context
*/
void cpudl_cleanup(struct cpudl *cp)
{
free_cpumask_var(cp->free_cpus);
kfree(cp->elements);
}