forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
296 lines
6.3 KiB
296 lines
6.3 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* kernel/sched/cpudl.c |
|
* |
|
* Global CPU deadline management |
|
* |
|
* Author: Juri Lelli <[email protected]> |
|
*/ |
|
#include "sched.h" |
|
|
|
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 (!static_branch_unlikely(&sched_asym_cpucapacity)) |
|
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 = capacity_orig_of(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); |
|
}
|
|
|