mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-22 17:01:14 +00:00
![Thomas Gleixner](/assets/img/avatar_default.png)
Use the future-safe accessor for struct task_struct's. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1462969411-17735-1-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
241 lines
5.4 KiB
C
241 lines
5.4 KiB
C
/*
|
|
* kernel/sched/cpudl.c
|
|
*
|
|
* Global CPU deadline management
|
|
*
|
|
* Author: Juri Lelli <j.lelli@sssup.it>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; version 2
|
|
* of the License.
|
|
*/
|
|
|
|
#include <linux/gfp.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include "cpudeadline.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_exchange(struct cpudl *cp, int a, int b)
|
|
{
|
|
int cpu_a = cp->elements[a].cpu, cpu_b = cp->elements[b].cpu;
|
|
|
|
swap(cp->elements[a].cpu, cp->elements[b].cpu);
|
|
swap(cp->elements[a].dl , cp->elements[b].dl );
|
|
|
|
swap(cp->elements[cpu_a].idx, cp->elements[cpu_b].idx);
|
|
}
|
|
|
|
static void cpudl_heapify(struct cpudl *cp, int idx)
|
|
{
|
|
int l, r, largest;
|
|
|
|
/* adapted from lib/prio_heap.c */
|
|
while(1) {
|
|
l = left_child(idx);
|
|
r = right_child(idx);
|
|
largest = idx;
|
|
|
|
if ((l < cp->size) && dl_time_before(cp->elements[idx].dl,
|
|
cp->elements[l].dl))
|
|
largest = l;
|
|
if ((r < cp->size) && dl_time_before(cp->elements[largest].dl,
|
|
cp->elements[r].dl))
|
|
largest = r;
|
|
if (largest == idx)
|
|
break;
|
|
|
|
/* Push idx down the heap one level and bump one up */
|
|
cpudl_exchange(cp, largest, idx);
|
|
idx = largest;
|
|
}
|
|
}
|
|
|
|
static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl)
|
|
{
|
|
WARN_ON(idx == IDX_INVALID || !cpu_present(idx));
|
|
|
|
if (dl_time_before(new_dl, cp->elements[idx].dl)) {
|
|
cp->elements[idx].dl = new_dl;
|
|
cpudl_heapify(cp, idx);
|
|
} else {
|
|
cp->elements[idx].dl = new_dl;
|
|
while (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
|
|
cp->elements[idx].dl)) {
|
|
cpudl_exchange(cp, idx, parent(idx));
|
|
idx = parent(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 - best CPU (heap maximum if suitable)
|
|
*/
|
|
int cpudl_find(struct cpudl *cp, struct task_struct *p,
|
|
struct cpumask *later_mask)
|
|
{
|
|
int best_cpu = -1;
|
|
const struct sched_dl_entity *dl_se = &p->dl;
|
|
|
|
if (later_mask &&
|
|
cpumask_and(later_mask, cp->free_cpus, tsk_cpus_allowed(p))) {
|
|
best_cpu = cpumask_any(later_mask);
|
|
goto out;
|
|
} else if (cpumask_test_cpu(cpudl_maximum(cp), tsk_cpus_allowed(p)) &&
|
|
dl_time_before(dl_se->deadline, cp->elements[0].dl)) {
|
|
best_cpu = cpudl_maximum(cp);
|
|
if (later_mask)
|
|
cpumask_set_cpu(best_cpu, later_mask);
|
|
}
|
|
|
|
out:
|
|
WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
|
|
|
|
return best_cpu;
|
|
}
|
|
|
|
/*
|
|
* 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 is_valid)
|
|
{
|
|
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 (!is_valid) {
|
|
/* remove item */
|
|
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.
|
|
*/
|
|
goto out;
|
|
}
|
|
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;
|
|
while (old_idx > 0 && dl_time_before(
|
|
cp->elements[parent(old_idx)].dl,
|
|
cp->elements[old_idx].dl)) {
|
|
cpudl_exchange(cp, old_idx, parent(old_idx));
|
|
old_idx = parent(old_idx);
|
|
}
|
|
cpumask_set_cpu(cpu, cp->free_cpus);
|
|
cpudl_heapify(cp, old_idx);
|
|
|
|
goto out;
|
|
}
|
|
|
|
if (old_idx == IDX_INVALID) {
|
|
cp->size++;
|
|
cp->elements[cp->size - 1].dl = 0;
|
|
cp->elements[cp->size - 1].cpu = cpu;
|
|
cp->elements[cpu].idx = cp->size - 1;
|
|
cpudl_change_key(cp, cp->size - 1, dl);
|
|
cpumask_clear_cpu(cpu, cp->free_cpus);
|
|
} else {
|
|
cpudl_change_key(cp, old_idx, dl);
|
|
}
|
|
|
|
out:
|
|
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;
|
|
|
|
memset(cp, 0, sizeof(*cp));
|
|
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);
|
|
}
|