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authorIngo Molnar <mingo@elte.hu>2011-07-21 17:59:54 +0200
committerIngo Molnar <mingo@elte.hu>2011-07-21 18:00:01 +0200
commit994bf1c92270e3d7731ea08f1d1bd7a668314e60 (patch)
tree4409a21eab486e53fbe350a66e8a4f28b7a720c0 /kernel/sched.c
parentbd96efe17d945f0bad56d592f8686dc6309905e7 (diff)
parentcf6ace16a3cd8b728fb0afa68368fd40bbeae19f (diff)
Merge branch 'linus' into sched/core
Merge reason: pick up the latest scheduler fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c245
1 files changed, 199 insertions, 46 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 4380a80c1e7..b0e7ad796d3 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -292,8 +292,8 @@ static DEFINE_SPINLOCK(task_group_lock);
* (The default weight is 1024 - so there's no practical
* limitation from this.)
*/
-#define MIN_SHARES 2
-#define MAX_SHARES (1UL << (18 + SCHED_LOAD_RESOLUTION))
+#define MIN_SHARES (1UL << 1)
+#define MAX_SHARES (1UL << 18)
static int root_task_group_load = ROOT_TASK_GROUP_LOAD;
#endif
@@ -2544,13 +2544,9 @@ static int ttwu_remote(struct task_struct *p, int wake_flags)
}
#ifdef CONFIG_SMP
-static void sched_ttwu_pending(void)
+static void sched_ttwu_do_pending(struct task_struct *list)
{
struct rq *rq = this_rq();
- struct task_struct *list = xchg(&rq->wake_list, NULL);
-
- if (!list)
- return;
raw_spin_lock(&rq->lock);
@@ -2563,9 +2559,45 @@ static void sched_ttwu_pending(void)
raw_spin_unlock(&rq->lock);
}
+#ifdef CONFIG_HOTPLUG_CPU
+
+static void sched_ttwu_pending(void)
+{
+ struct rq *rq = this_rq();
+ struct task_struct *list = xchg(&rq->wake_list, NULL);
+
+ if (!list)
+ return;
+
+ sched_ttwu_do_pending(list);
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
void scheduler_ipi(void)
{
- sched_ttwu_pending();
+ struct rq *rq = this_rq();
+ struct task_struct *list = xchg(&rq->wake_list, NULL);
+
+ if (!list)
+ return;
+
+ /*
+ * Not all reschedule IPI handlers call irq_enter/irq_exit, since
+ * traditionally all their work was done from the interrupt return
+ * path. Now that we actually do some work, we need to make sure
+ * we do call them.
+ *
+ * Some archs already do call them, luckily irq_enter/exit nest
+ * properly.
+ *
+ * Arguably we should visit all archs and update all handlers,
+ * however a fair share of IPIs are still resched only so this would
+ * somewhat pessimize the simple resched case.
+ */
+ irq_enter();
+ sched_ttwu_do_pending(list);
+ irq_exit();
}
static void ttwu_queue_remote(struct task_struct *p, int cpu)
@@ -6550,7 +6582,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
break;
}
- if (!group->cpu_power) {
+ if (!group->sgp->power) {
printk(KERN_CONT "\n");
printk(KERN_ERR "ERROR: domain->cpu_power not "
"set\n");
@@ -6574,9 +6606,9 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
printk(KERN_CONT " %s", str);
- if (group->cpu_power != SCHED_POWER_SCALE) {
+ if (group->sgp->power != SCHED_POWER_SCALE) {
printk(KERN_CONT " (cpu_power = %d)",
- group->cpu_power);
+ group->sgp->power);
}
group = group->next;
@@ -6767,11 +6799,39 @@ static struct root_domain *alloc_rootdomain(void)
return rd;
}
+static void free_sched_groups(struct sched_group *sg, int free_sgp)
+{
+ struct sched_group *tmp, *first;
+
+ if (!sg)
+ return;
+
+ first = sg;
+ do {
+ tmp = sg->next;
+
+ if (free_sgp && atomic_dec_and_test(&sg->sgp->ref))
+ kfree(sg->sgp);
+
+ kfree(sg);
+ sg = tmp;
+ } while (sg != first);
+}
+
static void free_sched_domain(struct rcu_head *rcu)
{
struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu);
- if (atomic_dec_and_test(&sd->groups->ref))
+
+ /*
+ * If its an overlapping domain it has private groups, iterate and
+ * nuke them all.
+ */
+ if (sd->flags & SD_OVERLAP) {
+ free_sched_groups(sd->groups, 1);
+ } else if (atomic_dec_and_test(&sd->groups->ref)) {
+ kfree(sd->groups->sgp);
kfree(sd->groups);
+ }
kfree(sd);
}
@@ -6938,6 +6998,7 @@ int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
struct sd_data {
struct sched_domain **__percpu sd;
struct sched_group **__percpu sg;
+ struct sched_group_power **__percpu sgp;
};
struct s_data {
@@ -6957,15 +7018,73 @@ struct sched_domain_topology_level;
typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu);
typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
+#define SDTL_OVERLAP 0x01
+
struct sched_domain_topology_level {
sched_domain_init_f init;
sched_domain_mask_f mask;
+ int flags;
struct sd_data data;
};
-/*
- * Assumes the sched_domain tree is fully constructed
- */
+static int
+build_overlap_sched_groups(struct sched_domain *sd, int cpu)
+{
+ struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg;
+ const struct cpumask *span = sched_domain_span(sd);
+ struct cpumask *covered = sched_domains_tmpmask;
+ struct sd_data *sdd = sd->private;
+ struct sched_domain *child;
+ int i;
+
+ cpumask_clear(covered);
+
+ for_each_cpu(i, span) {
+ struct cpumask *sg_span;
+
+ if (cpumask_test_cpu(i, covered))
+ continue;
+
+ sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
+ GFP_KERNEL, cpu_to_node(i));
+
+ if (!sg)
+ goto fail;
+
+ sg_span = sched_group_cpus(sg);
+
+ child = *per_cpu_ptr(sdd->sd, i);
+ if (child->child) {
+ child = child->child;
+ cpumask_copy(sg_span, sched_domain_span(child));
+ } else
+ cpumask_set_cpu(i, sg_span);
+
+ cpumask_or(covered, covered, sg_span);
+
+ sg->sgp = *per_cpu_ptr(sdd->sgp, cpumask_first(sg_span));
+ atomic_inc(&sg->sgp->ref);
+
+ if (cpumask_test_cpu(cpu, sg_span))
+ groups = sg;
+
+ if (!first)
+ first = sg;
+ if (last)
+ last->next = sg;
+ last = sg;
+ last->next = first;
+ }
+ sd->groups = groups;
+
+ return 0;
+
+fail:
+ free_sched_groups(first, 0);
+
+ return -ENOMEM;
+}
+
static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
{
struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu);
@@ -6974,24 +7093,24 @@ static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
if (child)
cpu = cpumask_first(sched_domain_span(child));
- if (sg)
+ if (sg) {
*sg = *per_cpu_ptr(sdd->sg, cpu);
+ (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu);
+ atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */
+ }
return cpu;
}
/*
- * build_sched_groups takes the cpumask we wish to span, and a pointer
- * to a function which identifies what group(along with sched group) a CPU
- * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids
- * (due to the fact that we keep track of groups covered with a struct cpumask).
- *
* build_sched_groups will build a circular linked list of the groups
* covered by the given span, and will set each group's ->cpumask correctly,
* and ->cpu_power to 0.
+ *
+ * Assumes the sched_domain tree is fully constructed
*/
-static void
-build_sched_groups(struct sched_domain *sd)
+static int
+build_sched_groups(struct sched_domain *sd, int cpu)
{
struct sched_group *first = NULL, *last = NULL;
struct sd_data *sdd = sd->private;
@@ -6999,6 +7118,12 @@ build_sched_groups(struct sched_domain *sd)
struct cpumask *covered;
int i;
+ get_group(cpu, sdd, &sd->groups);
+ atomic_inc(&sd->groups->ref);
+
+ if (cpu != cpumask_first(sched_domain_span(sd)))
+ return 0;
+
lockdep_assert_held(&sched_domains_mutex);
covered = sched_domains_tmpmask;
@@ -7013,7 +7138,7 @@ build_sched_groups(struct sched_domain *sd)
continue;
cpumask_clear(sched_group_cpus(sg));
- sg->cpu_power = 0;
+ sg->sgp->power = 0;
for_each_cpu(j, span) {
if (get_group(j, sdd, NULL) != group)
@@ -7030,6 +7155,8 @@ build_sched_groups(struct sched_domain *sd)
last = sg;
}
last->next = first;
+
+ return 0;
}
/*
@@ -7044,12 +7171,17 @@ build_sched_groups(struct sched_domain *sd)
*/
static void init_sched_groups_power(int cpu, struct sched_domain *sd)
{
- WARN_ON(!sd || !sd->groups);
+ struct sched_group *sg = sd->groups;
- if (cpu != group_first_cpu(sd->groups))
- return;
+ WARN_ON(!sd || !sg);
+
+ do {
+ sg->group_weight = cpumask_weight(sched_group_cpus(sg));
+ sg = sg->next;
+ } while (sg != sd->groups);
- sd->groups->group_weight = cpumask_weight(sched_group_cpus(sd->groups));
+ if (cpu != group_first_cpu(sg))
+ return;
update_group_power(sd, cpu);
}
@@ -7170,15 +7302,15 @@ static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
static void claim_allocations(int cpu, struct sched_domain *sd)
{
struct sd_data *sdd = sd->private;
- struct sched_group *sg = sd->groups;
WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd);
*per_cpu_ptr(sdd->sd, cpu) = NULL;
- if (cpu == cpumask_first(sched_group_cpus(sg))) {
- WARN_ON_ONCE(*per_cpu_ptr(sdd->sg, cpu) != sg);
+ if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref))
*per_cpu_ptr(sdd->sg, cpu) = NULL;
- }
+
+ if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref))
+ *per_cpu_ptr(sdd->sgp, cpu) = NULL;
}
#ifdef CONFIG_SCHED_SMT
@@ -7203,7 +7335,7 @@ static struct sched_domain_topology_level default_topology[] = {
#endif
{ sd_init_CPU, cpu_cpu_mask, },
#ifdef CONFIG_NUMA
- { sd_init_NODE, cpu_node_mask, },
+ { sd_init_NODE, cpu_node_mask, SDTL_OVERLAP, },
{ sd_init_ALLNODES, cpu_allnodes_mask, },
#endif
{ NULL, },
@@ -7227,9 +7359,14 @@ static int __sdt_alloc(const struct cpumask *cpu_map)
if (!sdd->sg)
return -ENOMEM;
+ sdd->sgp = alloc_percpu(struct sched_group_power *);
+ if (!sdd->sgp)
+ return -ENOMEM;
+
for_each_cpu(j, cpu_map) {
struct sched_domain *sd;
struct sched_group *sg;
+ struct sched_group_power *sgp;
sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(),
GFP_KERNEL, cpu_to_node(j));
@@ -7244,6 +7381,13 @@ static int __sdt_alloc(const struct cpumask *cpu_map)
return -ENOMEM;
*per_cpu_ptr(sdd->sg, j) = sg;
+
+ sgp = kzalloc_node(sizeof(struct sched_group_power),
+ GFP_KERNEL, cpu_to_node(j));
+ if (!sgp)
+ return -ENOMEM;
+
+ *per_cpu_ptr(sdd->sgp, j) = sgp;
}
}
@@ -7259,11 +7403,15 @@ static void __sdt_free(const struct cpumask *cpu_map)
struct sd_data *sdd = &tl->data;
for_each_cpu(j, cpu_map) {
- kfree(*per_cpu_ptr(sdd->sd, j));
+ struct sched_domain *sd = *per_cpu_ptr(sdd->sd, j);
+ if (sd && (sd->flags & SD_OVERLAP))
+ free_sched_groups(sd->groups, 0);
kfree(*per_cpu_ptr(sdd->sg, j));
+ kfree(*per_cpu_ptr(sdd->sgp, j));
}
free_percpu(sdd->sd);
free_percpu(sdd->sg);
+ free_percpu(sdd->sgp);
}
}
@@ -7309,8 +7457,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
struct sched_domain_topology_level *tl;
sd = NULL;
- for (tl = sched_domain_topology; tl->init; tl++)
+ for (tl = sched_domain_topology; tl->init; tl++) {
sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
+ if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
+ sd->flags |= SD_OVERLAP;
+ if (cpumask_equal(cpu_map, sched_domain_span(sd)))
+ break;
+ }
while (sd->child)
sd = sd->child;
@@ -7322,13 +7475,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
for_each_cpu(i, cpu_map) {
for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
sd->span_weight = cpumask_weight(sched_domain_span(sd));
- get_group(i, sd->private, &sd->groups);
- atomic_inc(&sd->groups->ref);
-
- if (i != cpumask_first(sched_domain_span(sd)))
- continue;
-
- build_sched_groups(sd);
+ if (sd->flags & SD_OVERLAP) {
+ if (build_overlap_sched_groups(sd, i))
+ goto error;
+ } else {
+ if (build_sched_groups(sd, i))
+ goto error;
+ }
}
}
@@ -7750,6 +7903,9 @@ static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq)
#endif
#endif
cfs_rq->min_vruntime = (u64)(-(1LL << 20));
+#ifndef CONFIG_64BIT
+ cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
+#endif
}
static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
@@ -8441,10 +8597,7 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
if (!tg->se[0])
return -EINVAL;
- if (shares < MIN_SHARES)
- shares = MIN_SHARES;
- else if (shares > MAX_SHARES)
- shares = MAX_SHARES;
+ shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES));
mutex_lock(&shares_mutex);
if (tg->shares == shares)