summaryrefslogtreecommitdiffstats
path: root/kernel/sched.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c231
1 files changed, 101 insertions, 130 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index ad10d0aae1d..338340a3fb8 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -397,9 +397,9 @@ struct cfs_rq {
* 'curr' points to currently running entity on this cfs_rq.
* It is set to NULL otherwise (i.e when none are currently running).
*/
- struct sched_entity *curr, *next;
+ struct sched_entity *curr, *next, *last;
- unsigned long nr_spread_over;
+ unsigned int nr_spread_over;
#ifdef CONFIG_FAIR_GROUP_SCHED
struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
@@ -703,45 +703,18 @@ static __read_mostly char *sched_feat_names[] = {
#undef SCHED_FEAT
-static int sched_feat_open(struct inode *inode, struct file *filp)
-{
- filp->private_data = inode->i_private;
- return 0;
-}
-
-static ssize_t
-sched_feat_read(struct file *filp, char __user *ubuf,
- size_t cnt, loff_t *ppos)
+static int sched_feat_show(struct seq_file *m, void *v)
{
- char *buf;
- int r = 0;
- int len = 0;
int i;
for (i = 0; sched_feat_names[i]; i++) {
- len += strlen(sched_feat_names[i]);
- len += 4;
+ if (!(sysctl_sched_features & (1UL << i)))
+ seq_puts(m, "NO_");
+ seq_printf(m, "%s ", sched_feat_names[i]);
}
+ seq_puts(m, "\n");
- buf = kmalloc(len + 2, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- for (i = 0; sched_feat_names[i]; i++) {
- if (sysctl_sched_features & (1UL << i))
- r += sprintf(buf + r, "%s ", sched_feat_names[i]);
- else
- r += sprintf(buf + r, "NO_%s ", sched_feat_names[i]);
- }
-
- r += sprintf(buf + r, "\n");
- WARN_ON(r >= len + 2);
-
- r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-
- kfree(buf);
-
- return r;
+ return 0;
}
static ssize_t
@@ -786,10 +759,17 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
return cnt;
}
+static int sched_feat_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, sched_feat_show, NULL);
+}
+
static struct file_operations sched_feat_fops = {
- .open = sched_feat_open,
- .read = sched_feat_read,
- .write = sched_feat_write,
+ .open = sched_feat_open,
+ .write = sched_feat_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
};
static __init int sched_init_debug(void)
@@ -969,6 +949,14 @@ static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
}
}
+void task_rq_unlock_wait(struct task_struct *p)
+{
+ struct rq *rq = task_rq(p);
+
+ smp_mb(); /* spin-unlock-wait is not a full memory barrier */
+ spin_unlock_wait(&rq->lock);
+}
+
static void __task_rq_unlock(struct rq *rq)
__releases(rq->lock)
{
@@ -1448,6 +1436,8 @@ static unsigned long cpu_avg_load_per_task(int cpu)
if (rq->nr_running)
rq->avg_load_per_task = rq->load.weight / rq->nr_running;
+ else
+ rq->avg_load_per_task = 0;
return rq->avg_load_per_task;
}
@@ -1463,27 +1453,13 @@ static void
update_group_shares_cpu(struct task_group *tg, int cpu,
unsigned long sd_shares, unsigned long sd_rq_weight)
{
- int boost = 0;
unsigned long shares;
unsigned long rq_weight;
if (!tg->se[cpu])
return;
- rq_weight = tg->cfs_rq[cpu]->load.weight;
-
- /*
- * If there are currently no tasks on the cpu pretend there is one of
- * average load so that when a new task gets to run here it will not
- * get delayed by group starvation.
- */
- if (!rq_weight) {
- boost = 1;
- rq_weight = NICE_0_LOAD;
- }
-
- if (unlikely(rq_weight > sd_rq_weight))
- rq_weight = sd_rq_weight;
+ rq_weight = tg->cfs_rq[cpu]->rq_weight;
/*
* \Sum shares * rq_weight
@@ -1491,7 +1467,7 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
* \Sum rq_weight
*
*/
- shares = (sd_shares * rq_weight) / (sd_rq_weight + 1);
+ shares = (sd_shares * rq_weight) / sd_rq_weight;
shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES);
if (abs(shares - tg->se[cpu]->load.weight) >
@@ -1500,11 +1476,7 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
unsigned long flags;
spin_lock_irqsave(&rq->lock, flags);
- /*
- * record the actual number of shares, not the boosted amount.
- */
- tg->cfs_rq[cpu]->shares = boost ? 0 : shares;
- tg->cfs_rq[cpu]->rq_weight = rq_weight;
+ tg->cfs_rq[cpu]->shares = shares;
__set_se_shares(tg->se[cpu], shares);
spin_unlock_irqrestore(&rq->lock, flags);
@@ -1518,13 +1490,23 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
*/
static int tg_shares_up(struct task_group *tg, void *data)
{
- unsigned long rq_weight = 0;
+ unsigned long weight, rq_weight = 0;
unsigned long shares = 0;
struct sched_domain *sd = data;
int i;
for_each_cpu_mask(i, sd->span) {
- rq_weight += tg->cfs_rq[i]->load.weight;
+ /*
+ * If there are currently no tasks on the cpu pretend there
+ * is one of average load so that when a new task gets to
+ * run here it will not get delayed by group starvation.
+ */
+ weight = tg->cfs_rq[i]->load.weight;
+ if (!weight)
+ weight = NICE_0_LOAD;
+
+ tg->cfs_rq[i]->rq_weight = weight;
+ rq_weight += weight;
shares += tg->cfs_rq[i]->shares;
}
@@ -1534,9 +1516,6 @@ static int tg_shares_up(struct task_group *tg, void *data)
if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE))
shares = tg->shares;
- if (!rq_weight)
- rq_weight = cpus_weight(sd->span) * NICE_0_LOAD;
-
for_each_cpu_mask(i, sd->span)
update_group_shares_cpu(tg, i, shares, rq_weight);
@@ -1805,7 +1784,9 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
/*
* Buddy candidates are cache hot:
*/
- if (sched_feat(CACHE_HOT_BUDDY) && (&p->se == cfs_rq_of(&p->se)->next))
+ if (sched_feat(CACHE_HOT_BUDDY) &&
+ (&p->se == cfs_rq_of(&p->se)->next ||
+ &p->se == cfs_rq_of(&p->se)->last))
return 1;
if (p->sched_class != &fair_sched_class)
@@ -5858,6 +5839,8 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
+ spin_lock_irqsave(&rq->lock, flags);
+
__sched_fork(idle);
idle->se.exec_start = sched_clock();
@@ -5865,7 +5848,6 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
idle->cpus_allowed = cpumask_of_cpu(cpu);
__set_task_cpu(idle, cpu);
- spin_lock_irqsave(&rq->lock, flags);
rq->curr = rq->idle = idle;
#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
idle->oncpu = 1;
@@ -6112,7 +6094,6 @@ static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
/*
* Figure out where task on dead CPU should go, use force if necessary.
- * NOTE: interrupts should be disabled by the caller
*/
static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
{
@@ -6622,28 +6603,6 @@ early_initcall(migration_init);
#ifdef CONFIG_SCHED_DEBUG
-static inline const char *sd_level_to_string(enum sched_domain_level lvl)
-{
- switch (lvl) {
- case SD_LV_NONE:
- return "NONE";
- case SD_LV_SIBLING:
- return "SIBLING";
- case SD_LV_MC:
- return "MC";
- case SD_LV_CPU:
- return "CPU";
- case SD_LV_NODE:
- return "NODE";
- case SD_LV_ALLNODES:
- return "ALLNODES";
- case SD_LV_MAX:
- return "MAX";
-
- }
- return "MAX";
-}
-
static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
cpumask_t *groupmask)
{
@@ -6663,8 +6622,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
return -1;
}
- printk(KERN_CONT "span %s level %s\n",
- str, sd_level_to_string(sd->level));
+ printk(KERN_CONT "span %s level %s\n", str, sd->name);
if (!cpu_isset(cpu, sd->span)) {
printk(KERN_ERR "ERROR: domain->span does not contain "
@@ -6875,15 +6833,17 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
struct sched_domain *tmp;
/* Remove the sched domains which do not contribute to scheduling. */
- for (tmp = sd; tmp; tmp = tmp->parent) {
+ for (tmp = sd; tmp; ) {
struct sched_domain *parent = tmp->parent;
if (!parent)
break;
+
if (sd_parent_degenerate(tmp, parent)) {
tmp->parent = parent->parent;
if (parent->parent)
parent->parent->child = tmp;
- }
+ } else
+ tmp = tmp->parent;
}
if (sd && sd_degenerate(sd)) {
@@ -7318,13 +7278,21 @@ struct allmasks {
};
#if NR_CPUS > 128
-#define SCHED_CPUMASK_ALLOC 1
-#define SCHED_CPUMASK_FREE(v) kfree(v)
-#define SCHED_CPUMASK_DECLARE(v) struct allmasks *v
+#define SCHED_CPUMASK_DECLARE(v) struct allmasks *v
+static inline void sched_cpumask_alloc(struct allmasks **masks)
+{
+ *masks = kmalloc(sizeof(**masks), GFP_KERNEL);
+}
+static inline void sched_cpumask_free(struct allmasks *masks)
+{
+ kfree(masks);
+}
#else
-#define SCHED_CPUMASK_ALLOC 0
-#define SCHED_CPUMASK_FREE(v)
-#define SCHED_CPUMASK_DECLARE(v) struct allmasks _v, *v = &_v
+#define SCHED_CPUMASK_DECLARE(v) struct allmasks _v, *v = &_v
+static inline void sched_cpumask_alloc(struct allmasks **masks)
+{ }
+static inline void sched_cpumask_free(struct allmasks *masks)
+{ }
#endif
#define SCHED_CPUMASK_VAR(v, a) cpumask_t *v = (cpumask_t *) \
@@ -7400,9 +7368,8 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
return -ENOMEM;
}
-#if SCHED_CPUMASK_ALLOC
/* get space for all scratch cpumask variables */
- allmasks = kmalloc(sizeof(*allmasks), GFP_KERNEL);
+ sched_cpumask_alloc(&allmasks);
if (!allmasks) {
printk(KERN_WARNING "Cannot alloc cpumask array\n");
kfree(rd);
@@ -7411,7 +7378,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
#endif
return -ENOMEM;
}
-#endif
+
tmpmask = (cpumask_t *)allmasks;
@@ -7665,13 +7632,14 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
cpu_attach_domain(sd, rd, i);
}
- SCHED_CPUMASK_FREE((void *)allmasks);
+ sched_cpumask_free(allmasks);
return 0;
#ifdef CONFIG_NUMA
error:
free_sched_groups(cpu_map, tmpmask);
- SCHED_CPUMASK_FREE((void *)allmasks);
+ sched_cpumask_free(allmasks);
+ kfree(rd);
return -ENOMEM;
#endif
}
@@ -7734,8 +7702,6 @@ static void detach_destroy_domains(const cpumask_t *cpu_map)
cpumask_t tmpmask;
int i;
- unregister_sched_domain_sysctl();
-
for_each_cpu_mask_nr(i, *cpu_map)
cpu_attach_domain(NULL, &def_root_domain, i);
synchronize_sched();
@@ -7773,13 +7739,14 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
*
* The passed in 'doms_new' should be kmalloc'd. This routine takes
* ownership of it and will kfree it when done with it. If the caller
- * failed the kmalloc call, then it can pass in doms_new == NULL,
- * and partition_sched_domains() will fallback to the single partition
- * 'fallback_doms', it also forces the domains to be rebuilt.
+ * failed the kmalloc call, then it can pass in doms_new == NULL &&
+ * ndoms_new == 1, and partition_sched_domains() will fallback to
+ * the single partition 'fallback_doms', it also forces the domains
+ * to be rebuilt.
*
- * If doms_new==NULL it will be replaced with cpu_online_map.
- * ndoms_new==0 is a special case for destroying existing domains.
- * It will not create the default domain.
+ * If doms_new == NULL it will be replaced with cpu_online_map.
+ * ndoms_new == 0 is a special case for destroying existing domains,
+ * and it will not create the default domain.
*
* Call with hotplug lock held
*/
@@ -7812,7 +7779,7 @@ match1:
ndoms_cur = 0;
doms_new = &fallback_doms;
cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map);
- dattr_new = NULL;
+ WARN_ON_ONCE(dattr_new);
}
/* Build new domains */
@@ -8472,7 +8439,7 @@ static
int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
{
struct cfs_rq *cfs_rq;
- struct sched_entity *se, *parent_se;
+ struct sched_entity *se;
struct rq *rq;
int i;
@@ -8488,18 +8455,17 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
for_each_possible_cpu(i) {
rq = cpu_rq(i);
- cfs_rq = kmalloc_node(sizeof(struct cfs_rq),
- GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
+ cfs_rq = kzalloc_node(sizeof(struct cfs_rq),
+ GFP_KERNEL, cpu_to_node(i));
if (!cfs_rq)
goto err;
- se = kmalloc_node(sizeof(struct sched_entity),
- GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
+ se = kzalloc_node(sizeof(struct sched_entity),
+ GFP_KERNEL, cpu_to_node(i));
if (!se)
goto err;
- parent_se = parent ? parent->se[i] : NULL;
- init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent_se);
+ init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]);
}
return 1;
@@ -8560,7 +8526,7 @@ static
int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
{
struct rt_rq *rt_rq;
- struct sched_rt_entity *rt_se, *parent_se;
+ struct sched_rt_entity *rt_se;
struct rq *rq;
int i;
@@ -8577,18 +8543,17 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
for_each_possible_cpu(i) {
rq = cpu_rq(i);
- rt_rq = kmalloc_node(sizeof(struct rt_rq),
- GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
+ rt_rq = kzalloc_node(sizeof(struct rt_rq),
+ GFP_KERNEL, cpu_to_node(i));
if (!rt_rq)
goto err;
- rt_se = kmalloc_node(sizeof(struct sched_rt_entity),
- GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
+ rt_se = kzalloc_node(sizeof(struct sched_rt_entity),
+ GFP_KERNEL, cpu_to_node(i));
if (!rt_se)
goto err;
- parent_se = parent ? parent->rt_se[i] : NULL;
- init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent_se);
+ init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]);
}
return 1;
@@ -9231,11 +9196,12 @@ struct cgroup_subsys cpu_cgroup_subsys = {
* (balbir@in.ibm.com).
*/
-/* track cpu usage of a group of tasks */
+/* track cpu usage of a group of tasks and its child groups */
struct cpuacct {
struct cgroup_subsys_state css;
/* cpuusage holds pointer to a u64-type object on every cpu */
u64 *cpuusage;
+ struct cpuacct *parent;
};
struct cgroup_subsys cpuacct_subsys;
@@ -9269,6 +9235,9 @@ static struct cgroup_subsys_state *cpuacct_create(
return ERR_PTR(-ENOMEM);
}
+ if (cgrp->parent)
+ ca->parent = cgroup_ca(cgrp->parent);
+
return &ca->css;
}
@@ -9348,14 +9317,16 @@ static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
static void cpuacct_charge(struct task_struct *tsk, u64 cputime)
{
struct cpuacct *ca;
+ int cpu;
if (!cpuacct_subsys.active)
return;
+ cpu = task_cpu(tsk);
ca = task_ca(tsk);
- if (ca) {
- u64 *cpuusage = percpu_ptr(ca->cpuusage, task_cpu(tsk));
+ for (; ca; ca = ca->parent) {
+ u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
*cpuusage += cputime;
}
}