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-rw-r--r--kernel/sched.c968
1 files changed, 394 insertions, 574 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index dc91a4d09ac3..a0eb0941fa84 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -75,9 +75,11 @@
#include <asm/tlb.h>
#include <asm/irq_regs.h>
+#include <asm/mutex.h>
#include "sched_cpupri.h"
#include "workqueue_sched.h"
+#include "sched_autogroup.h"
#define CREATE_TRACE_POINTS
#include <trace/events/sched.h>
@@ -253,6 +255,8 @@ struct task_group {
/* runqueue "owned" by this group on each cpu */
struct cfs_rq **cfs_rq;
unsigned long shares;
+
+ atomic_t load_weight;
#endif
#ifdef CONFIG_RT_GROUP_SCHED
@@ -268,25 +272,18 @@ struct task_group {
struct task_group *parent;
struct list_head siblings;
struct list_head children;
-};
-#define root_task_group init_task_group
+#ifdef CONFIG_SCHED_AUTOGROUP
+ struct autogroup *autogroup;
+#endif
+};
-/* task_group_lock serializes add/remove of task groups and also changes to
- * a task group's cpu shares.
- */
+/* task_group_lock serializes the addition/removal of task groups */
static DEFINE_SPINLOCK(task_group_lock);
#ifdef CONFIG_FAIR_GROUP_SCHED
-#ifdef CONFIG_SMP
-static int root_task_group_empty(void)
-{
- return list_empty(&root_task_group.children);
-}
-#endif
-
-# define INIT_TASK_GROUP_LOAD NICE_0_LOAD
+# define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
/*
* A weight of 0 or 1 can cause arithmetics problems.
@@ -299,13 +296,13 @@ static int root_task_group_empty(void)
#define MIN_SHARES 2
#define MAX_SHARES (1UL << 18)
-static int init_task_group_load = INIT_TASK_GROUP_LOAD;
+static int root_task_group_load = ROOT_TASK_GROUP_LOAD;
#endif
/* Default task group.
* Every task in system belong to this group at bootup.
*/
-struct task_group init_task_group;
+struct task_group root_task_group;
#endif /* CONFIG_CGROUP_SCHED */
@@ -342,6 +339,7 @@ struct cfs_rq {
* leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
* list is used during load balance.
*/
+ int on_list;
struct list_head leaf_cfs_rq_list;
struct task_group *tg; /* group that "owns" this runqueue */
@@ -360,14 +358,17 @@ struct cfs_rq {
unsigned long h_load;
/*
- * this cpu's part of tg->shares
+ * Maintaining per-cpu shares distribution for group scheduling
+ *
+ * load_stamp is the last time we updated the load average
+ * load_last is the last time we updated the load average and saw load
+ * load_unacc_exec_time is currently unaccounted execution time
*/
- unsigned long shares;
+ u64 load_avg;
+ u64 load_period;
+ u64 load_stamp, load_last, load_unacc_exec_time;
- /*
- * load.weight at the time we set shares
- */
- unsigned long rq_weight;
+ unsigned long load_contribution;
#endif
#endif
};
@@ -605,11 +606,14 @@ static inline int cpu_of(struct rq *rq)
*/
static inline struct task_group *task_group(struct task_struct *p)
{
+ struct task_group *tg;
struct cgroup_subsys_state *css;
css = task_subsys_state_check(p, cpu_cgroup_subsys_id,
lockdep_is_held(&task_rq(p)->lock));
- return container_of(css, struct task_group, css);
+ tg = container_of(css, struct task_group, css);
+
+ return autogroup_task_group(p, tg);
}
/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
@@ -636,22 +640,18 @@ static inline struct task_group *task_group(struct task_struct *p)
#endif /* CONFIG_CGROUP_SCHED */
-static u64 irq_time_cpu(int cpu);
-static void sched_irq_time_avg_update(struct rq *rq, u64 irq_time);
+static void update_rq_clock_task(struct rq *rq, s64 delta);
-inline void update_rq_clock(struct rq *rq)
+static void update_rq_clock(struct rq *rq)
{
- if (!rq->skip_clock_update) {
- int cpu = cpu_of(rq);
- u64 irq_time;
+ s64 delta;
- rq->clock = sched_clock_cpu(cpu);
- irq_time = irq_time_cpu(cpu);
- if (rq->clock - irq_time > rq->clock_task)
- rq->clock_task = rq->clock - irq_time;
+ if (rq->skip_clock_update)
+ return;
- sched_irq_time_avg_update(rq, irq_time);
- }
+ delta = sched_clock_cpu(cpu_of(rq)) - rq->clock;
+ rq->clock += delta;
+ update_rq_clock_task(rq, delta);
}
/*
@@ -741,7 +741,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
buf[cnt] = 0;
cmp = strstrip(buf);
- if (strncmp(buf, "NO_", 3) == 0) {
+ if (strncmp(cmp, "NO_", 3) == 0) {
neg = 1;
cmp += 3;
}
@@ -797,20 +797,6 @@ late_initcall(sched_init_debug);
const_debug unsigned int sysctl_sched_nr_migrate = 32;
/*
- * ratelimit for updating the group shares.
- * default: 0.25ms
- */
-unsigned int sysctl_sched_shares_ratelimit = 250000;
-unsigned int normalized_sysctl_sched_shares_ratelimit = 250000;
-
-/*
- * Inject some fuzzyness into changing the per-cpu group shares
- * this avoids remote rq-locks at the expense of fairness.
- * default: 4
- */
-unsigned int sysctl_sched_shares_thresh = 4;
-
-/*
* period over which we average the RT time consumption, measured
* in ms.
*
@@ -1359,6 +1345,12 @@ static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
lw->inv_weight = 0;
}
+static inline void update_load_set(struct load_weight *lw, unsigned long w)
+{
+ lw->weight = w;
+ lw->inv_weight = 0;
+}
+
/*
* To aid in avoiding the subversion of "niceness" due to uneven distribution
* of tasks with abnormal "nice" values across CPUs the contribution that
@@ -1547,101 +1539,6 @@ static unsigned long cpu_avg_load_per_task(int cpu)
#ifdef CONFIG_FAIR_GROUP_SCHED
-static __read_mostly unsigned long __percpu *update_shares_data;
-
-static void __set_se_shares(struct sched_entity *se, unsigned long shares);
-
-/*
- * Calculate and set the cpu's group shares.
- */
-static void update_group_shares_cpu(struct task_group *tg, int cpu,
- unsigned long sd_shares,
- unsigned long sd_rq_weight,
- unsigned long *usd_rq_weight)
-{
- unsigned long shares, rq_weight;
- int boost = 0;
-
- rq_weight = usd_rq_weight[cpu];
- if (!rq_weight) {
- boost = 1;
- rq_weight = NICE_0_LOAD;
- }
-
- /*
- * \Sum_j shares_j * rq_weight_i
- * shares_i = -----------------------------
- * \Sum_j rq_weight_j
- */
- 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) >
- sysctl_sched_shares_thresh) {
- struct rq *rq = cpu_rq(cpu);
- unsigned long flags;
-
- raw_spin_lock_irqsave(&rq->lock, flags);
- tg->cfs_rq[cpu]->rq_weight = boost ? 0 : rq_weight;
- tg->cfs_rq[cpu]->shares = boost ? 0 : shares;
- __set_se_shares(tg->se[cpu], shares);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
- }
-}
-
-/*
- * Re-compute the task group their per cpu shares over the given domain.
- * This needs to be done in a bottom-up fashion because the rq weight of a
- * parent group depends on the shares of its child groups.
- */
-static int tg_shares_up(struct task_group *tg, void *data)
-{
- unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0;
- unsigned long *usd_rq_weight;
- struct sched_domain *sd = data;
- unsigned long flags;
- int i;
-
- if (!tg->se[0])
- return 0;
-
- local_irq_save(flags);
- usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id());
-
- for_each_cpu(i, sched_domain_span(sd)) {
- weight = tg->cfs_rq[i]->load.weight;
- usd_rq_weight[i] = weight;
-
- rq_weight += 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 (!weight)
- weight = NICE_0_LOAD;
-
- sum_weight += weight;
- shares += tg->cfs_rq[i]->shares;
- }
-
- if (!rq_weight)
- rq_weight = sum_weight;
-
- if ((!shares && rq_weight) || shares > tg->shares)
- shares = tg->shares;
-
- if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE))
- shares = tg->shares;
-
- for_each_cpu(i, sched_domain_span(sd))
- update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight);
-
- local_irq_restore(flags);
-
- return 0;
-}
-
/*
* Compute the cpu's hierarchical load factor for each task group.
* This needs to be done in a top-down fashion because the load of a child
@@ -1656,7 +1553,7 @@ static int tg_load_down(struct task_group *tg, void *data)
load = cpu_rq(cpu)->load.weight;
} else {
load = tg->parent->cfs_rq[cpu]->h_load;
- load *= tg->cfs_rq[cpu]->shares;
+ load *= tg->se[cpu]->load.weight;
load /= tg->parent->cfs_rq[cpu]->load.weight + 1;
}
@@ -1665,34 +1562,11 @@ static int tg_load_down(struct task_group *tg, void *data)
return 0;
}
-static void update_shares(struct sched_domain *sd)
-{
- s64 elapsed;
- u64 now;
-
- if (root_task_group_empty())
- return;
-
- now = local_clock();
- elapsed = now - sd->last_update;
-
- if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) {
- sd->last_update = now;
- walk_tg_tree(tg_nop, tg_shares_up, sd);
- }
-}
-
static void update_h_load(long cpu)
{
walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
}
-#else
-
-static inline void update_shares(struct sched_domain *sd)
-{
-}
-
#endif
#ifdef CONFIG_PREEMPT
@@ -1814,15 +1688,6 @@ static void double_rq_unlock(struct rq *rq1, struct rq *rq2)
#endif
-#ifdef CONFIG_FAIR_GROUP_SCHED
-static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
-{
-#ifdef CONFIG_SMP
- cfs_rq->shares = shares;
-#endif
-}
-#endif
-
static void calc_load_account_idle(struct rq *this_rq);
static void update_sysctl(void);
static int get_update_sysctl_factor(void);
@@ -1924,10 +1789,9 @@ static void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
* They are read and saved off onto struct rq in update_rq_clock().
* This may result in other CPU reading this CPU's irq time and can
* race with irq/account_system_vtime on this CPU. We would either get old
- * or new value (or semi updated value on 32 bit) with a side effect of
- * accounting a slice of irq time to wrong task when irq is in progress
- * while we read rq->clock. That is a worthy compromise in place of having
- * locks on each irq in account_system_time.
+ * or new value with a side effect of accounting a slice of irq time to wrong
+ * task when irq is in progress while we read rq->clock. That is a worthy
+ * compromise in place of having locks on each irq in account_system_time.
*/
static DEFINE_PER_CPU(u64, cpu_hardirq_time);
static DEFINE_PER_CPU(u64, cpu_softirq_time);
@@ -1945,19 +1809,58 @@ void disable_sched_clock_irqtime(void)
sched_clock_irqtime = 0;
}
-static u64 irq_time_cpu(int cpu)
+#ifndef CONFIG_64BIT
+static DEFINE_PER_CPU(seqcount_t, irq_time_seq);
+
+static inline void irq_time_write_begin(void)
{
- if (!sched_clock_irqtime)
- return 0;
+ __this_cpu_inc(irq_time_seq.sequence);
+ smp_wmb();
+}
+
+static inline void irq_time_write_end(void)
+{
+ smp_wmb();
+ __this_cpu_inc(irq_time_seq.sequence);
+}
+
+static inline u64 irq_time_read(int cpu)
+{
+ u64 irq_time;
+ unsigned seq;
+
+ do {
+ seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
+ irq_time = per_cpu(cpu_softirq_time, cpu) +
+ per_cpu(cpu_hardirq_time, cpu);
+ } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));
+
+ return irq_time;
+}
+#else /* CONFIG_64BIT */
+static inline void irq_time_write_begin(void)
+{
+}
+static inline void irq_time_write_end(void)
+{
+}
+
+static inline u64 irq_time_read(int cpu)
+{
return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
}
+#endif /* CONFIG_64BIT */
+/*
+ * Called before incrementing preempt_count on {soft,}irq_enter
+ * and before decrementing preempt_count on {soft,}irq_exit.
+ */
void account_system_vtime(struct task_struct *curr)
{
unsigned long flags;
+ s64 delta;
int cpu;
- u64 now, delta;
if (!sched_clock_irqtime)
return;
@@ -1965,9 +1868,10 @@ void account_system_vtime(struct task_struct *curr)
local_irq_save(flags);
cpu = smp_processor_id();
- now = sched_clock_cpu(cpu);
- delta = now - per_cpu(irq_start_time, cpu);
- per_cpu(irq_start_time, cpu) = now;
+ delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time);
+ __this_cpu_add(irq_start_time, delta);
+
+ irq_time_write_begin();
/*
* We do not account for softirq time from ksoftirqd here.
* We want to continue accounting softirq time to ksoftirqd thread
@@ -1975,37 +1879,60 @@ void account_system_vtime(struct task_struct *curr)
* that do not consume any time, but still wants to run.
*/
if (hardirq_count())
- per_cpu(cpu_hardirq_time, cpu) += delta;
+ __this_cpu_add(cpu_hardirq_time, delta);
else if (in_serving_softirq() && !(curr->flags & PF_KSOFTIRQD))
- per_cpu(cpu_softirq_time, cpu) += delta;
+ __this_cpu_add(cpu_softirq_time, delta);
+ irq_time_write_end();
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(account_system_vtime);
-static void sched_irq_time_avg_update(struct rq *rq, u64 curr_irq_time)
+static void update_rq_clock_task(struct rq *rq, s64 delta)
{
- if (sched_clock_irqtime && sched_feat(NONIRQ_POWER)) {
- u64 delta_irq = curr_irq_time - rq->prev_irq_time;
- rq->prev_irq_time = curr_irq_time;
- sched_rt_avg_update(rq, delta_irq);
- }
+ s64 irq_delta;
+
+ irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time;
+
+ /*
+ * Since irq_time is only updated on {soft,}irq_exit, we might run into
+ * this case when a previous update_rq_clock() happened inside a
+ * {soft,}irq region.
+ *
+ * When this happens, we stop ->clock_task and only update the
+ * prev_irq_time stamp to account for the part that fit, so that a next
+ * update will consume the rest. This ensures ->clock_task is
+ * monotonic.
+ *
+ * It does however cause some slight miss-attribution of {soft,}irq
+ * time, a more accurate solution would be to update the irq_time using
+ * the current rq->clock timestamp, except that would require using
+ * atomic ops.
+ */
+ if (irq_delta > delta)
+ irq_delta = delta;
+
+ rq->prev_irq_time += irq_delta;
+ delta -= irq_delta;
+ rq->clock_task += delta;
+
+ if (irq_delta && sched_feat(NONIRQ_POWER))
+ sched_rt_avg_update(rq, irq_delta);
}
-#else
+#else /* CONFIG_IRQ_TIME_ACCOUNTING */
-static u64 irq_time_cpu(int cpu)
+static void update_rq_clock_task(struct rq *rq, s64 delta)
{
- return 0;
+ rq->clock_task += delta;
}
-static void sched_irq_time_avg_update(struct rq *rq, u64 curr_irq_time) { }
-
-#endif
+#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
#include "sched_idletask.c"
#include "sched_fair.c"
#include "sched_rt.c"
+#include "sched_autogroup.c"
#include "sched_stoptask.c"
#ifdef CONFIG_SCHED_DEBUG
# include "sched_debug.c"
@@ -2129,7 +2056,7 @@ static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
* A queue event has occurred, and we're going to schedule. In
* this case, we can save a useless back to back clock update.
*/
- if (test_tsk_need_resched(rq->curr))
+ if (rq->curr->se.on_rq && test_tsk_need_resched(rq->curr))
rq->skip_clock_update = 1;
}
@@ -2198,10 +2125,8 @@ static int migration_cpu_stop(void *data);
* The task's runqueue lock must be held.
* Returns true if you have to wait for migration thread.
*/
-static bool migrate_task(struct task_struct *p, int dest_cpu)
+static bool migrate_task(struct task_struct *p, struct rq *rq)
{
- struct rq *rq = task_rq(p);
-
/*
* If the task is not on a runqueue (and not running), then
* the next wake-up will properly place the task.
@@ -2381,18 +2306,15 @@ static int select_fallback_rq(int cpu, struct task_struct *p)
return dest_cpu;
/* No more Mr. Nice Guy. */
- if (unlikely(dest_cpu >= nr_cpu_ids)) {
- dest_cpu = cpuset_cpus_allowed_fallback(p);
- /*
- * Don't tell them about moving exiting tasks or
- * kernel threads (both mm NULL), since they never
- * leave kernel.
- */
- if (p->mm && printk_ratelimit()) {
- printk(KERN_INFO "process %d (%s) no "
- "longer affine to cpu%d\n",
- task_pid_nr(p), p->comm, cpu);
- }
+ dest_cpu = cpuset_cpus_allowed_fallback(p);
+ /*
+ * Don't tell them about moving exiting tasks or
+ * kernel threads (both mm NULL), since they never
+ * leave kernel.
+ */
+ if (p->mm && printk_ratelimit()) {
+ printk(KERN_INFO "process %d (%s) no longer affine to cpu%d\n",
+ task_pid_nr(p), p->comm, cpu);
}
return dest_cpu;
@@ -2728,7 +2650,9 @@ void sched_fork(struct task_struct *p, int clone_flags)
/* Want to start with kernel preemption disabled. */
task_thread_info(p)->preempt_count = 1;
#endif
+#ifdef CONFIG_SMP
plist_node_init(&p->pushable_tasks, MAX_PRIO);
+#endif
put_cpu();
}
@@ -3119,6 +3043,15 @@ static long calc_load_fold_active(struct rq *this_rq)
return delta;
}
+static unsigned long
+calc_load(unsigned long load, unsigned long exp, unsigned long active)
+{
+ load *= exp;
+ load += active * (FIXED_1 - exp);
+ load += 1UL << (FSHIFT - 1);
+ return load >> FSHIFT;
+}
+
#ifdef CONFIG_NO_HZ
/*
* For NO_HZ we delay the active fold to the next LOAD_FREQ update.
@@ -3148,6 +3081,128 @@ static long calc_load_fold_idle(void)
return delta;
}
+
+/**
+ * fixed_power_int - compute: x^n, in O(log n) time
+ *
+ * @x: base of the power
+ * @frac_bits: fractional bits of @x
+ * @n: power to raise @x to.
+ *
+ * By exploiting the relation between the definition of the natural power
+ * function: x^n := x*x*...*x (x multiplied by itself for n times), and
+ * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i,
+ * (where: n_i \elem {0, 1}, the binary vector representing n),
+ * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is
+ * of course trivially computable in O(log_2 n), the length of our binary
+ * vector.
+ */
+static unsigned long
+fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n)
+{
+ unsigned long result = 1UL << frac_bits;
+
+ if (n) for (;;) {
+ if (n & 1) {
+ result *= x;
+ result += 1UL << (frac_bits - 1);
+ result >>= frac_bits;
+ }
+ n >>= 1;
+ if (!n)
+ break;
+ x *= x;
+ x += 1UL << (frac_bits - 1);
+ x >>= frac_bits;
+ }
+
+ return result;
+}
+
+/*
+ * a1 = a0 * e + a * (1 - e)
+ *
+ * a2 = a1 * e + a * (1 - e)
+ * = (a0 * e + a * (1 - e)) * e + a * (1 - e)
+ * = a0 * e^2 + a * (1 - e) * (1 + e)
+ *
+ * a3 = a2 * e + a * (1 - e)
+ * = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e)
+ * = a0 * e^3 + a * (1 - e) * (1 + e + e^2)
+ *
+ * ...
+ *
+ * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1]
+ * = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e)
+ * = a0 * e^n + a * (1 - e^n)
+ *
+ * [1] application of the geometric series:
+ *
+ * n 1 - x^(n+1)
+ * S_n := \Sum x^i = -------------
+ * i=0 1 - x
+ */
+static unsigned long
+calc_load_n(unsigned long load, unsigned long exp,
+ unsigned long active, unsigned int n)
+{
+
+ return calc_load(load, fixed_power_int(exp, FSHIFT, n), active);
+}
+
+/*
+ * NO_HZ can leave us missing all per-cpu ticks calling
+ * calc_load_account_active(), but since an idle CPU folds its delta into
+ * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold
+ * in the pending idle delta if our idle period crossed a load cycle boundary.
+ *
+ * Once we've updated the global active value, we need to apply the exponential
+ * weights adjusted to the number of cycles missed.
+ */
+static void calc_global_nohz(unsigned long ticks)
+{
+ long delta, active, n;
+
+ if (time_before(jiffies, calc_load_update))
+ return;
+
+ /*
+ * If we crossed a calc_load_update boundary, make sure to fold
+ * any pending idle changes, the respective CPUs might have
+ * missed the tick driven calc_load_account_active() update
+ * due to NO_HZ.
+ */
+ delta = calc_load_fold_idle();
+ if (delta)
+ atomic_long_add(delta, &calc_load_tasks);
+
+ /*
+ * If we were idle for multiple load cycles, apply them.
+ */
+ if (ticks >= LOAD_FREQ) {
+ n = ticks / LOAD_FREQ;
+
+ active = atomic_long_read(&calc_load_tasks);
+ active = active > 0 ? active * FIXED_1 : 0;
+
+ avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n);
+ avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n);
+ avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);
+
+ calc_load_update += n * LOAD_FREQ;
+ }
+
+ /*
+ * Its possible the remainder of the above division also crosses
+ * a LOAD_FREQ period, the regular check in calc_global_load()
+ * which comes after this will take care of that.
+ *
+ * Consider us being 11 ticks before a cycle completion, and us
+ * sleeping for 4*LOAD_FREQ + 22 ticks, then the above code will
+ * age us 4 cycles, and the test in calc_global_load() will
+ * pick up the final one.
+ */
+}
#else
static void calc_load_account_idle(struct rq *this_rq)
{
@@ -3157,6 +3212,10 @@ static inline long calc_load_fold_idle(void)
{
return 0;
}
+
+static void calc_global_nohz(unsigned long ticks)
+{
+}
#endif
/**
@@ -3174,24 +3233,17 @@ void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
loads[2] = (avenrun[2] + offset) << shift;
}
-static unsigned long
-calc_load(unsigned long load, unsigned long exp, unsigned long active)
-{
- load *= exp;
- load += active * (FIXED_1 - exp);
- return load >> FSHIFT;
-}
-
/*
* calc_load - update the avenrun load estimates 10 ticks after the
* CPUs have updated calc_load_tasks.
*/
-void calc_global_load(void)
+void calc_global_load(unsigned long ticks)
{
- unsigned long upd = calc_load_update + 10;
long active;
- if (time_before(jiffies, upd))
+ calc_global_nohz(ticks);
+
+ if (time_before(jiffies, calc_load_update + 10))
return;
active = atomic_long_read(&calc_load_tasks);
@@ -3364,7 +3416,7 @@ void sched_exec(void)
* select_task_rq() can race against ->cpus_allowed
*/
if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed) &&
- likely(cpu_active(dest_cpu)) && migrate_task(p, dest_cpu)) {
+ likely(cpu_active(dest_cpu)) && migrate_task(p, rq)) {
struct migration_arg arg = { p, dest_cpu };
task_rq_unlock(rq, &flags);
@@ -3845,7 +3897,6 @@ static void put_prev_task(struct rq *rq, struct task_struct *prev)
{
if (prev->se.on_rq)
update_rq_clock(rq);
- rq->skip_clock_update = 0;
prev->sched_class->put_prev_task(rq, prev);
}
@@ -3903,7 +3954,6 @@ need_resched_nonpreemptible:
hrtick_clear(rq);
raw_spin_lock_irq(&rq->lock);
- clear_tsk_need_resched(prev);
switch_count = &prev->nivcsw;
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
@@ -3935,6 +3985,8 @@ need_resched_nonpreemptible:
put_prev_task(rq, prev);
next = pick_next_task(rq);
+ clear_tsk_need_resched(prev);
+ rq->skip_clock_update = 0;
if (likely(prev != next)) {
sched_info_switch(prev, next);
@@ -4029,7 +4081,7 @@ int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
if (task_thread_info(rq->curr) != owner || need_resched())
return 0;
- cpu_relax();
+ arch_mutex_cpu_relax();
}
return 1;
@@ -4341,7 +4393,7 @@ EXPORT_SYMBOL(wait_for_completion_interruptible);
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. It is interruptible. The timeout is in jiffies.
*/
-unsigned long __sched
+long __sched
wait_for_completion_interruptible_timeout(struct completion *x,
unsigned long timeout)
{
@@ -4374,7 +4426,7 @@ EXPORT_SYMBOL(wait_for_completion_killable);
* signaled or for a specified timeout to expire. It can be
* interrupted by a kill signal. The timeout is in jiffies.
*/
-unsigned long __sched
+long __sched
wait_for_completion_killable_timeout(struct completion *x,
unsigned long timeout)
{
@@ -4716,7 +4768,7 @@ static bool check_same_owner(struct task_struct *p)
}
static int __sched_setscheduler(struct task_struct *p, int policy,
- struct sched_param *param, bool user)
+ const struct sched_param *param, bool user)
{
int retval, oldprio, oldpolicy = -1, on_rq, running;
unsigned long flags;
@@ -4871,7 +4923,7 @@ recheck:
* NOTE that the task may be already dead.
*/
int sched_setscheduler(struct task_struct *p, int policy,
- struct sched_param *param)
+ const struct sched_param *param)
{
return __sched_setscheduler(p, policy, param, true);
}
@@ -4889,7 +4941,7 @@ EXPORT_SYMBOL_GPL(sched_setscheduler);
* but our caller might not have that capability.
*/
int sched_setscheduler_nocheck(struct task_struct *p, int policy,
- struct sched_param *param)
+ const struct sched_param *param)
{
return __sched_setscheduler(p, policy, param, false);
}
@@ -5405,7 +5457,7 @@ void sched_show_task(struct task_struct *p)
unsigned state;
state = p->state ? __ffs(p->state) + 1 : 0;
- printk(KERN_INFO "%-13.13s %c", p->comm,
+ printk(KERN_INFO "%-15.15s %c", p->comm,
state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
#if BITS_PER_LONG == 32
if (state == TASK_RUNNING)
@@ -5569,7 +5621,6 @@ static void update_sysctl(void)
SET_SYSCTL(sched_min_granularity);
SET_SYSCTL(sched_latency);
SET_SYSCTL(sched_wakeup_granularity);
- SET_SYSCTL(sched_shares_ratelimit);
#undef SET_SYSCTL
}
@@ -5645,7 +5696,7 @@ again:
goto out;
dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
- if (migrate_task(p, dest_cpu)) {
+ if (migrate_task(p, rq)) {
struct migration_arg arg = { p, dest_cpu };
/* Need help from migration thread: drop lock and wait. */
task_rq_unlock(rq, &flags);
@@ -5727,29 +5778,20 @@ static int migration_cpu_stop(void *data)
}
#ifdef CONFIG_HOTPLUG_CPU
+
/*
- * Figure out where task on dead CPU should go, use force if necessary.
+ * Ensures that the idle task is using init_mm right before its cpu goes
+ * offline.
*/
-void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
+void idle_task_exit(void)
{
- struct rq *rq = cpu_rq(dead_cpu);
- int needs_cpu, uninitialized_var(dest_cpu);
- unsigned long flags;
+ struct mm_struct *mm = current->active_mm;
- local_irq_save(flags);
+ BUG_ON(cpu_online(smp_processor_id()));
- raw_spin_lock(&rq->lock);
- needs_cpu = (task_cpu(p) == dead_cpu) && (p->state != TASK_WAKING);
- if (needs_cpu)
- dest_cpu = select_fallback_rq(dead_cpu, p);
- raw_spin_unlock(&rq->lock);
- /*
- * It can only fail if we race with set_cpus_allowed(),
- * in the racer should migrate the task anyway.
- */
- if (needs_cpu)
- __migrate_task(p, dead_cpu, dest_cpu);
- local_irq_restore(flags);
+ if (mm != &init_mm)
+ switch_mm(mm, &init_mm, current);
+ mmdrop(mm);
}
/*
@@ -5762,128 +5804,69 @@ void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
static void migrate_nr_uninterruptible(struct rq *rq_src)
{
struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask));
- unsigned long flags;
- local_irq_save(flags);
- double_rq_lock(rq_src, rq_dest);
rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible;
rq_src->nr_uninterruptible = 0;
- double_rq_unlock(rq_src, rq_dest);
- local_irq_restore(flags);
-}
-
-/* Run through task list and migrate tasks from the dead cpu. */
-static void migrate_live_tasks(int src_cpu)
-{
- struct task_struct *p, *t;
-
- read_lock(&tasklist_lock);
-
- do_each_thread(t, p) {
- if (p == current)
- continue;
-
- if (task_cpu(p) == src_cpu)
- move_task_off_dead_cpu(src_cpu, p);
- } while_each_thread(t, p);
-
- read_unlock(&tasklist_lock);
}
/*
- * Schedules idle task to be the next runnable task on current CPU.
- * It does so by boosting its priority to highest possible.
- * Used by CPU offline code.
+ * remove the tasks which were accounted by rq from calc_load_tasks.
*/
-void sched_idle_next(void)
+static void calc_global_load_remove(struct rq *rq)
{
- int this_cpu = smp_processor_id();
- struct rq *rq = cpu_rq(this_cpu);
- struct task_struct *p = rq->idle;
- unsigned long flags;
-
- /* cpu has to be offline */
- BUG_ON(cpu_online(this_cpu));
-
- /*
- * Strictly not necessary since rest of the CPUs are stopped by now
- * and interrupts disabled on the current cpu.
- */
- raw_spin_lock_irqsave(&rq->lock, flags);
-
- __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
-
- activate_task(rq, p, 0);
-
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ atomic_long_sub(rq->calc_load_active, &calc_load_tasks);
+ rq->calc_load_active = 0;
}
/*
- * Ensures that the idle task is using init_mm right before its cpu goes
- * offline.
+ * Migrate all tasks from the rq, sleeping tasks will be migrated by
+ * try_to_wake_up()->select_task_rq().
+ *
+ * Called with rq->lock held even though we'er in stop_machine() and
+ * there's no concurrency possible, we hold the required locks anyway
+ * because of lock validation efforts.
*/
-void idle_task_exit(void)
-{
- struct mm_struct *mm = current->active_mm;
-
- BUG_ON(cpu_online(smp_processor_id()));
-
- if (mm != &init_mm)
- switch_mm(mm, &init_mm, current);
- mmdrop(mm);
-}
-
-/* called under rq->lock with disabled interrupts */
-static void migrate_dead(unsigned int dead_cpu, struct task_struct *p)
+static void migrate_tasks(unsigned int dead_cpu)
{
struct rq *rq = cpu_rq(dead_cpu);
-
- /* Must be exiting, otherwise would be on tasklist. */
- BUG_ON(!p->exit_state);
-
- /* Cannot have done final schedule yet: would have vanished. */
- BUG_ON(p->state == TASK_DEAD);
-
- get_task_struct(p);
+ struct task_struct *next, *stop = rq->stop;
+ int dest_cpu;
/*
- * Drop lock around migration; if someone else moves it,
- * that's OK. No task can be added to this CPU, so iteration is
- * fine.
+ * Fudge the rq selection such that the below task selection loop
+ * doesn't get stuck on the currently eligible stop task.
+ *
+ * We're currently inside stop_machine() and the rq is either stuck
+ * in the stop_machine_cpu_stop() loop, or we're executing this code,
+ * either way we should never end up calling schedule() until we're
+ * done here.
*/
- raw_spin_unlock_irq(&rq->lock);
- move_task_off_dead_cpu(dead_cpu, p);
- raw_spin_lock_irq(&rq->lock);
-
- put_task_struct(p);
-}
-
-/* release_task() removes task from tasklist, so we won't find dead tasks. */
-static void migrate_dead_tasks(unsigned int dead_cpu)
-{
- struct rq *rq = cpu_rq(dead_cpu);
- struct task_struct *next;
+ rq->stop = NULL;
for ( ; ; ) {
- if (!rq->nr_running)
+ /*
+ * There's this thread running, bail when that's the only
+ * remaining thread.
+ */
+ if (rq->nr_running == 1)
break;
+
next = pick_next_task(rq);
- if (!next)
- break;
+ BUG_ON(!next);
next->sched_class->put_prev_task(rq, next);
- migrate_dead(dead_cpu, next);
+ /* Find suitable destination for @next, with force if needed. */
+ dest_cpu = select_fallback_rq(dead_cpu, next);
+ raw_spin_unlock(&rq->lock);
+
+ __migrate_task(next, dead_cpu, dest_cpu);
+
+ raw_spin_lock(&rq->lock);
}
-}
-/*
- * remove the tasks which were accounted by rq from calc_load_tasks.
- */
-static void calc_global_load_remove(struct rq *rq)
-{
- atomic_long_sub(rq->calc_load_active, &calc_load_tasks);
- rq->calc_load_active = 0;
+ rq->stop = stop;
}
+
#endif /* CONFIG_HOTPLUG_CPU */
#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
@@ -6093,15 +6076,13 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
unsigned long flags;
struct rq *rq = cpu_rq(cpu);
- switch (action) {
+ switch (action & ~CPU_TASKS_FROZEN) {
case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
rq->calc_load_update = calc_load_update;
break;
case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
/* Update our root-domain */
raw_spin_lock_irqsave(&rq->lock, flags);
if (rq->rd) {
@@ -6113,30 +6094,19 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
break;
#ifdef CONFIG_HOTPLUG_CPU
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- migrate_live_tasks(cpu);
- /* Idle task back to normal (off runqueue, low prio) */
- raw_spin_lock_irq(&rq->lock);
- deactivate_task(rq, rq->idle, 0);
- __setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
- rq->idle->sched_class = &idle_sched_class;
- migrate_dead_tasks(cpu);
- raw_spin_unlock_irq(&rq->lock);
- migrate_nr_uninterruptible(rq);
- BUG_ON(rq->nr_running != 0);
- calc_global_load_remove(rq);
- break;
-
case CPU_DYING:
- case CPU_DYING_FROZEN:
/* Update our root-domain */
raw_spin_lock_irqsave(&rq->lock, flags);
if (rq->rd) {
BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
set_rq_offline(rq);
}
+ migrate_tasks(cpu);
+ BUG_ON(rq->nr_running != 1); /* the migration thread */
raw_spin_unlock_irqrestore(&rq->lock, flags);
+
+ migrate_nr_uninterruptible(rq);
+ calc_global_load_remove(rq);
break;
#endif
}
@@ -7867,18 +7837,16 @@ static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
#ifdef CONFIG_FAIR_GROUP_SCHED
static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
- struct sched_entity *se, int cpu, int add,
+ struct sched_entity *se, int cpu,
struct sched_entity *parent)
{
struct rq *rq = cpu_rq(cpu);
tg->cfs_rq[cpu] = cfs_rq;
init_cfs_rq(cfs_rq, rq);
cfs_rq->tg = tg;
- if (add)
- list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list);
tg->se[cpu] = se;
- /* se could be NULL for init_task_group */
+ /* se could be NULL for root_task_group */
if (!se)
return;
@@ -7888,15 +7856,14 @@ static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
se->cfs_rq = parent->my_q;
se->my_q = cfs_rq;
- se->load.weight = tg->shares;
- se->load.inv_weight = 0;
+ update_load_set(&se->load, 0);
se->parent = parent;
}
#endif
#ifdef CONFIG_RT_GROUP_SCHED
static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
- struct sched_rt_entity *rt_se, int cpu, int add,
+ struct sched_rt_entity *rt_se, int cpu,
struct sched_rt_entity *parent)
{
struct rq *rq = cpu_rq(cpu);
@@ -7905,8 +7872,6 @@ static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
init_rt_rq(rt_rq, rq);
rt_rq->tg = tg;
rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime;
- if (add)
- list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list);
tg->rt_se[cpu] = rt_se;
if (!rt_se)
@@ -7941,18 +7906,18 @@ void __init sched_init(void)
ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
#ifdef CONFIG_FAIR_GROUP_SCHED
- init_task_group.se = (struct sched_entity **)ptr;
+ root_task_group.se = (struct sched_entity **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
- init_task_group.cfs_rq = (struct cfs_rq **)ptr;
+ root_task_group.cfs_rq = (struct cfs_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
- init_task_group.rt_se = (struct sched_rt_entity **)ptr;
+ root_task_group.rt_se = (struct sched_rt_entity **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
- init_task_group.rt_rq = (struct rt_rq **)ptr;
+ root_task_group.rt_rq = (struct rt_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
#endif /* CONFIG_RT_GROUP_SCHED */
@@ -7972,20 +7937,16 @@ void __init sched_init(void)
global_rt_period(), global_rt_runtime());
#ifdef CONFIG_RT_GROUP_SCHED
- init_rt_bandwidth(&init_task_group.rt_bandwidth,
+ init_rt_bandwidth(&root_task_group.rt_bandwidth,
global_rt_period(), global_rt_runtime());
#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_CGROUP_SCHED
- list_add(&init_task_group.list, &task_groups);
- INIT_LIST_HEAD(&init_task_group.children);
-
+ list_add(&root_task_group.list, &task_groups);
+ INIT_LIST_HEAD(&root_task_group.children);
+ autogroup_init(&init_task);
#endif /* CONFIG_CGROUP_SCHED */
-#if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP
- update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long),
- __alignof__(unsigned long));
-#endif
for_each_possible_cpu(i) {
struct rq *rq;
@@ -7997,38 +7958,34 @@ void __init sched_init(void)
init_cfs_rq(&rq->cfs, rq);
init_rt_rq(&rq->rt, rq);
#ifdef CONFIG_FAIR_GROUP_SCHED
- init_task_group.shares = init_task_group_load;
+ root_task_group.shares = root_task_group_load;
INIT_LIST_HEAD(&rq->leaf_cfs_rq_list);
-#ifdef CONFIG_CGROUP_SCHED
/*
- * How much cpu bandwidth does init_task_group get?
+ * How much cpu bandwidth does root_task_group get?
*
* In case of task-groups formed thr' the cgroup filesystem, it
* gets 100% of the cpu resources in the system. This overall
* system cpu resource is divided among the tasks of
- * init_task_group and its child task-groups in a fair manner,
+ * root_task_group and its child task-groups in a fair manner,
* based on each entity's (task or task-group's) weight
* (se->load.weight).
*
- * In other words, if init_task_group has 10 tasks of weight
+ * In other words, if root_task_group has 10 tasks of weight
* 1024) and two child groups A0 and A1 (of weight 1024 each),
* then A0's share of the cpu resource is:
*
* A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33%
*
- * We achieve this by letting init_task_group's tasks sit
- * directly in rq->cfs (i.e init_task_group->se[] = NULL).
+ * We achieve this by letting root_task_group's tasks sit
+ * directly in rq->cfs (i.e root_task_group->se[] = NULL).
*/
- init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL);
-#endif
+ init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL);
#endif /* CONFIG_FAIR_GROUP_SCHED */
rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime;
#ifdef CONFIG_RT_GROUP_SCHED
INIT_LIST_HEAD(&rq->leaf_rt_rq_list);
-#ifdef CONFIG_CGROUP_SCHED
- init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL);
-#endif
+ init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL);
#endif
for (j = 0; j < CPU_LOAD_IDX_MAX; j++)
@@ -8108,8 +8065,6 @@ void __init sched_init(void)
zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
#endif /* SMP */
- perf_event_init();
-
scheduler_running = 1;
}
@@ -8303,7 +8258,7 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
if (!se)
goto err_free_rq;
- init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]);
+ init_tg_cfs_entry(tg, cfs_rq, se, i, parent->se[i]);
}
return 1;
@@ -8314,15 +8269,21 @@ err:
return 0;
}
-static inline void register_fair_sched_group(struct task_group *tg, int cpu)
-{
- list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list,
- &cpu_rq(cpu)->leaf_cfs_rq_list);
-}
-
static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
{
- list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list);
+ struct rq *rq = cpu_rq(cpu);
+ unsigned long flags;
+
+ /*
+ * Only empty task groups can be destroyed; so we can speculatively
+ * check on_list without danger of it being re-added.
+ */
+ if (!tg->cfs_rq[cpu]->on_list)
+ return;
+
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ list_del_leaf_cfs_rq(tg->cfs_rq[cpu]);
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
}
#else /* !CONFG_FAIR_GROUP_SCHED */
static inline void free_fair_sched_group(struct task_group *tg)
@@ -8335,10 +8296,6 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
return 1;
}
-static inline void register_fair_sched_group(struct task_group *tg, int cpu)
-{
-}
-
static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
{
}
@@ -8393,7 +8350,7 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
if (!rt_se)
goto err_free_rq;
- init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]);
+ init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]);
}
return 1;
@@ -8403,17 +8360,6 @@ err_free_rq:
err:
return 0;
}
-
-static inline void register_rt_sched_group(struct task_group *tg, int cpu)
-{
- list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list,
- &cpu_rq(cpu)->leaf_rt_rq_list);
-}
-
-static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
-{
- list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list);
-}
#else /* !CONFIG_RT_GROUP_SCHED */
static inline void free_rt_sched_group(struct task_group *tg)
{
@@ -8424,14 +8370,6 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
{
return 1;
}
-
-static inline void register_rt_sched_group(struct task_group *tg, int cpu)
-{
-}
-
-static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
-{
-}
#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_CGROUP_SCHED
@@ -8439,6 +8377,7 @@ static void free_sched_group(struct task_group *tg)
{
free_fair_sched_group(tg);
free_rt_sched_group(tg);
+ autogroup_free(tg);
kfree(tg);
}
@@ -8447,7 +8386,6 @@ struct task_group *sched_create_group(struct task_group *parent)
{
struct task_group *tg;
unsigned long flags;
- int i;
tg = kzalloc(sizeof(*tg), GFP_KERNEL);
if (!tg)
@@ -8460,10 +8398,6 @@ struct task_group *sched_create_group(struct task_group *parent)
goto err;
spin_lock_irqsave(&task_group_lock, flags);
- for_each_possible_cpu(i) {
- register_fair_sched_group(tg, i);
- register_rt_sched_group(tg, i);
- }
list_add_rcu(&tg->list, &task_groups);
WARN_ON(!parent); /* root should already exist */
@@ -8493,11 +8427,11 @@ void sched_destroy_group(struct task_group *tg)
unsigned long flags;
int i;
- spin_lock_irqsave(&task_group_lock, flags);
- for_each_possible_cpu(i) {
+ /* end participation in shares distribution */
+ for_each_possible_cpu(i)
unregister_fair_sched_group(tg, i);
- unregister_rt_sched_group(tg, i);
- }
+
+ spin_lock_irqsave(&task_group_lock, flags);
list_del_rcu(&tg->list);
list_del_rcu(&tg->siblings);
spin_unlock_irqrestore(&task_group_lock, flags);
@@ -8544,33 +8478,6 @@ void sched_move_task(struct task_struct *tsk)
#endif /* CONFIG_CGROUP_SCHED */
#ifdef CONFIG_FAIR_GROUP_SCHED
-static void __set_se_shares(struct sched_entity *se, unsigned long shares)
-{
- struct cfs_rq *cfs_rq = se->cfs_rq;
- int on_rq;
-
- on_rq = se->on_rq;
- if (on_rq)
- dequeue_entity(cfs_rq, se, 0);
-
- se->load.weight = shares;
- se->load.inv_weight = 0;
-
- if (on_rq)
- enqueue_entity(cfs_rq, se, 0);
-}
-
-static void set_se_shares(struct sched_entity *se, unsigned long shares)
-{
- struct cfs_rq *cfs_rq = se->cfs_rq;
- struct rq *rq = cfs_rq->rq;
- unsigned long flags;
-
- raw_spin_lock_irqsave(&rq->lock, flags);
- __set_se_shares(se, shares);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
-}
-
static DEFINE_MUTEX(shares_mutex);
int sched_group_set_shares(struct task_group *tg, unsigned long shares)
@@ -8593,37 +8500,19 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
if (tg->shares == shares)
goto done;
- spin_lock_irqsave(&task_group_lock, flags);
- for_each_possible_cpu(i)
- unregister_fair_sched_group(tg, i);
- list_del_rcu(&tg->siblings);
- spin_unlock_irqrestore(&task_group_lock, flags);
-
- /* wait for any ongoing reference to this group to finish */
- synchronize_sched();
-
- /*
- * Now we are free to modify the group's share on each cpu
- * w/o tripping rebalance_share or load_balance_fair.
- */
tg->shares = shares;
for_each_possible_cpu(i) {
- /*
- * force a rebalance
- */
- cfs_rq_set_shares(tg->cfs_rq[i], 0);
- set_se_shares(tg->se[i], shares);
+ struct rq *rq = cpu_rq(i);
+ struct sched_entity *se;
+
+ se = tg->se[i];
+ /* Propagate contribution to hierarchy */
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ for_each_sched_entity(se)
+ update_cfs_shares(group_cfs_rq(se), 0);
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
}
- /*
- * Enable load balance activity on this group, by inserting it back on
- * each cpu's rq->leaf_cfs_rq_list.
- */
- spin_lock_irqsave(&task_group_lock, flags);
- for_each_possible_cpu(i)
- register_fair_sched_group(tg, i);
- list_add_rcu(&tg->siblings, &tg->parent->children);
- spin_unlock_irqrestore(&task_group_lock, flags);
done:
mutex_unlock(&shares_mutex);
return 0;
@@ -8922,7 +8811,7 @@ cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
if (!cgrp->parent) {
/* This is early initialization for the top cgroup */
- return &init_task_group.css;
+ return &root_task_group.css;
}
parent = cgroup_tg(cgrp->parent);
@@ -9349,72 +9238,3 @@ struct cgroup_subsys cpuacct_subsys = {
};
#endif /* CONFIG_CGROUP_CPUACCT */
-#ifndef CONFIG_SMP
-
-void synchronize_sched_expedited(void)
-{
- barrier();
-}
-EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
-
-#else /* #ifndef CONFIG_SMP */
-
-static atomic_t synchronize_sched_expedited_count = ATOMIC_INIT(0);
-
-static int synchronize_sched_expedited_cpu_stop(void *data)
-{
- /*
- * There must be a full memory barrier on each affected CPU
- * between the time that try_stop_cpus() is called and the
- * time that it returns.
- *
- * In the current initial implementation of cpu_stop, the
- * above condition is already met when the control reaches
- * this point and the following smp_mb() is not strictly
- * necessary. Do smp_mb() anyway for documentation and
- * robustness against future implementation changes.
- */
- smp_mb(); /* See above comment block. */
- return 0;
-}
-
-/*
- * Wait for an rcu-sched grace period to elapse, but use "big hammer"
- * approach to force grace period to end quickly. This consumes
- * significant time on all CPUs, and is thus not recommended for
- * any sort of common-case code.
- *
- * Note that it is illegal to call this function while holding any
- * lock that is acquired by a CPU-hotplug notifier. Failing to
- * observe this restriction will result in deadlock.
- */
-void synchronize_sched_expedited(void)
-{
- int snap, trycount = 0;
-
- smp_mb(); /* ensure prior mod happens before capturing snap. */
- snap = atomic_read(&synchronize_sched_expedited_count) + 1;
- get_online_cpus();
- while (try_stop_cpus(cpu_online_mask,
- synchronize_sched_expedited_cpu_stop,
- NULL) == -EAGAIN) {
- put_online_cpus();
- if (trycount++ < 10)
- udelay(trycount * num_online_cpus());
- else {
- synchronize_sched();
- return;
- }
- if (atomic_read(&synchronize_sched_expedited_count) - snap > 0) {
- smp_mb(); /* ensure test happens before caller kfree */
- return;
- }
- get_online_cpus();
- }
- atomic_inc(&synchronize_sched_expedited_count);
- smp_mb__after_atomic_inc(); /* ensure post-GP actions seen after GP. */
- put_online_cpus();
-}
-EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
-
-#endif /* #else #ifndef CONFIG_SMP */