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-rw-r--r--kernel/sched.c103
1 files changed, 70 insertions, 33 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 4ee400f9d56b..b44b9a43b0fc 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -51,6 +51,7 @@
#include <linux/times.h>
#include <linux/acct.h>
#include <linux/kprobes.h>
+#include <linux/delayacct.h>
#include <asm/tlb.h>
#include <asm/unistd.h>
@@ -501,9 +502,36 @@ struct file_operations proc_schedstat_operations = {
.release = single_release,
};
+/*
+ * Expects runqueue lock to be held for atomicity of update
+ */
+static inline void
+rq_sched_info_arrive(struct rq *rq, unsigned long delta_jiffies)
+{
+ if (rq) {
+ rq->rq_sched_info.run_delay += delta_jiffies;
+ rq->rq_sched_info.pcnt++;
+ }
+}
+
+/*
+ * Expects runqueue lock to be held for atomicity of update
+ */
+static inline void
+rq_sched_info_depart(struct rq *rq, unsigned long delta_jiffies)
+{
+ if (rq)
+ rq->rq_sched_info.cpu_time += delta_jiffies;
+}
# define schedstat_inc(rq, field) do { (rq)->field++; } while (0)
# define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0)
#else /* !CONFIG_SCHEDSTATS */
+static inline void
+rq_sched_info_arrive(struct rq *rq, unsigned long delta_jiffies)
+{}
+static inline void
+rq_sched_info_depart(struct rq *rq, unsigned long delta_jiffies)
+{}
# define schedstat_inc(rq, field) do { } while (0)
# define schedstat_add(rq, field, amt) do { } while (0)
#endif
@@ -523,7 +551,7 @@ static inline struct rq *this_rq_lock(void)
return rq;
}
-#ifdef CONFIG_SCHEDSTATS
+#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
/*
* Called when a process is dequeued from the active array and given
* the cpu. We should note that with the exception of interactive
@@ -551,21 +579,16 @@ static inline void sched_info_dequeued(struct task_struct *t)
*/
static void sched_info_arrive(struct task_struct *t)
{
- unsigned long now = jiffies, diff = 0;
- struct rq *rq = task_rq(t);
+ unsigned long now = jiffies, delta_jiffies = 0;
if (t->sched_info.last_queued)
- diff = now - t->sched_info.last_queued;
+ delta_jiffies = now - t->sched_info.last_queued;
sched_info_dequeued(t);
- t->sched_info.run_delay += diff;
+ t->sched_info.run_delay += delta_jiffies;
t->sched_info.last_arrival = now;
t->sched_info.pcnt++;
- if (!rq)
- return;
-
- rq->rq_sched_info.run_delay += diff;
- rq->rq_sched_info.pcnt++;
+ rq_sched_info_arrive(task_rq(t), delta_jiffies);
}
/*
@@ -585,8 +608,9 @@ static void sched_info_arrive(struct task_struct *t)
*/
static inline void sched_info_queued(struct task_struct *t)
{
- if (!t->sched_info.last_queued)
- t->sched_info.last_queued = jiffies;
+ if (unlikely(sched_info_on()))
+ if (!t->sched_info.last_queued)
+ t->sched_info.last_queued = jiffies;
}
/*
@@ -595,13 +619,10 @@ static inline void sched_info_queued(struct task_struct *t)
*/
static inline void sched_info_depart(struct task_struct *t)
{
- struct rq *rq = task_rq(t);
- unsigned long diff = jiffies - t->sched_info.last_arrival;
+ unsigned long delta_jiffies = jiffies - t->sched_info.last_arrival;
- t->sched_info.cpu_time += diff;
-
- if (rq)
- rq->rq_sched_info.cpu_time += diff;
+ t->sched_info.cpu_time += delta_jiffies;
+ rq_sched_info_depart(task_rq(t), delta_jiffies);
}
/*
@@ -610,7 +631,7 @@ static inline void sched_info_depart(struct task_struct *t)
* the idle task.) We are only called when prev != next.
*/
static inline void
-sched_info_switch(struct task_struct *prev, struct task_struct *next)
+__sched_info_switch(struct task_struct *prev, struct task_struct *next)
{
struct rq *rq = task_rq(prev);
@@ -625,10 +646,16 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next)
if (next != rq->idle)
sched_info_arrive(next);
}
+static inline void
+sched_info_switch(struct task_struct *prev, struct task_struct *next)
+{
+ if (unlikely(sched_info_on()))
+ __sched_info_switch(prev, next);
+}
#else
#define sched_info_queued(t) do { } while (0)
#define sched_info_switch(t, next) do { } while (0)
-#endif /* CONFIG_SCHEDSTATS */
+#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
/*
* Adding/removing a task to/from a priority array:
@@ -1530,8 +1557,9 @@ void fastcall sched_fork(struct task_struct *p, int clone_flags)
INIT_LIST_HEAD(&p->run_list);
p->array = NULL;
-#ifdef CONFIG_SCHEDSTATS
- memset(&p->sched_info, 0, sizeof(p->sched_info));
+#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
+ if (unlikely(sched_info_on()))
+ memset(&p->sched_info, 0, sizeof(p->sched_info));
#endif
#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
p->oncpu = 0;
@@ -1788,7 +1816,15 @@ context_switch(struct rq *rq, struct task_struct *prev,
WARN_ON(rq->prev_mm);
rq->prev_mm = oldmm;
}
+ /*
+ * Since the runqueue lock will be released by the next
+ * task (which is an invalid locking op but in the case
+ * of the scheduler it's an obvious special-case), so we
+ * do an early lockdep release here:
+ */
+#ifndef __ARCH_WANT_UNLOCKED_CTXSW
spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
+#endif
/* Here we just switch the register state and the stack. */
switch_to(prev, next, prev);
@@ -3384,7 +3420,7 @@ EXPORT_SYMBOL(schedule);
#ifdef CONFIG_PREEMPT
/*
- * this is is the entry point to schedule() from in-kernel preemption
+ * this is the entry point to schedule() from in-kernel preemption
* off of preempt_enable. Kernel preemptions off return from interrupt
* occur there and call schedule directly.
*/
@@ -3427,7 +3463,7 @@ need_resched:
EXPORT_SYMBOL(preempt_schedule);
/*
- * this is is the entry point to schedule() from kernel preemption
+ * this is the entry point to schedule() from kernel preemption
* off of irq context.
* Note, that this is called and return with irqs disabled. This will
* protect us against recursive calling from irq.
@@ -3439,7 +3475,7 @@ asmlinkage void __sched preempt_schedule_irq(void)
struct task_struct *task = current;
int saved_lock_depth;
#endif
- /* Catch callers which need to be fixed*/
+ /* Catch callers which need to be fixed */
BUG_ON(ti->preempt_count || !irqs_disabled());
need_resched:
@@ -4526,9 +4562,11 @@ void __sched io_schedule(void)
{
struct rq *rq = &__raw_get_cpu_var(runqueues);
+ delayacct_blkio_start();
atomic_inc(&rq->nr_iowait);
schedule();
atomic_dec(&rq->nr_iowait);
+ delayacct_blkio_end();
}
EXPORT_SYMBOL(io_schedule);
@@ -4537,9 +4575,11 @@ long __sched io_schedule_timeout(long timeout)
struct rq *rq = &__raw_get_cpu_var(runqueues);
long ret;
+ delayacct_blkio_start();
atomic_inc(&rq->nr_iowait);
ret = schedule_timeout(timeout);
atomic_dec(&rq->nr_iowait);
+ delayacct_blkio_end();
return ret;
}
@@ -4650,7 +4690,7 @@ static inline struct task_struct *younger_sibling(struct task_struct *p)
return list_entry(p->sibling.next,struct task_struct,sibling);
}
-static const char *stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
+static const char stat_nam[] = "RSDTtZX";
static void show_task(struct task_struct *p)
{
@@ -4658,12 +4698,9 @@ static void show_task(struct task_struct *p)
unsigned long free = 0;
unsigned state;
- printk("%-13.13s ", p->comm);
state = p->state ? __ffs(p->state) + 1 : 0;
- if (state < ARRAY_SIZE(stat_nam))
- printk(stat_nam[state]);
- else
- printk("?");
+ printk("%-13.13s %c", p->comm,
+ state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
#if (BITS_PER_LONG == 32)
if (state == TASK_RUNNING)
printk(" running ");
@@ -4877,7 +4914,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
p->timestamp = p->timestamp - rq_src->timestamp_last_tick
+ rq_dest->timestamp_last_tick;
deactivate_task(p, rq_src);
- activate_task(p, rq_dest, 0);
+ __activate_task(p, rq_dest);
if (TASK_PREEMPTS_CURR(p, rq_dest))
resched_task(rq_dest->curr);
}
@@ -5776,7 +5813,7 @@ static unsigned long long measure_migration_cost(int cpu1, int cpu2)
cache = vmalloc(max_size);
if (!cache) {
printk("could not vmalloc %d bytes for cache!\n", 2*max_size);
- return 1000000; // return 1 msec on very small boxen
+ return 1000000; /* return 1 msec on very small boxen */
}
while (size <= max_size) {