diff options
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 103 |
1 files changed, 70 insertions, 33 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 4ee400f9d56..b44b9a43b0f 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) { |