Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Simplify sys_sched_rr_get_interval() system call
  sched: Fix potential NULL derference of doms_cur
  sched: Fix raciness in runqueue_is_locked()
  sched: Re-add lost cpu_allowed check to sched_fair.c::select_task_rq_fair()
  sched: Remove unneeded indentation in sched_fair.c::place_entity()
This commit is contained in:
Linus Torvalds 2009-09-21 09:06:17 -07:00
commit 8e4bc3dd2c
6 changed files with 76 additions and 50 deletions

View file

@ -257,7 +257,7 @@ extern asmlinkage void schedule_tail(struct task_struct *prev);
extern void init_idle(struct task_struct *idle, int cpu);
extern void init_idle_bootup_task(struct task_struct *idle);
extern int runqueue_is_locked(void);
extern int runqueue_is_locked(int cpu);
extern void task_rq_unlock_wait(struct task_struct *p);
extern cpumask_var_t nohz_cpu_mask;
@ -1075,6 +1075,8 @@ struct sched_class {
void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
int oldprio, int running);
unsigned int (*get_rr_interval) (struct task_struct *task);
#ifdef CONFIG_FAIR_GROUP_SCHED
void (*moved_group) (struct task_struct *p);
#endif

View file

@ -681,15 +681,9 @@ inline void update_rq_clock(struct rq *rq)
* This interface allows printk to be called with the runqueue lock
* held and know whether or not it is OK to wake up the klogd.
*/
int runqueue_is_locked(void)
int runqueue_is_locked(int cpu)
{
int cpu = get_cpu();
struct rq *rq = cpu_rq(cpu);
int ret;
ret = spin_is_locked(&rq->lock);
put_cpu();
return ret;
return spin_is_locked(&cpu_rq(cpu)->lock);
}
/*
@ -6825,23 +6819,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
if (retval)
goto out_unlock;
/*
* Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER
* tasks that are on an otherwise idle runqueue:
*/
time_slice = 0;
if (p->policy == SCHED_RR) {
time_slice = DEF_TIMESLICE;
} else if (p->policy != SCHED_FIFO) {
struct sched_entity *se = &p->se;
unsigned long flags;
struct rq *rq;
time_slice = p->sched_class->get_rr_interval(p);
rq = task_rq_lock(p, &flags);
if (rq->cfs.load.weight)
time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
task_rq_unlock(rq, &flags);
}
read_unlock(&tasklist_lock);
jiffies_to_timespec(time_slice, &t);
retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
@ -9171,6 +9150,7 @@ void __init sched_init_smp(void)
cpumask_var_t non_isolated_cpus;
alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
#if defined(CONFIG_NUMA)
sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
@ -9202,7 +9182,6 @@ void __init sched_init_smp(void)
sched_init_granularity();
free_cpumask_var(non_isolated_cpus);
alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
init_sched_rt_class();
}
#else

View file

@ -710,31 +710,28 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
if (initial && sched_feat(START_DEBIT))
vruntime += sched_vslice(cfs_rq, se);
if (!initial) {
/* sleeps upto a single latency don't count. */
if (sched_feat(FAIR_SLEEPERS)) {
unsigned long thresh = sysctl_sched_latency;
/* sleeps up to a single latency don't count. */
if (!initial && sched_feat(FAIR_SLEEPERS)) {
unsigned long thresh = sysctl_sched_latency;
/*
* Convert the sleeper threshold into virtual time.
* SCHED_IDLE is a special sub-class. We care about
* fairness only relative to other SCHED_IDLE tasks,
* all of which have the same weight.
*/
if (sched_feat(NORMALIZED_SLEEPER) &&
(!entity_is_task(se) ||
task_of(se)->policy != SCHED_IDLE))
thresh = calc_delta_fair(thresh, se);
/*
* Convert the sleeper threshold into virtual time.
* SCHED_IDLE is a special sub-class. We care about
* fairness only relative to other SCHED_IDLE tasks,
* all of which have the same weight.
*/
if (sched_feat(NORMALIZED_SLEEPER) && (!entity_is_task(se) ||
task_of(se)->policy != SCHED_IDLE))
thresh = calc_delta_fair(thresh, se);
/*
* Halve their sleep time's effect, to allow
* for a gentler effect of sleepers:
*/
if (sched_feat(GENTLE_FAIR_SLEEPERS))
thresh >>= 1;
/*
* Halve their sleep time's effect, to allow
* for a gentler effect of sleepers:
*/
if (sched_feat(GENTLE_FAIR_SLEEPERS))
thresh >>= 1;
vruntime -= thresh;
}
vruntime -= thresh;
}
/* ensure we never gain time by being placed backwards. */
@ -1343,7 +1340,8 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
int sync = wake_flags & WF_SYNC;
if (sd_flag & SD_BALANCE_WAKE) {
if (sched_feat(AFFINE_WAKEUPS))
if (sched_feat(AFFINE_WAKEUPS) &&
cpumask_test_cpu(cpu, &p->cpus_allowed))
want_affine = 1;
new_cpu = prev_cpu;
}
@ -1941,6 +1939,25 @@ static void moved_group_fair(struct task_struct *p)
}
#endif
unsigned int get_rr_interval_fair(struct task_struct *task)
{
struct sched_entity *se = &task->se;
unsigned long flags;
struct rq *rq;
unsigned int rr_interval = 0;
/*
* Time slice is 0 for SCHED_OTHER tasks that are on an otherwise
* idle runqueue:
*/
rq = task_rq_lock(task, &flags);
if (rq->cfs.load.weight)
rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
task_rq_unlock(rq, &flags);
return rr_interval;
}
/*
* All the scheduling class methods:
*/
@ -1969,6 +1986,8 @@ static const struct sched_class fair_sched_class = {
.prio_changed = prio_changed_fair,
.switched_to = switched_to_fair,
.get_rr_interval = get_rr_interval_fair,
#ifdef CONFIG_FAIR_GROUP_SCHED
.moved_group = moved_group_fair,
#endif

View file

@ -97,6 +97,11 @@ static void prio_changed_idle(struct rq *rq, struct task_struct *p,
check_preempt_curr(rq, p, 0);
}
unsigned int get_rr_interval_idle(struct task_struct *task)
{
return 0;
}
/*
* Simple, special scheduling class for the per-CPU idle tasks:
*/
@ -122,6 +127,8 @@ static const struct sched_class idle_sched_class = {
.set_curr_task = set_curr_task_idle,
.task_tick = task_tick_idle,
.get_rr_interval = get_rr_interval_idle,
.prio_changed = prio_changed_idle,
.switched_to = switched_to_idle,

View file

@ -1734,6 +1734,17 @@ static void set_curr_task_rt(struct rq *rq)
dequeue_pushable_task(rq, p);
}
unsigned int get_rr_interval_rt(struct task_struct *task)
{
/*
* Time slice is 0 for SCHED_FIFO tasks
*/
if (task->policy == SCHED_RR)
return DEF_TIMESLICE;
else
return 0;
}
static const struct sched_class rt_sched_class = {
.next = &fair_sched_class,
.enqueue_task = enqueue_task_rt,
@ -1762,6 +1773,8 @@ static const struct sched_class rt_sched_class = {
.set_curr_task = set_curr_task_rt,
.task_tick = task_tick_rt,
.get_rr_interval = get_rr_interval_rt,
.prio_changed = prio_changed_rt,
.switched_to = switched_to_rt,
};

View file

@ -268,12 +268,18 @@ static DEFINE_SPINLOCK(tracing_start_lock);
*/
void trace_wake_up(void)
{
int cpu;
if (trace_flags & TRACE_ITER_BLOCK)
return;
/*
* The runqueue_is_locked() can fail, but this is the best we
* have for now:
*/
if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked())
cpu = get_cpu();
if (!runqueue_is_locked(cpu))
wake_up(&trace_wait);
put_cpu();
}
static int __init set_buf_size(char *str)