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authorIngo Molnar <mingo@elte.hu>2008-06-25 17:49:08 +0200
committerIngo Molnar <mingo@elte.hu>2008-06-25 17:49:08 +0200
commitc7e745c6de92a757ec525fbc9a74891651a5f1c6 (patch)
treec91b5dbb44adea2b2353e1fc0195582328561151 /kernel
parent688c91755dc3d3c03d8c67c1df13c02be258768e (diff)
parent543cf4cb3fe6f6cae3651ba918b9c56200b257d0 (diff)
downloadop-kernel-dev-c7e745c6de92a757ec525fbc9a74891651a5f1c6.zip
op-kernel-dev-c7e745c6de92a757ec525fbc9a74891651a5f1c6.tar.gz
Merge commit 'v2.6.26-rc8' into core/softlockup
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpuset.c10
-rw-r--r--kernel/futex.c93
-rw-r--r--kernel/kgdb.c3
-rw-r--r--kernel/rcupreempt.c2
-rw-r--r--kernel/sched.c48
-rw-r--r--kernel/sched_rt.c66
-rw-r--r--kernel/sched_stats.h6
7 files changed, 164 insertions, 64 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 039baa4..9fceb97 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1037,8 +1037,8 @@ int current_cpuset_is_being_rebound(void)
static int update_relax_domain_level(struct cpuset *cs, s64 val)
{
- if ((int)val < 0)
- val = -1;
+ if (val < -1 || val >= SD_LV_MAX)
+ return -EINVAL;
if (val != cs->relax_domain_level) {
cs->relax_domain_level = val;
@@ -1890,6 +1890,12 @@ static void common_cpu_mem_hotplug_unplug(void)
top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
scan_for_empty_cpusets(&top_cpuset);
+ /*
+ * Scheduler destroys domains on hotplug events.
+ * Rebuild them based on the current settings.
+ */
+ rebuild_sched_domains();
+
cgroup_unlock();
}
diff --git a/kernel/futex.c b/kernel/futex.c
index 449def8..7d1136e 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1096,21 +1096,64 @@ static void unqueue_me_pi(struct futex_q *q)
* private futexes.
*/
static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
- struct task_struct *newowner)
+ struct task_struct *newowner,
+ struct rw_semaphore *fshared)
{
u32 newtid = task_pid_vnr(newowner) | FUTEX_WAITERS;
struct futex_pi_state *pi_state = q->pi_state;
+ struct task_struct *oldowner = pi_state->owner;
u32 uval, curval, newval;
- int ret;
+ int ret, attempt = 0;
/* Owner died? */
+ if (!pi_state->owner)
+ newtid |= FUTEX_OWNER_DIED;
+
+ /*
+ * We are here either because we stole the rtmutex from the
+ * pending owner or we are the pending owner which failed to
+ * get the rtmutex. We have to replace the pending owner TID
+ * in the user space variable. This must be atomic as we have
+ * to preserve the owner died bit here.
+ *
+ * Note: We write the user space value _before_ changing the
+ * pi_state because we can fault here. Imagine swapped out
+ * pages or a fork, which was running right before we acquired
+ * mmap_sem, that marked all the anonymous memory readonly for
+ * cow.
+ *
+ * Modifying pi_state _before_ the user space value would
+ * leave the pi_state in an inconsistent state when we fault
+ * here, because we need to drop the hash bucket lock to
+ * handle the fault. This might be observed in the PID check
+ * in lookup_pi_state.
+ */
+retry:
+ if (get_futex_value_locked(&uval, uaddr))
+ goto handle_fault;
+
+ while (1) {
+ newval = (uval & FUTEX_OWNER_DIED) | newtid;
+
+ curval = cmpxchg_futex_value_locked(uaddr, uval, newval);
+
+ if (curval == -EFAULT)
+ goto handle_fault;
+ if (curval == uval)
+ break;
+ uval = curval;
+ }
+
+ /*
+ * We fixed up user space. Now we need to fix the pi_state
+ * itself.
+ */
if (pi_state->owner != NULL) {
spin_lock_irq(&pi_state->owner->pi_lock);
WARN_ON(list_empty(&pi_state->list));
list_del_init(&pi_state->list);
spin_unlock_irq(&pi_state->owner->pi_lock);
- } else
- newtid |= FUTEX_OWNER_DIED;
+ }
pi_state->owner = newowner;
@@ -1118,26 +1161,35 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
WARN_ON(!list_empty(&pi_state->list));
list_add(&pi_state->list, &newowner->pi_state_list);
spin_unlock_irq(&newowner->pi_lock);
+ return 0;
/*
- * We own it, so we have to replace the pending owner
- * TID. This must be atomic as we have preserve the
- * owner died bit here.
+ * To handle the page fault we need to drop the hash bucket
+ * lock here. That gives the other task (either the pending
+ * owner itself or the task which stole the rtmutex) the
+ * chance to try the fixup of the pi_state. So once we are
+ * back from handling the fault we need to check the pi_state
+ * after reacquiring the hash bucket lock and before trying to
+ * do another fixup. When the fixup has been done already we
+ * simply return.
*/
- ret = get_futex_value_locked(&uval, uaddr);
+handle_fault:
+ spin_unlock(q->lock_ptr);
- while (!ret) {
- newval = (uval & FUTEX_OWNER_DIED) | newtid;
+ ret = futex_handle_fault((unsigned long)uaddr, fshared, attempt++);
- curval = cmpxchg_futex_value_locked(uaddr, uval, newval);
+ spin_lock(q->lock_ptr);
- if (curval == -EFAULT)
- ret = -EFAULT;
- if (curval == uval)
- break;
- uval = curval;
- }
- return ret;
+ /*
+ * Check if someone else fixed it for us:
+ */
+ if (pi_state->owner != oldowner)
+ return 0;
+
+ if (ret)
+ return ret;
+
+ goto retry;
}
/*
@@ -1507,7 +1559,7 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
* that case:
*/
if (q.pi_state->owner != curr)
- ret = fixup_pi_state_owner(uaddr, &q, curr);
+ ret = fixup_pi_state_owner(uaddr, &q, curr, fshared);
} else {
/*
* Catch the rare case, where the lock was released
@@ -1539,7 +1591,8 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
int res;
owner = rt_mutex_owner(&q.pi_state->pi_mutex);
- res = fixup_pi_state_owner(uaddr, &q, owner);
+ res = fixup_pi_state_owner(uaddr, &q, owner,
+ fshared);
/* propagate -EFAULT, if the fixup failed */
if (res)
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index 79e3c90..3ec23c3 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -1499,7 +1499,8 @@ int kgdb_nmicallback(int cpu, void *regs)
return 1;
}
-void kgdb_console_write(struct console *co, const char *s, unsigned count)
+static void kgdb_console_write(struct console *co, const char *s,
+ unsigned count)
{
unsigned long flags;
diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c
index e1cdf19..5e02b774 100644
--- a/kernel/rcupreempt.c
+++ b/kernel/rcupreempt.c
@@ -217,8 +217,6 @@ long rcu_batches_completed(void)
}
EXPORT_SYMBOL_GPL(rcu_batches_completed);
-EXPORT_SYMBOL_GPL(rcu_batches_completed_bh);
-
void __rcu_read_lock(void)
{
int idx;
diff --git a/kernel/sched.c b/kernel/sched.c
index eaf6751..3aaa5c8 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1127,6 +1127,7 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer)
return HRTIMER_NORESTART;
}
+#ifdef CONFIG_SMP
static void hotplug_hrtick_disable(int cpu)
{
struct rq *rq = cpu_rq(cpu);
@@ -1182,6 +1183,7 @@ static void init_hrtick(void)
{
hotcpu_notifier(hotplug_hrtick, 0);
}
+#endif /* CONFIG_SMP */
static void init_rq_hrtick(struct rq *rq)
{
@@ -4396,22 +4398,20 @@ do_wait_for_common(struct completion *x, long timeout, int state)
signal_pending(current)) ||
(state == TASK_KILLABLE &&
fatal_signal_pending(current))) {
- __remove_wait_queue(&x->wait, &wait);
- return -ERESTARTSYS;
+ timeout = -ERESTARTSYS;
+ break;
}
__set_current_state(state);
spin_unlock_irq(&x->wait.lock);
timeout = schedule_timeout(timeout);
spin_lock_irq(&x->wait.lock);
- if (!timeout) {
- __remove_wait_queue(&x->wait, &wait);
- return timeout;
- }
- } while (!x->done);
+ } while (!x->done && timeout);
__remove_wait_queue(&x->wait, &wait);
+ if (!x->done)
+ return timeout;
}
x->done--;
- return timeout;
+ return timeout ?: 1;
}
static long __sched
@@ -6877,7 +6877,12 @@ static int default_relax_domain_level = -1;
static int __init setup_relax_domain_level(char *str)
{
- default_relax_domain_level = simple_strtoul(str, NULL, 0);
+ unsigned long val;
+
+ val = simple_strtoul(str, NULL, 0);
+ if (val < SD_LV_MAX)
+ default_relax_domain_level = val;
+
return 1;
}
__setup("relax_domain_level=", setup_relax_domain_level);
@@ -7236,6 +7241,18 @@ void __attribute__((weak)) arch_update_cpu_topology(void)
}
/*
+ * Free current domain masks.
+ * Called after all cpus are attached to NULL domain.
+ */
+static void free_sched_domains(void)
+{
+ ndoms_cur = 0;
+ if (doms_cur != &fallback_doms)
+ kfree(doms_cur);
+ doms_cur = &fallback_doms;
+}
+
+/*
* Set up scheduler domains and groups. Callers must hold the hotplug lock.
* For now this just excludes isolated cpus, but could be used to
* exclude other special cases in the future.
@@ -7382,6 +7399,7 @@ int arch_reinit_sched_domains(void)
get_online_cpus();
mutex_lock(&sched_domains_mutex);
detach_destroy_domains(&cpu_online_map);
+ free_sched_domains();
err = arch_init_sched_domains(&cpu_online_map);
mutex_unlock(&sched_domains_mutex);
put_online_cpus();
@@ -7467,6 +7485,7 @@ static int update_sched_domains(struct notifier_block *nfb,
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
detach_destroy_domains(&cpu_online_map);
+ free_sched_domains();
return NOTIFY_OK;
case CPU_UP_CANCELED:
@@ -7485,8 +7504,16 @@ static int update_sched_domains(struct notifier_block *nfb,
return NOTIFY_DONE;
}
+#ifndef CONFIG_CPUSETS
+ /*
+ * Create default domain partitioning if cpusets are disabled.
+ * Otherwise we let cpusets rebuild the domains based on the
+ * current setup.
+ */
+
/* The hotplug lock is already held by cpu_up/cpu_down */
arch_init_sched_domains(&cpu_online_map);
+#endif
return NOTIFY_OK;
}
@@ -7626,7 +7653,6 @@ static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
else
rt_se->rt_rq = parent->my_q;
- rt_se->rt_rq = &rq->rt;
rt_se->my_q = rt_rq;
rt_se->parent = parent;
INIT_LIST_HEAD(&rt_se->run_list);
@@ -8348,7 +8374,7 @@ static unsigned long to_ratio(u64 period, u64 runtime)
#ifdef CONFIG_CGROUP_SCHED
static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
{
- struct task_group *tgi, *parent = tg->parent;
+ struct task_group *tgi, *parent = tg ? tg->parent : NULL;
unsigned long total = 0;
if (!parent) {
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 3432d57..0f3c191 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -250,7 +250,8 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
if (rt_rq->rt_time || rt_rq->rt_nr_running)
idle = 0;
spin_unlock(&rt_rq->rt_runtime_lock);
- }
+ } else if (rt_rq->rt_nr_running)
+ idle = 0;
if (enqueue)
sched_rt_rq_enqueue(rt_rq);
@@ -449,13 +450,19 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
#endif
}
-static void enqueue_rt_entity(struct sched_rt_entity *rt_se)
+static void __enqueue_rt_entity(struct sched_rt_entity *rt_se)
{
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
struct rt_prio_array *array = &rt_rq->active;
struct rt_rq *group_rq = group_rt_rq(rt_se);
- if (group_rq && rt_rq_throttled(group_rq))
+ /*
+ * Don't enqueue the group if its throttled, or when empty.
+ * The latter is a consequence of the former when a child group
+ * get throttled and the current group doesn't have any other
+ * active members.
+ */
+ if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))
return;
list_add_tail(&rt_se->run_list, array->queue + rt_se_prio(rt_se));
@@ -464,7 +471,7 @@ static void enqueue_rt_entity(struct sched_rt_entity *rt_se)
inc_rt_tasks(rt_se, rt_rq);
}
-static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
+static void __dequeue_rt_entity(struct sched_rt_entity *rt_se)
{
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
struct rt_prio_array *array = &rt_rq->active;
@@ -480,11 +487,10 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
* Because the prio of an upper entry depends on the lower
* entries, we must remove entries top - down.
*/
-static void dequeue_rt_stack(struct task_struct *p)
+static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
{
- struct sched_rt_entity *rt_se, *back = NULL;
+ struct sched_rt_entity *back = NULL;
- rt_se = &p->rt;
for_each_sched_rt_entity(rt_se) {
rt_se->back = back;
back = rt_se;
@@ -492,7 +498,26 @@ static void dequeue_rt_stack(struct task_struct *p)
for (rt_se = back; rt_se; rt_se = rt_se->back) {
if (on_rt_rq(rt_se))
- dequeue_rt_entity(rt_se);
+ __dequeue_rt_entity(rt_se);
+ }
+}
+
+static void enqueue_rt_entity(struct sched_rt_entity *rt_se)
+{
+ dequeue_rt_stack(rt_se);
+ for_each_sched_rt_entity(rt_se)
+ __enqueue_rt_entity(rt_se);
+}
+
+static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
+{
+ dequeue_rt_stack(rt_se);
+
+ for_each_sched_rt_entity(rt_se) {
+ struct rt_rq *rt_rq = group_rt_rq(rt_se);
+
+ if (rt_rq && rt_rq->rt_nr_running)
+ __enqueue_rt_entity(rt_se);
}
}
@@ -506,32 +531,15 @@ static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
if (wakeup)
rt_se->timeout = 0;
- dequeue_rt_stack(p);
-
- /*
- * enqueue everybody, bottom - up.
- */
- for_each_sched_rt_entity(rt_se)
- enqueue_rt_entity(rt_se);
+ enqueue_rt_entity(rt_se);
}
static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
{
struct sched_rt_entity *rt_se = &p->rt;
- struct rt_rq *rt_rq;
update_curr_rt(rq);
-
- dequeue_rt_stack(p);
-
- /*
- * re-enqueue all non-empty rt_rq entities.
- */
- for_each_sched_rt_entity(rt_se) {
- rt_rq = group_rt_rq(rt_se);
- if (rt_rq && rt_rq->rt_nr_running)
- enqueue_rt_entity(rt_se);
- }
+ dequeue_rt_entity(rt_se);
}
/*
@@ -542,8 +550,10 @@ static
void requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se)
{
struct rt_prio_array *array = &rt_rq->active;
+ struct list_head *queue = array->queue + rt_se_prio(rt_se);
- list_move_tail(&rt_se->run_list, array->queue + rt_se_prio(rt_se));
+ if (on_rt_rq(rt_se))
+ list_move_tail(&rt_se->run_list, queue);
}
static void requeue_task_rt(struct rq *rq, struct task_struct *p)
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index a38878e..80179ef 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -198,6 +198,9 @@ static inline void sched_info_queued(struct task_struct *t)
/*
* Called when a process ceases being the active-running process, either
* voluntarily or involuntarily. Now we can calculate how long we ran.
+ * Also, if the process is still in the TASK_RUNNING state, call
+ * sched_info_queued() to mark that it has now again started waiting on
+ * the runqueue.
*/
static inline void sched_info_depart(struct task_struct *t)
{
@@ -206,6 +209,9 @@ static inline void sched_info_depart(struct task_struct *t)
t->sched_info.cpu_time += delta;
rq_sched_info_depart(task_rq(t), delta);
+
+ if (t->state == TASK_RUNNING)
+ sched_info_queued(t);
}
/*
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