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

* '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()

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8af3d249170e07f2e03d131540a0bc7b0f00f962..239c8e0dba9f9b9ce33a7f5a56ce89659478933a 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -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

diff --git a/kernel/sched.c b/kernel/sched.c
index faf4d463bbffb9a561beed93bd59282ea7c7092e..830967e1828568435b90e0a0cb0f158a6c0a3768 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -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

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 990b188803ced00f8b3554bb1fe570b14b716c69..ecc637a0d591b74ced8c17eea315631296b0b205 100644 (file)
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -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

diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index a8b448af004b4361402d8146af596e44898641ba..b133a28fcde32cbf20421f077686c14319871f74 100644 (file)
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -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,
 

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 13de7126a6abebca2e2c6bdaede88fcaadca25de..a4d790cddb1983196ba9881936d8abf7a8870dbe 100644 (file)
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -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,
 };

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 861308072d2883bc3826d5023e82ec0c6d0d326d..a35925d222baa5b8b31f54c86327e605552c1ec9 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -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)