Index: linux-rt.git/kernel/sched_cpupri.c
===================================================================
--- linux-rt.git.orig/kernel/sched_cpupri.c
+++ linux-rt.git/kernel/sched_cpupri.c
@@ -122,8 +122,8 @@ static int convert_prio(int prio)
return cpupri;
}
-#define for_each_cpupri_active(array, idx) \
- for_each_set_bit(idx, array, CPUPRI_NR_PRIORITIES)
+#define for_each_cpupri_active(array, idx) \
+ for(idx = 0; (idx) < MAX_RT_PRIO; (idx)++)
/**
* cpupri_find - find the best (lowest-pri) CPU in the system
@@ -153,6 +153,13 @@ int cpupri_find(struct cpupri *cp, struc
if (idx >= task_pri)
break;
+ /*
+ * When a mask is updated, the new prio is set before
+ * the old prio is cleared. This makes sure that we
+ * don't miss this run queue.
+ */
+ smp_rmb();
+
if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids)
continue;
@@ -193,7 +200,6 @@ void cpupri_set(struct cpupri *cp, int c
{
int *currpri = &cp->cpu_to_pri[cpu];
int oldpri = *currpri;
- unsigned long flags;
newpri = convert_prio(newpri);
@@ -213,26 +219,17 @@ void cpupri_set(struct cpupri *cp, int c
if (likely(newpri != CPUPRI_INVALID)) {
struct cpupri_vec *vec = &cp->pri_to_cpu[newpri];
- raw_spin_lock_irqsave(&vec->lock, flags);
-
cpumask_set_cpu(cpu, vec->mask);
- vec->count++;
- if (vec->count == 1)
- set_bit(newpri, cp->pri_active);
-
- raw_spin_unlock_irqrestore(&vec->lock, flags);
}
+ /*
+ * Set the new prio before clearing the old prio so we
+ * don't miss this run queue during the loop.
+ */
+ smp_wmb();
if (likely(oldpri != CPUPRI_INVALID)) {
struct cpupri_vec *vec = &cp->pri_to_cpu[oldpri];
- raw_spin_lock_irqsave(&vec->lock, flags);
-
- vec->count--;
- if (!vec->count)
- clear_bit(oldpri, cp->pri_active);
cpumask_clear_cpu(cpu, vec->mask);
-
- raw_spin_unlock_irqrestore(&vec->lock, flags);
}
cpupri_stop_vec();
@@ -255,7 +252,6 @@ int cpupri_init(struct cpupri *cp)
for (i = 0; i < CPUPRI_NR_PRIORITIES; i++) {
struct cpupri_vec *vec = &cp->pri_to_cpu[i];
- raw_spin_lock_init(&vec->lock);
vec->count = 0;
if (!zalloc_cpumask_var(&vec->mask, GFP_KERNEL))
goto cleanup;
Index: linux-rt.git/kernel/sched_cpupri.h
===================================================================
--- linux-rt.git.orig/kernel/sched_cpupri.h
+++ linux-rt.git/kernel/sched_cpupri.h
@@ -12,7 +12,6 @@
/* values 2-101 are RT priorities 0-99 */
struct cpupri_vec {
- raw_spinlock_t lock;
int count;
cpumask_var_t mask;
};
--
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