if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids)
continue;
- if (lowest_mask)
+ if (lowest_mask) {
cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask);
+
+ /*
+ * We have to ensure that we have at least one bit
+ * still set in the array, since the map could have
+ * been concurrently emptied between the first and
+ * second reads of vec->mask. If we hit this
+ * condition, simply act as though we never hit this
+ * priority level and continue on.
+ */
+ if (cpumask_any(lowest_mask) >= nr_cpu_ids)
+ continue;
+ }
+
return 1;
}
/*
* If the cpu was currently mapped to a different value, we
- * first need to unmap the old value
+ * need to map it to the new value then remove the old value.
+ * Note, we must add the new value first, otherwise we risk the
+ * cpu being cleared from pri_active, and this cpu could be
+ * missed for a push or pull.
*/
- if (likely(oldpri != CPUPRI_INVALID)) {
- struct cpupri_vec *vec = &cp->pri_to_cpu[oldpri];
-
- spin_lock_irqsave(&vec->lock, flags);
-
- vec->count--;
- if (!vec->count)
- clear_bit(oldpri, cp->pri_active);
- cpumask_clear_cpu(cpu, vec->mask);
-
- spin_unlock_irqrestore(&vec->lock, flags);
- }
-
if (likely(newpri != CPUPRI_INVALID)) {
struct cpupri_vec *vec = &cp->pri_to_cpu[newpri];
- spin_lock_irqsave(&vec->lock, flags);
+ 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);
- spin_unlock_irqrestore(&vec->lock, flags);
+ raw_spin_unlock_irqrestore(&vec->lock, flags);
+ }
+ 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);
}
*currpri = newpri;
*
* Returns: -ENOMEM if memory fails.
*/
-int __init_refok cpupri_init(struct cpupri *cp, bool bootmem)
+int cpupri_init(struct cpupri *cp, bool bootmem)
{
+ gfp_t gfp = GFP_KERNEL;
int i;
+ if (bootmem)
+ gfp = GFP_NOWAIT;
+
memset(cp, 0, sizeof(*cp));
for (i = 0; i < CPUPRI_NR_PRIORITIES; i++) {
struct cpupri_vec *vec = &cp->pri_to_cpu[i];
- spin_lock_init(&vec->lock);
+ raw_spin_lock_init(&vec->lock);
vec->count = 0;
- if (bootmem)
- alloc_bootmem_cpumask_var(&vec->mask);
- else if (!alloc_cpumask_var(&vec->mask, GFP_KERNEL))
+ if (!zalloc_cpumask_var(&vec->mask, gfp))
goto cleanup;
}