sched: convert struct root_domain to cpumask_var_t.
Impact: (future) size reduction for large NR_CPUS.
Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves
space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t
is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK.
def_root_domain is static, and so its masks are initialized with
alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 2723d7a..93309c3 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -487,14 +487,14 @@
*/
struct root_domain {
atomic_t refcount;
- cpumask_t span;
- cpumask_t online;
+ cpumask_var_t span;
+ cpumask_var_t online;
/*
* The "RT overload" flag: it gets set if a CPU has more than
* one runnable RT task.
*/
- cpumask_t rto_mask;
+ cpumask_var_t rto_mask;
atomic_t rto_count;
#ifdef CONFIG_SMP
struct cpupri cpupri;
@@ -6444,7 +6444,7 @@
if (!rq->online) {
const struct sched_class *class;
- cpu_set(rq->cpu, rq->rd->online);
+ cpumask_set_cpu(rq->cpu, rq->rd->online);
rq->online = 1;
for_each_class(class) {
@@ -6464,7 +6464,7 @@
class->rq_offline(rq);
}
- cpu_clear(rq->cpu, rq->rd->online);
+ cpumask_clear_cpu(rq->cpu, rq->rd->online);
rq->online = 0;
}
}
@@ -6505,7 +6505,7 @@
rq = cpu_rq(cpu);
spin_lock_irqsave(&rq->lock, flags);
if (rq->rd) {
- BUG_ON(!cpu_isset(cpu, rq->rd->span));
+ BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
set_rq_online(rq);
}
@@ -6567,7 +6567,7 @@
rq = cpu_rq(cpu);
spin_lock_irqsave(&rq->lock, flags);
if (rq->rd) {
- BUG_ON(!cpu_isset(cpu, rq->rd->span));
+ BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
set_rq_offline(rq);
}
spin_unlock_irqrestore(&rq->lock, flags);
@@ -6768,6 +6768,14 @@
return 1;
}
+static void free_rootdomain(struct root_domain *rd)
+{
+ free_cpumask_var(rd->rto_mask);
+ free_cpumask_var(rd->online);
+ free_cpumask_var(rd->span);
+ kfree(rd);
+}
+
static void rq_attach_root(struct rq *rq, struct root_domain *rd)
{
unsigned long flags;
@@ -6777,38 +6785,60 @@
if (rq->rd) {
struct root_domain *old_rd = rq->rd;
- if (cpu_isset(rq->cpu, old_rd->online))
+ if (cpumask_test_cpu(rq->cpu, old_rd->online))
set_rq_offline(rq);
- cpu_clear(rq->cpu, old_rd->span);
+ cpumask_clear_cpu(rq->cpu, old_rd->span);
if (atomic_dec_and_test(&old_rd->refcount))
- kfree(old_rd);
+ free_rootdomain(old_rd);
}
atomic_inc(&rd->refcount);
rq->rd = rd;
- cpu_set(rq->cpu, rd->span);
- if (cpu_isset(rq->cpu, cpu_online_map))
+ cpumask_set_cpu(rq->cpu, rd->span);
+ if (cpumask_test_cpu(rq->cpu, cpu_online_mask))
set_rq_online(rq);
spin_unlock_irqrestore(&rq->lock, flags);
}
-static void init_rootdomain(struct root_domain *rd)
+static int init_rootdomain(struct root_domain *rd, bool bootmem)
{
memset(rd, 0, sizeof(*rd));
- cpus_clear(rd->span);
- cpus_clear(rd->online);
+ if (bootmem) {
+ alloc_bootmem_cpumask_var(&def_root_domain.span);
+ alloc_bootmem_cpumask_var(&def_root_domain.online);
+ alloc_bootmem_cpumask_var(&def_root_domain.rto_mask);
+ cpupri_init(&rd->cpupri);
+ return 0;
+ }
+
+ if (!alloc_cpumask_var(&rd->span, GFP_KERNEL))
+ goto free_rd;
+ if (!alloc_cpumask_var(&rd->online, GFP_KERNEL))
+ goto free_span;
+ if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
+ goto free_online;
cpupri_init(&rd->cpupri);
+ return 0;
+
+free_online:
+ free_cpumask_var(rd->online);
+free_span:
+ free_cpumask_var(rd->span);
+free_rd:
+ kfree(rd);
+ return -ENOMEM;
}
static void init_defrootdomain(void)
{
- init_rootdomain(&def_root_domain);
+ init_rootdomain(&def_root_domain, true);
+
atomic_set(&def_root_domain.refcount, 1);
}
@@ -6820,7 +6850,10 @@
if (!rd)
return NULL;
- init_rootdomain(rd);
+ if (init_rootdomain(rd, false) != 0) {
+ kfree(rd);
+ return NULL;
+ }
return rd;
}
@@ -7632,7 +7665,7 @@
#ifdef CONFIG_NUMA
error:
free_sched_groups(cpu_map, tmpmask);
- kfree(rd);
+ free_rootdomain(rd);
goto free_tmpmask;
#endif
}