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>
This commit is contained in:
Rusty Russell 2008-11-25 02:35:05 +10:30 committed by Ingo Molnar
parent 6a7b3dc344
commit c6c4927b22
2 changed files with 64 additions and 31 deletions

View File

@ -487,14 +487,14 @@ struct rt_rq {
*/
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 @@ static void set_rq_online(struct rq *rq)
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 @@ static void set_rq_offline(struct rq *rq)
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 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
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 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
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 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
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 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd)
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 @@ static struct root_domain *alloc_rootdomain(void)
if (!rd)
return NULL;
init_rootdomain(rd);
if (init_rootdomain(rd, false) != 0) {
kfree(rd);
return NULL;
}
return rd;
}
@ -7632,7 +7665,7 @@ free_sched_groups:
#ifdef CONFIG_NUMA
error:
free_sched_groups(cpu_map, tmpmask);
kfree(rd);
free_rootdomain(rd);
goto free_tmpmask;
#endif
}

View File

@ -15,7 +15,7 @@ static inline void rt_set_overload(struct rq *rq)
if (!rq->online)
return;
cpu_set(rq->cpu, rq->rd->rto_mask);
cpumask_set_cpu(rq->cpu, rq->rd->rto_mask);
/*
* Make sure the mask is visible before we set
* the overload count. That is checked to determine
@ -34,7 +34,7 @@ static inline void rt_clear_overload(struct rq *rq)
/* the order here really doesn't matter */
atomic_dec(&rq->rd->rto_count);
cpu_clear(rq->cpu, rq->rd->rto_mask);
cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask);
}
static void update_rt_migration(struct rq *rq)
@ -139,14 +139,14 @@ static int rt_se_boosted(struct sched_rt_entity *rt_se)
}
#ifdef CONFIG_SMP
static inline cpumask_t sched_rt_period_mask(void)
static inline const struct cpumask *sched_rt_period_mask(void)
{
return cpu_rq(smp_processor_id())->rd->span;
}
#else
static inline cpumask_t sched_rt_period_mask(void)
static inline const struct cpumask *sched_rt_period_mask(void)
{
return cpu_online_map;
return cpu_online_mask;
}
#endif
@ -212,9 +212,9 @@ static inline int rt_rq_throttled(struct rt_rq *rt_rq)
return rt_rq->rt_throttled;
}
static inline cpumask_t sched_rt_period_mask(void)
static inline const struct cpumask *sched_rt_period_mask(void)
{
return cpu_online_map;
return cpu_online_mask;
}
static inline
@ -241,11 +241,11 @@ static int do_balance_runtime(struct rt_rq *rt_rq)
int i, weight, more = 0;
u64 rt_period;
weight = cpus_weight(rd->span);
weight = cpumask_weight(rd->span);
spin_lock(&rt_b->rt_runtime_lock);
rt_period = ktime_to_ns(rt_b->rt_period);
for_each_cpu_mask_nr(i, rd->span) {
for_each_cpu(i, rd->span) {
struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
s64 diff;
@ -324,7 +324,7 @@ static void __disable_runtime(struct rq *rq)
/*
* Greedy reclaim, take back as much as we can.
*/
for_each_cpu_mask(i, rd->span) {
for_each_cpu(i, rd->span) {
struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
s64 diff;
@ -429,13 +429,13 @@ static inline int balance_runtime(struct rt_rq *rt_rq)
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
{
int i, idle = 1;
cpumask_t span;
const struct cpumask *span;
if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
return 1;
span = sched_rt_period_mask();
for_each_cpu_mask(i, span) {
for_each_cpu(i, span) {
int enqueue = 0;
struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
struct rq *rq = rq_of_rt_rq(rt_rq);
@ -1181,7 +1181,7 @@ static int pull_rt_task(struct rq *this_rq)
next = pick_next_task_rt(this_rq);
for_each_cpu_mask_nr(cpu, this_rq->rd->rto_mask) {
for_each_cpu(cpu, this_rq->rd->rto_mask) {
if (this_cpu == cpu)
continue;