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sched: convert local_cpu_mask 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.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
hifive-unleashed-5.1
Rusty Russell 2008-11-25 02:35:13 +10:30 committed by Ingo Molnar
parent 24600ce89a
commit 0e3900e6d3
2 changed files with 12 additions and 2 deletions
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1
kernel/sched.c
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@ -8018,6 +8018,7 @@ void __init sched_init_smp(void)
free_cpumask_var(non_isolated_cpus);
alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
init_sched_rt_class();
}
#else
void __init sched_init_smp(void)

13
kernel/sched_rt.c
View File

@ -962,7 +962,7 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)
return next;
}
static DEFINE_PER_CPU(cpumask_t, local_cpu_mask);
static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);
static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
{
@ -982,7 +982,7 @@ static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
static int find_lowest_rq(struct task_struct *task)
{
struct sched_domain *sd;
cpumask_t *lowest_mask = &__get_cpu_var(local_cpu_mask);
cpumask_t *lowest_mask = __get_cpu_var(local_cpu_mask);
int this_cpu = smp_processor_id();
int cpu = task_cpu(task);
@ -1551,3 +1551,12 @@ static void print_rt_stats(struct seq_file *m, int cpu)
rcu_read_unlock();
}
#endif /* CONFIG_SCHED_DEBUG */
/* Note that this is never called for !SMP, but that's OK. */
static inline void init_sched_rt_class(void)
{
unsigned int i;
for_each_possible_cpu(i)
alloc_cpumask_var(&per_cpu(local_cpu_mask, i), GFP_KERNEL);
}