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authorRusty Russell <rusty@rustcorp.com.au>2008-11-24 11:05:13 -0500
committerIngo Molnar <mingo@elte.hu>2008-11-24 11:52:28 -0500
commit24600ce89a819a8f2fb4fd69fd777218a82ade20 (patch)
tree01a0e82bb6396b6f5de6300bd30d34e4fb0c76e7
parent68e74568fbe5854952355e942acca51f138096d9 (diff)
sched: convert check_preempt_equal_prio to cpumask_var_t.
Impact: stack reduction for large NR_CPUS Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves stack space. We simply return if the allocation fails: since we don't use it we could just pass NULL to cpupri_find and have it handle that. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/sched_rt.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 820fc422c6df..1fa13624293e 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -805,17 +805,20 @@ static int select_task_rq_rt(struct task_struct *p, int sync)
805 805
806static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) 806static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
807{ 807{
808 cpumask_t mask; 808 cpumask_var_t mask;
809 809
810 if (rq->curr->rt.nr_cpus_allowed == 1) 810 if (rq->curr->rt.nr_cpus_allowed == 1)
811 return; 811 return;
812 812
813 if (p->rt.nr_cpus_allowed != 1 813 if (!alloc_cpumask_var(&mask, GFP_ATOMIC))
814 && cpupri_find(&rq->rd->cpupri, p, &mask))
815 return; 814 return;
816 815
817 if (!cpupri_find(&rq->rd->cpupri, rq->curr, &mask)) 816 if (p->rt.nr_cpus_allowed != 1
818 return; 817 && cpupri_find(&rq->rd->cpupri, p, mask))
818 goto free;
819
820 if (!cpupri_find(&rq->rd->cpupri, rq->curr, mask))
821 goto free;
819 822
820 /* 823 /*
821 * There appears to be other cpus that can accept 824 * There appears to be other cpus that can accept
@@ -824,6 +827,8 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
824 */ 827 */
825 requeue_task_rt(rq, p, 1); 828 requeue_task_rt(rq, p, 1);
826 resched_task(rq->curr); 829 resched_task(rq->curr);
830free:
831 free_cpumask_var(mask);
827} 832}
828 833
829#endif /* CONFIG_SMP */ 834#endif /* CONFIG_SMP */