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| author | Rusty Russell <rusty@rustcorp.com.au> | 2008-11-25 02:35:13 +1030 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-24 17:52:28 +0100 |
| commit | 24600ce89a819a8f2fb4fd69fd777218a82ade20 (patch) | |
| tree | 01a0e82bb6396b6f5de6300bd30d34e4fb0c76e7 | |
| parent | 68e74568fbe5854952355e942acca51f138096d9 (diff) | |
| download | linux-24600ce89a819a8f2fb4fd69fd777218a82ade20.tar.gz linux-24600ce89a819a8f2fb4fd69fd777218a82ade20.tar.bz2 linux-24600ce89a819a8f2fb4fd69fd777218a82ade20.zip | |
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.c | 15 |
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) static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) { - cpumask_t mask; + cpumask_var_t mask; if (rq->curr->rt.nr_cpus_allowed == 1) return; - if (p->rt.nr_cpus_allowed != 1 - && cpupri_find(&rq->rd->cpupri, p, &mask)) + if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) return; - if (!cpupri_find(&rq->rd->cpupri, rq->curr, &mask)) - return; + if (p->rt.nr_cpus_allowed != 1 + && cpupri_find(&rq->rd->cpupri, p, mask)) + goto free; + + if (!cpupri_find(&rq->rd->cpupri, rq->curr, mask)) + goto free; /* * 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) */ requeue_task_rt(rq, p, 1); resched_task(rq->curr); +free: + free_cpumask_var(mask); } #endif /* CONFIG_SMP */ |