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sched_rt: don't allocate cpumask in fastpath 

Impact: cleanup

As pointed out by Steven Rostedt.  Since the arg in question is
unused, we simply change cpupri_find() to accept NULL.

Reported-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <200903251501.22664.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
hifive-unleashed-5.1
Rusty Russell 2009-03-25 15:01:22 +10:30 committed by Ingo Molnar
parent a18b83b7ef
commit 13b8bd0a57
2 changed files with 7 additions and 13 deletions
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5
kernel/sched_cpupri.c
View File

@ -55,7 +55,7 @@ static int convert_prio(int prio)
* cpupri_find - find the best (lowest-pri) CPU in the system
* @cp: The cpupri context
* @p: The task
* @lowest_mask: A mask to fill in with selected CPUs
* @lowest_mask: A mask to fill in with selected CPUs (or NULL)
*
* Note: This function returns the recommended CPUs as calculated during the
* current invokation. By the time the call returns, the CPUs may have in
@ -81,7 +81,8 @@ int cpupri_find(struct cpupri *cp, struct task_struct *p,
if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids)
continue;
cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask);
if (lowest_mask)
cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask);
return 1;
}

15
kernel/sched_rt.c
View File

@ -805,20 +805,15 @@ 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_var_t mask;
if (rq->curr->rt.nr_cpus_allowed == 1)
return;
if (!alloc_cpumask_var(&mask, GFP_ATOMIC))
if (p->rt.nr_cpus_allowed != 1
&& cpupri_find(&rq->rd->cpupri, p, NULL))
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;
if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
return;
/*
* There appears to be other cpus that can accept
@ -827,8 +822,6 @@ 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 */