Messages in this thread Patch in this message | | | From | Rusty Russell <> | Subject | [PATCH] sched_rt: don't allocate cpumask in fastpath | Date | Wed, 25 Mar 2009 15:01:22 +1030 |
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Impact: cleanup
As pointed out by Steven Rostedt. Since the arg in question is unused, we simply change cpupri_find() to accept NULL.
Cc: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- kernel/sched_cpupri.c | 5 +++-- kernel/sched_rt.c | 15 ++++----------- 2 files changed, 7 insertions(+), 13 deletions(-)
diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c --- a/kernel/sched_cpupri.c +++ b/kernel/sched_cpupri.c @@ -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, struc 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; } diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -805,20 +805,15 @@ static int select_task_rq_rt(struct task 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(str */ requeue_task_rt(rq, p, 1); resched_task(rq->curr); -free: - free_cpumask_var(mask); } #endif /* CONFIG_SMP */
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