[1/2] sched/deadline: Modify cpudl.free_cpus to reflect rd->span

Message ID 1416240664-7200-1-git-send-email-pang.xunlei@linaro.org
State New
Headers show

Commit Message

pang.xunlei Nov. 17, 2014, 4:11 p.m.
Currently, cpudl.free_cpus contains all cpus during init(see cpudl_init()),
so when calling cpudl_find() we have to add rd->span cpumask(cpus_allowed is
undependable when performing clustered scheduling using the cpuset) to avoid
selecting the cpu outside current root domain, see find_later_rq().

This patch adds cpudl_set_freecpu() to initialize cpudl.free_cpus when doing
rq_attach_root(), so we can avoid the extra rd->span operation when calling
cpudl_find().

Signed-off-by: pang.xunlei <pang.xunlei@linaro.org>
---
 kernel/sched/core.c        |  2 ++
 kernel/sched/cpudeadline.c | 19 +++++++++++++++----
 kernel/sched/cpudeadline.h |  1 +
 kernel/sched/deadline.c    |  3 ---
 4 files changed, 18 insertions(+), 7 deletions(-)
 mode change 100644 => 100755 kernel/sched/cpudeadline.c
 mode change 100644 => 100755 kernel/sched/deadline.c

Comments

Steven Rostedt Nov. 17, 2014, 7:39 p.m. | #1
On Tue, 18 Nov 2014 00:11:03 +0800

> index 539ca3c..9a69353
> --- a/kernel/sched/cpudeadline.c
> +++ b/kernel/sched/cpudeadline.c
> @@ -107,7 +107,9 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
>  	int best_cpu = -1;
>  	const struct sched_dl_entity *dl_se = &p->dl;
>  
> -	if (later_mask && cpumask_and(later_mask, later_mask, cp->free_cpus)) {
> +	if (later_mask && cpumask_and(later_mask, cp->free_cpus,
> +			&p->cpus_allowed) && cpumask_and(later_mask,
> +			later_mask, cpu_active_mask)) {

I did a quick review of this patch, and it looks fine to me. But the
above looks ugly. Please change it to something more readable like:

	if (later_mask &&
	    cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed) &&
	    cpumask_and(later_mask, later_mask, cpu_active_mask)) {

Thanks,

-- Steve


>  		best_cpu = cpumask_any(later_mask);
>  		goto out;
>  	} else if (cpumask_test_cpu(cpudl_maximum(cp), &p->cpus_allowed) &&
> @@ -186,6 +188,17 @@ out:
>  }
>  

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pang.xunlei Nov. 18, 2014, 1:32 p.m. | #2
On 18 November 2014 03:39, Steven Rostedt <rostedt@goodmis.org> wrote:
> On Tue, 18 Nov 2014 00:11:03 +0800
>
>> index 539ca3c..9a69353
>> --- a/kernel/sched/cpudeadline.c
>> +++ b/kernel/sched/cpudeadline.c
>> @@ -107,7 +107,9 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
>>       int best_cpu = -1;
>>       const struct sched_dl_entity *dl_se = &p->dl;
>>
>> -     if (later_mask && cpumask_and(later_mask, later_mask, cp->free_cpus)) {
>> +     if (later_mask && cpumask_and(later_mask, cp->free_cpus,
>> +                     &p->cpus_allowed) && cpumask_and(later_mask,
>> +                     later_mask, cpu_active_mask)) {
>
> I did a quick review of this patch, and it looks fine to me. But the
> above looks ugly. Please change it to something more readable like:

Yes, the following looks beautiful. I'll adjust it, thanks!
>
>         if (later_mask &&
>             cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed) &&
>             cpumask_and(later_mask, later_mask, cpu_active_mask)) {
>
> Thanks,
>
> -- Steve
>
>
>>               best_cpu = cpumask_any(later_mask);
>>               goto out;
>>       } else if (cpumask_test_cpu(cpudl_maximum(cp), &p->cpus_allowed) &&
>> @@ -186,6 +188,17 @@ out:
>>  }
>>
>
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Patch

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 240157c..1b417de 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5584,6 +5584,8 @@  static void rq_attach_root(struct rq *rq, struct root_domain *rd)
 	rq->rd = rd;
 
 	cpumask_set_cpu(rq->cpu, rd->span);
+	cpudl_set_freecpu(&rd->cpudl, rq->cpu);
+
 	if (cpumask_test_cpu(rq->cpu, cpu_active_mask))
 		set_rq_online(rq);
 
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
old mode 100644
new mode 100755
index 539ca3c..9a69353
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -107,7 +107,9 @@  int cpudl_find(struct cpudl *cp, struct task_struct *p,
 	int best_cpu = -1;
 	const struct sched_dl_entity *dl_se = &p->dl;
 
-	if (later_mask && cpumask_and(later_mask, later_mask, cp->free_cpus)) {
+	if (later_mask && cpumask_and(later_mask, cp->free_cpus,
+			&p->cpus_allowed) && cpumask_and(later_mask,
+			later_mask, cpu_active_mask)) {
 		best_cpu = cpumask_any(later_mask);
 		goto out;
 	} else if (cpumask_test_cpu(cpudl_maximum(cp), &p->cpus_allowed) &&
@@ -186,6 +188,17 @@  out:
 }
 
 /*
+ * cpudl_set_freecpu - Set the cpudl.free_cpus
+ * @cp: the cpudl max-heap context
+ * @cpu: rd attached cpu
+ */
+void cpudl_set_freecpu(struct cpudl *cp, int cpu)
+{
+	cpumask_set_cpu(cpu, cp->free_cpus);
+}
+
+
+/*
  * cpudl_init - initialize the cpudl structure
  * @cp: the cpudl max-heap context
  */
@@ -203,7 +216,7 @@  int cpudl_init(struct cpudl *cp)
 	if (!cp->elements)
 		return -ENOMEM;
 
-	if (!alloc_cpumask_var(&cp->free_cpus, GFP_KERNEL)) {
+	if (!zalloc_cpumask_var(&cp->free_cpus, GFP_KERNEL)) {
 		kfree(cp->elements);
 		return -ENOMEM;
 	}
@@ -211,8 +224,6 @@  int cpudl_init(struct cpudl *cp)
 	for_each_possible_cpu(i)
 		cp->elements[i].idx = IDX_INVALID;
 
-	cpumask_setall(cp->free_cpus);
-
 	return 0;
 }
 
diff --git a/kernel/sched/cpudeadline.h b/kernel/sched/cpudeadline.h
index 020039b..4a10a65 100755
--- a/kernel/sched/cpudeadline.h
+++ b/kernel/sched/cpudeadline.h
@@ -24,6 +24,7 @@  int cpudl_find(struct cpudl *cp, struct task_struct *p,
 	       struct cpumask *later_mask);
 void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid);
 int cpudl_init(struct cpudl *cp);
+void cpudl_set_freecpu(struct cpudl *cp, int cpu);
 void cpudl_cleanup(struct cpudl *cp);
 #endif /* CONFIG_SMP */
 
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
old mode 100644
new mode 100755
index 5285332..bd83272
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1187,9 +1187,6 @@  static int find_later_rq(struct task_struct *task)
 	 * We have to consider system topology and task affinity
 	 * first, then we can look for a suitable cpu.
 	 */
-	cpumask_copy(later_mask, task_rq(task)->rd->span);
-	cpumask_and(later_mask, later_mask, cpu_active_mask);
-	cpumask_and(later_mask, later_mask, &task->cpus_allowed);
 	best_cpu = cpudl_find(&task_rq(task)->rd->cpudl,
 			task, later_mask);
 	if (best_cpu == -1)