diff mbox

[v5,04/12] sched: Allow all archs to set the capacity_orig

Message ID 20140910135039.GP3190@worktop.ger.corp.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Peter Zijlstra Sept. 10, 2014, 1:50 p.m. UTC 
On Sat, Aug 30, 2014 at 10:37:40PM +0530, Preeti U Murthy wrote:
> > -	if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) {
> > -		if (sched_feat(ARCH_CAPACITY))
> 
> Aren't you missing this check above? I understand that it is not
> crucial, but that would also mean removing ARCH_CAPACITY sched_feat
> altogether, wouldn't it?

Yes he's missing that, I added the below bit on top.

So the argument last time:
lkml.kernel.org/r/20140709105721.GT19379@twins.programming.kicks-ass.net
was that you cannot put sched_feat(ARCH_CAPACITY) inside a weak arch_*
function. The test has to be outside, seeing how it needs to decide to
call the arch function at all (or revert to the default implementation).

---

Comments

Vincent Guittot Sept. 10, 2014, 2:22 p.m. UTC | #1 
On 10 September 2014 15:50, Peter Zijlstra <peterz@infradead.org> wrote:
> On Sat, Aug 30, 2014 at 10:37:40PM +0530, Preeti U Murthy wrote:
>> > -   if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) {
>> > -           if (sched_feat(ARCH_CAPACITY))
>>
>> Aren't you missing this check above? I understand that it is not
>> crucial, but that would also mean removing ARCH_CAPACITY sched_feat
>> altogether, wouldn't it?
>
> Yes he's missing that, I added the below bit on top.

FWIW, your changes are fine for me

>
> So the argument last time:
> lkml.kernel.org/r/20140709105721.GT19379@twins.programming.kicks-ass.net
> was that you cannot put sched_feat(ARCH_CAPACITY) inside a weak arch_*
> function. The test has to be outside, seeing how it needs to decide to
> call the arch function at all (or revert to the default implementation).
>
> ---
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -5700,7 +5700,7 @@ unsigned long __weak arch_scale_freq_cap
>         return default_scale_capacity(sd, cpu);
>  }
>
> -unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
> +static unsigned long default_scale_cpu_capacity(struct sched_domain *sd, int cpu)
>  {
>         if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
>                 return sd->smt_gain / sd->span_weight;
> @@ -5708,6 +5708,11 @@ unsigned long __weak arch_scale_cpu_capa
>         return SCHED_CAPACITY_SCALE;
>  }
>
> +unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
> +{
> +       return default_scale_cpu_capacity(sd, cpu);
> +}
> +
>  static unsigned long scale_rt_capacity(int cpu)
>  {
>         struct rq *rq = cpu_rq(cpu);
> @@ -5747,7 +5752,10 @@ static void update_cpu_capacity(struct s
>         unsigned long capacity = SCHED_CAPACITY_SCALE;
>         struct sched_group *sdg = sd->groups;
>
> -       capacity *= arch_scale_cpu_capacity(sd, cpu);
> +       if (sched_feat(ARCH_CAPACITY))
> +               capacity *= arch_scale_cpu_capacity(sd, cpu);
> +       else
> +               capacity *= default_scale_cpu_capacity(sd, cpu);
>
>         capacity >>= SCHED_CAPACITY_SHIFT;
>
preeti Sept. 11, 2014, 10:36 a.m. UTC | #2 
On 09/10/2014 07:20 PM, Peter Zijlstra wrote:
> On Sat, Aug 30, 2014 at 10:37:40PM +0530, Preeti U Murthy wrote:
>>> -	if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) {
>>> -		if (sched_feat(ARCH_CAPACITY))
>>
>> Aren't you missing this check above? I understand that it is not
>> crucial, but that would also mean removing ARCH_CAPACITY sched_feat
>> altogether, wouldn't it?
> 
> Yes he's missing that, I added the below bit on top.
> 
> So the argument last time:
> lkml.kernel.org/r/20140709105721.GT19379@twins.programming.kicks-ass.net
> was that you cannot put sched_feat(ARCH_CAPACITY) inside a weak arch_*
> function. The test has to be outside, seeing how it needs to decide to
> call the arch function at all (or revert to the default implementation).
> 
> ---
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -5700,7 +5700,7 @@ unsigned long __weak arch_scale_freq_cap
>  	return default_scale_capacity(sd, cpu);
>  }
> 
> -unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
> +static unsigned long default_scale_cpu_capacity(struct sched_domain *sd, int cpu)
>  {
>  	if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
>  		return sd->smt_gain / sd->span_weight;
> @@ -5708,6 +5708,11 @@ unsigned long __weak arch_scale_cpu_capa
>  	return SCHED_CAPACITY_SCALE;
>  }
> 
> +unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
> +{
> +	return default_scale_cpu_capacity(sd, cpu);
> +}
> +
>  static unsigned long scale_rt_capacity(int cpu)
>  {
>  	struct rq *rq = cpu_rq(cpu);
> @@ -5747,7 +5752,10 @@ static void update_cpu_capacity(struct s
>  	unsigned long capacity = SCHED_CAPACITY_SCALE;
>  	struct sched_group *sdg = sd->groups;
> 
> -	capacity *= arch_scale_cpu_capacity(sd, cpu);
> +	if (sched_feat(ARCH_CAPACITY))
> +		capacity *= arch_scale_cpu_capacity(sd, cpu);
> +	else
> +		capacity *= default_scale_cpu_capacity(sd, cpu);
> 
>  	capacity >>= SCHED_CAPACITY_SHIFT;
> 
> 
Alright, I see now. Thanks!

Regards
Preeti U Murthy
diff mbox

Patch

--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5700,7 +5700,7 @@  unsigned long __weak arch_scale_freq_cap
 	return default_scale_capacity(sd, cpu);
 }
 
-unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
+static unsigned long default_scale_cpu_capacity(struct sched_domain *sd, int cpu)
 {
 	if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
 		return sd->smt_gain / sd->span_weight;
@@ -5708,6 +5708,11 @@  unsigned long __weak arch_scale_cpu_capa
 	return SCHED_CAPACITY_SCALE;
 }
 
+unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
+{
+	return default_scale_cpu_capacity(sd, cpu);
+}
+
 static unsigned long scale_rt_capacity(int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
@@ -5747,7 +5752,10 @@  static void update_cpu_capacity(struct s
 	unsigned long capacity = SCHED_CAPACITY_SCALE;
 	struct sched_group *sdg = sd->groups;
 
-	capacity *= arch_scale_cpu_capacity(sd, cpu);
+	if (sched_feat(ARCH_CAPACITY))
+		capacity *= arch_scale_cpu_capacity(sd, cpu);
+	else
+		capacity *= default_scale_cpu_capacity(sd, cpu);
 
 	capacity >>= SCHED_CAPACITY_SHIFT;