Re: [RFC PATCH v2 1/6] sched/fair: Create util_fits_capacity()

[Dietmar Eggemann]

On 04/12/2018 09:02 AM, Viresh Kumar wrote:

On 06-04-18, 16:36, Dietmar Eggemann wrote:

The functionality that a given utilization fits into a given capacity
is factored out into a separate function.

Currently it is only used in wake_cap() but will be re-used to figure
out if a cpu or a scheduler group is over-utilized.

Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Signed-off-by: Dietmar Eggemann 
---
  kernel/sched/fair.c | 7 ++-
  1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0951d1c58d2f..0a76ad2ef022 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6574,6 +6574,11 @@ static unsigned long cpu_util_wake(int cpu, struct 
task_struct *p)
return min_t(unsigned long, util, capacity_orig_of(cpu));
  }
  
+static inline int util_fits_capacity(unsigned long util, unsigned long capacity)

+{
+   return capacity * 1024 > util * capacity_margin;


This changes the behavior slightly compared to existing code. If that
wasn't intentional, perhaps you should use >= here.


You're right here ... Already on our v3 list. Thanks!

The 'misfit' patch-set comes with a similar function 
task_fits_capacity() so we have to align on this one with this patch-set 
as well.


[...]

Re: [RFC PATCH v2 1/6] sched/fair: Create util_fits_capacity()

[Dietmar Eggemann]

On 04/12/2018 09:02 AM, Viresh Kumar wrote:

On 06-04-18, 16:36, Dietmar Eggemann wrote:

The functionality that a given utilization fits into a given capacity
is factored out into a separate function.

Currently it is only used in wake_cap() but will be re-used to figure
out if a cpu or a scheduler group is over-utilized.

Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Signed-off-by: Dietmar Eggemann 
---
  kernel/sched/fair.c | 7 ++-
  1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0951d1c58d2f..0a76ad2ef022 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6574,6 +6574,11 @@ static unsigned long cpu_util_wake(int cpu, struct 
task_struct *p)
return min_t(unsigned long, util, capacity_orig_of(cpu));
  }
  
+static inline int util_fits_capacity(unsigned long util, unsigned long capacity)

+{
+   return capacity * 1024 > util * capacity_margin;


This changes the behavior slightly compared to existing code. If that
wasn't intentional, perhaps you should use >= here.


You're right here ... Already on our v3 list. Thanks!

The 'misfit' patch-set comes with a similar function 
task_fits_capacity() so we have to align on this one with this patch-set 
as well.


[...]

Re: [RFC PATCH v2 1/6] sched/fair: Create util_fits_capacity()

[Viresh Kumar]

On 06-04-18, 16:36, Dietmar Eggemann wrote:
> The functionality that a given utilization fits into a given capacity
> is factored out into a separate function.
> 
> Currently it is only used in wake_cap() but will be re-used to figure
> out if a cpu or a scheduler group is over-utilized.
> 
> Cc: Ingo Molnar 
> Cc: Peter Zijlstra 
> Signed-off-by: Dietmar Eggemann 
> ---
>  kernel/sched/fair.c | 7 ++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 0951d1c58d2f..0a76ad2ef022 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -6574,6 +6574,11 @@ static unsigned long cpu_util_wake(int cpu, struct 
> task_struct *p)
>   return min_t(unsigned long, util, capacity_orig_of(cpu));
>  }
>  
> +static inline int util_fits_capacity(unsigned long util, unsigned long 
> capacity)
> +{
> + return capacity * 1024 > util * capacity_margin;

This changes the behavior slightly compared to existing code. If that
wasn't intentional, perhaps you should use >= here.

> +}
> +
>  /*
>   * Disable WAKE_AFFINE in the case where task @p doesn't fit in the
>   * capacity of either the waking CPU @cpu or the previous CPU @prev_cpu.
> @@ -6595,7 +6600,7 @@ static int wake_cap(struct task_struct *p, int cpu, int 
> prev_cpu)
>   /* Bring task utilization in sync with prev_cpu */
>   sync_entity_load_avg(>se);
>  
> - return min_cap * 1024 < task_util(p) * capacity_margin;
> + return !util_fits_capacity(task_util(p), min_cap);
>  }
>  
>  /*
> -- 
> 2.11.0

-- 
viresh

Re: [RFC PATCH v2 1/6] sched/fair: Create util_fits_capacity()

[Viresh Kumar]

On 06-04-18, 16:36, Dietmar Eggemann wrote:
> The functionality that a given utilization fits into a given capacity
> is factored out into a separate function.
> 
> Currently it is only used in wake_cap() but will be re-used to figure
> out if a cpu or a scheduler group is over-utilized.
> 
> Cc: Ingo Molnar 
> Cc: Peter Zijlstra 
> Signed-off-by: Dietmar Eggemann 
> ---
>  kernel/sched/fair.c | 7 ++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 0951d1c58d2f..0a76ad2ef022 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -6574,6 +6574,11 @@ static unsigned long cpu_util_wake(int cpu, struct 
> task_struct *p)
>   return min_t(unsigned long, util, capacity_orig_of(cpu));
>  }
>  
> +static inline int util_fits_capacity(unsigned long util, unsigned long 
> capacity)
> +{
> + return capacity * 1024 > util * capacity_margin;

This changes the behavior slightly compared to existing code. If that
wasn't intentional, perhaps you should use >= here.

> +}
> +
>  /*
>   * Disable WAKE_AFFINE in the case where task @p doesn't fit in the
>   * capacity of either the waking CPU @cpu or the previous CPU @prev_cpu.
> @@ -6595,7 +6600,7 @@ static int wake_cap(struct task_struct *p, int cpu, int 
> prev_cpu)
>   /* Bring task utilization in sync with prev_cpu */
>   sync_entity_load_avg(>se);
>  
> - return min_cap * 1024 < task_util(p) * capacity_margin;
> + return !util_fits_capacity(task_util(p), min_cap);
>  }
>  
>  /*
> -- 
> 2.11.0

-- 
viresh

[RFC PATCH v2 1/6] sched/fair: Create util_fits_capacity()

[Dietmar Eggemann]

The functionality that a given utilization fits into a given capacity
is factored out into a separate function.

Currently it is only used in wake_cap() but will be re-used to figure
out if a cpu or a scheduler group is over-utilized.

Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Signed-off-by: Dietmar Eggemann 
---
 kernel/sched/fair.c | 7 ++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0951d1c58d2f..0a76ad2ef022 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6574,6 +6574,11 @@ static unsigned long cpu_util_wake(int cpu, struct 
task_struct *p)
return min_t(unsigned long, util, capacity_orig_of(cpu));
 }
 
+static inline int util_fits_capacity(unsigned long util, unsigned long 
capacity)
+{
+   return capacity * 1024 > util * capacity_margin;
+}
+
 /*
  * Disable WAKE_AFFINE in the case where task @p doesn't fit in the
  * capacity of either the waking CPU @cpu or the previous CPU @prev_cpu.
@@ -6595,7 +6600,7 @@ static int wake_cap(struct task_struct *p, int cpu, int 
prev_cpu)
/* Bring task utilization in sync with prev_cpu */
sync_entity_load_avg(>se);
 
-   return min_cap * 1024 < task_util(p) * capacity_margin;
+   return !util_fits_capacity(task_util(p), min_cap);
 }
 
 /*
-- 
2.11.0

[RFC PATCH v2 1/6] sched/fair: Create util_fits_capacity()

[Dietmar Eggemann]

The functionality that a given utilization fits into a given capacity
is factored out into a separate function.

Currently it is only used in wake_cap() but will be re-used to figure
out if a cpu or a scheduler group is over-utilized.

Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Signed-off-by: Dietmar Eggemann 
---
 kernel/sched/fair.c | 7 ++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0951d1c58d2f..0a76ad2ef022 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6574,6 +6574,11 @@ static unsigned long cpu_util_wake(int cpu, struct 
task_struct *p)
return min_t(unsigned long, util, capacity_orig_of(cpu));
 }
 
+static inline int util_fits_capacity(unsigned long util, unsigned long 
capacity)
+{
+   return capacity * 1024 > util * capacity_margin;
+}
+
 /*
  * Disable WAKE_AFFINE in the case where task @p doesn't fit in the
  * capacity of either the waking CPU @cpu or the previous CPU @prev_cpu.
@@ -6595,7 +6600,7 @@ static int wake_cap(struct task_struct *p, int cpu, int 
prev_cpu)
/* Bring task utilization in sync with prev_cpu */
sync_entity_load_avg(>se);
 
-   return min_cap * 1024 < task_util(p) * capacity_margin;
+   return !util_fits_capacity(task_util(p), min_cap);
 }
 
 /*
-- 
2.11.0