[PATCH] sched/deadline: fix runtime accounting in documentation

[PATCH] sched/deadline: fix runtime accounting in documentation

[Claudio Scordino]

Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
---
 Documentation/scheduler/sched-deadline.txt | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/Documentation/scheduler/sched-deadline.txt b/Documentation/scheduler/sched-deadline.txt
index e89e36e..79f40c6 100644
--- a/Documentation/scheduler/sched-deadline.txt
+++ b/Documentation/scheduler/sched-deadline.txt
@@ -204,10 +204,16 @@ CONTENTS
  It does so by decrementing the runtime of the executing task Ti at a pace equal
  to
 
-           dq = -max{ Ui, (1 - Uinact) } dt
+           dq = -max{ Ui / Umax, (1 - Uinact - Uextra) } dt
 
- where Uinact is the inactive utilization, computed as (this_bq - running_bw),
- and Ui is the bandwidth of task Ti.
+ where:
+
+  - Ui is the bandwidth of task Ti;
+  - Umax is the maximum reclaimable utilization (subject to RT limits);
+  - Uinact is the (per runqueue) inactive utilization, computed as
+    (this_bq - running_bw);
+  - Uextra is the (per runqueue) extra reclaimable utilization
+    (subject to RT limits).
 
 
  Let's now see a trivial example of two deadline tasks with runtime equal
-- 
2.7.4

Re: [PATCH] sched/deadline: fix runtime accounting in documentation

[Daniel Bristot de Oliveira]

On 10/13/2017 12:08 PM, Claudio Scordino wrote:
> Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
> Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
> ---
>  Documentation/scheduler/sched-deadline.txt | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/scheduler/sched-deadline.txt b/Documentation/scheduler/sched-deadline.txt
> index e89e36e..79f40c6 100644
> --- a/Documentation/scheduler/sched-deadline.txt
> +++ b/Documentation/scheduler/sched-deadline.txt
> @@ -204,10 +204,16 @@ CONTENTS
>   It does so by decrementing the runtime of the executing task Ti at a pace equal
>   to
>  
> -           dq = -max{ Ui, (1 - Uinact) } dt
> +           dq = -max{ Ui / Umax, (1 - Uinact - Uextra) } dt
>  
> - where Uinact is the inactive utilization, computed as (this_bq - running_bw),
> - and Ui is the bandwidth of task Ti.
> + where:
> +
> +  - Ui is the bandwidth of task Ti;

Just one very very small addition to make it more clear:

> +  - Umax is the maximum reclaimable utilization (subject to RT limits);
                                                    ^^^^^^^^^^^^^^^^^^^
				     (subjected to RT Throttling limits)

Anyways,

Acked-by: Daniel Bristot de Oliveira <bristot@redhat.com>

> +  - Uinact is the (per runqueue) inactive utilization, computed as
> +    (this_bq - running_bw);
> +  - Uextra is the (per runqueue) extra reclaimable utilization
> +    (subject to RT limits).
>  
>  
>   Let's now see a trivial example of two deadline tasks with runtime equal
>