Re: [PATCH] Documentation/scheduler/sched-deadline.txt: correct definition of density as C_i/min{D_i,P_i}

From: Luca Abeni
Date: Fri Apr 03 2015 - 07:03:27 EST


Hi,

On Fri, 3 Apr 2015 16:18:33 +0800
Zhiqiang Zhang <zhangzhiqiang.zhang@xxxxxxxxxx> wrote:

> >From the contex,the definition of the destiny of a task
> C_i/min{D_i,T_i},where T_i is not referred before, should be
> substituted by C_i/min{D_i,P_i}.
You are right, "T_i" should be substituted with "P_i"...
But now that I look at it more carefully, I think that "C_i" is also
wrong... It should be "WCET_i".


BTW, speaking about documentation: I still have some SCHED_DEADLINE
documentation patches in my local tree... I'll update and send them in
next week. Juri, should I send the patches to you, or submit directly
to the mailing list?

Thanks,
Luca
>
> ----------------------------------------
>
> Signed-off-by: Zhiqiang Zhang <zhangzhiqiang.zhang@xxxxxxxxxx>
> ---
> Documentation/scheduler/sched-deadline.txt | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/scheduler/sched-deadline.txt
> b/Documentation/scheduler/sched-deadline.txt index 21461a0..194664b
> 100644 --- a/Documentation/scheduler/sched-deadline.txt
> +++ b/Documentation/scheduler/sched-deadline.txt
> @@ -169,8 +169,8 @@ CONTENTS
> of all the tasks executing on a CPU if and only if the total
> utilisation of the tasks running on such a CPU is smaller or equal
> than 1. If D_i != P_i for some task, then it is possible to define
> the density of
> - a task as C_i/min{D_i,T_i}, and EDF is able to respect all the
> deadlines
> - of all the tasks running on a CPU if the sum sum_i C_i/min{D_i,T_i}
> of the
> + a task as C_i/min{D_i,P_i}, and EDF is able to respect all the
> deadlines
> + of all the tasks running on a CPU if the sum sum_i C_i/min{D_i,P_i}
> of the densities of the tasks running on such a CPU is smaller or
> equal than 1 (notice that this condition is only sufficient, and not
> necessary).

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