Re: [PATCH v2] sched/Documentation: Add RT_RUNTIME_SHARE documentation

From: Zhang Qiao
Date: Sun May 26 2024 - 23:13:49 EST


Ping.

在 2024/4/19 17:04, Zhang Qiao 写道:
> RT_RUNTIME_SHARE is an important strategy for rt bandwidth, and
> we should document this sched feature.
>
> Signed-off-by: Zhang Qiao <zhangqiao22@xxxxxxxxxx>
> Improvements-suggested-by: Bagas Sanjaya <bagasdotme@xxxxxxxxx>
> ---
> Documentation/scheduler/sched-rt-group.rst | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/Documentation/scheduler/sched-rt-group.rst b/Documentation/scheduler/sched-rt-group.rst
> index d685609ed3d7..eea2fc6f068f 100644
> --- a/Documentation/scheduler/sched-rt-group.rst
> +++ b/Documentation/scheduler/sched-rt-group.rst
> @@ -12,6 +12,7 @@ Real-Time group scheduling
> 2.1 System-wide settings
> 2.2 Default behaviour
> 2.3 Basis for grouping tasks
> + 2.4 RT_RUNTIME_SHARE sched feature
> 3. Future plans
>
>
> @@ -146,6 +147,17 @@ For now, this can be simplified to just the following (but see Future plans):
>
> \Sum_{i} runtime_{i} <= global_runtime
>
> +2.4 RT_RUNTIME_SHARE sched feature
> +----------------------------------
> +
> +RT_RUNTIME_SHARE allows a cpu to borrow rt-runtime from other cpus if it runs
> +out of its own rt-runtime.
> +
> +With this feature enabled, a rt-task may hit 100% cpu usage and can stall other
> +per-cpu tasks like kworkers, as a result, which leads into system hang.
> +
> +Thus, it is advised to disable this feature by default to avoid aforementioned
> +issue unless you know what you're doing.
>
> 3. Future plans
> ===============
>