Re: [PATCH v2] sched/rt: Disable RT_RUNTIME_SHARE by default

From: Daniel Bristot de Oliveira
Date: Mon Jan 02 2017 - 12:22:26 EST


On 11/16/2016 09:19 PM, Daniel Bristot de Oliveira wrote:
> The RT_RUNTIME_SHARE sched feature enables the sharing of rt_runtime
> between CPUs, allowing a CPU to run a real-time task up to 100% of the
> time while leaving more space for non-real-time tasks to run on the CPU
> that lend rt_runtime.
>
> The problem is that a CPU can easily borrow enough rt_runtime to allow
> a spinning rt-task to run forever, starving per-cpu tasks like kworkers,
> which are non-real-time by design.
>
> This patch disables RT_RUNTIME_SHARE by default, avoiding this problem.
> The feature will still be present for users that want to enable it,
> though. It also documents this option.
>
> v1->v2:
> Unified the documentation and the disabling in a single patch
>
> Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Clark Williams <williams@xxxxxxxxxx>
> Cc: Luis Claudio R. Goncalves <lgoncalv@xxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Acked-by: Luis Claudio R. Goncalves <lgoncalv@xxxxxxxxxx>

This is a gentle ping :-)

any additional comment for this patch?

-- Daniel