lkml.org 
[lkml]   [2022]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 5.4] sched/rt: Disable RT_RUNTIME_SHARE by default
On Thu, Jul 14, 2022 at 03:30:52PM +0800, Mark-PK Tsai wrote:
> From: Daniel Bristot de Oliveira <bristot@redhat.com>
>
> commit 2586af1ac187f6b3a50930a4e33497074e81762d upstream.
>
> 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.
>
> Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Tested-by: Wei Wang <wvw@google.com>
> Link: https://lkml.kernel.org/r/b776ab46817e3db5d8ef79175fa0d71073c051c7.1600697903.git.bristot@redhat.com
> Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
> Cc: stable@vger.kernel.org
> ---
> kernel/sched/features.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Now queued up, thanks.

greg k-h

\
 
 \ /
  Last update: 2022-07-15 16:14    [W:0.198 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site