| Message ID | 20220714073055.15049-1-mark-pk.tsai@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [5.4] sched/rt: Disable RT_RUNTIME_SHARE by default | expand |
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
diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 2410db5e9a35..66c74aa4753e 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -77,7 +77,7 @@ SCHED_FEAT(WARN_DOUBLE_CLOCK, false) SCHED_FEAT(RT_PUSH_IPI, true) #endif -SCHED_FEAT(RT_RUNTIME_SHARE, true) +SCHED_FEAT(RT_RUNTIME_SHARE, false) SCHED_FEAT(LB_MIN, false) SCHED_FEAT(ATTACH_AGE_LOAD, true)