[ looks good? if so, I will send a v2 patch set including the ] [ RT_RUNTIME_GREED patch and this one. ]
Currently, the option RT_RUNTIME_SHARE is enabled by default. This option enables the sharing of rt_runtime between CPUs, allowing a CPU to borrow rt_runtime from another CPU, permitting a real-time task to run 100% of the time on a single CPU. The problem is that this can lead to the starvation of a non-real-time task pinned to the CPU running the CPU bound RT workload. One example of non-real-time task pinned to a CPU are the kworkers. Often kworkers starve on this scenario, causing a system hang. This patch changes the default setup for RT THROTTLING, disabling the RT_RUNTIME_SHARE option while enabling the RT_RUNTIME_GREED option. In such configuration, real-time tasks will be able to run 100% of the time in the absence of non-real-time tasks starving in the local CPU. Signed-off-by: Daniel Bristot de Oliveira <bris...@redhat.com> Cc: Ingo Molnar <mi...@redhat.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Christoph Lameter <c...@linux.com> Cc: Tommaso Cucinotta <tommaso.cucino...@sssup.it> Cc: Luca Abeni <luca.ab...@unitn.it> Cc: Clark Williams <willi...@redhat.com> Cc: linux-rt-users <linux-rt-us...@vger.kernel.org> Cc: LKML <linux-kernel@vger.kernel.org> diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 3bd7a6d..265c0db 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -65,8 +65,8 @@ SCHED_FEAT(RT_PUSH_IPI, true) #endif SCHED_FEAT(FORCE_SD_OVERLAP, false) -SCHED_FEAT(RT_RUNTIME_SHARE, true) -SCHED_FEAT(RT_RUNTIME_GREED, false) +SCHED_FEAT(RT_RUNTIME_SHARE, false) +SCHED_FEAT(RT_RUNTIME_GREED, true) SCHED_FEAT(LB_MIN, false) SCHED_FEAT(ATTACH_AGE_LOAD, true)
