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-rw-r--r--arch/Kconfig3
-rw-r--r--kernel/Kconfig.preempt25
2 files changed, 26 insertions, 2 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index ac0fba400ded..a7b57dd42c26 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -796,6 +796,9 @@ config ARCH_NO_COHERENT_DMA_MMAP
config ARCH_NO_PREEMPT
bool
+config ARCH_SUPPORTS_RT
+ bool
+
config CPU_NO_EFFICIENT_FFS
def_bool n
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index dc0b682ec2d9..fc020c09b7e8 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -35,10 +35,10 @@ config PREEMPT_VOLUNTARY
Select this if you are building a kernel for a desktop system.
-config PREEMPT
+config PREEMPT_LL
bool "Preemptible Kernel (Low-Latency Desktop)"
depends on !ARCH_NO_PREEMPT
- select PREEMPT_COUNT
+ select PREEMPT
select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK
help
This option reduces the latency of the kernel by making
@@ -55,7 +55,28 @@ config PREEMPT
embedded system with latency requirements in the milliseconds
range.
+config PREEMPT_RT
+ bool "Fully Preemptible Kernel (Real-Time)"
+ depends on EXPERT && ARCH_SUPPORTS_RT
+ select PREEMPT
+ help
+ This option turns the kernel into a real-time kernel by replacing
+ various locking primitives (spinlocks, rwlocks, etc.) with
+ preemptible priority-inheritance aware variants, enforcing
+ interrupt threading and introducing mechanisms to break up long
+ non-preemptible sections. This makes the kernel, except for very
+ low level and critical code pathes (entry code, scheduler, low
+ level interrupt handling) fully preemptible and brings most
+ execution contexts under scheduler control.
+
+ Select this if you are building a kernel for systems which
+ require real-time guarantees.
+
endchoice
config PREEMPT_COUNT
bool
+
+config PREEMPT
+ bool
+ select PREEMPT_COUNT