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