config PREEMPT bool select PREEMPT_COUNT config PREEMPT_RT_BASE bool select PREEMPT config HAVE_PREEMPT_LAZY bool config PREEMPT_LAZY def_bool y if HAVE_PREEMPT_LAZY && PREEMPT_RT_FULL choice prompt "Preemption Model" default PREEMPT_NONE config PREEMPT_NONE bool "No Forced Preemption (Server)" help This is the traditional Linux preemption model, geared towards throughput. It will still provide good latencies most of the time, but there are no guarantees and occasional longer delays are possible. Select this option if you are building a kernel for a server or scientific/computation system, or if you want to maximize the raw processing power of the kernel, irrespective of scheduling latencies. config PREEMPT_VOLUNTARY bool "Voluntary Kernel Preemption (Desktop)" help This option reduces the latency of the kernel by adding more "explicit preemption points" to the kernel code. These new preemption points have been selected to reduce the maximum latency of rescheduling, providing faster application reactions, at the cost of slightly lower throughput. This allows reaction to interactive events by allowing a low priority process to voluntarily preempt itself even if it is in kernel mode executing a system call. This allows applications to run more 'smoothly' even when the system is under load. Select this if you are building a kernel for a desktop system. config PREEMPT__LL bool "Preemptible Kernel (Low-Latency Desktop)" select PREEMPT select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK help This option reduces the latency of the kernel by making all kernel code (that is not executing in a critical section) preemptible. This allows reaction to interactive events by permitting a low priority process to be preempted involuntarily even if it is in kernel mode executing a system call and would otherwise not be about to reach a natural preemption point. This allows applications to run more 'smoothly' even when the system is under load, at the cost of slightly lower throughput and a slight runtime overhead to kernel code. Select this if you are building a kernel for a desktop or embedded system with latency requirements in the milliseconds range. config PREEMPT_RTB bool "Preemptible Kernel (Basic RT)" select PREEMPT_RT_BASE help This option is basically the same as (Low-Latency Desktop) but enables changes which are preliminary for the full preemptible RT kernel. config PREEMPT_RT_FULL bool "Fully Preemptible Kernel (RT)" depends on IRQ_FORCED_THREADING select PREEMPT_RT_BASE select PREEMPT_RCU help All and everything endchoice config PREEMPT_COUNT bool