# SPDX-License-Identifier: GPL-2.0-only choice prompt "Preemption Model" default [31mCONFIG_PREEMPT_NONE[0m config [31mCONFIG_PREEMPT_NONE[0m 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 [31mCONFIG_PREEMPT_VOLUNTARY[0m bool "Voluntary Kernel Preemption (Desktop)" depends on ![31mCONFIG_ARCH_NO_PREEMPT[0m 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 [31mCONFIG_PREEMPT[0m bool "Preemptible Kernel (Low-Latency Desktop)" depends on ![31mCONFIG_ARCH_NO_PREEMPT[0m select [31mCONFIG_PREEMPTION[0m select [31mCONFIG_UNINLINE_SPIN_UNLOCK[0m if ![31mCONFIG_ARCH_INLINE_SPIN_UNLOCK[0m 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 [31mCONFIG_PREEMPT_RT[0m bool "Fully Preemptible Kernel (Real-Time)" depends on [31mCONFIG_EXPERT[0m && [31mCONFIG_ARCH_SUPPORTS_RT[0m select [31mCONFIG_PREEMPTION[0m 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 [31mCONFIG_PREEMPT_COUNT[0m bool config [31mCONFIG_PREEMPTION[0m bool select [31mCONFIG_PREEMPT_COUNT[0m |