# SPDX-License-Identifier: GPL-2.0-only 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)"	depends on !ARCH_NO_PREEMPT	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	bool "Preemptible Kernel (Low-Latency Desktop)"	depends on !ARCH_NO_PREEMPT	select PREEMPTION	select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK	select PREEMPT_DYNAMIC if HAVE_PREEMPT_DYNAMIC	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_RT	bool "Fully Preemptible Kernel (Real-Time)"	depends on EXPERT && ARCH_SUPPORTS_RT	select PREEMPTION	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 paths (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 PREEMPTION       bool       select PREEMPT_COUNT config PREEMPT_DYNAMIC	bool	help	  This option allows to define the preemption model on the kernel	  command line parameter and thus override the default preemption	  model defined during compile time. 	  The feature is primarily interesting for Linux distributions which	  provide a pre-built kernel binary to reduce the number of kernel	  flavors they offer while still offering different usecases. 	  The runtime overhead is negligible with HAVE_STATIC_CALL_INLINE enabled	  but if runtime patching is not available for the specific architecture	  then the potential overhead should be considered. 	  Interesting if you want the same pre-built kernel should be used for	  both Server and Desktop workloads.