FM / kernel

/usr/src/kernels/4.18.0-553.121.1.el8_10.x86_64/kernel/

/usr/src/kernels/4.18.0-553.121.1.el8_10.x86_64/kernel

Name	Size	Mode	Actions
bpf/	-	0755	rm
cgroup/	-	0755	rm
debug/	-	0755	rm
dma/	-	0755	rm
events/	-	0755	rm
gcov/	-	0755	rm
irq/	-	0755	rm
kcsan/	-	0755	rm
livepatch/	-	0755	rm
locking/	-	0755	rm
power/	-	0755	rm
printk/	-	0755	rm
rcu/	-	0755	rm
sched/	-	0755	rm
time/	-	0755	rm
trace/	-	0755	rm
Kconfig.freezer	52	0644	edit dl rm
Kconfig.hz	1669	0644	edit dl rm
Kconfig.locks	4985	0644	edit dl rm
Kconfig.preempt	2993	0644	edit dl rm
Makefile	5039	0644	edit dl rm

Edit: /usr/src/kernels/4.18.0-553.121.1.el8_10.x86_64/kernel/Kconfig.preempt (2993B)

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
	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 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 PREEMPTION
       bool
       select PREEMPT_COUNT

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 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 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 PREEMPTION bool select PREEMPT_COUNT