mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 13:43:55 +08:00
d61ca3c25e
Fix a spelling mistake in the help text for PREEMPT_RT. Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/157204450499.10518.4542293884417101528.stgit@srivatsa-ubuntu
83 lines
3.0 KiB
Plaintext
83 lines
3.0 KiB
Plaintext
# 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
|
|
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
|