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Diffstat (limited to 'kernel/Kconfig.preempt')
| -rw-r--r-- | kernel/Kconfig.preempt | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt new file mode 100644 index 000000000..bf82259cf --- /dev/null +++ b/kernel/Kconfig.preempt @@ -0,0 +1,82 @@ +# 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 |