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-rw-r--r--kernel/Kconfig.preempt54
1 files changed, 48 insertions, 6 deletions
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index c2f1fd95a821..54ea59ff8fbe 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -11,12 +11,16 @@ config PREEMPT_BUILD
select PREEMPTION
select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK
+config ARCH_HAS_PREEMPT_LAZY
+ bool
+
choice
prompt "Preemption Model"
default PREEMPT_NONE
config PREEMPT_NONE
bool "No Forced Preemption (Server)"
+ depends on !PREEMPT_RT
select PREEMPT_NONE_BUILD if !PREEMPT_DYNAMIC
help
This is the traditional Linux preemption model, geared towards
@@ -32,6 +36,7 @@ config PREEMPT_NONE
config PREEMPT_VOLUNTARY
bool "Voluntary Kernel Preemption (Desktop)"
depends on !ARCH_NO_PREEMPT
+ depends on !PREEMPT_RT
select PREEMPT_VOLUNTARY_BUILD if !PREEMPT_DYNAMIC
help
This option reduces the latency of the kernel by adding more
@@ -51,7 +56,7 @@ config PREEMPT_VOLUNTARY
config PREEMPT
bool "Preemptible Kernel (Low-Latency Desktop)"
depends on !ARCH_NO_PREEMPT
- select PREEMPT_BUILD
+ select PREEMPT_BUILD if !PREEMPT_DYNAMIC
help
This option reduces the latency of the kernel by making
all kernel code (that is not executing in a critical section)
@@ -67,9 +72,23 @@ config PREEMPT
embedded system with latency requirements in the milliseconds
range.
+config PREEMPT_LAZY
+ bool "Scheduler controlled preemption model"
+ depends on !ARCH_NO_PREEMPT
+ depends on ARCH_HAS_PREEMPT_LAZY
+ select PREEMPT_BUILD if !PREEMPT_DYNAMIC
+ help
+ This option provides a scheduler driven preemption model that
+ is fundamentally similar to full preemption, but is less
+ eager to preempt SCHED_NORMAL tasks in an attempt to
+ reduce lock holder preemption and recover some of the performance
+ gains seen from using Voluntary preemption.
+
+endchoice
+
config PREEMPT_RT
bool "Fully Preemptible Kernel (Real-Time)"
- depends on EXPERT && ARCH_SUPPORTS_RT
+ depends on EXPERT && ARCH_SUPPORTS_RT && !COMPILE_TEST
select PREEMPTION
help
This option turns the kernel into a real-time kernel by replacing
@@ -84,8 +103,6 @@ config PREEMPT_RT
Select this if you are building a kernel for systems which
require real-time guarantees.
-endchoice
-
config PREEMPT_COUNT
bool
@@ -95,7 +112,7 @@ config PREEMPTION
config PREEMPT_DYNAMIC
bool "Preemption behaviour defined on boot"
- depends on HAVE_PREEMPT_DYNAMIC && !PREEMPT_RT
+ depends on HAVE_PREEMPT_DYNAMIC
select JUMP_LABEL if HAVE_PREEMPT_DYNAMIC_KEY
select PREEMPT_BUILD
default y if HAVE_PREEMPT_DYNAMIC_CALL
@@ -133,4 +150,29 @@ config SCHED_CORE
which is the likely usage by Linux distributions, there should
be no measurable impact on performance.
-
+config SCHED_CLASS_EXT
+ bool "Extensible Scheduling Class"
+ depends on BPF_SYSCALL && BPF_JIT && DEBUG_INFO_BTF
+ select STACKTRACE if STACKTRACE_SUPPORT
+ help
+ This option enables a new scheduler class sched_ext (SCX), which
+ allows scheduling policies to be implemented as BPF programs to
+ achieve the following:
+
+ - Ease of experimentation and exploration: Enabling rapid
+ iteration of new scheduling policies.
+ - Customization: Building application-specific schedulers which
+ implement policies that are not applicable to general-purpose
+ schedulers.
+ - Rapid scheduler deployments: Non-disruptive swap outs of
+ scheduling policies in production environments.
+
+ sched_ext leverages BPF struct_ops feature to define a structure
+ which exports function callbacks and flags to BPF programs that
+ wish to implement scheduling policies. The struct_ops structure
+ exported by sched_ext is struct sched_ext_ops, and is conceptually
+ similar to struct sched_class.
+
+ For more information:
+ Documentation/scheduler/sched-ext.rst
+ https://github.com/sched-ext/scx