[PATCH] consolidate PREEMPT options into kernel/Kconfig.preempt
This patch consolidates the CONFIG_PREEMPT and CONFIG_PREEMPT_BKL
preemption options into kernel/Kconfig.preempt. This, besides reducing
source-code, also enables more centralized tweaking of preemption related
options.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index b4cd11e..961ab20 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -510,28 +510,7 @@
cost of slightly increased overhead in some places. If unsure say
N here.
-config PREEMPT
- bool "Preemptible Kernel"
- help
- This option reduces the latency of the kernel when reacting to
- real-time or interactive events by allowing a low priority process to
- be preempted even if it is in kernel mode executing a system call.
- This allows applications to run more reliably even when the system is
- under load.
-
- Say Y here if you are building a kernel for a desktop, embedded
- or real-time system. Say N if you are unsure.
-
-config PREEMPT_BKL
- bool "Preempt The Big Kernel Lock"
- depends on PREEMPT
- default y
- help
- This option reduces the latency of the kernel by making the
- big kernel lock preemptible.
-
- Say Y here if you are building a kernel for a desktop system.
- Say N if you are unsure.
+source "kernel/Kconfig.preempt"
config X86_UP_APIC
bool "Local APIC support on uniprocessors"
diff --git a/arch/ppc64/Kconfig b/arch/ppc64/Kconfig
index cb27068..5f40b43 100644
--- a/arch/ppc64/Kconfig
+++ b/arch/ppc64/Kconfig
@@ -270,26 +270,7 @@
when dealing with POWER5 cpus at a cost of slightly increased
overhead in some places. If unsure say N here.
-config PREEMPT
- bool "Preemptible Kernel"
- help
- This option reduces the latency of the kernel when reacting to
- real-time or interactive events by allowing a low priority process to
- be preempted even if it is in kernel mode executing a system call.
-
- Say Y here if you are building a kernel for a desktop, embedded
- or real-time system. Say N if you are unsure.
-
-config PREEMPT_BKL
- bool "Preempt The Big Kernel Lock"
- depends on PREEMPT
- default y
- help
- This option reduces the latency of the kernel by making the
- big kernel lock preemptible.
-
- Say Y here if you are building a kernel for a desktop system.
- Say N if you are unsure.
+source "kernel/Kconfig.preempt"
config EEH
bool "PCI Extended Error Handling (EEH)" if EMBEDDED
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 92f5a52..a853d87 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -207,33 +207,6 @@
If you don't know what to do here, say N.
-config PREEMPT
- bool "Preemptible Kernel"
- ---help---
- This option reduces the latency of the kernel when reacting to
- real-time or interactive events by allowing a low priority process to
- be preempted even if it is in kernel mode executing a system call.
- This allows applications to run more reliably even when the system is
- under load. On contrary it may also break your drivers and add
- priority inheritance problems to your system. Don't select it if
- you rely on a stable system or have slightly obscure hardware.
- It's also not very well tested on x86-64 currently.
- You have been warned.
-
- Say Y here if you are feeling brave and building a kernel for a
- desktop, embedded or real-time system. Say N if you are unsure.
-
-config PREEMPT_BKL
- bool "Preempt The Big Kernel Lock"
- depends on PREEMPT
- default y
- help
- This option reduces the latency of the kernel by making the
- big kernel lock preemptible.
-
- Say Y here if you are building a kernel for a desktop system.
- Say N if you are unsure.
-
config SCHED_SMT
bool "SMT (Hyperthreading) scheduler support"
depends on SMP
@@ -244,6 +217,8 @@
cost of slightly increased overhead in some places. If unsure say
N here.
+source "kernel/Kconfig.preempt"
+
config K8_NUMA
bool "K8 NUMA support"
select NUMA
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
new file mode 100644
index 0000000..587328b
--- /dev/null
+++ b/kernel/Kconfig.preempt
@@ -0,0 +1,24 @@
+
+config PREEMPT
+ bool "Preemptible Kernel"
+ help
+ This option reduces the latency of the kernel when reacting to
+ real-time or interactive events by allowing a low priority process to
+ be preempted even if it is in kernel mode executing a system call.
+ This allows applications to run more reliably even when the system is
+ under load.
+
+ Say Y here if you are building a kernel for a desktop, embedded
+ or real-time system. Say N if you are unsure.
+
+config PREEMPT_BKL
+ bool "Preempt The Big Kernel Lock"
+ depends on PREEMPT
+ default y
+ help
+ This option reduces the latency of the kernel by making the
+ big kernel lock preemptible.
+
+ Say Y here if you are building a kernel for a desktop system.
+ Say N if you are unsure.
+
