Commit cc19ca86 authored by Ingo Molnar's avatar Ingo Molnar Committed by Linus Torvalds
Browse files

[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: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7f1867a5

arch/i386/Kconfig

+1 −22
Original line number Diff line number Diff line
@@ -510,28 +510,7 @@ config SCHED_SMT 
	  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"

arch/ppc64/Kconfig

+1 −20
Original line number Diff line number Diff line
@@ -270,26 +270,7 @@ config SCHED_SMT 
	  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

arch/x86_64/Kconfig

+2 −27
Original line number Diff line number Diff line
@@ -207,33 +207,6 @@ config SMP 


	  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 @@ config SCHED_SMT 
	  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

kernel/Kconfig.preempt

0 → 100644
+24 −0
Original line number Diff line number Diff line 


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.

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