[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.

Ingo Molnar committed 21 years ago

Commit cc19ca81 parent 7f1867a4 files · +28 −69Browse files

Unified · Split

4 files

arch/i386/Kconfig +1 −22
arch/ppc64/Kconfig +1 −20
arch/x86_64/Kconfig +2 −27
kernel/Kconfig.preempt +24 −0

arch/i386/Kconfig+1−22

@@ -510,28 +510,7 @@ config SCHED_SMT · 509 unmodified lines
510	510	cost of slightly increased overhead in some places. If unsure say
511	511	N here.
512	512
513		−config PREEMPT
514		− bool "Preemptible Kernel"
515		− help
516		− This option reduces the latency of the kernel when reacting to
517		− real-time or interactive events by allowing a low priority process to
518		− be preempted even if it is in kernel mode executing a system call.
519		− This allows applications to run more reliably even when the system is
520		− under load.
521		−
522		− Say Y here if you are building a kernel for a desktop, embedded
523		− or real-time system. Say N if you are unsure.
524		−
525		−config PREEMPT_BKL
526		− bool "Preempt The Big Kernel Lock"
527		− depends on PREEMPT
528		− default y
529		− help
530		− This option reduces the latency of the kernel by making the
531		− big kernel lock preemptible.
532		−
533		− Say Y here if you are building a kernel for a desktop system.
534		− Say N if you are unsure.
	513	+source "kernel/Kconfig.preempt"
535	514
536	515	config X86_UP_APIC
537	516	bool "Local APIC support on uniprocessors"

arch/ppc64/Kconfig+1−20

@@ -270,26 +270,7 @@ config SCHED_SMT · 269 unmodified lines
270	270	when dealing with POWER5 cpus at a cost of slightly increased
271	271	overhead in some places. If unsure say N here.
272	272
273		−config PREEMPT
274		− bool "Preemptible Kernel"
275		− help
276		− This option reduces the latency of the kernel when reacting to
277		− real-time or interactive events by allowing a low priority process to
278		− be preempted even if it is in kernel mode executing a system call.
279		−
280		− Say Y here if you are building a kernel for a desktop, embedded
281		− or real-time system. Say N if you are unsure.
282		−
283		−config PREEMPT_BKL
284		− bool "Preempt The Big Kernel Lock"
285		− depends on PREEMPT
286		− default y
287		− help
288		− This option reduces the latency of the kernel by making the
289		− big kernel lock preemptible.
290		−
291		− Say Y here if you are building a kernel for a desktop system.
292		− Say N if you are unsure.
	273	+source "kernel/Kconfig.preempt"
293	274
294	275	config EEH
295	276	bool "PCI Extended Error Handling (EEH)" if EMBEDDED

arch/x86_64/Kconfig+2−27

@@ -207,33 +207,6 @@ config SMP · 206 unmodified lines
207	207
208	208	If you don't know what to do here, say N.
209	209
210		−config PREEMPT
211		− bool "Preemptible Kernel"
212		− ---help---
213		− This option reduces the latency of the kernel when reacting to
214		− real-time or interactive events by allowing a low priority process to
215		− be preempted even if it is in kernel mode executing a system call.
216		− This allows applications to run more reliably even when the system is
217		− under load. On contrary it may also break your drivers and add
218		− priority inheritance problems to your system. Don't select it if
219		− you rely on a stable system or have slightly obscure hardware.
220		− It's also not very well tested on x86-64 currently.
221		− You have been warned.
222		−
223		− Say Y here if you are feeling brave and building a kernel for a
224		− desktop, embedded or real-time system. Say N if you are unsure.
225		−
226		−config PREEMPT_BKL
227		− bool "Preempt The Big Kernel Lock"
228		− depends on PREEMPT
229		− default y
230		− help
231		− This option reduces the latency of the kernel by making the
232		− big kernel lock preemptible.
233		−
234		− Say Y here if you are building a kernel for a desktop system.
235		− Say N if you are unsure.
236		−
237	210	config SCHED_SMT
238	211	bool "SMT (Hyperthreading) scheduler support"
239	212	depends on SMP
@@ -244,6 +217,8 @@ config SCHED_SMT · 4 unmodified lines
244	217	cost of slightly increased overhead in some places. If unsure say
245	218	N here.
246	219
	220	+source "kernel/Kconfig.preempt"
	221	+
247	222	config K8_NUMA
248	223	bool "K8 NUMA support"
249	224	select NUMA

kernel/Kconfig.preempt+24−0

@@ -0,0 +1,24 @@
	1	+
	2	+config PREEMPT
	3	+ bool "Preemptible Kernel"
	4	+ help
	5	+ This option reduces the latency of the kernel when reacting to
	6	+ real-time or interactive events by allowing a low priority process to
	7	+ be preempted even if it is in kernel mode executing a system call.
	8	+ This allows applications to run more reliably even when the system is
	9	+ under load.
	10	+
	11	+ Say Y here if you are building a kernel for a desktop, embedded
	12	+ or real-time system. Say N if you are unsure.
	13	+
	14	+config PREEMPT_BKL
	15	+ bool "Preempt The Big Kernel Lock"
	16	+ depends on PREEMPT
	17	+ default y
	18	+ help
	19	+ This option reduces the latency of the kernel by making the
	20	+ big kernel lock preemptible.
	21	+
	22	+ Say Y here if you are building a kernel for a desktop system.
	23	+ Say N if you are unsure.
	24	+