[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	cost of slightly increased overhead in some places. If unsure say	510	cost of slightly increased overhead in some places. If unsure say
511	N here.	511	N here.
512		512
513	config PREEMPT	513	source "kernel/Kconfig.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.
535		514
536	config X86_UP_APIC	515	config X86_UP_APIC
537	bool "Local APIC support on uniprocessors"	516	bool "Local APIC support on uniprocessors"

arch/ppc64/Kconfig+1−20

@@ -270,26 +270,7 @@ config SCHED_SMT · 269 unmodified lines
270	when dealing with POWER5 cpus at a cost of slightly increased	270	when dealing with POWER5 cpus at a cost of slightly increased
271	overhead in some places. If unsure say N here.	271	overhead in some places. If unsure say N here.
272		272
273	config PREEMPT	273	source "kernel/Kconfig.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.
293		274
294	config EEH	275	config EEH
295	bool "PCI Extended Error Handling (EEH)" if EMBEDDED	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	If you don't know what to do here, say N.	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	config SCHED_SMT	210	config SCHED_SMT
238	bool "SMT (Hyperthreading) scheduler support"	211	bool "SMT (Hyperthreading) scheduler support"
239	depends on SMP	212	depends on SMP
@@ -244,6 +217,8 @@ config SCHED_SMT · 4 unmodified lines
244	cost of slightly increased overhead in some places. If unsure say	217	cost of slightly increased overhead in some places. If unsure say
245	N here.	218	N here.
246		219
		220	source "kernel/Kconfig.preempt"
		221
247	config K8_NUMA	222	config K8_NUMA
248	bool "K8 NUMA support"	223	bool "K8 NUMA support"
249	select NUMA	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