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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#
2# For a description of the syntax of this configuration file,
3# see Documentation/kbuild/kconfig-language.txt.
4#
5
6config MMU
7 bool
8 default y
9
10config RWSEM_GENERIC_SPINLOCK
11 bool
12
13config RWSEM_XCHGADD_ALGORITHM
14 bool
15 default y
16
17config GENERIC_CALIBRATE_DELAY
18 bool
19 default y
20
21config GENERIC_BUST_SPINLOCK
22 bool
23
24mainmenu "Linux Kernel Configuration"
25
26config ARCH_S390
27 bool
28 default y
29
30config UID16
31 bool
32 default y
33 depends on ARCH_S390X = 'n'
34
35source "init/Kconfig"
36
37menu "Base setup"
38
39comment "Processor type and features"
40
41config ARCH_S390X
42 bool "64 bit kernel"
43 help
44 Select this option if you have a 64 bit IBM zSeries machine
45 and want to use the 64 bit addressing mode.
46
47config 64BIT
48 def_bool ARCH_S390X
49
50config ARCH_S390_31
51 bool
52 depends on ARCH_S390X = 'n'
53 default y
54
55config SMP
56 bool "Symmetric multi-processing support"
57 ---help---
58 This enables support for systems with more than one CPU. If you have
59 a system with only one CPU, like most personal computers, say N. If
60 you have a system with more than one CPU, say Y.
61
62 If you say N here, the kernel will run on single and multiprocessor
63 machines, but will use only one CPU of a multiprocessor machine. If
64 you say Y here, the kernel will run on many, but not all,
65 singleprocessor machines. On a singleprocessor machine, the kernel
66 will run faster if you say N here.
67
68 See also the <file:Documentation/smp.txt> and the SMP-HOWTO
69 available at <http://www.tldp.org/docs.html#howto>.
70
71 Even if you don't know what to do here, say Y.
72
73config NR_CPUS
74 int "Maximum number of CPUs (2-64)"
75 range 2 64
76 depends on SMP
77 default "32"
78 help
79 This allows you to specify the maximum number of CPUs which this
80 kernel will support. The maximum supported value is 64 and the
81 minimum value which makes sense is 2.
82
83 This is purely to save memory - each supported CPU adds
84 approximately sixteen kilobytes to the kernel image.
85
86config HOTPLUG_CPU
87 bool "Support for hot-pluggable CPUs"
88 depends on SMP
89 select HOTPLUG
90 default n
91 help
92 Say Y here to be able to turn CPUs off and on. CPUs
93 can be controlled through /sys/devices/system/cpu/cpu#.
94 Say N if you want to disable CPU hotplug.
95
96config MATHEMU
97 bool "IEEE FPU emulation"
98 depends on MARCH_G5
99 help
100 This option is required for IEEE compliant floating point arithmetic
101 on older S/390 machines. Say Y unless you know your machine doesn't
102 need this.
103
104config S390_SUPPORT
105 bool "Kernel support for 31 bit emulation"
106 depends on ARCH_S390X
107 help
108 Select this option if you want to enable your system kernel to
109 handle system-calls from ELF binaries for 31 bit ESA. This option
110 (and some other stuff like libraries and such) is needed for
111 executing 31 bit applications. It is safe to say "Y".
112
113config COMPAT
114 bool
115 depends on S390_SUPPORT
116 default y
117
118config SYSVIPC_COMPAT
119 bool
120 depends on COMPAT && SYSVIPC
121 default y
122
123config BINFMT_ELF32
124 tristate "Kernel support for 31 bit ELF binaries"
125 depends on S390_SUPPORT
126 help
127 This allows you to run 32-bit Linux/ELF binaries on your zSeries
128 in 64 bit mode. Everybody wants this; say Y.
129
130comment "Code generation options"
131
132choice
133 prompt "Processor type"
134 default MARCH_G5
135
136config MARCH_G5
137 bool "S/390 model G5 and G6"
138 depends on ARCH_S390_31
139 help
140 Select this to build a 31 bit kernel that works
141 on all S/390 and zSeries machines.
142
143config MARCH_Z900
144 bool "IBM eServer zSeries model z800 and z900"
145 help
146 Select this to optimize for zSeries machines. This
147 will enable some optimizations that are not available
148 on older 31 bit only CPUs.
149
150config MARCH_Z990
151 bool "IBM eServer zSeries model z890 and z990"
152 help
153 Select this enable optimizations for model z890/z990.
154 This will be slightly faster but does not work on
155 older machines such as the z900.
156
157endchoice
158
159config PACK_STACK
160 bool "Pack kernel stack"
161 help
162 This option enables the compiler option -mkernel-backchain if it
163 is available. If the option is available the compiler supports
164 the new stack layout which dramatically reduces the minimum stack
165 frame size. With an old compiler a non-leaf function needs a
166 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
167 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
168 and 24 byte on 64 bit.
169
170 Say Y if you are unsure.
171
172config SMALL_STACK
173 bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
174 depends on PACK_STACK
175 help
176 If you say Y here and the compiler supports the -mkernel-backchain
177 option the kernel will use a smaller kernel stack size. For 31 bit
178 the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
179 instead of 16kb. This allows to run more thread on a system and
180 reduces the pressure on the memory management for higher order
181 page allocations.
182
183 Say N if you are unsure.
184
185
186config CHECK_STACK
187 bool "Detect kernel stack overflow"
188 help
189 This option enables the compiler option -mstack-guard and
190 -mstack-size if they are available. If the compiler supports them
191 it will emit additional code to each function prolog to trigger
192 an illegal operation if the kernel stack is about to overflow.
193
194 Say N if you are unsure.
195
196config STACK_GUARD
197 int "Size of the guard area (128-1024)"
198 range 128 1024
199 depends on CHECK_STACK
200 default "256"
201 help
202 This allows you to specify the size of the guard area at the lower
203 end of the kernel stack. If the kernel stack points into the guard
204 area on function entry an illegal operation is triggered. The size
205 needs to be a power of 2. Please keep in mind that the size of an
206 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
207 The minimum size for the stack guard should be 256 for 31 bit and
208 512 for 64 bit.
209
210config WARN_STACK
211 bool "Emit compiler warnings for function with broken stack usage"
212 help
213 This option enables the compiler options -mwarn-framesize and
214 -mwarn-dynamicstack. If the compiler supports these options it
215 will generate warnings for function which either use alloca or
216 create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
217
218 Say N if you are unsure.
219
220config WARN_STACK_SIZE
221 int "Maximum frame size considered safe (128-2048)"
222 range 128 2048
223 depends on WARN_STACK
224 default "256"
225 help
226 This allows you to specify the maximum frame size a function may
227 have without the compiler complaining about it.
228
229comment "I/O subsystem configuration"
230
231config MACHCHK_WARNING
232 bool "Process warning machine checks"
233 help
234 Select this option if you want the machine check handler on IBM S/390 or
235 zSeries to process warning machine checks (e.g. on power failures).
236 If unsure, say "Y".
237
238config QDIO
239 tristate "QDIO support"
240 ---help---
241 This driver provides the Queued Direct I/O base support for the
242 IBM S/390 (G5 and G6) and eServer zSeries (z800, z890, z900 and z990).
243
244 For details please refer to the documentation provided by IBM at
245 <http://www10.software.ibm.com/developerworks/opensource/linux390>
246
247 To compile this driver as a module, choose M here: the
248 module will be called qdio.
249
250 If unsure, say Y.
251
252config QDIO_PERF_STATS
253 bool "Performance statistics in /proc"
254 depends on QDIO
255 help
256 Say Y here to get performance statistics in /proc/qdio_perf
257
258 If unsure, say N.
259
260config QDIO_DEBUG
261 bool "Extended debugging information"
262 depends on QDIO
263 help
264 Say Y here to get extended debugging output in /proc/s390dbf/qdio...
265 Warning: this option reduces the performance of the QDIO module.
266
267 If unsure, say N.
268
269comment "Misc"
270
271config PREEMPT
272 bool "Preemptible Kernel"
273 help
274 This option reduces the latency of the kernel when reacting to
275 real-time or interactive events by allowing a low priority process to
276 be preempted even if it is in kernel mode executing a system call.
277 This allows applications to run more reliably even when the system is
278 under load.
279
280 Say N if you are unsure.
281
282config IPL
283 bool "Builtin IPL record support"
284 help
285 If you want to use the produced kernel to IPL directly from a
286 device, you have to merge a bootsector specific to the device
287 into the first bytes of the kernel. You will have to select the
288 IPL device.
289
290choice
291 prompt "IPL method generated into head.S"
292 depends on IPL
293 default IPL_TAPE
294 help
295 Select "tape" if you want to IPL the image from a Tape.
296
297 Select "vm_reader" if you are running under VM/ESA and want
298 to IPL the image from the emulated card reader.
299
300config IPL_TAPE
301 bool "tape"
302
303config IPL_VM
304 bool "vm_reader"
305
306endchoice
307
308source "fs/Kconfig.binfmt"
309
310config PROCESS_DEBUG
311 bool "Show crashed user process info"
312 help
313 Say Y to print all process fault locations to the console. This is
314 a debugging option; you probably do not want to set it unless you
315 are an S390 port maintainer.
316
317config PFAULT
318 bool "Pseudo page fault support"
319 help
320 Select this option, if you want to use PFAULT pseudo page fault
321 handling under VM. If running native or in LPAR, this option
322 has no effect. If your VM does not support PFAULT, PAGEEX
323 pseudo page fault handling will be used.
324 Note that VM 4.2 supports PFAULT but has a bug in its
325 implementation that causes some problems.
326 Everybody who wants to run Linux under VM != VM4.2 should select
327 this option.
328
329config SHARED_KERNEL
330 bool "VM shared kernel support"
331 help
332 Select this option, if you want to share the text segment of the
333 Linux kernel between different VM guests. This reduces memory
334 usage with lots of guests but greatly increases kernel size.
335 You should only select this option if you know what you are
336 doing and want to exploit this feature.
337
338config CMM
339 tristate "Cooperative memory management"
340 help
341 Select this option, if you want to enable the kernel interface
342 to reduce the memory size of the system. This is accomplished
343 by allocating pages of memory and put them "on hold". This only
344 makes sense for a system running under VM where the unused pages
345 will be reused by VM for other guest systems. The interface
346 allows an external monitor to balance memory of many systems.
347 Everybody who wants to run Linux under VM should select this
348 option.
349
350config CMM_PROC
351 bool "/proc interface to cooperative memory management"
352 depends on CMM
353 help
354 Select this option to enable the /proc interface to the
355 cooperative memory management.
356
357config CMM_IUCV
358 bool "IUCV special message interface to cooperative memory management"
359 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
360 help
361 Select this option to enable the special message interface to
362 the cooperative memory management.
363
364config VIRT_TIMER
365 bool "Virtual CPU timer support"
366 help
367 This provides a kernel interface for virtual CPU timers.
368 Default is disabled.
369
370config VIRT_CPU_ACCOUNTING
371 bool "Base user process accounting on virtual cpu timer"
372 depends on VIRT_TIMER
373 help
374 Select this option to use CPU timer deltas to do user
375 process accounting.
376
377config APPLDATA_BASE
378 bool "Linux - VM Monitor Stream, base infrastructure"
379 depends on PROC_FS && VIRT_TIMER=y
380 help
381 This provides a kernel interface for creating and updating z/VM APPLDATA
382 monitor records. The monitor records are updated at certain time
383 intervals, once the timer is started.
384 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
385 i.e. enables or disables monitoring on the Linux side.
386 A custom interval value (in seconds) can be written to
387 /proc/appldata/interval.
388
389 Defaults are 60 seconds interval and timer off.
390 The /proc entries can also be read from, showing the current settings.
391
392config APPLDATA_MEM
393 tristate "Monitor memory management statistics"
394 depends on APPLDATA_BASE
395 help
396 This provides memory management related data to the Linux - VM Monitor
397 Stream, like paging/swapping rate, memory utilisation, etc.
398 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
399 APPLDATA monitor record, i.e. enables or disables monitoring this record
400 on the z/VM side.
401
402 Default is disabled.
403 The /proc entry can also be read from, showing the current settings.
404
405 This can also be compiled as a module, which will be called
406 appldata_mem.o.
407
408config APPLDATA_OS
409 tristate "Monitor OS statistics"
410 depends on APPLDATA_BASE
411 help
412 This provides OS related data to the Linux - VM Monitor Stream, like
413 CPU utilisation, etc.
414 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
415 APPLDATA monitor record, i.e. enables or disables monitoring this record
416 on the z/VM side.
417
418 Default is disabled.
419 This can also be compiled as a module, which will be called
420 appldata_os.o.
421
422config APPLDATA_NET_SUM
423 tristate "Monitor overall network statistics"
424 depends on APPLDATA_BASE
425 help
426 This provides network related data to the Linux - VM Monitor Stream,
427 currently there is only a total sum of network I/O statistics, no
428 per-interface data.
429 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
430 APPLDATA monitor record, i.e. enables or disables monitoring this record
431 on the z/VM side.
432
433 Default is disabled.
434 This can also be compiled as a module, which will be called
435 appldata_net_sum.o.
436
437config NO_IDLE_HZ
438 bool "No HZ timer ticks in idle"
439 help
440 Switches the regular HZ timer off when the system is going idle.
441 This helps z/VM to detect that the Linux system is idle. VM can
442 then "swap-out" this guest which reduces memory usage. It also
443 reduces the overhead of idle systems.
444
445 The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
446 hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
447 timer is active.
448
449config NO_IDLE_HZ_INIT
450 bool "HZ timer in idle off by default"
451 depends on NO_IDLE_HZ
452 help
453 The HZ timer is switched off in idle by default. That means the
454 HZ timer is already disabled at boot time.
455
456endmenu
457
458config PCMCIA
459 bool
460 default n
461
462source "drivers/base/Kconfig"
463
464source "drivers/scsi/Kconfig"
465
466source "drivers/s390/Kconfig"
467
468source "net/Kconfig"
469
470source "fs/Kconfig"
471
472source "arch/s390/oprofile/Kconfig"
473
474source "arch/s390/Kconfig.debug"
475
476source "security/Kconfig"
477
478source "crypto/Kconfig"
479
480source "lib/Kconfig"