2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
17 config LOCKDEP_SUPPORT
20 config STACKTRACE_SUPPORT
23 config HAVE_LATENCYTOP_SUPPORT
26 config RWSEM_GENERIC_SPINLOCK
29 config RWSEM_XCHGADD_ALGORITHM
32 config ARCH_HAS_ILOG2_U32
36 config ARCH_HAS_ILOG2_U64
40 config GENERIC_HWEIGHT
46 config GENERIC_CLOCKEVENTS
60 config GENERIC_LOCKBREAK
63 depends on SMP && PREEMPT
69 mainmenu "Linux Kernel Configuration"
75 select HAVE_KRETPROBES
76 select HAVE_KVM if 64BIT
77 select HAVE_ARCH_TRACEHOOK
83 comment "Processor type and features"
85 source "kernel/time/Kconfig"
90 Select this option if you have a 64 bit IBM zSeries machine
91 and want to use the 64 bit addressing mode.
98 bool "Symmetric multi-processing support"
100 This enables support for systems with more than one CPU. If you have
101 a system with only one CPU, like most personal computers, say N. If
102 you have a system with more than one CPU, say Y.
104 If you say N here, the kernel will run on single and multiprocessor
105 machines, but will use only one CPU of a multiprocessor machine. If
106 you say Y here, the kernel will run on many, but not all,
107 singleprocessor machines. On a singleprocessor machine, the kernel
108 will run faster if you say N here.
110 See also the SMP-HOWTO available at
111 <http://www.tldp.org/docs.html#howto>.
113 Even if you don't know what to do here, say Y.
116 int "Maximum number of CPUs (2-64)"
119 default "32" if !64BIT
120 default "64" if 64BIT
122 This allows you to specify the maximum number of CPUs which this
123 kernel will support. The maximum supported value is 64 and the
124 minimum value which makes sense is 2.
126 This is purely to save memory - each supported CPU adds
127 approximately sixteen kilobytes to the kernel image.
130 bool "Support for hot-pluggable CPUs"
135 Say Y here to be able to turn CPUs off and on. CPUs
136 can be controlled through /sys/devices/system/cpu/cpu#.
137 Say N if you want to disable CPU hotplug.
140 bool "IEEE FPU emulation"
143 This option is required for IEEE compliant floating point arithmetic
144 on older S/390 machines. Say Y unless you know your machine doesn't
148 bool "Kernel support for 31 bit emulation"
150 select COMPAT_BINFMT_ELF
152 Select this option if you want to enable your system kernel to
153 handle system-calls from ELF binaries for 31 bit ESA. This option
154 (and some other stuff like libraries and such) is needed for
155 executing 31 bit applications. It is safe to say "Y".
157 config SYSVIPC_COMPAT
159 depends on COMPAT && SYSVIPC
166 config S390_SWITCH_AMODE
167 bool "Switch kernel/user addressing modes"
169 This option allows to switch the addressing modes of kernel and user
170 space. The kernel parameter switch_amode=on will enable this feature,
171 default is disabled. Enabling this (via kernel parameter) on machines
172 earlier than IBM System z9-109 EC/BC will reduce system performance.
174 Note that this option will also be selected by selecting the execute
175 protection option below. Enabling the execute protection via the
176 noexec kernel parameter will also switch the addressing modes,
177 independent of the switch_amode kernel parameter.
180 config S390_EXEC_PROTECT
181 bool "Data execute protection"
182 select S390_SWITCH_AMODE
184 This option allows to enable a buffer overflow protection for user
185 space programs and it also selects the addressing mode option above.
186 The kernel parameter noexec=on will enable this feature and also
187 switch the addressing modes, default is disabled. Enabling this (via
188 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
189 will reduce system performance.
191 comment "Code generation options"
194 prompt "Processor type"
198 bool "S/390 model G5 and G6"
201 Select this to build a 31 bit kernel that works
202 on all S/390 and zSeries machines.
205 bool "IBM eServer zSeries model z800 and z900"
207 Select this to optimize for zSeries machines. This
208 will enable some optimizations that are not available
209 on older 31 bit only CPUs.
212 bool "IBM eServer zSeries model z890 and z990"
214 Select this enable optimizations for model z890/z990.
215 This will be slightly faster but does not work on
216 older machines such as the z900.
221 Select this to enable optimizations for IBM System z9-109, IBM
222 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
223 Class (z9 BC). The kernel will be slightly faster but will not
224 work on older machines such as the z990, z890, z900, and z800.
229 bool "Pack kernel stack"
231 This option enables the compiler option -mkernel-backchain if it
232 is available. If the option is available the compiler supports
233 the new stack layout which dramatically reduces the minimum stack
234 frame size. With an old compiler a non-leaf function needs a
235 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
236 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
237 and 24 byte on 64 bit.
239 Say Y if you are unsure.
242 bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
243 depends on PACK_STACK && !LOCKDEP
245 If you say Y here and the compiler supports the -mkernel-backchain
246 option the kernel will use a smaller kernel stack size. For 31 bit
247 the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
248 instead of 16kb. This allows to run more thread on a system and
249 reduces the pressure on the memory management for higher order
252 Say N if you are unsure.
256 bool "Detect kernel stack overflow"
258 This option enables the compiler option -mstack-guard and
259 -mstack-size if they are available. If the compiler supports them
260 it will emit additional code to each function prolog to trigger
261 an illegal operation if the kernel stack is about to overflow.
263 Say N if you are unsure.
266 int "Size of the guard area (128-1024)"
268 depends on CHECK_STACK
271 This allows you to specify the size of the guard area at the lower
272 end of the kernel stack. If the kernel stack points into the guard
273 area on function entry an illegal operation is triggered. The size
274 needs to be a power of 2. Please keep in mind that the size of an
275 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
276 The minimum size for the stack guard should be 256 for 31 bit and
280 bool "Emit compiler warnings for function with broken stack usage"
282 This option enables the compiler options -mwarn-framesize and
283 -mwarn-dynamicstack. If the compiler supports these options it
284 will generate warnings for function which either use alloca or
285 create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
287 Say N if you are unsure.
289 config WARN_STACK_SIZE
290 int "Maximum frame size considered safe (128-2048)"
292 depends on WARN_STACK
295 This allows you to specify the maximum frame size a function may
296 have without the compiler complaining about it.
298 config ARCH_POPULATES_NODE_MAP
301 comment "Kernel preemption"
303 source "kernel/Kconfig.preempt"
305 config ARCH_SPARSEMEM_ENABLE
307 select SPARSEMEM_VMEMMAP_ENABLE
308 select SPARSEMEM_VMEMMAP
309 select SPARSEMEM_STATIC if !64BIT
311 config ARCH_SPARSEMEM_DEFAULT
314 config ARCH_SELECT_MEMORY_MODEL
317 config ARCH_ENABLE_MEMORY_HOTPLUG
321 config ARCH_ENABLE_MEMORY_HOTREMOVE
326 comment "I/O subsystem configuration"
328 config MACHCHK_WARNING
329 bool "Process warning machine checks"
331 Select this option if you want the machine check handler on IBM S/390 or
332 zSeries to process warning machine checks (e.g. on power failures).
336 tristate "QDIO support"
338 This driver provides the Queued Direct I/O base support for
341 To compile this driver as a module, choose M here: the
342 module will be called qdio.
347 bool "Extended debugging information"
350 Say Y here to get extended debugging output in
351 /sys/kernel/debug/s390dbf/qdio...
352 Warning: this option reduces the performance of the QDIO module.
357 tristate "Support for CHSC subchannels"
359 This driver allows usage of CHSC subchannels. A CHSC subchannel
360 is usually present on LPAR only.
361 The driver creates a device /dev/chsc, which may be used to
362 obtain I/O configuration information about the machine and
363 to issue asynchronous chsc commands (DANGEROUS).
364 You will usually only want to use this interface on a special
365 LPAR designated for system management.
367 To compile this driver as a module, choose M here: the
368 module will be called chsc_sch.
375 bool "Builtin IPL record support"
377 If you want to use the produced kernel to IPL directly from a
378 device, you have to merge a bootsector specific to the device
379 into the first bytes of the kernel. You will have to select the
383 prompt "IPL method generated into head.S"
387 Select "tape" if you want to IPL the image from a Tape.
389 Select "vm_reader" if you are running under VM/ESA and want
390 to IPL the image from the emulated card reader.
400 source "fs/Kconfig.binfmt"
402 config FORCE_MAX_ZONEORDER
407 bool "Show crashed user process info"
409 Say Y to print all process fault locations to the console. This is
410 a debugging option; you probably do not want to set it unless you
411 are an S390 port maintainer.
414 bool "Pseudo page fault support"
416 Select this option, if you want to use PFAULT pseudo page fault
417 handling under VM. If running native or in LPAR, this option
418 has no effect. If your VM does not support PFAULT, PAGEEX
419 pseudo page fault handling will be used.
420 Note that VM 4.2 supports PFAULT but has a bug in its
421 implementation that causes some problems.
422 Everybody who wants to run Linux under VM != VM4.2 should select
426 bool "VM shared kernel support"
428 Select this option, if you want to share the text segment of the
429 Linux kernel between different VM guests. This reduces memory
430 usage with lots of guests but greatly increases kernel size.
431 Also if a kernel was IPL'ed from a shared segment the kexec system
433 You should only select this option if you know what you are
434 doing and want to exploit this feature.
437 tristate "Cooperative memory management"
439 Select this option, if you want to enable the kernel interface
440 to reduce the memory size of the system. This is accomplished
441 by allocating pages of memory and put them "on hold". This only
442 makes sense for a system running under VM where the unused pages
443 will be reused by VM for other guest systems. The interface
444 allows an external monitor to balance memory of many systems.
445 Everybody who wants to run Linux under VM should select this
449 bool "/proc interface to cooperative memory management"
452 Select this option to enable the /proc interface to the
453 cooperative memory management.
456 bool "IUCV special message interface to cooperative memory management"
457 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
459 Select this option to enable the special message interface to
460 the cooperative memory management.
463 bool "Unused page notification"
465 This enables the notification of unused pages to the
466 hypervisor. The ESSA instruction is used to do the states
467 changes between a page that has content and the unused state.
470 bool "Virtual CPU timer support"
472 This provides a kernel interface for virtual CPU timers.
475 config VIRT_CPU_ACCOUNTING
476 bool "Base user process accounting on virtual cpu timer"
477 depends on VIRT_TIMER
479 Select this option to use CPU timer deltas to do user
483 bool "Linux - VM Monitor Stream, base infrastructure"
484 depends on PROC_FS && VIRT_TIMER=y
486 This provides a kernel interface for creating and updating z/VM APPLDATA
487 monitor records. The monitor records are updated at certain time
488 intervals, once the timer is started.
489 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
490 i.e. enables or disables monitoring on the Linux side.
491 A custom interval value (in seconds) can be written to
492 /proc/appldata/interval.
494 Defaults are 60 seconds interval and timer off.
495 The /proc entries can also be read from, showing the current settings.
498 tristate "Monitor memory management statistics"
499 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
501 This provides memory management related data to the Linux - VM Monitor
502 Stream, like paging/swapping rate, memory utilisation, etc.
503 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
504 APPLDATA monitor record, i.e. enables or disables monitoring this record
508 The /proc entry can also be read from, showing the current settings.
510 This can also be compiled as a module, which will be called
514 tristate "Monitor OS statistics"
515 depends on APPLDATA_BASE
517 This provides OS related data to the Linux - VM Monitor Stream, like
518 CPU utilisation, etc.
519 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
520 APPLDATA monitor record, i.e. enables or disables monitoring this record
524 This can also be compiled as a module, which will be called
527 config APPLDATA_NET_SUM
528 tristate "Monitor overall network statistics"
529 depends on APPLDATA_BASE
531 This provides network related data to the Linux - VM Monitor Stream,
532 currently there is only a total sum of network I/O statistics, no
534 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
535 APPLDATA monitor record, i.e. enables or disables monitoring this record
539 This can also be compiled as a module, which will be called
542 source kernel/Kconfig.hz
545 bool "s390 hypervisor file system support"
546 select SYS_HYPERVISOR
549 This is a virtual file system intended to provide accounting
550 information in an s390 hypervisor environment.
553 bool "kexec system call"
555 kexec is a system call that implements the ability to shutdown your
556 current kernel, and to start another kernel. It is like a reboot
557 but is independent of hardware/microcode support.
560 tristate "zfcpdump support"
564 Select this option if you want to build an zfcpdump enabled kernel.
565 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
568 bool "s390 guest support for KVM (EXPERIMENTAL)"
569 depends on 64BIT && EXPERIMENTAL
572 select VIRTIO_CONSOLE
574 Select this option if you want to run the kernel as a guest under
575 the KVM hypervisor. This will add detection for KVM as well as a
576 virtio transport. If KVM is detected, the virtio console will be
588 source "drivers/Kconfig"
592 source "arch/s390/Kconfig.debug"
594 source "security/Kconfig"
596 source "crypto/Kconfig"
600 source "arch/s390/kvm/Kconfig"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blob