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_TIME_VSYSCALL
49 config GENERIC_CLOCKEVENTS
63 config GENERIC_LOCKBREAK
66 depends on SMP && PREEMPT
72 config VIRT_CPU_ACCOUNTING
75 mainmenu "Linux Kernel Configuration"
79 select USE_GENERIC_SMP_HELPERS if SMP
80 select HAVE_SYSCALL_WRAPPERS
81 select HAVE_FUNCTION_TRACER
84 select HAVE_KRETPROBES
85 select HAVE_KVM if 64BIT
86 select HAVE_ARCH_TRACEHOOK
87 select INIT_ALL_POSSIBLE
91 source "kernel/Kconfig.freezer"
95 comment "Processor type and features"
97 source "kernel/time/Kconfig"
102 Select this option if you have a 64 bit IBM zSeries machine
103 and want to use the 64 bit addressing mode.
110 bool "Symmetric multi-processing support"
112 This enables support for systems with more than one CPU. If you have
113 a system with only one CPU, like most personal computers, say N. If
114 you have a system with more than one CPU, say Y.
116 If you say N here, the kernel will run on single and multiprocessor
117 machines, but will use only one CPU of a multiprocessor machine. If
118 you say Y here, the kernel will run on many, but not all,
119 singleprocessor machines. On a singleprocessor machine, the kernel
120 will run faster if you say N here.
122 See also the SMP-HOWTO available at
123 <http://www.tldp.org/docs.html#howto>.
125 Even if you don't know what to do here, say Y.
128 int "Maximum number of CPUs (2-64)"
131 default "32" if !64BIT
132 default "64" if 64BIT
134 This allows you to specify the maximum number of CPUs which this
135 kernel will support. The maximum supported value is 64 and the
136 minimum value which makes sense is 2.
138 This is purely to save memory - each supported CPU adds
139 approximately sixteen kilobytes to the kernel image.
142 bool "Support for hot-pluggable CPUs"
147 Say Y here to be able to turn CPUs off and on. CPUs
148 can be controlled through /sys/devices/system/cpu/cpu#.
149 Say N if you want to disable CPU hotplug.
152 bool "IEEE FPU emulation"
155 This option is required for IEEE compliant floating point arithmetic
156 on older S/390 machines. Say Y unless you know your machine doesn't
160 bool "Kernel support for 31 bit emulation"
162 select COMPAT_BINFMT_ELF
164 Select this option if you want to enable your system kernel to
165 handle system-calls from ELF binaries for 31 bit ESA. This option
166 (and some other stuff like libraries and such) is needed for
167 executing 31 bit applications. It is safe to say "Y".
169 config SYSVIPC_COMPAT
171 depends on COMPAT && SYSVIPC
178 config S390_SWITCH_AMODE
179 bool "Switch kernel/user addressing modes"
181 This option allows to switch the addressing modes of kernel and user
182 space. The kernel parameter switch_amode=on will enable this feature,
183 default is disabled. Enabling this (via kernel parameter) on machines
184 earlier than IBM System z9-109 EC/BC will reduce system performance.
186 Note that this option will also be selected by selecting the execute
187 protection option below. Enabling the execute protection via the
188 noexec kernel parameter will also switch the addressing modes,
189 independent of the switch_amode kernel parameter.
192 config S390_EXEC_PROTECT
193 bool "Data execute protection"
194 select S390_SWITCH_AMODE
196 This option allows to enable a buffer overflow protection for user
197 space programs and it also selects the addressing mode option above.
198 The kernel parameter noexec=on will enable this feature and also
199 switch the addressing modes, default is disabled. Enabling this (via
200 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
201 will reduce system performance.
203 comment "Code generation options"
206 prompt "Processor type"
210 bool "S/390 model G5 and G6"
213 Select this to build a 31 bit kernel that works
214 on all S/390 and zSeries machines.
217 bool "IBM eServer zSeries model z800 and z900"
219 Select this to optimize for zSeries machines. This
220 will enable some optimizations that are not available
221 on older 31 bit only CPUs.
224 bool "IBM eServer zSeries model z890 and z990"
226 Select this enable optimizations for model z890/z990.
227 This will be slightly faster but does not work on
228 older machines such as the z900.
233 Select this to enable optimizations for IBM System z9-109, IBM
234 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
235 Class (z9 BC). The kernel will be slightly faster but will not
236 work on older machines such as the z990, z890, z900, and z800.
239 bool "IBM System z10"
241 Select this to enable optimizations for IBM System z10. The
242 kernel will be slightly faster but will not work on older
243 machines such as the z990, z890, z900, z800, z9-109, z9-ec
249 bool "Pack kernel stack"
251 This option enables the compiler option -mkernel-backchain if it
252 is available. If the option is available the compiler supports
253 the new stack layout which dramatically reduces the minimum stack
254 frame size. With an old compiler a non-leaf function needs a
255 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
256 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
257 and 24 byte on 64 bit.
259 Say Y if you are unsure.
262 bool "Use 8kb for kernel stack instead of 16kb"
263 depends on PACK_STACK && 64BIT && !LOCKDEP
265 If you say Y here and the compiler supports the -mkernel-backchain
266 option the kernel will use a smaller kernel stack size. The reduced
267 size is 8kb instead of 16kb. This allows to run more threads on a
268 system and reduces the pressure on the memory management for higher
269 order page allocations.
271 Say N if you are unsure.
274 bool "Detect kernel stack overflow"
276 This option enables the compiler option -mstack-guard and
277 -mstack-size if they are available. If the compiler supports them
278 it will emit additional code to each function prolog to trigger
279 an illegal operation if the kernel stack is about to overflow.
281 Say N if you are unsure.
284 int "Size of the guard area (128-1024)"
286 depends on CHECK_STACK
289 This allows you to specify the size of the guard area at the lower
290 end of the kernel stack. If the kernel stack points into the guard
291 area on function entry an illegal operation is triggered. The size
292 needs to be a power of 2. Please keep in mind that the size of an
293 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
294 The minimum size for the stack guard should be 256 for 31 bit and
298 bool "Emit compiler warnings for function with broken stack usage"
300 This option enables the compiler options -mwarn-framesize and
301 -mwarn-dynamicstack. If the compiler supports these options it
302 will generate warnings for function which either use alloca or
303 create a stack frame bigger than CONFIG_WARN_STACK_SIZE.
305 Say N if you are unsure.
307 config WARN_STACK_SIZE
308 int "Maximum frame size considered safe (128-2048)"
310 depends on WARN_STACK
313 This allows you to specify the maximum frame size a function may
314 have without the compiler complaining about it.
316 config ARCH_POPULATES_NODE_MAP
319 comment "Kernel preemption"
321 source "kernel/Kconfig.preempt"
323 config ARCH_SPARSEMEM_ENABLE
325 select SPARSEMEM_VMEMMAP_ENABLE
326 select SPARSEMEM_VMEMMAP
327 select SPARSEMEM_STATIC if !64BIT
329 config ARCH_SPARSEMEM_DEFAULT
332 config ARCH_SELECT_MEMORY_MODEL
335 config ARCH_ENABLE_MEMORY_HOTPLUG
339 config ARCH_ENABLE_MEMORY_HOTREMOVE
344 comment "I/O subsystem configuration"
347 tristate "QDIO support"
349 This driver provides the Queued Direct I/O base support for
352 To compile this driver as a module, choose M here: the
353 module will be called qdio.
358 tristate "Support for CHSC subchannels"
360 This driver allows usage of CHSC subchannels. A CHSC subchannel
361 is usually present on LPAR only.
362 The driver creates a device /dev/chsc, which may be used to
363 obtain I/O configuration information about the machine and
364 to issue asynchronous chsc commands (DANGEROUS).
365 You will usually only want to use this interface on a special
366 LPAR designated for system management.
368 To compile this driver as a module, choose M here: the
369 module will be called chsc_sch.
376 bool "Builtin IPL record support"
378 If you want to use the produced kernel to IPL directly from a
379 device, you have to merge a bootsector specific to the device
380 into the first bytes of the kernel. You will have to select the
384 prompt "IPL method generated into head.S"
388 Select "tape" if you want to IPL the image from a Tape.
390 Select "vm_reader" if you are running under VM/ESA and want
391 to IPL the image from the emulated card reader.
401 source "fs/Kconfig.binfmt"
403 config FORCE_MAX_ZONEORDER
408 bool "Show crashed user process info"
410 Say Y to print all process fault locations to the console. This is
411 a debugging option; you probably do not want to set it unless you
412 are an S390 port maintainer.
415 bool "Pseudo page fault support"
417 Select this option, if you want to use PFAULT pseudo page fault
418 handling under VM. If running native or in LPAR, this option
419 has no effect. If your VM does not support PFAULT, PAGEEX
420 pseudo page fault handling will be used.
421 Note that VM 4.2 supports PFAULT but has a bug in its
422 implementation that causes some problems.
423 Everybody who wants to run Linux under VM != VM4.2 should select
427 bool "VM shared kernel support"
429 Select this option, if you want to share the text segment of the
430 Linux kernel between different VM guests. This reduces memory
431 usage with lots of guests but greatly increases kernel size.
432 Also if a kernel was IPL'ed from a shared segment the kexec system
434 You should only select this option if you know what you are
435 doing and want to exploit this feature.
438 tristate "Cooperative memory management"
440 Select this option, if you want to enable the kernel interface
441 to reduce the memory size of the system. This is accomplished
442 by allocating pages of memory and put them "on hold". This only
443 makes sense for a system running under VM where the unused pages
444 will be reused by VM for other guest systems. The interface
445 allows an external monitor to balance memory of many systems.
446 Everybody who wants to run Linux under VM should select this
450 bool "/proc interface to cooperative memory management"
453 Select this option to enable the /proc interface to the
454 cooperative memory management.
457 bool "IUCV special message interface to cooperative memory management"
458 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
460 Select this option to enable the special message interface to
461 the cooperative memory management.
464 bool "Unused page notification"
466 This enables the notification of unused pages to the
467 hypervisor. The ESSA instruction is used to do the states
468 changes between a page that has content and the unused state.
471 bool "Linux - VM Monitor Stream, base infrastructure"
474 This provides a kernel interface for creating and updating z/VM APPLDATA
475 monitor records. The monitor records are updated at certain time
476 intervals, once the timer is started.
477 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
478 i.e. enables or disables monitoring on the Linux side.
479 A custom interval value (in seconds) can be written to
480 /proc/appldata/interval.
482 Defaults are 60 seconds interval and timer off.
483 The /proc entries can also be read from, showing the current settings.
486 tristate "Monitor memory management statistics"
487 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
489 This provides memory management related data to the Linux - VM Monitor
490 Stream, like paging/swapping rate, memory utilisation, etc.
491 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
492 APPLDATA monitor record, i.e. enables or disables monitoring this record
496 The /proc entry can also be read from, showing the current settings.
498 This can also be compiled as a module, which will be called
502 tristate "Monitor OS statistics"
503 depends on APPLDATA_BASE
505 This provides OS related data to the Linux - VM Monitor Stream, like
506 CPU utilisation, etc.
507 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
508 APPLDATA monitor record, i.e. enables or disables monitoring this record
512 This can also be compiled as a module, which will be called
515 config APPLDATA_NET_SUM
516 tristate "Monitor overall network statistics"
517 depends on APPLDATA_BASE && NET
519 This provides network related data to the Linux - VM Monitor Stream,
520 currently there is only a total sum of network I/O statistics, no
522 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
523 APPLDATA monitor record, i.e. enables or disables monitoring this record
527 This can also be compiled as a module, which will be called
530 source kernel/Kconfig.hz
533 bool "s390 hypervisor file system support"
534 select SYS_HYPERVISOR
537 This is a virtual file system intended to provide accounting
538 information in an s390 hypervisor environment.
541 bool "kexec system call"
543 kexec is a system call that implements the ability to shutdown your
544 current kernel, and to start another kernel. It is like a reboot
545 but is independent of hardware/microcode support.
548 bool "zfcpdump support"
552 Select this option if you want to build an zfcpdump enabled kernel.
553 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
556 bool "s390 guest support for KVM (EXPERIMENTAL)"
557 depends on 64BIT && EXPERIMENTAL
560 select VIRTIO_CONSOLE
562 Select this option if you want to run the kernel as a guest under
563 the KVM hypervisor. This will add detection for KVM as well as a
564 virtio transport. If KVM is detected, the virtio console will be
576 source "drivers/Kconfig"
580 source "arch/s390/Kconfig.debug"
582 source "security/Kconfig"
584 source "crypto/Kconfig"
588 source "arch/s390/kvm/Kconfig"