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 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
78 mainmenu "Linux Kernel Configuration"
82 select USE_GENERIC_SMP_HELPERS if SMP
83 select HAVE_SYSCALL_WRAPPERS
84 select HAVE_FUNCTION_TRACER
87 select HAVE_KRETPROBES
88 select HAVE_KVM if 64BIT
89 select HAVE_ARCH_TRACEHOOK
90 select INIT_ALL_POSSIBLE
94 source "kernel/Kconfig.freezer"
98 comment "Processor type and features"
100 source "kernel/time/Kconfig"
105 Select this option if you have a 64 bit IBM zSeries machine
106 and want to use the 64 bit addressing mode.
113 bool "Symmetric multi-processing support"
115 This enables support for systems with more than one CPU. If you have
116 a system with only one CPU, like most personal computers, say N. If
117 you have a system with more than one CPU, say Y.
119 If you say N here, the kernel will run on single and multiprocessor
120 machines, but will use only one CPU of a multiprocessor machine. If
121 you say Y here, the kernel will run on many, but not all,
122 singleprocessor machines. On a singleprocessor machine, the kernel
123 will run faster if you say N here.
125 See also the SMP-HOWTO available at
126 <http://www.tldp.org/docs.html#howto>.
128 Even if you don't know what to do here, say Y.
131 int "Maximum number of CPUs (2-64)"
134 default "32" if !64BIT
135 default "64" if 64BIT
137 This allows you to specify the maximum number of CPUs which this
138 kernel will support. The maximum supported value is 64 and the
139 minimum value which makes sense is 2.
141 This is purely to save memory - each supported CPU adds
142 approximately sixteen kilobytes to the kernel image.
145 bool "Support for hot-pluggable CPUs"
150 Say Y here to be able to turn CPUs off and on. CPUs
151 can be controlled through /sys/devices/system/cpu/cpu#.
152 Say N if you want to disable CPU hotplug.
155 bool "IEEE FPU emulation"
158 This option is required for IEEE compliant floating point arithmetic
159 on older S/390 machines. Say Y unless you know your machine doesn't
163 bool "Kernel support for 31 bit emulation"
165 select COMPAT_BINFMT_ELF
167 Select this option if you want to enable your system kernel to
168 handle system-calls from ELF binaries for 31 bit ESA. This option
169 (and some other stuff like libraries and such) is needed for
170 executing 31 bit applications. It is safe to say "Y".
172 config SYSVIPC_COMPAT
174 depends on COMPAT && SYSVIPC
181 config S390_SWITCH_AMODE
182 bool "Switch kernel/user addressing modes"
184 This option allows to switch the addressing modes of kernel and user
185 space. The kernel parameter switch_amode=on will enable this feature,
186 default is disabled. Enabling this (via kernel parameter) on machines
187 earlier than IBM System z9-109 EC/BC will reduce system performance.
189 Note that this option will also be selected by selecting the execute
190 protection option below. Enabling the execute protection via the
191 noexec kernel parameter will also switch the addressing modes,
192 independent of the switch_amode kernel parameter.
195 config S390_EXEC_PROTECT
196 bool "Data execute protection"
197 select S390_SWITCH_AMODE
199 This option allows to enable a buffer overflow protection for user
200 space programs and it also selects the addressing mode option above.
201 The kernel parameter noexec=on will enable this feature and also
202 switch the addressing modes, default is disabled. Enabling this (via
203 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
204 will reduce system performance.
206 comment "Code generation options"
209 prompt "Processor type"
213 bool "S/390 model G5 and G6"
216 Select this to build a 31 bit kernel that works
217 on all S/390 and zSeries machines.
220 bool "IBM eServer zSeries model z800 and z900"
222 Select this to optimize for zSeries machines. This
223 will enable some optimizations that are not available
224 on older 31 bit only CPUs.
227 bool "IBM eServer zSeries model z890 and z990"
229 Select this enable optimizations for model z890/z990.
230 This will be slightly faster but does not work on
231 older machines such as the z900.
236 Select this to enable optimizations for IBM System z9-109, IBM
237 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
238 Class (z9 BC). The kernel will be slightly faster but will not
239 work on older machines such as the z990, z890, z900, and z800.
242 bool "IBM System z10"
244 Select this to enable optimizations for IBM System z10. The
245 kernel will be slightly faster but will not work on older
246 machines such as the z990, z890, z900, z800, z9-109, z9-ec
252 bool "Pack kernel stack"
254 This option enables the compiler option -mkernel-backchain if it
255 is available. If the option is available the compiler supports
256 the new stack layout which dramatically reduces the minimum stack
257 frame size. With an old compiler a non-leaf function needs a
258 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
259 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
260 and 24 byte on 64 bit.
262 Say Y if you are unsure.
265 bool "Use 8kb for kernel stack instead of 16kb"
266 depends on PACK_STACK && 64BIT && !LOCKDEP
268 If you say Y here and the compiler supports the -mkernel-backchain
269 option the kernel will use a smaller kernel stack size. The reduced
270 size is 8kb instead of 16kb. This allows to run more threads on a
271 system and reduces the pressure on the memory management for higher
272 order page allocations.
274 Say N if you are unsure.
277 bool "Detect kernel stack overflow"
279 This option enables the compiler option -mstack-guard and
280 -mstack-size if they are available. If the compiler supports them
281 it will emit additional code to each function prolog to trigger
282 an illegal operation if the kernel stack is about to overflow.
284 Say N if you are unsure.
287 int "Size of the guard area (128-1024)"
289 depends on CHECK_STACK
292 This allows you to specify the size of the guard area at the lower
293 end of the kernel stack. If the kernel stack points into the guard
294 area on function entry an illegal operation is triggered. The size
295 needs to be a power of 2. Please keep in mind that the size of an
296 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
297 The minimum size for the stack guard should be 256 for 31 bit and
301 bool "Emit compiler warnings for function with broken stack usage"
303 This option enables the compiler options -mwarn-framesize and
304 -mwarn-dynamicstack. If the compiler supports these options it
305 will generate warnings for function which either use alloca or
306 create a stack frame bigger than CONFIG_WARN_STACK_SIZE.
308 Say N if you are unsure.
310 config WARN_STACK_SIZE
311 int "Maximum frame size considered safe (128-2048)"
313 depends on WARN_STACK
316 This allows you to specify the maximum frame size a function may
317 have without the compiler complaining about it.
319 config ARCH_POPULATES_NODE_MAP
322 comment "Kernel preemption"
324 source "kernel/Kconfig.preempt"
326 config ARCH_SPARSEMEM_ENABLE
328 select SPARSEMEM_VMEMMAP_ENABLE
329 select SPARSEMEM_VMEMMAP
330 select SPARSEMEM_STATIC if !64BIT
332 config ARCH_SPARSEMEM_DEFAULT
335 config ARCH_SELECT_MEMORY_MODEL
338 config ARCH_ENABLE_MEMORY_HOTPLUG
342 config ARCH_ENABLE_MEMORY_HOTREMOVE
347 comment "I/O subsystem configuration"
350 tristate "QDIO support"
352 This driver provides the Queued Direct I/O base support for
355 To compile this driver as a module, choose M here: the
356 module will be called qdio.
361 tristate "Support for CHSC subchannels"
363 This driver allows usage of CHSC subchannels. A CHSC subchannel
364 is usually present on LPAR only.
365 The driver creates a device /dev/chsc, which may be used to
366 obtain I/O configuration information about the machine and
367 to issue asynchronous chsc commands (DANGEROUS).
368 You will usually only want to use this interface on a special
369 LPAR designated for system management.
371 To compile this driver as a module, choose M here: the
372 module will be called chsc_sch.
379 bool "Builtin IPL record support"
381 If you want to use the produced kernel to IPL directly from a
382 device, you have to merge a bootsector specific to the device
383 into the first bytes of the kernel. You will have to select the
387 prompt "IPL method generated into head.S"
391 Select "tape" if you want to IPL the image from a Tape.
393 Select "vm_reader" if you are running under VM/ESA and want
394 to IPL the image from the emulated card reader.
404 source "fs/Kconfig.binfmt"
406 config FORCE_MAX_ZONEORDER
411 bool "Show crashed user process info"
413 Say Y to print all process fault locations to the console. This is
414 a debugging option; you probably do not want to set it unless you
415 are an S390 port maintainer.
418 bool "Pseudo page fault support"
420 Select this option, if you want to use PFAULT pseudo page fault
421 handling under VM. If running native or in LPAR, this option
422 has no effect. If your VM does not support PFAULT, PAGEEX
423 pseudo page fault handling will be used.
424 Note that VM 4.2 supports PFAULT but has a bug in its
425 implementation that causes some problems.
426 Everybody who wants to run Linux under VM != VM4.2 should select
430 bool "VM shared kernel support"
432 Select this option, if you want to share the text segment of the
433 Linux kernel between different VM guests. This reduces memory
434 usage with lots of guests but greatly increases kernel size.
435 Also if a kernel was IPL'ed from a shared segment the kexec system
437 You should only select this option if you know what you are
438 doing and want to exploit this feature.
441 tristate "Cooperative memory management"
443 Select this option, if you want to enable the kernel interface
444 to reduce the memory size of the system. This is accomplished
445 by allocating pages of memory and put them "on hold". This only
446 makes sense for a system running under VM where the unused pages
447 will be reused by VM for other guest systems. The interface
448 allows an external monitor to balance memory of many systems.
449 Everybody who wants to run Linux under VM should select this
453 bool "/proc interface to cooperative memory management"
456 Select this option to enable the /proc interface to the
457 cooperative memory management.
460 bool "IUCV special message interface to cooperative memory management"
461 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
463 Select this option to enable the special message interface to
464 the cooperative memory management.
467 bool "Unused page notification"
469 This enables the notification of unused pages to the
470 hypervisor. The ESSA instruction is used to do the states
471 changes between a page that has content and the unused state.
474 bool "Linux - VM Monitor Stream, base infrastructure"
477 This provides a kernel interface for creating and updating z/VM APPLDATA
478 monitor records. The monitor records are updated at certain time
479 intervals, once the timer is started.
480 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
481 i.e. enables or disables monitoring on the Linux side.
482 A custom interval value (in seconds) can be written to
483 /proc/appldata/interval.
485 Defaults are 60 seconds interval and timer off.
486 The /proc entries can also be read from, showing the current settings.
489 tristate "Monitor memory management statistics"
490 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
492 This provides memory management related data to the Linux - VM Monitor
493 Stream, like paging/swapping rate, memory utilisation, etc.
494 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
495 APPLDATA monitor record, i.e. enables or disables monitoring this record
499 The /proc entry can also be read from, showing the current settings.
501 This can also be compiled as a module, which will be called
505 tristate "Monitor OS statistics"
506 depends on APPLDATA_BASE
508 This provides OS related data to the Linux - VM Monitor Stream, like
509 CPU utilisation, etc.
510 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
511 APPLDATA monitor record, i.e. enables or disables monitoring this record
515 This can also be compiled as a module, which will be called
518 config APPLDATA_NET_SUM
519 tristate "Monitor overall network statistics"
520 depends on APPLDATA_BASE && NET
522 This provides network related data to the Linux - VM Monitor Stream,
523 currently there is only a total sum of network I/O statistics, no
525 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
526 APPLDATA monitor record, i.e. enables or disables monitoring this record
530 This can also be compiled as a module, which will be called
533 source kernel/Kconfig.hz
536 bool "s390 hypervisor file system support"
537 select SYS_HYPERVISOR
540 This is a virtual file system intended to provide accounting
541 information in an s390 hypervisor environment.
544 bool "kexec system call"
546 kexec is a system call that implements the ability to shutdown your
547 current kernel, and to start another kernel. It is like a reboot
548 but is independent of hardware/microcode support.
551 bool "zfcpdump support"
555 Select this option if you want to build an zfcpdump enabled kernel.
556 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
559 bool "s390 guest support for KVM (EXPERIMENTAL)"
560 depends on 64BIT && EXPERIMENTAL
563 select VIRTIO_CONSOLE
565 Select this option if you want to run the kernel as a guest under
566 the KVM hypervisor. This will add detection for KVM as well as a
567 virtio transport. If KVM is detected, the virtio console will be
579 source "drivers/Kconfig"
583 source "arch/s390/Kconfig.debug"
585 source "security/Kconfig"
587 source "crypto/Kconfig"
591 source "arch/s390/kvm/Kconfig"
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