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_FUNCTION_TRACER
83 select HAVE_KRETPROBES
84 select HAVE_KVM if 64BIT
85 select HAVE_ARCH_TRACEHOOK
89 source "kernel/Kconfig.freezer"
93 comment "Processor type and features"
95 source "kernel/time/Kconfig"
100 Select this option if you have a 64 bit IBM zSeries machine
101 and want to use the 64 bit addressing mode.
108 bool "Symmetric multi-processing support"
110 This enables support for systems with more than one CPU. If you have
111 a system with only one CPU, like most personal computers, say N. If
112 you have a system with more than one CPU, say Y.
114 If you say N here, the kernel will run on single and multiprocessor
115 machines, but will use only one CPU of a multiprocessor machine. If
116 you say Y here, the kernel will run on many, but not all,
117 singleprocessor machines. On a singleprocessor machine, the kernel
118 will run faster if you say N here.
120 See also the SMP-HOWTO available at
121 <http://www.tldp.org/docs.html#howto>.
123 Even if you don't know what to do here, say Y.
126 int "Maximum number of CPUs (2-64)"
129 default "32" if !64BIT
130 default "64" if 64BIT
132 This allows you to specify the maximum number of CPUs which this
133 kernel will support. The maximum supported value is 64 and the
134 minimum value which makes sense is 2.
136 This is purely to save memory - each supported CPU adds
137 approximately sixteen kilobytes to the kernel image.
140 bool "Support for hot-pluggable CPUs"
145 Say Y here to be able to turn CPUs off and on. CPUs
146 can be controlled through /sys/devices/system/cpu/cpu#.
147 Say N if you want to disable CPU hotplug.
150 bool "IEEE FPU emulation"
153 This option is required for IEEE compliant floating point arithmetic
154 on older S/390 machines. Say Y unless you know your machine doesn't
158 bool "Kernel support for 31 bit emulation"
160 select COMPAT_BINFMT_ELF
162 Select this option if you want to enable your system kernel to
163 handle system-calls from ELF binaries for 31 bit ESA. This option
164 (and some other stuff like libraries and such) is needed for
165 executing 31 bit applications. It is safe to say "Y".
167 config SYSVIPC_COMPAT
169 depends on COMPAT && SYSVIPC
176 config S390_SWITCH_AMODE
177 bool "Switch kernel/user addressing modes"
179 This option allows to switch the addressing modes of kernel and user
180 space. The kernel parameter switch_amode=on will enable this feature,
181 default is disabled. Enabling this (via kernel parameter) on machines
182 earlier than IBM System z9-109 EC/BC will reduce system performance.
184 Note that this option will also be selected by selecting the execute
185 protection option below. Enabling the execute protection via the
186 noexec kernel parameter will also switch the addressing modes,
187 independent of the switch_amode kernel parameter.
190 config S390_EXEC_PROTECT
191 bool "Data execute protection"
192 select S390_SWITCH_AMODE
194 This option allows to enable a buffer overflow protection for user
195 space programs and it also selects the addressing mode option above.
196 The kernel parameter noexec=on will enable this feature and also
197 switch the addressing modes, default is disabled. Enabling this (via
198 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
199 will reduce system performance.
201 comment "Code generation options"
204 prompt "Processor type"
208 bool "S/390 model G5 and G6"
211 Select this to build a 31 bit kernel that works
212 on all S/390 and zSeries machines.
215 bool "IBM eServer zSeries model z800 and z900"
217 Select this to optimize for zSeries machines. This
218 will enable some optimizations that are not available
219 on older 31 bit only CPUs.
222 bool "IBM eServer zSeries model z890 and z990"
224 Select this enable optimizations for model z890/z990.
225 This will be slightly faster but does not work on
226 older machines such as the z900.
231 Select this to enable optimizations for IBM System z9-109, IBM
232 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
233 Class (z9 BC). The kernel will be slightly faster but will not
234 work on older machines such as the z990, z890, z900, and z800.
237 bool "IBM System z10"
239 Select this to enable optimizations for IBM System z10. The
240 kernel will be slightly faster but will not work on older
241 machines such as the z990, z890, z900, z800, z9-109, z9-ec
247 bool "Pack kernel stack"
249 This option enables the compiler option -mkernel-backchain if it
250 is available. If the option is available the compiler supports
251 the new stack layout which dramatically reduces the minimum stack
252 frame size. With an old compiler a non-leaf function needs a
253 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
254 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
255 and 24 byte on 64 bit.
257 Say Y if you are unsure.
260 bool "Use 8kb for kernel stack instead of 16kb"
261 depends on PACK_STACK && 64BIT && !LOCKDEP
263 If you say Y here and the compiler supports the -mkernel-backchain
264 option the kernel will use a smaller kernel stack size. The reduced
265 size is 8kb instead of 16kb. This allows to run more threads on a
266 system and reduces the pressure on the memory management for higher
267 order page allocations.
269 Say N if you are unsure.
272 bool "Detect kernel stack overflow"
274 This option enables the compiler option -mstack-guard and
275 -mstack-size if they are available. If the compiler supports them
276 it will emit additional code to each function prolog to trigger
277 an illegal operation if the kernel stack is about to overflow.
279 Say N if you are unsure.
282 int "Size of the guard area (128-1024)"
284 depends on CHECK_STACK
287 This allows you to specify the size of the guard area at the lower
288 end of the kernel stack. If the kernel stack points into the guard
289 area on function entry an illegal operation is triggered. The size
290 needs to be a power of 2. Please keep in mind that the size of an
291 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
292 The minimum size for the stack guard should be 256 for 31 bit and
296 bool "Emit compiler warnings for function with broken stack usage"
298 This option enables the compiler options -mwarn-framesize and
299 -mwarn-dynamicstack. If the compiler supports these options it
300 will generate warnings for function which either use alloca or
301 create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
303 Say N if you are unsure.
305 config WARN_STACK_SIZE
306 int "Maximum frame size considered safe (128-2048)"
308 depends on WARN_STACK
311 This allows you to specify the maximum frame size a function may
312 have without the compiler complaining about it.
314 config ARCH_POPULATES_NODE_MAP
317 comment "Kernel preemption"
319 source "kernel/Kconfig.preempt"
321 config ARCH_SPARSEMEM_ENABLE
323 select SPARSEMEM_VMEMMAP_ENABLE
324 select SPARSEMEM_VMEMMAP
325 select SPARSEMEM_STATIC if !64BIT
327 config ARCH_SPARSEMEM_DEFAULT
330 config ARCH_SELECT_MEMORY_MODEL
333 config ARCH_ENABLE_MEMORY_HOTPLUG
337 config ARCH_ENABLE_MEMORY_HOTREMOVE
342 comment "I/O subsystem configuration"
344 config MACHCHK_WARNING
345 bool "Process warning machine checks"
347 Select this option if you want the machine check handler on IBM S/390 or
348 zSeries to process warning machine checks (e.g. on power failures).
352 tristate "QDIO support"
354 This driver provides the Queued Direct I/O base support for
357 To compile this driver as a module, choose M here: the
358 module will be called qdio.
363 tristate "Support for CHSC subchannels"
365 This driver allows usage of CHSC subchannels. A CHSC subchannel
366 is usually present on LPAR only.
367 The driver creates a device /dev/chsc, which may be used to
368 obtain I/O configuration information about the machine and
369 to issue asynchronous chsc commands (DANGEROUS).
370 You will usually only want to use this interface on a special
371 LPAR designated for system management.
373 To compile this driver as a module, choose M here: the
374 module will be called chsc_sch.
381 bool "Builtin IPL record support"
383 If you want to use the produced kernel to IPL directly from a
384 device, you have to merge a bootsector specific to the device
385 into the first bytes of the kernel. You will have to select the
389 prompt "IPL method generated into head.S"
393 Select "tape" if you want to IPL the image from a Tape.
395 Select "vm_reader" if you are running under VM/ESA and want
396 to IPL the image from the emulated card reader.
406 source "fs/Kconfig.binfmt"
408 config FORCE_MAX_ZONEORDER
413 bool "Show crashed user process info"
415 Say Y to print all process fault locations to the console. This is
416 a debugging option; you probably do not want to set it unless you
417 are an S390 port maintainer.
420 bool "Pseudo page fault support"
422 Select this option, if you want to use PFAULT pseudo page fault
423 handling under VM. If running native or in LPAR, this option
424 has no effect. If your VM does not support PFAULT, PAGEEX
425 pseudo page fault handling will be used.
426 Note that VM 4.2 supports PFAULT but has a bug in its
427 implementation that causes some problems.
428 Everybody who wants to run Linux under VM != VM4.2 should select
432 bool "VM shared kernel support"
434 Select this option, if you want to share the text segment of the
435 Linux kernel between different VM guests. This reduces memory
436 usage with lots of guests but greatly increases kernel size.
437 Also if a kernel was IPL'ed from a shared segment the kexec system
439 You should only select this option if you know what you are
440 doing and want to exploit this feature.
443 tristate "Cooperative memory management"
445 Select this option, if you want to enable the kernel interface
446 to reduce the memory size of the system. This is accomplished
447 by allocating pages of memory and put them "on hold". This only
448 makes sense for a system running under VM where the unused pages
449 will be reused by VM for other guest systems. The interface
450 allows an external monitor to balance memory of many systems.
451 Everybody who wants to run Linux under VM should select this
455 bool "/proc interface to cooperative memory management"
458 Select this option to enable the /proc interface to the
459 cooperative memory management.
462 bool "IUCV special message interface to cooperative memory management"
463 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
465 Select this option to enable the special message interface to
466 the cooperative memory management.
469 bool "Unused page notification"
471 This enables the notification of unused pages to the
472 hypervisor. The ESSA instruction is used to do the states
473 changes between a page that has content and the unused state.
476 bool "Linux - VM Monitor Stream, base infrastructure"
479 This provides a kernel interface for creating and updating z/VM APPLDATA
480 monitor records. The monitor records are updated at certain time
481 intervals, once the timer is started.
482 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
483 i.e. enables or disables monitoring on the Linux side.
484 A custom interval value (in seconds) can be written to
485 /proc/appldata/interval.
487 Defaults are 60 seconds interval and timer off.
488 The /proc entries can also be read from, showing the current settings.
491 tristate "Monitor memory management statistics"
492 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
494 This provides memory management related data to the Linux - VM Monitor
495 Stream, like paging/swapping rate, memory utilisation, etc.
496 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
497 APPLDATA monitor record, i.e. enables or disables monitoring this record
501 The /proc entry can also be read from, showing the current settings.
503 This can also be compiled as a module, which will be called
507 tristate "Monitor OS statistics"
508 depends on APPLDATA_BASE
510 This provides OS related data to the Linux - VM Monitor Stream, like
511 CPU utilisation, etc.
512 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
513 APPLDATA monitor record, i.e. enables or disables monitoring this record
517 This can also be compiled as a module, which will be called
520 config APPLDATA_NET_SUM
521 tristate "Monitor overall network statistics"
522 depends on APPLDATA_BASE
524 This provides network related data to the Linux - VM Monitor Stream,
525 currently there is only a total sum of network I/O statistics, no
527 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
528 APPLDATA monitor record, i.e. enables or disables monitoring this record
532 This can also be compiled as a module, which will be called
535 source kernel/Kconfig.hz
538 bool "s390 hypervisor file system support"
539 select SYS_HYPERVISOR
542 This is a virtual file system intended to provide accounting
543 information in an s390 hypervisor environment.
546 bool "kexec system call"
548 kexec is a system call that implements the ability to shutdown your
549 current kernel, and to start another kernel. It is like a reboot
550 but is independent of hardware/microcode support.
553 tristate "zfcpdump support"
557 Select this option if you want to build an zfcpdump enabled kernel.
558 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
561 bool "s390 guest support for KVM (EXPERIMENTAL)"
562 depends on 64BIT && EXPERIMENTAL
565 select VIRTIO_CONSOLE
567 Select this option if you want to run the kernel as a guest under
568 the KVM hypervisor. This will add detection for KVM as well as a
569 virtio transport. If KVM is detected, the virtio console will be
581 source "drivers/Kconfig"
585 source "arch/s390/Kconfig.debug"
587 source "security/Kconfig"
589 source "crypto/Kconfig"
593 source "arch/s390/kvm/Kconfig"
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