2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
13 config LOCKDEP_SUPPORT
16 config STACKTRACE_SUPPORT
19 config HAVE_LATENCYTOP_SUPPORT
22 config RWSEM_GENERIC_SPINLOCK
25 config RWSEM_XCHGADD_ALGORITHM
28 config ARCH_HAS_ILOG2_U32
32 config ARCH_HAS_ILOG2_U64
36 config GENERIC_HWEIGHT
53 config GENERIC_LOCKBREAK
56 depends on SMP && PREEMPT
58 mainmenu "Linux Kernel Configuration"
64 <<<<<<< HEAD:arch/s390/Kconfig
66 select HAVE_KRETPROBES
67 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:arch/s390/Kconfig
73 comment "Processor type and features"
78 Select this option if you have a 64 bit IBM zSeries machine
79 and want to use the 64 bit addressing mode.
86 bool "Symmetric multi-processing support"
88 This enables support for systems with more than one CPU. If you have
89 a system with only one CPU, like most personal computers, say N. If
90 you have a system with more than one CPU, say Y.
92 If you say N here, the kernel will run on single and multiprocessor
93 machines, but will use only one CPU of a multiprocessor machine. If
94 you say Y here, the kernel will run on many, but not all,
95 singleprocessor machines. On a singleprocessor machine, the kernel
96 will run faster if you say N here.
98 See also the SMP-HOWTO available at
99 <http://www.tldp.org/docs.html#howto>.
101 Even if you don't know what to do here, say Y.
104 int "Maximum number of CPUs (2-64)"
107 <<<<<<< HEAD:arch/s390/Kconfig
110 default "32" if !64BIT
111 default "64" if 64BIT
112 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:arch/s390/Kconfig
114 This allows you to specify the maximum number of CPUs which this
115 kernel will support. The maximum supported value is 64 and the
116 minimum value which makes sense is 2.
118 This is purely to save memory - each supported CPU adds
119 approximately sixteen kilobytes to the kernel image.
122 bool "Support for hot-pluggable CPUs"
127 Say Y here to be able to turn CPUs off and on. CPUs
128 can be controlled through /sys/devices/system/cpu/cpu#.
129 Say N if you want to disable CPU hotplug.
132 bool "IEEE FPU emulation"
135 This option is required for IEEE compliant floating point arithmetic
136 on older S/390 machines. Say Y unless you know your machine doesn't
140 bool "Kernel support for 31 bit emulation"
143 Select this option if you want to enable your system kernel to
144 handle system-calls from ELF binaries for 31 bit ESA. This option
145 (and some other stuff like libraries and such) is needed for
146 executing 31 bit applications. It is safe to say "Y".
148 config SYSVIPC_COMPAT
150 depends on COMPAT && SYSVIPC
157 config S390_SWITCH_AMODE
158 bool "Switch kernel/user addressing modes"
160 This option allows to switch the addressing modes of kernel and user
161 space. The kernel parameter switch_amode=on will enable this feature,
162 default is disabled. Enabling this (via kernel parameter) on machines
163 earlier than IBM System z9-109 EC/BC will reduce system performance.
165 Note that this option will also be selected by selecting the execute
166 protection option below. Enabling the execute protection via the
167 noexec kernel parameter will also switch the addressing modes,
168 independent of the switch_amode kernel parameter.
171 config S390_EXEC_PROTECT
172 bool "Data execute protection"
173 select S390_SWITCH_AMODE
175 This option allows to enable a buffer overflow protection for user
176 space programs and it also selects the addressing mode option above.
177 The kernel parameter noexec=on will enable this feature and also
178 switch the addressing modes, default is disabled. Enabling this (via
179 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
180 will reduce system performance.
182 comment "Code generation options"
185 prompt "Processor type"
189 bool "S/390 model G5 and G6"
192 Select this to build a 31 bit kernel that works
193 on all S/390 and zSeries machines.
196 bool "IBM eServer zSeries model z800 and z900"
198 Select this to optimize for zSeries machines. This
199 will enable some optimizations that are not available
200 on older 31 bit only CPUs.
203 bool "IBM eServer zSeries model z890 and z990"
205 Select this enable optimizations for model z890/z990.
206 This will be slightly faster but does not work on
207 older machines such as the z900.
212 Select this to enable optimizations for IBM System z9-109, IBM
213 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
214 Class (z9 BC). The kernel will be slightly faster but will not
215 work on older machines such as the z990, z890, z900, and z800.
220 bool "Pack kernel stack"
222 This option enables the compiler option -mkernel-backchain if it
223 is available. If the option is available the compiler supports
224 the new stack layout which dramatically reduces the minimum stack
225 frame size. With an old compiler a non-leaf function needs a
226 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
227 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
228 and 24 byte on 64 bit.
230 Say Y if you are unsure.
233 bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
234 depends on PACK_STACK && !LOCKDEP
236 If you say Y here and the compiler supports the -mkernel-backchain
237 option the kernel will use a smaller kernel stack size. For 31 bit
238 the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
239 instead of 16kb. This allows to run more thread on a system and
240 reduces the pressure on the memory management for higher order
243 Say N if you are unsure.
247 bool "Detect kernel stack overflow"
249 This option enables the compiler option -mstack-guard and
250 -mstack-size if they are available. If the compiler supports them
251 it will emit additional code to each function prolog to trigger
252 an illegal operation if the kernel stack is about to overflow.
254 Say N if you are unsure.
257 int "Size of the guard area (128-1024)"
259 depends on CHECK_STACK
262 This allows you to specify the size of the guard area at the lower
263 end of the kernel stack. If the kernel stack points into the guard
264 area on function entry an illegal operation is triggered. The size
265 needs to be a power of 2. Please keep in mind that the size of an
266 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
267 The minimum size for the stack guard should be 256 for 31 bit and
271 bool "Emit compiler warnings for function with broken stack usage"
273 This option enables the compiler options -mwarn-framesize and
274 -mwarn-dynamicstack. If the compiler supports these options it
275 will generate warnings for function which either use alloca or
276 create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
278 Say N if you are unsure.
280 config WARN_STACK_SIZE
281 int "Maximum frame size considered safe (128-2048)"
283 depends on WARN_STACK
286 This allows you to specify the maximum frame size a function may
287 have without the compiler complaining about it.
289 config ARCH_POPULATES_NODE_MAP
292 comment "Kernel preemption"
294 source "kernel/Kconfig.preempt"
298 comment "I/O subsystem configuration"
300 config MACHCHK_WARNING
301 bool "Process warning machine checks"
303 Select this option if you want the machine check handler on IBM S/390 or
304 zSeries to process warning machine checks (e.g. on power failures).
308 tristate "QDIO support"
310 This driver provides the Queued Direct I/O base support for
313 For details please refer to the documentation provided by IBM at
314 <http://www10.software.ibm.com/developerworks/opensource/linux390>
316 To compile this driver as a module, choose M here: the
317 module will be called qdio.
322 bool "Extended debugging information"
325 Say Y here to get extended debugging output in
326 /sys/kernel/debug/s390dbf/qdio...
327 Warning: this option reduces the performance of the QDIO module.
334 bool "Builtin IPL record support"
336 If you want to use the produced kernel to IPL directly from a
337 device, you have to merge a bootsector specific to the device
338 into the first bytes of the kernel. You will have to select the
342 prompt "IPL method generated into head.S"
346 Select "tape" if you want to IPL the image from a Tape.
348 Select "vm_reader" if you are running under VM/ESA and want
349 to IPL the image from the emulated card reader.
359 source "fs/Kconfig.binfmt"
361 <<<<<<< HEAD:arch/s390/Kconfig
363 config FORCE_MAX_ZONEORDER
367 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:arch/s390/Kconfig
369 bool "Show crashed user process info"
371 Say Y to print all process fault locations to the console. This is
372 a debugging option; you probably do not want to set it unless you
373 are an S390 port maintainer.
376 bool "Pseudo page fault support"
378 Select this option, if you want to use PFAULT pseudo page fault
379 handling under VM. If running native or in LPAR, this option
380 has no effect. If your VM does not support PFAULT, PAGEEX
381 pseudo page fault handling will be used.
382 Note that VM 4.2 supports PFAULT but has a bug in its
383 implementation that causes some problems.
384 Everybody who wants to run Linux under VM != VM4.2 should select
388 bool "VM shared kernel support"
390 Select this option, if you want to share the text segment of the
391 Linux kernel between different VM guests. This reduces memory
392 usage with lots of guests but greatly increases kernel size.
393 Also if a kernel was IPL'ed from a shared segment the kexec system
395 You should only select this option if you know what you are
396 doing and want to exploit this feature.
399 tristate "Cooperative memory management"
401 Select this option, if you want to enable the kernel interface
402 to reduce the memory size of the system. This is accomplished
403 by allocating pages of memory and put them "on hold". This only
404 makes sense for a system running under VM where the unused pages
405 will be reused by VM for other guest systems. The interface
406 allows an external monitor to balance memory of many systems.
407 Everybody who wants to run Linux under VM should select this
411 bool "/proc interface to cooperative memory management"
414 Select this option to enable the /proc interface to the
415 cooperative memory management.
418 bool "IUCV special message interface to cooperative memory management"
419 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
421 Select this option to enable the special message interface to
422 the cooperative memory management.
425 bool "Virtual CPU timer support"
427 This provides a kernel interface for virtual CPU timers.
430 config VIRT_CPU_ACCOUNTING
431 bool "Base user process accounting on virtual cpu timer"
432 depends on VIRT_TIMER
434 Select this option to use CPU timer deltas to do user
438 bool "Linux - VM Monitor Stream, base infrastructure"
439 depends on PROC_FS && VIRT_TIMER=y
441 This provides a kernel interface for creating and updating z/VM APPLDATA
442 monitor records. The monitor records are updated at certain time
443 intervals, once the timer is started.
444 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
445 i.e. enables or disables monitoring on the Linux side.
446 A custom interval value (in seconds) can be written to
447 /proc/appldata/interval.
449 Defaults are 60 seconds interval and timer off.
450 The /proc entries can also be read from, showing the current settings.
453 tristate "Monitor memory management statistics"
454 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
456 This provides memory management related data to the Linux - VM Monitor
457 Stream, like paging/swapping rate, memory utilisation, etc.
458 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
459 APPLDATA monitor record, i.e. enables or disables monitoring this record
463 The /proc entry can also be read from, showing the current settings.
465 This can also be compiled as a module, which will be called
469 tristate "Monitor OS statistics"
470 depends on APPLDATA_BASE
472 This provides OS related data to the Linux - VM Monitor Stream, like
473 CPU utilisation, etc.
474 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
475 APPLDATA monitor record, i.e. enables or disables monitoring this record
479 This can also be compiled as a module, which will be called
482 config APPLDATA_NET_SUM
483 tristate "Monitor overall network statistics"
484 depends on APPLDATA_BASE
486 This provides network related data to the Linux - VM Monitor Stream,
487 currently there is only a total sum of network I/O statistics, no
489 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
490 APPLDATA monitor record, i.e. enables or disables monitoring this record
494 This can also be compiled as a module, which will be called
497 source kernel/Kconfig.hz
500 bool "No HZ timer ticks in idle"
502 Switches the regular HZ timer off when the system is going idle.
503 This helps z/VM to detect that the Linux system is idle. VM can
504 then "swap-out" this guest which reduces memory usage. It also
505 reduces the overhead of idle systems.
507 The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
508 hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
511 config NO_IDLE_HZ_INIT
512 bool "HZ timer in idle off by default"
513 depends on NO_IDLE_HZ
515 The HZ timer is switched off in idle by default. That means the
516 HZ timer is already disabled at boot time.
519 bool "s390 hypervisor file system support"
520 select SYS_HYPERVISOR
523 This is a virtual file system intended to provide accounting
524 information in an s390 hypervisor environment.
527 bool "kexec system call"
529 kexec is a system call that implements the ability to shutdown your
530 current kernel, and to start another kernel. It is like a reboot
531 but is independent of hardware/microcode support.
534 tristate "zfcpdump support"
538 Select this option if you want to build an zfcpdump enabled kernel.
539 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
551 source "drivers/Kconfig"
555 source "arch/s390/Kconfig.debug"
557 source "security/Kconfig"
559 source "crypto/Kconfig"