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
85 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
86 select HAVE_FTRACE_MCOUNT_RECORD
87 select HAVE_SYSCALL_TRACEPOINTS
88 select HAVE_DYNAMIC_FTRACE
89 select HAVE_FUNCTION_GRAPH_TRACER
90 select HAVE_DEFAULT_NO_SPIN_MUTEXES
93 select HAVE_KRETPROBES
94 select HAVE_KVM if 64BIT
95 select HAVE_ARCH_TRACEHOOK
96 select INIT_ALL_POSSIBLE
97 select HAVE_PERF_EVENTS
99 config SCHED_OMIT_FRAME_POINTER
103 source "init/Kconfig"
105 source "kernel/Kconfig.freezer"
109 comment "Processor type and features"
111 source "kernel/time/Kconfig"
116 Select this option if you have a 64 bit IBM zSeries machine
117 and want to use the 64 bit addressing mode.
127 bool "Symmetric multi-processing support"
129 This enables support for systems with more than one CPU. If you have
130 a system with only one CPU, like most personal computers, say N. If
131 you have a system with more than one CPU, say Y.
133 If you say N here, the kernel will run on single and multiprocessor
134 machines, but will use only one CPU of a multiprocessor machine. If
135 you say Y here, the kernel will run on many, but not all,
136 singleprocessor machines. On a singleprocessor machine, the kernel
137 will run faster if you say N here.
139 See also the SMP-HOWTO available at
140 <http://www.tldp.org/docs.html#howto>.
142 Even if you don't know what to do here, say Y.
145 int "Maximum number of CPUs (2-64)"
148 default "32" if !64BIT
149 default "64" if 64BIT
151 This allows you to specify the maximum number of CPUs which this
152 kernel will support. The maximum supported value is 64 and the
153 minimum value which makes sense is 2.
155 This is purely to save memory - each supported CPU adds
156 approximately sixteen kilobytes to the kernel image.
159 bool "Support for hot-pluggable CPUs"
164 Say Y here to be able to turn CPUs off and on. CPUs
165 can be controlled through /sys/devices/system/cpu/cpu#.
166 Say N if you want to disable CPU hotplug.
169 bool "IEEE FPU emulation"
172 This option is required for IEEE compliant floating point arithmetic
173 on older S/390 machines. Say Y unless you know your machine doesn't
177 bool "Kernel support for 31 bit emulation"
179 select COMPAT_BINFMT_ELF
181 Select this option if you want to enable your system kernel to
182 handle system-calls from ELF binaries for 31 bit ESA. This option
183 (and some other stuff like libraries and such) is needed for
184 executing 31 bit applications. It is safe to say "Y".
186 config SYSVIPC_COMPAT
188 depends on COMPAT && SYSVIPC
195 config S390_EXEC_PROTECT
196 bool "Data execute protection"
198 This option allows to enable a buffer overflow protection for user
199 space programs and it also selects the addressing mode option above.
200 The kernel parameter noexec=on will enable this feature and also
201 switch the addressing modes, default is disabled. Enabling this (via
202 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
203 will reduce system performance.
205 comment "Code generation options"
208 prompt "Processor type"
212 bool "S/390 model G5 and G6"
215 Select this to build a 31 bit kernel that works
216 on all S/390 and zSeries machines.
219 bool "IBM eServer zSeries model z800 and z900"
221 Select this to optimize for zSeries machines. This
222 will enable some optimizations that are not available
223 on older 31 bit only CPUs.
226 bool "IBM eServer zSeries model z890 and z990"
228 Select this enable optimizations for model z890/z990.
229 This will be slightly faster but does not work on
230 older machines such as the z900.
235 Select this to enable optimizations for IBM System z9-109, IBM
236 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
237 Class (z9 BC). The kernel will be slightly faster but will not
238 work on older machines such as the z990, z890, z900, and z800.
241 bool "IBM System z10"
243 Select this to enable optimizations for IBM System z10. The
244 kernel will be slightly faster but will not work on older
245 machines such as the z990, z890, z900, z800, z9-109, z9-ec
251 bool "Pack kernel stack"
253 This option enables the compiler option -mkernel-backchain if it
254 is available. If the option is available the compiler supports
255 the new stack layout which dramatically reduces the minimum stack
256 frame size. With an old compiler a non-leaf function needs a
257 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
258 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
259 and 24 byte on 64 bit.
261 Say Y if you are unsure.
264 bool "Use 8kb for kernel stack instead of 16kb"
265 depends on PACK_STACK && 64BIT && !LOCKDEP
267 If you say Y here and the compiler supports the -mkernel-backchain
268 option the kernel will use a smaller kernel stack size. The reduced
269 size is 8kb instead of 16kb. This allows to run more threads on a
270 system and reduces the pressure on the memory management for higher
271 order page allocations.
273 Say N if you are unsure.
276 bool "Detect kernel stack overflow"
278 This option enables the compiler option -mstack-guard and
279 -mstack-size if they are available. If the compiler supports them
280 it will emit additional code to each function prolog to trigger
281 an illegal operation if the kernel stack is about to overflow.
283 Say N if you are unsure.
286 int "Size of the guard area (128-1024)"
288 depends on CHECK_STACK
291 This allows you to specify the size of the guard area at the lower
292 end of the kernel stack. If the kernel stack points into the guard
293 area on function entry an illegal operation is triggered. The size
294 needs to be a power of 2. Please keep in mind that the size of an
295 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
296 The minimum size for the stack guard should be 256 for 31 bit and
300 bool "Emit compiler warnings for function with broken stack usage"
302 This option enables the compiler options -mwarn-framesize and
303 -mwarn-dynamicstack. If the compiler supports these options it
304 will generate warnings for function which either use alloca or
305 create a stack frame bigger than CONFIG_WARN_STACK_SIZE.
307 Say N if you are unsure.
309 config WARN_STACK_SIZE
310 int "Maximum frame size considered safe (128-2048)"
312 depends on WARN_STACK
315 This allows you to specify the maximum frame size a function may
316 have without the compiler complaining about it.
318 config ARCH_POPULATES_NODE_MAP
321 comment "Kernel preemption"
323 source "kernel/Kconfig.preempt"
325 config ARCH_SPARSEMEM_ENABLE
327 select SPARSEMEM_VMEMMAP_ENABLE
328 select SPARSEMEM_VMEMMAP
329 select SPARSEMEM_STATIC if !64BIT
331 config ARCH_SPARSEMEM_DEFAULT
334 config ARCH_SELECT_MEMORY_MODEL
337 config ARCH_ENABLE_MEMORY_HOTPLUG
341 config ARCH_ENABLE_MEMORY_HOTREMOVE
344 config ARCH_HIBERNATION_POSSIBLE
349 comment "I/O subsystem configuration"
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 "Linux - VM Monitor Stream, base infrastructure"
472 This provides a kernel interface for creating and updating z/VM APPLDATA
473 monitor records. The monitor records are updated at certain time
474 intervals, once the timer is started.
475 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
476 i.e. enables or disables monitoring on the Linux side.
477 A custom interval value (in seconds) can be written to
478 /proc/appldata/interval.
480 Defaults are 60 seconds interval and timer off.
481 The /proc entries can also be read from, showing the current settings.
484 tristate "Monitor memory management statistics"
485 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
487 This provides memory management related data to the Linux - VM Monitor
488 Stream, like paging/swapping rate, memory utilisation, etc.
489 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
490 APPLDATA monitor record, i.e. enables or disables monitoring this record
494 The /proc entry can also be read from, showing the current settings.
496 This can also be compiled as a module, which will be called
500 tristate "Monitor OS statistics"
501 depends on APPLDATA_BASE
503 This provides OS related data to the Linux - VM Monitor Stream, like
504 CPU utilisation, etc.
505 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
506 APPLDATA monitor record, i.e. enables or disables monitoring this record
510 This can also be compiled as a module, which will be called
513 config APPLDATA_NET_SUM
514 tristate "Monitor overall network statistics"
515 depends on APPLDATA_BASE && NET
517 This provides network related data to the Linux - VM Monitor Stream,
518 currently there is only a total sum of network I/O statistics, no
520 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
521 APPLDATA monitor record, i.e. enables or disables monitoring this record
525 This can also be compiled as a module, which will be called
528 source kernel/Kconfig.hz
531 bool "s390 hypervisor file system support"
532 select SYS_HYPERVISOR
535 This is a virtual file system intended to provide accounting
536 information in an s390 hypervisor environment.
539 bool "kexec system call"
541 kexec is a system call that implements the ability to shutdown your
542 current kernel, and to start another kernel. It is like a reboot
543 but is independent of hardware/microcode support.
546 bool "zfcpdump support"
550 Select this option if you want to build an zfcpdump enabled kernel.
551 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
554 bool "s390 guest support for KVM (EXPERIMENTAL)"
555 depends on 64BIT && EXPERIMENTAL
558 select VIRTIO_CONSOLE
560 Select this option if you want to run the kernel as a guest under
561 the KVM hypervisor. This will add detection for KVM as well as a
562 virtio transport. If KVM is detected, the virtio console will be
566 bool "Enable seccomp to safely compute untrusted bytecode"
570 This kernel feature is useful for number crunching applications
571 that may need to compute untrusted bytecode during their
572 execution. By using pipes or other transports made available to
573 the process as file descriptors supporting the read/write
574 syscalls, it's possible to isolate those applications in
575 their own address space using seccomp. Once seccomp is
576 enabled via /proc/<pid>/seccomp, it cannot be disabled
577 and the task is only allowed to execute a few safe syscalls
578 defined by each seccomp mode.
584 menu "Power Management"
586 source "kernel/power/Kconfig"
598 source "drivers/Kconfig"
602 source "arch/s390/Kconfig.debug"
604 source "security/Kconfig"
606 source "crypto/Kconfig"
610 source "arch/s390/kvm/Kconfig"