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
98 select ARCH_INLINE_SPIN_TRYLOCK
99 select ARCH_INLINE_SPIN_TRYLOCK_BH
100 select ARCH_INLINE_SPIN_LOCK
101 select ARCH_INLINE_SPIN_LOCK_BH
102 select ARCH_INLINE_SPIN_LOCK_IRQ
103 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
104 select ARCH_INLINE_SPIN_UNLOCK
105 select ARCH_INLINE_SPIN_UNLOCK_BH
106 select ARCH_INLINE_SPIN_UNLOCK_IRQ
107 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
108 select ARCH_INLINE_READ_TRYLOCK
109 select ARCH_INLINE_READ_LOCK
110 select ARCH_INLINE_READ_LOCK_BH
111 select ARCH_INLINE_READ_LOCK_IRQ
112 select ARCH_INLINE_READ_LOCK_IRQSAVE
113 select ARCH_INLINE_READ_UNLOCK
114 select ARCH_INLINE_READ_UNLOCK_BH
115 select ARCH_INLINE_READ_UNLOCK_IRQ
116 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
117 select ARCH_INLINE_WRITE_TRYLOCK
118 select ARCH_INLINE_WRITE_LOCK
119 select ARCH_INLINE_WRITE_LOCK_BH
120 select ARCH_INLINE_WRITE_LOCK_IRQ
121 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
122 select ARCH_INLINE_WRITE_UNLOCK
123 select ARCH_INLINE_WRITE_UNLOCK_BH
124 select ARCH_INLINE_WRITE_UNLOCK_IRQ
125 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
127 config SCHED_OMIT_FRAME_POINTER
131 source "init/Kconfig"
133 source "kernel/Kconfig.freezer"
137 comment "Processor type and features"
139 source "kernel/time/Kconfig"
144 Select this option if you have a 64 bit IBM zSeries machine
145 and want to use the 64 bit addressing mode.
155 bool "Symmetric multi-processing support"
157 This enables support for systems with more than one CPU. If you have
158 a system with only one CPU, like most personal computers, say N. If
159 you have a system with more than one CPU, say Y.
161 If you say N here, the kernel will run on single and multiprocessor
162 machines, but will use only one CPU of a multiprocessor machine. If
163 you say Y here, the kernel will run on many, but not all,
164 singleprocessor machines. On a singleprocessor machine, the kernel
165 will run faster if you say N here.
167 See also the SMP-HOWTO available at
168 <http://www.tldp.org/docs.html#howto>.
170 Even if you don't know what to do here, say Y.
173 int "Maximum number of CPUs (2-64)"
176 default "32" if !64BIT
177 default "64" if 64BIT
179 This allows you to specify the maximum number of CPUs which this
180 kernel will support. The maximum supported value is 64 and the
181 minimum value which makes sense is 2.
183 This is purely to save memory - each supported CPU adds
184 approximately sixteen kilobytes to the kernel image.
187 bool "Support for hot-pluggable CPUs"
192 Say Y here to be able to turn CPUs off and on. CPUs
193 can be controlled through /sys/devices/system/cpu/cpu#.
194 Say N if you want to disable CPU hotplug.
197 bool "IEEE FPU emulation"
200 This option is required for IEEE compliant floating point arithmetic
201 on older S/390 machines. Say Y unless you know your machine doesn't
205 bool "Kernel support for 31 bit emulation"
207 select COMPAT_BINFMT_ELF
209 Select this option if you want to enable your system kernel to
210 handle system-calls from ELF binaries for 31 bit ESA. This option
211 (and some other stuff like libraries and such) is needed for
212 executing 31 bit applications. It is safe to say "Y".
214 config SYSVIPC_COMPAT
216 depends on COMPAT && SYSVIPC
223 config S390_EXEC_PROTECT
224 bool "Data execute protection"
226 This option allows to enable a buffer overflow protection for user
227 space programs and it also selects the addressing mode option above.
228 The kernel parameter noexec=on will enable this feature and also
229 switch the addressing modes, default is disabled. Enabling this (via
230 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
231 will reduce system performance.
233 comment "Code generation options"
236 prompt "Processor type"
240 bool "S/390 model G5 and G6"
243 Select this to build a 31 bit kernel that works
244 on all S/390 and zSeries machines.
247 bool "IBM eServer zSeries model z800 and z900"
249 Select this to optimize for zSeries machines. This
250 will enable some optimizations that are not available
251 on older 31 bit only CPUs.
254 bool "IBM eServer zSeries model z890 and z990"
256 Select this enable optimizations for model z890/z990.
257 This will be slightly faster but does not work on
258 older machines such as the z900.
263 Select this to enable optimizations for IBM System z9-109, IBM
264 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
265 Class (z9 BC). The kernel will be slightly faster but will not
266 work on older machines such as the z990, z890, z900, and z800.
269 bool "IBM System z10"
271 Select this to enable optimizations for IBM System z10. The
272 kernel will be slightly faster but will not work on older
273 machines such as the z990, z890, z900, z800, z9-109, z9-ec
279 bool "Pack kernel stack"
281 This option enables the compiler option -mkernel-backchain if it
282 is available. If the option is available the compiler supports
283 the new stack layout which dramatically reduces the minimum stack
284 frame size. With an old compiler a non-leaf function needs a
285 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
286 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
287 and 24 byte on 64 bit.
289 Say Y if you are unsure.
292 bool "Use 8kb for kernel stack instead of 16kb"
293 depends on PACK_STACK && 64BIT && !LOCKDEP
295 If you say Y here and the compiler supports the -mkernel-backchain
296 option the kernel will use a smaller kernel stack size. The reduced
297 size is 8kb instead of 16kb. This allows to run more threads on a
298 system and reduces the pressure on the memory management for higher
299 order page allocations.
301 Say N if you are unsure.
304 bool "Detect kernel stack overflow"
306 This option enables the compiler option -mstack-guard and
307 -mstack-size if they are available. If the compiler supports them
308 it will emit additional code to each function prolog to trigger
309 an illegal operation if the kernel stack is about to overflow.
311 Say N if you are unsure.
314 int "Size of the guard area (128-1024)"
316 depends on CHECK_STACK
319 This allows you to specify the size of the guard area at the lower
320 end of the kernel stack. If the kernel stack points into the guard
321 area on function entry an illegal operation is triggered. The size
322 needs to be a power of 2. Please keep in mind that the size of an
323 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
324 The minimum size for the stack guard should be 256 for 31 bit and
328 bool "Emit compiler warnings for function with broken stack usage"
330 This option enables the compiler options -mwarn-framesize and
331 -mwarn-dynamicstack. If the compiler supports these options it
332 will generate warnings for function which either use alloca or
333 create a stack frame bigger than CONFIG_WARN_STACK_SIZE.
335 Say N if you are unsure.
337 config WARN_STACK_SIZE
338 int "Maximum frame size considered safe (128-2048)"
340 depends on WARN_STACK
343 This allows you to specify the maximum frame size a function may
344 have without the compiler complaining about it.
346 config ARCH_POPULATES_NODE_MAP
349 comment "Kernel preemption"
351 source "kernel/Kconfig.preempt"
353 config ARCH_SPARSEMEM_ENABLE
355 select SPARSEMEM_VMEMMAP_ENABLE
356 select SPARSEMEM_VMEMMAP
357 select SPARSEMEM_STATIC if !64BIT
359 config ARCH_SPARSEMEM_DEFAULT
362 config ARCH_SELECT_MEMORY_MODEL
365 config ARCH_ENABLE_MEMORY_HOTPLUG
369 config ARCH_ENABLE_MEMORY_HOTREMOVE
372 config ARCH_HIBERNATION_POSSIBLE
377 comment "I/O subsystem configuration"
380 tristate "QDIO support"
382 This driver provides the Queued Direct I/O base support for
385 To compile this driver as a module, choose M here: the
386 module will be called qdio.
391 tristate "Support for CHSC subchannels"
393 This driver allows usage of CHSC subchannels. A CHSC subchannel
394 is usually present on LPAR only.
395 The driver creates a device /dev/chsc, which may be used to
396 obtain I/O configuration information about the machine and
397 to issue asynchronous chsc commands (DANGEROUS).
398 You will usually only want to use this interface on a special
399 LPAR designated for system management.
401 To compile this driver as a module, choose M here: the
402 module will be called chsc_sch.
409 bool "Builtin IPL record support"
411 If you want to use the produced kernel to IPL directly from a
412 device, you have to merge a bootsector specific to the device
413 into the first bytes of the kernel. You will have to select the
417 prompt "IPL method generated into head.S"
421 Select "tape" if you want to IPL the image from a Tape.
423 Select "vm_reader" if you are running under VM/ESA and want
424 to IPL the image from the emulated card reader.
434 source "fs/Kconfig.binfmt"
436 config FORCE_MAX_ZONEORDER
441 bool "Show crashed user process info"
443 Say Y to print all process fault locations to the console. This is
444 a debugging option; you probably do not want to set it unless you
445 are an S390 port maintainer.
448 bool "Pseudo page fault support"
450 Select this option, if you want to use PFAULT pseudo page fault
451 handling under VM. If running native or in LPAR, this option
452 has no effect. If your VM does not support PFAULT, PAGEEX
453 pseudo page fault handling will be used.
454 Note that VM 4.2 supports PFAULT but has a bug in its
455 implementation that causes some problems.
456 Everybody who wants to run Linux under VM != VM4.2 should select
460 bool "VM shared kernel support"
462 Select this option, if you want to share the text segment of the
463 Linux kernel between different VM guests. This reduces memory
464 usage with lots of guests but greatly increases kernel size.
465 Also if a kernel was IPL'ed from a shared segment the kexec system
467 You should only select this option if you know what you are
468 doing and want to exploit this feature.
471 tristate "Cooperative memory management"
473 Select this option, if you want to enable the kernel interface
474 to reduce the memory size of the system. This is accomplished
475 by allocating pages of memory and put them "on hold". This only
476 makes sense for a system running under VM where the unused pages
477 will be reused by VM for other guest systems. The interface
478 allows an external monitor to balance memory of many systems.
479 Everybody who wants to run Linux under VM should select this
483 bool "/proc interface to cooperative memory management"
486 Select this option to enable the /proc interface to the
487 cooperative memory management.
490 bool "IUCV special message interface to cooperative memory management"
491 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
493 Select this option to enable the special message interface to
494 the cooperative memory management.
497 bool "Linux - VM Monitor Stream, base infrastructure"
500 This provides a kernel interface for creating and updating z/VM APPLDATA
501 monitor records. The monitor records are updated at certain time
502 intervals, once the timer is started.
503 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
504 i.e. enables or disables monitoring on the Linux side.
505 A custom interval value (in seconds) can be written to
506 /proc/appldata/interval.
508 Defaults are 60 seconds interval and timer off.
509 The /proc entries can also be read from, showing the current settings.
512 tristate "Monitor memory management statistics"
513 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
515 This provides memory management related data to the Linux - VM Monitor
516 Stream, like paging/swapping rate, memory utilisation, etc.
517 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
518 APPLDATA monitor record, i.e. enables or disables monitoring this record
522 The /proc entry can also be read from, showing the current settings.
524 This can also be compiled as a module, which will be called
528 tristate "Monitor OS statistics"
529 depends on APPLDATA_BASE
531 This provides OS related data to the Linux - VM Monitor Stream, like
532 CPU utilisation, etc.
533 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
534 APPLDATA monitor record, i.e. enables or disables monitoring this record
538 This can also be compiled as a module, which will be called
541 config APPLDATA_NET_SUM
542 tristate "Monitor overall network statistics"
543 depends on APPLDATA_BASE && NET
545 This provides network related data to the Linux - VM Monitor Stream,
546 currently there is only a total sum of network I/O statistics, no
548 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
549 APPLDATA monitor record, i.e. enables or disables monitoring this record
553 This can also be compiled as a module, which will be called
556 source kernel/Kconfig.hz
559 bool "s390 hypervisor file system support"
560 select SYS_HYPERVISOR
563 This is a virtual file system intended to provide accounting
564 information in an s390 hypervisor environment.
567 bool "kexec system call"
569 kexec is a system call that implements the ability to shutdown your
570 current kernel, and to start another kernel. It is like a reboot
571 but is independent of hardware/microcode support.
574 bool "zfcpdump support"
578 Select this option if you want to build an zfcpdump enabled kernel.
579 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
582 bool "s390 guest support for KVM (EXPERIMENTAL)"
583 depends on 64BIT && EXPERIMENTAL
586 select VIRTIO_CONSOLE
588 Select this option if you want to run the kernel as a guest under
589 the KVM hypervisor. This will add detection for KVM as well as a
590 virtio transport. If KVM is detected, the virtio console will be
594 bool "Enable seccomp to safely compute untrusted bytecode"
598 This kernel feature is useful for number crunching applications
599 that may need to compute untrusted bytecode during their
600 execution. By using pipes or other transports made available to
601 the process as file descriptors supporting the read/write
602 syscalls, it's possible to isolate those applications in
603 their own address space using seccomp. Once seccomp is
604 enabled via /proc/<pid>/seccomp, it cannot be disabled
605 and the task is only allowed to execute a few safe syscalls
606 defined by each seccomp mode.
612 menu "Power Management"
614 source "kernel/power/Kconfig"
626 source "drivers/Kconfig"
630 source "arch/s390/Kconfig.debug"
632 source "security/Kconfig"
634 source "crypto/Kconfig"
638 source "arch/s390/kvm/Kconfig"