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
57 config GENERIC_BUG_RELATIVE_POINTERS
66 config GENERIC_LOCKBREAK
69 depends on SMP && PREEMPT
75 config VIRT_CPU_ACCOUNTING
78 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
81 mainmenu "Linux Kernel Configuration"
85 select USE_GENERIC_SMP_HELPERS if SMP
86 select HAVE_SYSCALL_WRAPPERS
87 select HAVE_FUNCTION_TRACER
88 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
89 select HAVE_FTRACE_MCOUNT_RECORD
90 select HAVE_SYSCALL_TRACEPOINTS
91 select HAVE_DYNAMIC_FTRACE
92 select HAVE_FUNCTION_GRAPH_TRACER
93 select HAVE_REGS_AND_STACK_ACCESS_API
94 select HAVE_DEFAULT_NO_SPIN_MUTEXES
97 select HAVE_KRETPROBES
98 select HAVE_KVM if 64BIT
99 select HAVE_ARCH_TRACEHOOK
100 select INIT_ALL_POSSIBLE
101 select HAVE_PERF_EVENTS
102 select HAVE_KERNEL_GZIP
103 select HAVE_KERNEL_BZIP2
104 select HAVE_KERNEL_LZMA
105 select HAVE_KERNEL_LZO
106 select ARCH_INLINE_SPIN_TRYLOCK
107 select ARCH_INLINE_SPIN_TRYLOCK_BH
108 select ARCH_INLINE_SPIN_LOCK
109 select ARCH_INLINE_SPIN_LOCK_BH
110 select ARCH_INLINE_SPIN_LOCK_IRQ
111 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
112 select ARCH_INLINE_SPIN_UNLOCK
113 select ARCH_INLINE_SPIN_UNLOCK_BH
114 select ARCH_INLINE_SPIN_UNLOCK_IRQ
115 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
116 select ARCH_INLINE_READ_TRYLOCK
117 select ARCH_INLINE_READ_LOCK
118 select ARCH_INLINE_READ_LOCK_BH
119 select ARCH_INLINE_READ_LOCK_IRQ
120 select ARCH_INLINE_READ_LOCK_IRQSAVE
121 select ARCH_INLINE_READ_UNLOCK
122 select ARCH_INLINE_READ_UNLOCK_BH
123 select ARCH_INLINE_READ_UNLOCK_IRQ
124 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
125 select ARCH_INLINE_WRITE_TRYLOCK
126 select ARCH_INLINE_WRITE_LOCK
127 select ARCH_INLINE_WRITE_LOCK_BH
128 select ARCH_INLINE_WRITE_LOCK_IRQ
129 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
130 select ARCH_INLINE_WRITE_UNLOCK
131 select ARCH_INLINE_WRITE_UNLOCK_BH
132 select ARCH_INLINE_WRITE_UNLOCK_IRQ
133 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
135 config SCHED_OMIT_FRAME_POINTER
139 source "init/Kconfig"
141 source "kernel/Kconfig.freezer"
145 comment "Processor type and features"
147 source "kernel/time/Kconfig"
152 Select this option if you have a 64 bit IBM zSeries machine
153 and want to use the 64 bit addressing mode.
163 bool "Symmetric multi-processing support"
165 This enables support for systems with more than one CPU. If you have
166 a system with only one CPU, like most personal computers, say N. If
167 you have a system with more than one CPU, say Y.
169 If you say N here, the kernel will run on single and multiprocessor
170 machines, but will use only one CPU of a multiprocessor machine. If
171 you say Y here, the kernel will run on many, but not all,
172 singleprocessor machines. On a singleprocessor machine, the kernel
173 will run faster if you say N here.
175 See also the SMP-HOWTO available at
176 <http://www.tldp.org/docs.html#howto>.
178 Even if you don't know what to do here, say Y.
181 int "Maximum number of CPUs (2-64)"
184 default "32" if !64BIT
185 default "64" if 64BIT
187 This allows you to specify the maximum number of CPUs which this
188 kernel will support. The maximum supported value is 64 and the
189 minimum value which makes sense is 2.
191 This is purely to save memory - each supported CPU adds
192 approximately sixteen kilobytes to the kernel image.
195 bool "Support for hot-pluggable CPUs"
200 Say Y here to be able to turn CPUs off and on. CPUs
201 can be controlled through /sys/devices/system/cpu/cpu#.
202 Say N if you want to disable CPU hotplug.
205 bool "IEEE FPU emulation"
208 This option is required for IEEE compliant floating point arithmetic
209 on older S/390 machines. Say Y unless you know your machine doesn't
213 bool "Kernel support for 31 bit emulation"
215 select COMPAT_BINFMT_ELF
217 Select this option if you want to enable your system kernel to
218 handle system-calls from ELF binaries for 31 bit ESA. This option
219 (and some other stuff like libraries and such) is needed for
220 executing 31 bit applications. It is safe to say "Y".
222 config SYSVIPC_COMPAT
224 depends on COMPAT && SYSVIPC
231 config S390_EXEC_PROTECT
232 bool "Data execute protection"
234 This option allows to enable a buffer overflow protection for user
235 space programs and it also selects the addressing mode option above.
236 The kernel parameter noexec=on will enable this feature and also
237 switch the addressing modes, default is disabled. Enabling this (via
238 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
239 will reduce system performance.
241 comment "Code generation options"
244 prompt "Processor type"
248 bool "S/390 model G5 and G6"
251 Select this to build a 31 bit kernel that works
252 on all S/390 and zSeries machines.
255 bool "IBM eServer zSeries model z800 and z900"
257 Select this to optimize for zSeries machines. This
258 will enable some optimizations that are not available
259 on older 31 bit only CPUs.
262 bool "IBM eServer zSeries model z890 and z990"
264 Select this enable optimizations for model z890/z990.
265 This will be slightly faster but does not work on
266 older machines such as the z900.
271 Select this to enable optimizations for IBM System z9-109, IBM
272 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
273 Class (z9 BC). The kernel will be slightly faster but will not
274 work on older machines such as the z990, z890, z900, and z800.
277 bool "IBM System z10"
279 Select this to enable optimizations for IBM System z10. The
280 kernel will be slightly faster but will not work on older
281 machines such as the z990, z890, z900, z800, z9-109, z9-ec
287 bool "Pack kernel stack"
289 This option enables the compiler option -mkernel-backchain if it
290 is available. If the option is available the compiler supports
291 the new stack layout which dramatically reduces the minimum stack
292 frame size. With an old compiler a non-leaf function needs a
293 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
294 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
295 and 24 byte on 64 bit.
297 Say Y if you are unsure.
300 bool "Use 8kb for kernel stack instead of 16kb"
301 depends on PACK_STACK && 64BIT && !LOCKDEP
303 If you say Y here and the compiler supports the -mkernel-backchain
304 option the kernel will use a smaller kernel stack size. The reduced
305 size is 8kb instead of 16kb. This allows to run more threads on a
306 system and reduces the pressure on the memory management for higher
307 order page allocations.
309 Say N if you are unsure.
312 bool "Detect kernel stack overflow"
314 This option enables the compiler option -mstack-guard and
315 -mstack-size if they are available. If the compiler supports them
316 it will emit additional code to each function prolog to trigger
317 an illegal operation if the kernel stack is about to overflow.
319 Say N if you are unsure.
322 int "Size of the guard area (128-1024)"
324 depends on CHECK_STACK
327 This allows you to specify the size of the guard area at the lower
328 end of the kernel stack. If the kernel stack points into the guard
329 area on function entry an illegal operation is triggered. The size
330 needs to be a power of 2. Please keep in mind that the size of an
331 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
332 The minimum size for the stack guard should be 256 for 31 bit and
336 bool "Emit compiler warnings for function with broken stack usage"
338 This option enables the compiler options -mwarn-framesize and
339 -mwarn-dynamicstack. If the compiler supports these options it
340 will generate warnings for function which either use alloca or
341 create a stack frame bigger than CONFIG_WARN_STACK_SIZE.
343 Say N if you are unsure.
345 config WARN_STACK_SIZE
346 int "Maximum frame size considered safe (128-2048)"
348 depends on WARN_STACK
351 This allows you to specify the maximum frame size a function may
352 have without the compiler complaining about it.
354 config ARCH_POPULATES_NODE_MAP
357 comment "Kernel preemption"
359 source "kernel/Kconfig.preempt"
361 config ARCH_SPARSEMEM_ENABLE
363 select SPARSEMEM_VMEMMAP_ENABLE
364 select SPARSEMEM_VMEMMAP
365 select SPARSEMEM_STATIC if !64BIT
367 config ARCH_SPARSEMEM_DEFAULT
370 config ARCH_SELECT_MEMORY_MODEL
373 config ARCH_ENABLE_MEMORY_HOTPLUG
377 config ARCH_ENABLE_MEMORY_HOTREMOVE
380 config ARCH_HIBERNATION_POSSIBLE
385 comment "I/O subsystem configuration"
388 tristate "QDIO support"
390 This driver provides the Queued Direct I/O base support for
393 To compile this driver as a module, choose M here: the
394 module will be called qdio.
399 tristate "Support for CHSC subchannels"
401 This driver allows usage of CHSC subchannels. A CHSC subchannel
402 is usually present on LPAR only.
403 The driver creates a device /dev/chsc, which may be used to
404 obtain I/O configuration information about the machine and
405 to issue asynchronous chsc commands (DANGEROUS).
406 You will usually only want to use this interface on a special
407 LPAR designated for system management.
409 To compile this driver as a module, choose M here: the
410 module will be called chsc_sch.
417 bool "Builtin IPL record support"
419 If you want to use the produced kernel to IPL directly from a
420 device, you have to merge a bootsector specific to the device
421 into the first bytes of the kernel. You will have to select the
425 prompt "IPL method generated into head.S"
429 Select "tape" if you want to IPL the image from a Tape.
431 Select "vm_reader" if you are running under VM/ESA and want
432 to IPL the image from the emulated card reader.
442 source "fs/Kconfig.binfmt"
444 config FORCE_MAX_ZONEORDER
449 bool "Pseudo page fault support"
451 Select this option, if you want to use PFAULT pseudo page fault
452 handling under VM. If running native or in LPAR, this option
453 has no effect. If your VM does not support PFAULT, PAGEEX
454 pseudo page fault handling will be used.
455 Note that VM 4.2 supports PFAULT but has a bug in its
456 implementation that causes some problems.
457 Everybody who wants to run Linux under VM != VM4.2 should select
461 bool "VM shared kernel support"
463 Select this option, if you want to share the text segment of the
464 Linux kernel between different VM guests. This reduces memory
465 usage with lots of guests but greatly increases kernel size.
466 Also if a kernel was IPL'ed from a shared segment the kexec system
468 You should only select this option if you know what you are
469 doing and want to exploit this feature.
472 tristate "Cooperative memory management"
474 Select this option, if you want to enable the kernel interface
475 to reduce the memory size of the system. This is accomplished
476 by allocating pages of memory and put them "on hold". This only
477 makes sense for a system running under VM where the unused pages
478 will be reused by VM for other guest systems. The interface
479 allows an external monitor to balance memory of many systems.
480 Everybody who wants to run Linux under VM should select this
484 bool "IUCV special message interface to cooperative memory management"
485 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
487 Select this option to enable the special message interface to
488 the cooperative memory management.
491 bool "Linux - VM Monitor Stream, base infrastructure"
494 This provides a kernel interface for creating and updating z/VM APPLDATA
495 monitor records. The monitor records are updated at certain time
496 intervals, once the timer is started.
497 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
498 i.e. enables or disables monitoring on the Linux side.
499 A custom interval value (in seconds) can be written to
500 /proc/appldata/interval.
502 Defaults are 60 seconds interval and timer off.
503 The /proc entries can also be read from, showing the current settings.
506 tristate "Monitor memory management statistics"
507 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
509 This provides memory management related data to the Linux - VM Monitor
510 Stream, like paging/swapping rate, memory utilisation, etc.
511 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
512 APPLDATA monitor record, i.e. enables or disables monitoring this record
516 The /proc entry can also be read from, showing the current settings.
518 This can also be compiled as a module, which will be called
522 tristate "Monitor OS statistics"
523 depends on APPLDATA_BASE
525 This provides OS related data to the Linux - VM Monitor Stream, like
526 CPU utilisation, etc.
527 Writing 1 or 0 to /proc/appldata/os 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 config APPLDATA_NET_SUM
536 tristate "Monitor overall network statistics"
537 depends on APPLDATA_BASE && NET
539 This provides network related data to the Linux - VM Monitor Stream,
540 currently there is only a total sum of network I/O statistics, no
542 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
543 APPLDATA monitor record, i.e. enables or disables monitoring this record
547 This can also be compiled as a module, which will be called
550 source kernel/Kconfig.hz
553 bool "s390 hypervisor file system support"
554 select SYS_HYPERVISOR
557 This is a virtual file system intended to provide accounting
558 information in an s390 hypervisor environment.
561 bool "kexec system call"
563 kexec is a system call that implements the ability to shutdown your
564 current kernel, and to start another kernel. It is like a reboot
565 but is independent of hardware/microcode support.
568 bool "zfcpdump support"
572 Select this option if you want to build an zfcpdump enabled kernel.
573 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
576 bool "s390 guest support for KVM (EXPERIMENTAL)"
577 depends on 64BIT && EXPERIMENTAL
580 select VIRTIO_CONSOLE
582 Select this option if you want to run the kernel as a guest under
583 the KVM hypervisor. This will add detection for KVM as well as a
584 virtio transport. If KVM is detected, the virtio console will be
588 bool "Enable seccomp to safely compute untrusted bytecode"
592 This kernel feature is useful for number crunching applications
593 that may need to compute untrusted bytecode during their
594 execution. By using pipes or other transports made available to
595 the process as file descriptors supporting the read/write
596 syscalls, it's possible to isolate those applications in
597 their own address space using seccomp. Once seccomp is
598 enabled via /proc/<pid>/seccomp, it cannot be disabled
599 and the task is only allowed to execute a few safe syscalls
600 defined by each seccomp mode.
606 menu "Power Management"
608 source "kernel/power/Kconfig"
620 source "drivers/Kconfig"
624 source "arch/s390/Kconfig.debug"
626 source "security/Kconfig"
628 source "crypto/Kconfig"
632 source "arch/s390/kvm/Kconfig"