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_DEFAULT_NO_SPIN_MUTEXES
96 select HAVE_KRETPROBES
97 select HAVE_KVM if 64BIT
98 select HAVE_ARCH_TRACEHOOK
99 select INIT_ALL_POSSIBLE
100 select HAVE_PERF_EVENTS
101 select HAVE_KERNEL_GZIP
102 select HAVE_KERNEL_BZIP2
103 select HAVE_KERNEL_LZMA
104 select ARCH_INLINE_SPIN_TRYLOCK
105 select ARCH_INLINE_SPIN_TRYLOCK_BH
106 select ARCH_INLINE_SPIN_LOCK
107 select ARCH_INLINE_SPIN_LOCK_BH
108 select ARCH_INLINE_SPIN_LOCK_IRQ
109 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
110 select ARCH_INLINE_SPIN_UNLOCK
111 select ARCH_INLINE_SPIN_UNLOCK_BH
112 select ARCH_INLINE_SPIN_UNLOCK_IRQ
113 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
114 select ARCH_INLINE_READ_TRYLOCK
115 select ARCH_INLINE_READ_LOCK
116 select ARCH_INLINE_READ_LOCK_BH
117 select ARCH_INLINE_READ_LOCK_IRQ
118 select ARCH_INLINE_READ_LOCK_IRQSAVE
119 select ARCH_INLINE_READ_UNLOCK
120 select ARCH_INLINE_READ_UNLOCK_BH
121 select ARCH_INLINE_READ_UNLOCK_IRQ
122 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
123 select ARCH_INLINE_WRITE_TRYLOCK
124 select ARCH_INLINE_WRITE_LOCK
125 select ARCH_INLINE_WRITE_LOCK_BH
126 select ARCH_INLINE_WRITE_LOCK_IRQ
127 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
128 select ARCH_INLINE_WRITE_UNLOCK
129 select ARCH_INLINE_WRITE_UNLOCK_BH
130 select ARCH_INLINE_WRITE_UNLOCK_IRQ
131 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
133 config SCHED_OMIT_FRAME_POINTER
137 source "init/Kconfig"
139 source "kernel/Kconfig.freezer"
143 comment "Processor type and features"
145 source "kernel/time/Kconfig"
150 Select this option if you have a 64 bit IBM zSeries machine
151 and want to use the 64 bit addressing mode.
161 bool "Symmetric multi-processing support"
163 This enables support for systems with more than one CPU. If you have
164 a system with only one CPU, like most personal computers, say N. If
165 you have a system with more than one CPU, say Y.
167 If you say N here, the kernel will run on single and multiprocessor
168 machines, but will use only one CPU of a multiprocessor machine. If
169 you say Y here, the kernel will run on many, but not all,
170 singleprocessor machines. On a singleprocessor machine, the kernel
171 will run faster if you say N here.
173 See also the SMP-HOWTO available at
174 <http://www.tldp.org/docs.html#howto>.
176 Even if you don't know what to do here, say Y.
179 int "Maximum number of CPUs (2-64)"
182 default "32" if !64BIT
183 default "64" if 64BIT
185 This allows you to specify the maximum number of CPUs which this
186 kernel will support. The maximum supported value is 64 and the
187 minimum value which makes sense is 2.
189 This is purely to save memory - each supported CPU adds
190 approximately sixteen kilobytes to the kernel image.
193 bool "Support for hot-pluggable CPUs"
198 Say Y here to be able to turn CPUs off and on. CPUs
199 can be controlled through /sys/devices/system/cpu/cpu#.
200 Say N if you want to disable CPU hotplug.
203 bool "IEEE FPU emulation"
206 This option is required for IEEE compliant floating point arithmetic
207 on older S/390 machines. Say Y unless you know your machine doesn't
211 bool "Kernel support for 31 bit emulation"
213 select COMPAT_BINFMT_ELF
215 Select this option if you want to enable your system kernel to
216 handle system-calls from ELF binaries for 31 bit ESA. This option
217 (and some other stuff like libraries and such) is needed for
218 executing 31 bit applications. It is safe to say "Y".
220 config SYSVIPC_COMPAT
222 depends on COMPAT && SYSVIPC
229 config S390_EXEC_PROTECT
230 bool "Data execute protection"
232 This option allows to enable a buffer overflow protection for user
233 space programs and it also selects the addressing mode option above.
234 The kernel parameter noexec=on will enable this feature and also
235 switch the addressing modes, default is disabled. Enabling this (via
236 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
237 will reduce system performance.
239 comment "Code generation options"
242 prompt "Processor type"
246 bool "S/390 model G5 and G6"
249 Select this to build a 31 bit kernel that works
250 on all S/390 and zSeries machines.
253 bool "IBM eServer zSeries model z800 and z900"
255 Select this to optimize for zSeries machines. This
256 will enable some optimizations that are not available
257 on older 31 bit only CPUs.
260 bool "IBM eServer zSeries model z890 and z990"
262 Select this enable optimizations for model z890/z990.
263 This will be slightly faster but does not work on
264 older machines such as the z900.
269 Select this to enable optimizations for IBM System z9-109, IBM
270 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
271 Class (z9 BC). The kernel will be slightly faster but will not
272 work on older machines such as the z990, z890, z900, and z800.
275 bool "IBM System z10"
277 Select this to enable optimizations for IBM System z10. The
278 kernel will be slightly faster but will not work on older
279 machines such as the z990, z890, z900, z800, z9-109, z9-ec
285 bool "Pack kernel stack"
287 This option enables the compiler option -mkernel-backchain if it
288 is available. If the option is available the compiler supports
289 the new stack layout which dramatically reduces the minimum stack
290 frame size. With an old compiler a non-leaf function needs a
291 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
292 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
293 and 24 byte on 64 bit.
295 Say Y if you are unsure.
298 bool "Use 8kb for kernel stack instead of 16kb"
299 depends on PACK_STACK && 64BIT && !LOCKDEP
301 If you say Y here and the compiler supports the -mkernel-backchain
302 option the kernel will use a smaller kernel stack size. The reduced
303 size is 8kb instead of 16kb. This allows to run more threads on a
304 system and reduces the pressure on the memory management for higher
305 order page allocations.
307 Say N if you are unsure.
310 bool "Detect kernel stack overflow"
312 This option enables the compiler option -mstack-guard and
313 -mstack-size if they are available. If the compiler supports them
314 it will emit additional code to each function prolog to trigger
315 an illegal operation if the kernel stack is about to overflow.
317 Say N if you are unsure.
320 int "Size of the guard area (128-1024)"
322 depends on CHECK_STACK
325 This allows you to specify the size of the guard area at the lower
326 end of the kernel stack. If the kernel stack points into the guard
327 area on function entry an illegal operation is triggered. The size
328 needs to be a power of 2. Please keep in mind that the size of an
329 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
330 The minimum size for the stack guard should be 256 for 31 bit and
334 bool "Emit compiler warnings for function with broken stack usage"
336 This option enables the compiler options -mwarn-framesize and
337 -mwarn-dynamicstack. If the compiler supports these options it
338 will generate warnings for function which either use alloca or
339 create a stack frame bigger than CONFIG_WARN_STACK_SIZE.
341 Say N if you are unsure.
343 config WARN_STACK_SIZE
344 int "Maximum frame size considered safe (128-2048)"
346 depends on WARN_STACK
349 This allows you to specify the maximum frame size a function may
350 have without the compiler complaining about it.
352 config ARCH_POPULATES_NODE_MAP
355 comment "Kernel preemption"
357 source "kernel/Kconfig.preempt"
359 config ARCH_SPARSEMEM_ENABLE
361 select SPARSEMEM_VMEMMAP_ENABLE
362 select SPARSEMEM_VMEMMAP
363 select SPARSEMEM_STATIC if !64BIT
365 config ARCH_SPARSEMEM_DEFAULT
368 config ARCH_SELECT_MEMORY_MODEL
371 config ARCH_ENABLE_MEMORY_HOTPLUG
375 config ARCH_ENABLE_MEMORY_HOTREMOVE
378 config ARCH_HIBERNATION_POSSIBLE
383 comment "I/O subsystem configuration"
386 tristate "QDIO support"
388 This driver provides the Queued Direct I/O base support for
391 To compile this driver as a module, choose M here: the
392 module will be called qdio.
397 tristate "Support for CHSC subchannels"
399 This driver allows usage of CHSC subchannels. A CHSC subchannel
400 is usually present on LPAR only.
401 The driver creates a device /dev/chsc, which may be used to
402 obtain I/O configuration information about the machine and
403 to issue asynchronous chsc commands (DANGEROUS).
404 You will usually only want to use this interface on a special
405 LPAR designated for system management.
407 To compile this driver as a module, choose M here: the
408 module will be called chsc_sch.
415 bool "Builtin IPL record support"
417 If you want to use the produced kernel to IPL directly from a
418 device, you have to merge a bootsector specific to the device
419 into the first bytes of the kernel. You will have to select the
423 prompt "IPL method generated into head.S"
427 Select "tape" if you want to IPL the image from a Tape.
429 Select "vm_reader" if you are running under VM/ESA and want
430 to IPL the image from the emulated card reader.
440 source "fs/Kconfig.binfmt"
442 config FORCE_MAX_ZONEORDER
447 bool "Show crashed user process info"
449 Say Y to print all process fault locations to the console. This is
450 a debugging option; you probably do not want to set it unless you
451 are an S390 port maintainer.
454 bool "Pseudo page fault support"
456 Select this option, if you want to use PFAULT pseudo page fault
457 handling under VM. If running native or in LPAR, this option
458 has no effect. If your VM does not support PFAULT, PAGEEX
459 pseudo page fault handling will be used.
460 Note that VM 4.2 supports PFAULT but has a bug in its
461 implementation that causes some problems.
462 Everybody who wants to run Linux under VM != VM4.2 should select
466 bool "VM shared kernel support"
468 Select this option, if you want to share the text segment of the
469 Linux kernel between different VM guests. This reduces memory
470 usage with lots of guests but greatly increases kernel size.
471 Also if a kernel was IPL'ed from a shared segment the kexec system
473 You should only select this option if you know what you are
474 doing and want to exploit this feature.
477 tristate "Cooperative memory management"
479 Select this option, if you want to enable the kernel interface
480 to reduce the memory size of the system. This is accomplished
481 by allocating pages of memory and put them "on hold". This only
482 makes sense for a system running under VM where the unused pages
483 will be reused by VM for other guest systems. The interface
484 allows an external monitor to balance memory of many systems.
485 Everybody who wants to run Linux under VM should select this
489 bool "/proc interface to cooperative memory management"
492 Select this option to enable the /proc interface to the
493 cooperative memory management.
496 bool "IUCV special message interface to cooperative memory management"
497 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
499 Select this option to enable the special message interface to
500 the cooperative memory management.
503 bool "Linux - VM Monitor Stream, base infrastructure"
506 This provides a kernel interface for creating and updating z/VM APPLDATA
507 monitor records. The monitor records are updated at certain time
508 intervals, once the timer is started.
509 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
510 i.e. enables or disables monitoring on the Linux side.
511 A custom interval value (in seconds) can be written to
512 /proc/appldata/interval.
514 Defaults are 60 seconds interval and timer off.
515 The /proc entries can also be read from, showing the current settings.
518 tristate "Monitor memory management statistics"
519 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
521 This provides memory management related data to the Linux - VM Monitor
522 Stream, like paging/swapping rate, memory utilisation, etc.
523 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
524 APPLDATA monitor record, i.e. enables or disables monitoring this record
528 The /proc entry can also be read from, showing the current settings.
530 This can also be compiled as a module, which will be called
534 tristate "Monitor OS statistics"
535 depends on APPLDATA_BASE
537 This provides OS related data to the Linux - VM Monitor Stream, like
538 CPU utilisation, etc.
539 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
540 APPLDATA monitor record, i.e. enables or disables monitoring this record
544 This can also be compiled as a module, which will be called
547 config APPLDATA_NET_SUM
548 tristate "Monitor overall network statistics"
549 depends on APPLDATA_BASE && NET
551 This provides network related data to the Linux - VM Monitor Stream,
552 currently there is only a total sum of network I/O statistics, no
554 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
555 APPLDATA monitor record, i.e. enables or disables monitoring this record
559 This can also be compiled as a module, which will be called
562 source kernel/Kconfig.hz
565 bool "s390 hypervisor file system support"
566 select SYS_HYPERVISOR
569 This is a virtual file system intended to provide accounting
570 information in an s390 hypervisor environment.
573 bool "kexec system call"
575 kexec is a system call that implements the ability to shutdown your
576 current kernel, and to start another kernel. It is like a reboot
577 but is independent of hardware/microcode support.
580 bool "zfcpdump support"
584 Select this option if you want to build an zfcpdump enabled kernel.
585 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
588 bool "s390 guest support for KVM (EXPERIMENTAL)"
589 depends on 64BIT && EXPERIMENTAL
592 select VIRTIO_CONSOLE
594 Select this option if you want to run the kernel as a guest under
595 the KVM hypervisor. This will add detection for KVM as well as a
596 virtio transport. If KVM is detected, the virtio console will be
600 bool "Enable seccomp to safely compute untrusted bytecode"
604 This kernel feature is useful for number crunching applications
605 that may need to compute untrusted bytecode during their
606 execution. By using pipes or other transports made available to
607 the process as file descriptors supporting the read/write
608 syscalls, it's possible to isolate those applications in
609 their own address space using seccomp. Once seccomp is
610 enabled via /proc/<pid>/seccomp, it cannot be disabled
611 and the task is only allowed to execute a few safe syscalls
612 defined by each seccomp mode.
618 menu "Power Management"
620 source "kernel/power/Kconfig"
632 source "drivers/Kconfig"
636 source "arch/s390/Kconfig.debug"
638 source "security/Kconfig"
640 source "crypto/Kconfig"
644 source "arch/s390/kvm/Kconfig"