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
43 config GENERIC_TIME_VSYSCALL
46 config GENERIC_CLOCKEVENTS
54 config GENERIC_BUG_RELATIVE_POINTERS
63 config ARCH_DMA_ADDR_T_64BIT
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
102 select HAVE_PERF_EVENTS
103 select HAVE_KERNEL_GZIP
104 select HAVE_KERNEL_BZIP2
105 select HAVE_KERNEL_LZMA
106 select HAVE_KERNEL_LZO
107 select HAVE_GET_USER_PAGES_FAST
108 select ARCH_INLINE_SPIN_TRYLOCK
109 select ARCH_INLINE_SPIN_TRYLOCK_BH
110 select ARCH_INLINE_SPIN_LOCK
111 select ARCH_INLINE_SPIN_LOCK_BH
112 select ARCH_INLINE_SPIN_LOCK_IRQ
113 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
114 select ARCH_INLINE_SPIN_UNLOCK
115 select ARCH_INLINE_SPIN_UNLOCK_BH
116 select ARCH_INLINE_SPIN_UNLOCK_IRQ
117 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
118 select ARCH_INLINE_READ_TRYLOCK
119 select ARCH_INLINE_READ_LOCK
120 select ARCH_INLINE_READ_LOCK_BH
121 select ARCH_INLINE_READ_LOCK_IRQ
122 select ARCH_INLINE_READ_LOCK_IRQSAVE
123 select ARCH_INLINE_READ_UNLOCK
124 select ARCH_INLINE_READ_UNLOCK_BH
125 select ARCH_INLINE_READ_UNLOCK_IRQ
126 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
127 select ARCH_INLINE_WRITE_TRYLOCK
128 select ARCH_INLINE_WRITE_LOCK
129 select ARCH_INLINE_WRITE_LOCK_BH
130 select ARCH_INLINE_WRITE_LOCK_IRQ
131 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
132 select ARCH_INLINE_WRITE_UNLOCK
133 select ARCH_INLINE_WRITE_UNLOCK_BH
134 select ARCH_INLINE_WRITE_UNLOCK_IRQ
135 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
137 config SCHED_OMIT_FRAME_POINTER
141 source "init/Kconfig"
143 source "kernel/Kconfig.freezer"
147 comment "Processor type and features"
149 source "kernel/time/Kconfig"
154 Select this option if you have a 64 bit IBM zSeries machine
155 and want to use the 64 bit addressing mode.
165 bool "Symmetric multi-processing support"
167 This enables support for systems with more than one CPU. If you have
168 a system with only one CPU, like most personal computers, say N. If
169 you have a system with more than one CPU, say Y.
171 If you say N here, the kernel will run on single and multiprocessor
172 machines, but will use only one CPU of a multiprocessor machine. If
173 you say Y here, the kernel will run on many, but not all,
174 singleprocessor machines. On a singleprocessor machine, the kernel
175 will run faster if you say N here.
177 See also the SMP-HOWTO available at
178 <http://www.tldp.org/docs.html#howto>.
180 Even if you don't know what to do here, say Y.
183 int "Maximum number of CPUs (2-64)"
186 default "32" if !64BIT
187 default "64" if 64BIT
189 This allows you to specify the maximum number of CPUs which this
190 kernel will support. The maximum supported value is 64 and the
191 minimum value which makes sense is 2.
193 This is purely to save memory - each supported CPU adds
194 approximately sixteen kilobytes to the kernel image.
197 bool "Support for hot-pluggable CPUs"
202 Say Y here to be able to turn CPUs off and on. CPUs
203 can be controlled through /sys/devices/system/cpu/cpu#.
204 Say N if you want to disable CPU hotplug.
207 bool "Book scheduler support"
210 Book scheduler support improves the CPU scheduler's decision making
211 when dealing with machines that have several books.
214 bool "IEEE FPU emulation"
217 This option is required for IEEE compliant floating point arithmetic
218 on older S/390 machines. Say Y unless you know your machine doesn't
222 bool "Kernel support for 31 bit emulation"
224 select COMPAT_BINFMT_ELF
226 Select this option if you want to enable your system kernel to
227 handle system-calls from ELF binaries for 31 bit ESA. This option
228 (and some other stuff like libraries and such) is needed for
229 executing 31 bit applications. It is safe to say "Y".
231 config SYSVIPC_COMPAT
233 depends on COMPAT && SYSVIPC
240 config S390_EXEC_PROTECT
241 bool "Data execute protection"
243 This option allows to enable a buffer overflow protection for user
244 space programs and it also selects the addressing mode option above.
245 The kernel parameter noexec=on will enable this feature and also
246 switch the addressing modes, default is disabled. Enabling this (via
247 kernel parameter) on machines earlier than IBM System z9-109 EC/BC
248 will reduce system performance.
250 comment "Code generation options"
253 prompt "Processor type"
257 bool "S/390 model G5 and G6"
260 Select this to build a 31 bit kernel that works
261 on all S/390 and zSeries machines.
264 bool "IBM eServer zSeries model z800 and z900"
266 Select this to optimize for zSeries machines. This
267 will enable some optimizations that are not available
268 on older 31 bit only CPUs.
271 bool "IBM eServer zSeries model z890 and z990"
273 Select this enable optimizations for model z890/z990.
274 This will be slightly faster but does not work on
275 older machines such as the z900.
280 Select this to enable optimizations for IBM System z9-109, IBM
281 System z9 Enterprise Class (z9 EC), and IBM System z9 Business
282 Class (z9 BC). The kernel will be slightly faster but will not
283 work on older machines such as the z990, z890, z900, and z800.
286 bool "IBM System z10"
288 Select this to enable optimizations for IBM System z10. The
289 kernel will be slightly faster but will not work on older
290 machines such as the z990, z890, z900, z800, z9-109, z9-ec
294 bool "IBM zEnterprise 196"
296 Select this to enable optimizations for IBM zEnterprise 196.
297 The kernel will be slightly faster but will not work on older
298 machines such as the z990, z890, z900, z800, z9-109, z9-ec,
299 z9-bc, z10-ec and z10-bc.
304 bool "Pack kernel stack"
306 This option enables the compiler option -mkernel-backchain if it
307 is available. If the option is available the compiler supports
308 the new stack layout which dramatically reduces the minimum stack
309 frame size. With an old compiler a non-leaf function needs a
310 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
311 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
312 and 24 byte on 64 bit.
314 Say Y if you are unsure.
317 bool "Use 8kb for kernel stack instead of 16kb"
318 depends on PACK_STACK && 64BIT && !LOCKDEP
320 If you say Y here and the compiler supports the -mkernel-backchain
321 option the kernel will use a smaller kernel stack size. The reduced
322 size is 8kb instead of 16kb. This allows to run more threads on a
323 system and reduces the pressure on the memory management for higher
324 order page allocations.
326 Say N if you are unsure.
329 bool "Detect kernel stack overflow"
331 This option enables the compiler option -mstack-guard and
332 -mstack-size if they are available. If the compiler supports them
333 it will emit additional code to each function prolog to trigger
334 an illegal operation if the kernel stack is about to overflow.
336 Say N if you are unsure.
339 int "Size of the guard area (128-1024)"
341 depends on CHECK_STACK
344 This allows you to specify the size of the guard area at the lower
345 end of the kernel stack. If the kernel stack points into the guard
346 area on function entry an illegal operation is triggered. The size
347 needs to be a power of 2. Please keep in mind that the size of an
348 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
349 The minimum size for the stack guard should be 256 for 31 bit and
353 bool "Emit compiler warnings for function with broken stack usage"
355 This option enables the compiler options -mwarn-framesize and
356 -mwarn-dynamicstack. If the compiler supports these options it
357 will generate warnings for function which either use alloca or
358 create a stack frame bigger than CONFIG_WARN_STACK_SIZE.
360 Say N if you are unsure.
362 config WARN_STACK_SIZE
363 int "Maximum frame size considered safe (128-2048)"
365 depends on WARN_STACK
368 This allows you to specify the maximum frame size a function may
369 have without the compiler complaining about it.
371 config ARCH_POPULATES_NODE_MAP
374 comment "Kernel preemption"
376 source "kernel/Kconfig.preempt"
378 config ARCH_SPARSEMEM_ENABLE
380 select SPARSEMEM_VMEMMAP_ENABLE
381 select SPARSEMEM_VMEMMAP
382 select SPARSEMEM_STATIC if !64BIT
384 config ARCH_SPARSEMEM_DEFAULT
387 config ARCH_SELECT_MEMORY_MODEL
390 config ARCH_ENABLE_MEMORY_HOTPLUG
394 config ARCH_ENABLE_MEMORY_HOTREMOVE
397 config ARCH_HIBERNATION_POSSIBLE
402 comment "I/O subsystem configuration"
405 tristate "QDIO support"
407 This driver provides the Queued Direct I/O base support for
410 To compile this driver as a module, choose M here: the
411 module will be called qdio.
416 tristate "Support for CHSC subchannels"
418 This driver allows usage of CHSC subchannels. A CHSC subchannel
419 is usually present on LPAR only.
420 The driver creates a device /dev/chsc, which may be used to
421 obtain I/O configuration information about the machine and
422 to issue asynchronous chsc commands (DANGEROUS).
423 You will usually only want to use this interface on a special
424 LPAR designated for system management.
426 To compile this driver as a module, choose M here: the
427 module will be called chsc_sch.
434 bool "Builtin IPL record support"
436 If you want to use the produced kernel to IPL directly from a
437 device, you have to merge a bootsector specific to the device
438 into the first bytes of the kernel. You will have to select the
442 prompt "IPL method generated into head.S"
446 Select "tape" if you want to IPL the image from a Tape.
448 Select "vm_reader" if you are running under VM/ESA and want
449 to IPL the image from the emulated card reader.
459 source "fs/Kconfig.binfmt"
461 config FORCE_MAX_ZONEORDER
466 bool "Pseudo page fault support"
468 Select this option, if you want to use PFAULT pseudo page fault
469 handling under VM. If running native or in LPAR, this option
470 has no effect. If your VM does not support PFAULT, PAGEEX
471 pseudo page fault handling will be used.
472 Note that VM 4.2 supports PFAULT but has a bug in its
473 implementation that causes some problems.
474 Everybody who wants to run Linux under VM != VM4.2 should select
478 bool "VM shared kernel support"
480 Select this option, if you want to share the text segment of the
481 Linux kernel between different VM guests. This reduces memory
482 usage with lots of guests but greatly increases kernel size.
483 Also if a kernel was IPL'ed from a shared segment the kexec system
485 You should only select this option if you know what you are
486 doing and want to exploit this feature.
489 tristate "Cooperative memory management"
491 Select this option, if you want to enable the kernel interface
492 to reduce the memory size of the system. This is accomplished
493 by allocating pages of memory and put them "on hold". This only
494 makes sense for a system running under VM where the unused pages
495 will be reused by VM for other guest systems. The interface
496 allows an external monitor to balance memory of many systems.
497 Everybody who wants to run Linux under VM should select this
501 bool "IUCV special message interface to cooperative memory management"
502 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
504 Select this option to enable the special message interface to
505 the cooperative memory management.
508 bool "Linux - VM Monitor Stream, base infrastructure"
511 This provides a kernel interface for creating and updating z/VM APPLDATA
512 monitor records. The monitor records are updated at certain time
513 intervals, once the timer is started.
514 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
515 i.e. enables or disables monitoring on the Linux side.
516 A custom interval value (in seconds) can be written to
517 /proc/appldata/interval.
519 Defaults are 60 seconds interval and timer off.
520 The /proc entries can also be read from, showing the current settings.
523 tristate "Monitor memory management statistics"
524 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
526 This provides memory management related data to the Linux - VM Monitor
527 Stream, like paging/swapping rate, memory utilisation, etc.
528 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
529 APPLDATA monitor record, i.e. enables or disables monitoring this record
533 The /proc entry can also be read from, showing the current settings.
535 This can also be compiled as a module, which will be called
539 tristate "Monitor OS statistics"
540 depends on APPLDATA_BASE
542 This provides OS related data to the Linux - VM Monitor Stream, like
543 CPU utilisation, etc.
544 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
545 APPLDATA monitor record, i.e. enables or disables monitoring this record
549 This can also be compiled as a module, which will be called
552 config APPLDATA_NET_SUM
553 tristate "Monitor overall network statistics"
554 depends on APPLDATA_BASE && NET
556 This provides network related data to the Linux - VM Monitor Stream,
557 currently there is only a total sum of network I/O statistics, no
559 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
560 APPLDATA monitor record, i.e. enables or disables monitoring this record
564 This can also be compiled as a module, which will be called
567 source kernel/Kconfig.hz
570 bool "s390 hypervisor file system support"
571 select SYS_HYPERVISOR
574 This is a virtual file system intended to provide accounting
575 information in an s390 hypervisor environment.
578 bool "kexec system call"
580 kexec is a system call that implements the ability to shutdown your
581 current kernel, and to start another kernel. It is like a reboot
582 but is independent of hardware/microcode support.
585 bool "zfcpdump support"
589 Select this option if you want to build an zfcpdump enabled kernel.
590 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
593 bool "s390 guest support for KVM (EXPERIMENTAL)"
594 depends on 64BIT && EXPERIMENTAL
597 select VIRTIO_CONSOLE
599 Select this option if you want to run the kernel as a guest under
600 the KVM hypervisor. This will add detection for KVM as well as a
601 virtio transport. If KVM is detected, the virtio console will be
605 bool "Enable seccomp to safely compute untrusted bytecode"
609 This kernel feature is useful for number crunching applications
610 that may need to compute untrusted bytecode during their
611 execution. By using pipes or other transports made available to
612 the process as file descriptors supporting the read/write
613 syscalls, it's possible to isolate those applications in
614 their own address space using seccomp. Once seccomp is
615 enabled via /proc/<pid>/seccomp, it cannot be disabled
616 and the task is only allowed to execute a few safe syscalls
617 defined by each seccomp mode.
623 menu "Power Management"
625 source "kernel/power/Kconfig"
637 source "drivers/Kconfig"
641 source "arch/s390/Kconfig.debug"
643 source "security/Kconfig"
645 source "crypto/Kconfig"
649 source "arch/s390/kvm/Kconfig"