2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
10 config RWSEM_GENERIC_SPINLOCK
13 config RWSEM_XCHGADD_ALGORITHM
17 config GENERIC_BUST_SPINLOCK
20 mainmenu "Linux Kernel Configuration"
29 depends on ARCH_S390X = 'n'
35 comment "Processor type and features"
40 Select this option if you have a 64 bit IBM zSeries machine
41 and want to use the 64 bit addressing mode.
48 depends on ARCH_S390X = 'n'
52 prompt "Processor type"
56 bool "S/390 model G5 and G6"
57 depends on ARCH_S390_31
59 Select this to build a 31 bit kernel that works
60 on all S/390 and zSeries machines.
63 bool "IBM eServer zSeries model z800 and z900"
65 Select this to optimize for zSeries machines. This
66 will enable some optimizations that are not available
67 on older 31 bit only CPUs.
70 bool "IBM eServer zSeries model z890 and z990"
72 Select this enable optimizations for model z890/z990.
73 This will be slightly faster but does not work on
74 older machines such as the z900.
80 bool "Symmetric multi-processing support"
82 This enables support for systems with more than one CPU. If you have
83 a system with only one CPU, like most personal computers, say N. If
84 you have a system with more than one CPU, say Y.
86 If you say N here, the kernel will run on single and multiprocessor
87 machines, but will use only one CPU of a multiprocessor machine. If
88 you say Y here, the kernel will run on many, but not all,
89 singleprocessor machines. On a singleprocessor machine, the kernel
90 will run faster if you say N here.
92 See also the <file:Documentation/smp.txt> and the SMP-HOWTO
93 available at <http://www.tldp.org/docs.html#howto>.
95 Even if you don't know what to do here, say Y.
98 int "Maximum number of CPUs (2-64)"
103 This allows you to specify the maximum number of CPUs which this
104 kernel will support. The maximum supported value is 64 and the
105 minimum value which makes sense is 2.
107 This is purely to save memory - each supported CPU adds
108 approximately sixteen kilobytes to the kernel image.
111 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
112 depends on SMP && HOTPLUG && EXPERIMENTAL
115 Say Y here to experiment with turning CPUs off and on. CPUs
116 can be controlled through /sys/devices/system/cpu/cpu#.
117 Say N if you want to disable CPU hotplug.
120 bool "IEEE FPU emulation"
123 This option is required for IEEE compliant floating point arithmetic
124 on older S/390 machines. Say Y unless you know your machine doesn't
128 bool "Kernel support for 31 bit emulation"
129 depends on ARCH_S390X
131 Select this option if you want to enable your system kernel to
132 handle system-calls from ELF binaries for 31 bit ESA. This option
133 (and some other stuff like libraries and such) is needed for
134 executing 31 bit applications. It is safe to say "Y".
138 depends on S390_SUPPORT
141 config SYSVIPC_COMPAT
143 depends on COMPAT && SYSVIPC
147 tristate "Kernel support for 31 bit ELF binaries"
148 depends on S390_SUPPORT
150 This allows you to run 32-bit Linux/ELF binaries on your zSeries
151 in 64 bit mode. Everybody wants this; say Y.
153 comment "I/O subsystem configuration"
155 config MACHCHK_WARNING
156 bool "Process warning machine checks"
158 Select this option if you want the machine check handler on IBM S/390 or
159 zSeries to process warning machine checks (e.g. on power failures).
163 tristate "QDIO support"
165 This driver provides the Queued Direct I/O base support for the
166 IBM S/390 (G5 and G6) and eServer zSeries (z800, z890, z900 and z990).
168 For details please refer to the documentation provided by IBM at
169 <http://www10.software.ibm.com/developerworks/opensource/linux390>
171 To compile this driver as a module, choose M here: the
172 module will be called qdio.
176 config QDIO_PERF_STATS
177 bool "Performance statistics in /proc"
180 Say Y here to get performance statistics in /proc/qdio_perf
185 bool "Extended debugging information"
188 Say Y here to get extended debugging output in /proc/s390dbf/qdio...
189 Warning: this option reduces the performance of the QDIO module.
196 bool "Preemptible Kernel"
198 This option reduces the latency of the kernel when reacting to
199 real-time or interactive events by allowing a low priority process to
200 be preempted even if it is in kernel mode executing a system call.
201 This allows applications to run more reliably even when the system is
204 Say N if you are unsure.
207 bool "Builtin IPL record support"
209 If you want to use the produced kernel to IPL directly from a
210 device, you have to merge a bootsector specific to the device
211 into the first bytes of the kernel. You will have to select the
215 prompt "IPL method generated into head.S"
219 Select "tape" if you want to IPL the image from a Tape.
221 Select "vm_reader" if you are running under VM/ESA and want
222 to IPL the image from the emulated card reader.
232 source "fs/Kconfig.binfmt"
235 bool "Show crashed user process info"
237 Say Y to print all process fault locations to the console. This is
238 a debugging option; you probably do not want to set it unless you
239 are an S390 port maintainer.
242 bool "Pseudo page fault support"
244 Select this option, if you want to use PFAULT pseudo page fault
245 handling under VM. If running native or in LPAR, this option
246 has no effect. If your VM does not support PFAULT, PAGEEX
247 pseudo page fault handling will be used.
248 Note that VM 4.2 supports PFAULT but has a bug in its
249 implementation that causes some problems.
250 Everybody who wants to run Linux under VM != VM4.2 should select
254 bool "VM shared kernel support"
256 Select this option, if you want to share the text segment of the
257 Linux kernel between different VM guests. This reduces memory
258 usage with lots of guests but greatly increases kernel size.
259 You should only select this option if you know what you are
260 doing and want to exploit this feature.
263 tristate "Cooperative memory management"
265 Select this option, if you want to enable the kernel interface
266 to reduce the memory size of the system. This is accomplished
267 by allocating pages of memory and put them "on hold". This only
268 makes sense for a system running under VM where the unused pages
269 will be reused by VM for other guest systems. The interface
270 allows an external monitor to balance memory of many systems.
271 Everybody who wants to run Linux under VM should select this
275 bool "/proc interface to cooperative memory management"
278 Select this option to enable the /proc interface to the
279 cooperative memory management.
282 bool "IUCV special message interface to cooperative memory management"
283 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
285 Select this option to enable the special message interface to
286 the cooperative memory management.
289 bool "Virtual CPU timer support"
291 This provides a kernel interface for virtual CPU timers.
295 bool "Linux - VM Monitor Stream, base infrastructure"
296 depends on PROC_FS && VIRT_TIMER=y
298 This provides a kernel interface for creating and updating z/VM APPLDATA
299 monitor records. The monitor records are updated at certain time
300 intervals, once the timer is started.
301 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
302 i.e. enables or disables monitoring on the Linux side.
303 A custom interval value (in seconds) can be written to
304 /proc/appldata/interval.
306 Defaults are 60 seconds interval and timer off.
307 The /proc entries can also be read from, showing the current settings.
310 tristate "Monitor memory management statistics"
311 depends on APPLDATA_BASE
313 This provides memory management related data to the Linux - VM Monitor
314 Stream, like paging/swapping rate, memory utilisation, etc.
315 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
316 APPLDATA monitor record, i.e. enables or disables monitoring this record
320 The /proc entry can also be read from, showing the current settings.
322 This can also be compiled as a module, which will be called
326 tristate "Monitor OS statistics"
327 depends on APPLDATA_BASE
329 This provides OS related data to the Linux - VM Monitor Stream, like
330 CPU utilisation, etc.
331 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
332 APPLDATA monitor record, i.e. enables or disables monitoring this record
336 This can also be compiled as a module, which will be called
339 config APPLDATA_NET_SUM
340 tristate "Monitor overall network statistics"
341 depends on APPLDATA_BASE
343 This provides network related data to the Linux - VM Monitor Stream,
344 currently there is only a total sum of network I/O statistics, no
346 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
347 APPLDATA monitor record, i.e. enables or disables monitoring this record
351 This can also be compiled as a module, which will be called
355 bool "No HZ timer ticks in idle"
357 Switches the regular HZ timer off when the system is going idle.
358 This helps z/VM to detect that the Linux system is idle. VM can
359 then "swap-out" this guest which reduces memory usage. It also
360 reduces the overhead of idle systems.
362 The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
363 hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
366 config NO_IDLE_HZ_INIT
367 bool "HZ timer in idle off by default"
368 depends on NO_IDLE_HZ
370 The HZ timer is switched off in idle by default. That means the
371 HZ timer is already disabled at boot time.
379 source "drivers/base/Kconfig"
381 source "drivers/scsi/Kconfig"
383 source "drivers/s390/Kconfig"
389 source "arch/s390/oprofile/Kconfig"
391 menu "Kernel hacking"
394 bool "Kernel debugging"
396 Say Y here if you are developing drivers or trying to debug and
397 identify kernel problems.
400 bool "Magic SysRq key"
401 depends on DEBUG_KERNEL
403 If you say Y here, you will have some control over the system even
404 if the system crashes for example during kernel debugging (e.g., you
405 will be able to flush the buffer cache to disk, reboot the system
406 immediately or dump some status information). This is accomplished
407 by pressing various keys while holding SysRq (Alt+PrintScreen). It
408 also works on a serial console (on PC hardware at least), if you
409 send a BREAK and then within 5 seconds a command keypress. The
410 keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
411 unless you really know what this hack does.
414 bool "Debug memory allocations"
415 depends on DEBUG_KERNEL
417 Say Y here to have the kernel do limited verification on memory
418 allocation as well as poisoning memory on free to catch use of freed
422 bool "Load all symbols for debugging/kksymoops"
423 depends on DEBUG_KERNEL
425 Say Y here to let the kernel print out symbolic crash information and
426 symbolic stack backtraces. This increases the size of the kernel
427 somewhat, as all symbols have to be loaded into the kernel image.
430 bool "Compile the kernel with debug info"
431 depends on DEBUG_KERNEL
433 If you say Y here the resulting kernel image will include
434 debugging info resulting in a larger kernel image.
435 Say Y here only if you plan to use gdb to debug the kernel.
436 If you don't debug the kernel, you can say N.
438 config DEBUG_SPINLOCK_SLEEP
439 bool "Sleep-inside-spinlock checking"
441 If you say Y here, various routines which may sleep will become very
442 noisy if they are called with a spinlock held.
446 source "kernel/vserver/Kconfig"
448 source "security/Kconfig"
450 source "crypto/Kconfig"