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
187 bool "Preemptible Kernel"
189 This option reduces the latency of the kernel when reacting to
190 real-time or interactive events by allowing a low priority process to
191 be preempted even if it is in kernel mode executing a system call.
192 This allows applications to run more reliably even when the system is
195 Say N if you are unsure.
198 bool "Builtin IPL record support"
200 If you want to use the produced kernel to IPL directly from a
201 device, you have to merge a bootsector specific to the device
202 into the first bytes of the kernel. You will have to select the
206 prompt "IPL method generated into head.S"
210 Select "tape" if you want to IPL the image from a Tape.
212 Select "vm_reader" if you are running under VM/ESA and want
213 to IPL the image from the emulated card reader.
223 source "fs/Kconfig.binfmt"
226 bool "Show crashed user process info"
228 Say Y to print all process fault locations to the console. This is
229 a debugging option; you probably do not want to set it unless you
230 are an S390 port maintainer.
233 bool "Pseudo page fault support"
235 Select this option, if you want to use PFAULT pseudo page fault
236 handling under VM. If running native or in LPAR, this option
237 has no effect. If your VM does not support PFAULT, PAGEEX
238 pseudo page fault handling will be used.
239 Note that VM 4.2 supports PFAULT but has a bug in its
240 implementation that causes some problems.
241 Everybody who wants to run Linux under VM != VM4.2 should select
245 bool "VM shared kernel support"
247 Select this option, if you want to share the text segment of the
248 Linux kernel between different VM guests. This reduces memory
249 usage with lots of guests but greatly increases kernel size.
250 You should only select this option if you know what you are
251 doing and want to exploit this feature.
254 tristate "Cooperative memory management"
256 Select this option, if you want to enable the kernel interface
257 to reduce the memory size of the system. This is accomplished
258 by allocating pages of memory and put them "on hold". This only
259 makes sense for a system running under VM where the unused pages
260 will be reused by VM for other guest systems. The interface
261 allows an external monitor to balance memory of many systems.
262 Everybody who wants to run Linux under VM should select this
266 bool "/proc interface to cooperative memory management"
269 Select this option to enable the /proc interface to the
270 cooperative memory management.
273 bool "IUCV special message interface to cooperative memory management"
274 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
276 Select this option to enable the special message interface to
277 the cooperative memory management.
280 bool "Virtual CPU timer support"
282 This provides a kernel interface for virtual CPU timers.
286 bool "Linux - VM Monitor Stream, base infrastructure"
287 depends on PROC_FS && VIRT_TIMER=y
289 This provides a kernel interface for creating and updating z/VM APPLDATA
290 monitor records. The monitor records are updated at certain time
291 intervals, once the timer is started.
292 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
293 i.e. enables or disables monitoring on the Linux side.
294 A custom interval value (in seconds) can be written to
295 /proc/appldata/interval.
297 Defaults are 60 seconds interval and timer off.
298 The /proc entries can also be read from, showing the current settings.
301 tristate "Monitor memory management statistics"
302 depends on APPLDATA_BASE
304 This provides memory management related data to the Linux - VM Monitor
305 Stream, like paging/swapping rate, memory utilisation, etc.
306 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
307 APPLDATA monitor record, i.e. enables or disables monitoring this record
311 The /proc entry can also be read from, showing the current settings.
313 This can also be compiled as a module, which will be called
317 tristate "Monitor OS statistics"
318 depends on APPLDATA_BASE
320 This provides OS related data to the Linux - VM Monitor Stream, like
321 CPU utilisation, etc.
322 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
323 APPLDATA monitor record, i.e. enables or disables monitoring this record
327 This can also be compiled as a module, which will be called
330 config APPLDATA_NET_SUM
331 tristate "Monitor overall network statistics"
332 depends on APPLDATA_BASE
334 This provides network related data to the Linux - VM Monitor Stream,
335 currently there is only a total sum of network I/O statistics, no
337 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
338 APPLDATA monitor record, i.e. enables or disables monitoring this record
342 This can also be compiled as a module, which will be called
346 bool "No HZ timer ticks in idle"
348 Switches the regular HZ timer off when the system is going idle.
349 This helps z/VM to detect that the Linux system is idle. VM can
350 then "swap-out" this guest which reduces memory usage. It also
351 reduces the overhead of idle systems.
353 The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
354 hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
357 config NO_IDLE_HZ_INIT
358 bool "HZ timer in idle off by default"
359 depends on NO_IDLE_HZ
361 The HZ timer is switched off in idle by default. That means the
362 HZ timer is already disabled at boot time.
370 source "drivers/base/Kconfig"
372 source "drivers/scsi/Kconfig"
374 source "drivers/s390/Kconfig"
380 source "arch/s390/oprofile/Kconfig"
382 menu "Kernel hacking"
385 bool "Kernel debugging"
387 Say Y here if you are developing drivers or trying to debug and
388 identify kernel problems.
391 bool "Magic SysRq key"
392 depends on DEBUG_KERNEL
394 If you say Y here, you will have some control over the system even
395 if the system crashes for example during kernel debugging (e.g., you
396 will be able to flush the buffer cache to disk, reboot the system
397 immediately or dump some status information). This is accomplished
398 by pressing various keys while holding SysRq (Alt+PrintScreen). It
399 also works on a serial console (on PC hardware at least), if you
400 send a BREAK and then within 5 seconds a command keypress. The
401 keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
402 unless you really know what this hack does.
405 bool "Debug memory allocations"
406 depends on DEBUG_KERNEL
408 Say Y here to have the kernel do limited verification on memory
409 allocation as well as poisoning memory on free to catch use of freed
413 bool "Load all symbols for debugging/kksymoops"
414 depends on DEBUG_KERNEL
416 Say Y here to let the kernel print out symbolic crash information and
417 symbolic stack backtraces. This increases the size of the kernel
418 somewhat, as all symbols have to be loaded into the kernel image.
421 bool "Compile the kernel with debug info"
422 depends on DEBUG_KERNEL
424 If you say Y here the resulting kernel image will include
425 debugging info resulting in a larger kernel image.
426 Say Y here only if you plan to use gdb to debug the kernel.
427 If you don't debug the kernel, you can say N.
429 config DEBUG_SPINLOCK_SLEEP
430 bool "Sleep-inside-spinlock checking"
432 If you say Y here, various routines which may sleep will become very
433 noisy if they are called with a spinlock held.
437 source "kernel/vserver/Kconfig"
439 source "security/Kconfig"
441 source "crypto/Kconfig"