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.
45 depends on ARCH_S390X = 'n'
49 bool "Symmetric multi-processing support"
51 This enables support for systems with more than one CPU. If you have
52 a system with only one CPU, like most personal computers, say N. If
53 you have a system with more than one CPU, say Y.
55 If you say N here, the kernel will run on single and multiprocessor
56 machines, but will use only one CPU of a multiprocessor machine. If
57 you say Y here, the kernel will run on many, but not all,
58 singleprocessor machines. On a singleprocessor machine, the kernel
59 will run faster if you say N here.
61 See also the <file:Documentation/smp.tex>,
62 <file:Documentation/smp.txt> and the SMP-HOWTO available at
63 <http://www.tldp.org/docs.html#howto>.
65 Even if you don't know what to do here, say Y.
68 int "Maximum number of CPUs (2-32)"
69 depends on SMP && ARCH_S390X = 'n'
72 This allows you to specify the maximum number of CPUs which this
73 kernel will support. The maximum supported value is 32 and the
74 minimum value which makes sense is 2.
76 This is purely to save memory - each supported CPU adds
77 approximately eight kilobytes to the kernel image.
80 int "Maximum number of CPUs (2-64)"
81 depends on SMP && ARCH_S390X
84 This allows you to specify the maximum number of CPUs which this
85 kernel will support. The maximum supported value is 64 and the
86 minimum value which makes sense is 2.
88 This is purely to save memory - each supported CPU adds
89 approximately sixteen kilobytes to the kernel image.
92 bool "IEEE FPU emulation"
93 depends on ARCH_S390X = n
95 This option is required for IEEE compliant floating point arithmetic
96 on older S/390 machines. Say Y unless you know your machine doesn't
100 bool "Kernel support for 31 bit emulation"
101 depends on ARCH_S390X
103 Select this option if you want to enable your system kernel to
104 handle system-calls from ELF binaries for 31 bit ESA. This option
105 (and some other stuff like libraries and such) is needed for
106 executing 31 bit applications. It is safe to say "Y".
110 depends on S390_SUPPORT
114 tristate "Kernel support for 31 bit ELF binaries"
115 depends on S390_SUPPORT
117 This allows you to run 32-bit Linux/ELF binaries on your zSeries
118 in 64 bit mode. Everybody wants this; say Y.
120 comment "I/O subsystem configuration"
122 config MACHCHK_WARNING
123 bool "Process warning machine checks"
125 Select this option if you want the machine check handler on IBM S/390 or
126 zSeries to process warning machine checks (e.g. on power failures).
130 tristate "QDIO support"
132 This driver provides the Queued Direct I/O base support for the
133 IBM S/390 (G5 and G6) and eServer zSeries (z800 and z900).
135 For details please refer to the documentation provided by IBM at
136 <http://www10.software.ibm.com/developerworks/opensource/linux390>
138 This driver is also available as a module ( = code which can be
139 inserted in and removed from the running kernel whenever you want).
140 The module will be called qdio. If you want to compile it as a
141 module, say M here and read <file:Documentation/modules.txt>.
145 config QDIO_PERF_STATS
146 bool "Performance statistics in /proc"
149 Say Y here to get performance statistics in /proc/qdio_perf
156 bool "Preemptible Kernel"
158 This option reduces the latency of the kernel when reacting to
159 real-time or interactive events by allowing a low priority process to
160 be preempted even if it is in kernel mode executing a system call.
161 This allows applications to run more reliably even when the system is
164 Say N if you are unsure.
167 bool "Builtin IPL record support"
169 If you want to use the produced kernel to IPL directly from a
170 device, you have to merge a bootsector specific to the device
171 into the first bytes of the kernel. You will have to select the
175 prompt "IPL method generated into head.S"
179 Select "tape" if you want to IPL the image from a Tape.
181 Select "vm_reader" if you are running under VM/ESA and want
182 to IPL the image from the emulated card reader.
196 If you enabled support for /proc file system then the file
197 /proc/kcore will contain the kernel core image. This can be used
200 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
202 You have two choices here: ELF and A.OUT. Selecting ELF will make
203 /proc/kcore appear in ELF core format as defined by the Executable
204 and Linking Format specification. Selecting A.OUT will choose the
205 old "a.out" format which may be necessary for some old versions
206 of binutils or on some architectures.
208 This is especially useful if you have compiled the kernel with the
209 "-g" option to preserve debugging information. It is mainly used
210 for examining kernel data structures on the live kernel so if you
211 don't understand what this means or are not a kernel hacker, just
212 leave it at its default value ELF.
215 tristate "Kernel support for ELF binaries"
217 ELF (Executable and Linkable Format) is a format for libraries and
218 executables used across different architectures and operating
219 systems. Saying Y here will enable your kernel to run ELF binaries
220 and enlarge it by about 13 KB. ELF support under Linux has now all
221 but replaced the traditional Linux a.out formats (QMAGIC and ZMAGIC)
222 because it is portable (this does *not* mean that you will be able
223 to run executables from different architectures or operating systems
224 however) and makes building run-time libraries very easy. Many new
225 executables are distributed solely in ELF format. You definitely
228 Information about ELF is contained in the ELF HOWTO available from
229 <http://www.tldp.org/docs.html#howto>.
231 If you find that after upgrading from Linux kernel 1.2 and saying Y
232 here, you still can't run any ELF binaries (they just crash), then
233 you'll have to install the newest ELF runtime libraries, including
234 ld.so (check the file <file:Documentation/Changes> for location and
237 If you want to compile this as a module ( = code which can be
238 inserted in and removed from the running kernel whenever you want),
239 say M here and read <file:Documentation/modules.txt>. The module
240 will be called binfmt_elf. Saying M or N here is dangerous because
241 some crucial programs on your system might be in ELF format.
244 tristate "Kernel support for MISC binaries"
246 If you say Y here, it will be possible to plug wrapper-driven binary
247 formats into the kernel. You will like this especially when you use
248 programs that need an interpreter to run like Java, Python or
249 Emacs-Lisp. It's also useful if you often run DOS executables under
250 the Linux DOS emulator DOSEMU (read the DOSEMU-HOWTO, available from
251 <http://www.tldp.org/docs.html#howto>). Once you have
252 registered such a binary class with the kernel, you can start one of
253 those programs simply by typing in its name at a shell prompt; Linux
254 will automatically feed it to the correct interpreter.
256 You can do other nice things, too. Read the file
257 <file:Documentation/binfmt_misc.txt> to learn how to use this
258 feature, and <file:Documentation/java.txt> for information about how
259 to include Java support.
261 You must say Y to "/proc file system support" (CONFIG_PROC_FS) to
262 use this part of the kernel.
264 You may say M here for module support and later load the module when
265 you have use for it; the module is called binfmt_misc. If you
266 don't know what to answer at this point, say Y.
269 bool "Show crashed user process info"
271 Say Y to print all process fault locations to the console. This is
272 a debugging option; you probably do not want to set it unless you
273 are an S390 port maintainer.
276 bool "Pseudo page fault support"
278 Select this option, if you want to use PFAULT pseudo page fault
279 handling under VM. If running native or in LPAR, this option
280 has no effect. If your VM does not support PFAULT, PAGEEX
281 pseudo page fault handling will be used.
282 Note that VM 4.2 supports PFAULT but has a bug in its
283 implementation that causes some problems.
284 Everybody who wants to run Linux under VM != VM4.2 should select
288 bool "VM shared kernel support"
290 Select this option, if you want to share the text segment of the
291 Linux kernel between different VM guests. This reduces memory
292 usage with lots of guests but greatly increases kernel size.
293 You should only select this option if you know what you are
294 doing and want to exploit this feature.
305 tristate "SCSI support"
307 source "drivers/scsi/Kconfig"
311 source "drivers/s390/Kconfig"
318 menu "Kernel hacking"
321 bool "Kernel debugging"
323 Say Y here if you are developing drivers or trying to debug and
324 identify kernel problems.
327 bool "Magic SysRq key"
328 depends on DEBUG_KERNEL
330 If you say Y here, you will have some control over the system even
331 if the system crashes for example during kernel debugging (e.g., you
332 will be able to flush the buffer cache to disk, reboot the system
333 immediately or dump some status information). This is accomplished
334 by pressing various keys while holding SysRq (Alt+PrintScreen). It
335 also works on a serial console (on PC hardware at least), if you
336 send a BREAK and then within 5 seconds a command keypress. The
337 keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
338 unless you really know what this hack does.
341 bool "Debug memory allocations"
342 depends on DEBUG_KERNEL
344 Say Y here to have the kernel do limited verification on memory
345 allocation as well as poisoning memory on free to catch use of freed
349 bool "Load all symbols for debugging/kksymoops"
350 depends on DEBUG_KERNEL
352 Say Y here to let the kernel print out symbolic crash information and
353 symbolic stack backtraces. This increases the size of the kernel
354 somewhat, as all symbols have to be loaded into the kernel image.
356 config DEBUG_SPINLOCK_SLEEP
357 bool "Sleep-inside-spinlock checking"
359 If you say Y here, various routines which may sleep will become very
360 noisy if they are called with a spinlock held.
364 source "security/Kconfig"
366 source "crypto/Kconfig"
370 source "suse/Kconfig"