#
# For a description of the syntax of this configuration file,
# see Documentation/kbuild/kconfig-language.txt.
#
config MMU
bool
default y
config RWSEM_GENERIC_SPINLOCK
bool
config RWSEM_XCHGADD_ALGORITHM
bool
default y
config GENERIC_CALIBRATE_DELAY
bool
default y
config GENERIC_BUST_SPINLOCK
bool
mainmenu "Linux Kernel Configuration"
config ARCH_S390
bool
default y
config UID16
bool
default y
depends on ARCH_S390X = 'n'
source "init/Kconfig"
menu "Base setup"
comment "Processor type and features"
config ARCH_S390X
bool "64 bit kernel"
help
Select this option if you have a 64 bit IBM zSeries machine
and want to use the 64 bit addressing mode.
config 64BIT
def_bool ARCH_S390X
config ARCH_S390_31
bool
depends on ARCH_S390X = 'n'
default y
config SMP
bool "Symmetric multi-processing support"
---help---
This enables support for systems with more than one CPU. If you have
a system with only one CPU, like most personal computers, say N. If
you have a system with more than one CPU, say Y.
If you say N here, the kernel will run on single and multiprocessor
machines, but will use only one CPU of a multiprocessor machine. If
you say Y here, the kernel will run on many, but not all,
singleprocessor machines. On a singleprocessor machine, the kernel
will run faster if you say N here.
See also the <file:Documentation/smp.txt> and the SMP-HOWTO
available at <http://www.tldp.org/docs.html#howto>.
Even if you don't know what to do here, say Y.
config NR_CPUS
int "Maximum number of CPUs (2-64)"
range 2 64
depends on SMP
default "32"
help
This allows you to specify the maximum number of CPUs which this
kernel will support. The maximum supported value is 64 and the
minimum value which makes sense is 2.
This is purely to save memory - each supported CPU adds
approximately sixteen kilobytes to the kernel image.
config HOTPLUG_CPU
bool "Support for hot-pluggable CPUs"
depends on SMP
select HOTPLUG
default n
help
Say Y here to be able to turn CPUs off and on. CPUs
can be controlled through /sys/devices/system/cpu/cpu#.
Say N if you want to disable CPU hotplug.
config MATHEMU
bool "IEEE FPU emulation"
depends on MARCH_G5
help
This option is required for IEEE compliant floating point arithmetic
on older S/390 machines. Say Y unless you know your machine doesn't
need this.
config S390_SUPPORT
bool "Kernel support for 31 bit emulation"
depends on ARCH_S390X
help
Select this option if you want to enable your system kernel to
handle system-calls from ELF binaries for 31 bit ESA. This option
(and some other stuff like libraries and such) is needed for
executing 31 bit applications. It is safe to say "Y".
config COMPAT
bool
depends on S390_SUPPORT
default y
config SYSVIPC_COMPAT
bool
depends on COMPAT && SYSVIPC
default y
config BINFMT_ELF32
tristate "Kernel support for 31 bit ELF binaries"
depends on S390_SUPPORT
help
This allows you to run 32-bit Linux/ELF binaries on your zSeries
in 64 bit mode. Everybody wants this; say Y.
comment "Code generation options"
choice
prompt "Processor type"
default MARCH_G5
config MARCH_G5
bool "S/390 model G5 and G6"
depends on ARCH_S390_31
help
Select this to build a 31 bit kernel that works
on all S/390 and zSeries machines.
config MARCH_Z900
bool "IBM eServer zSeries model z800 and z900"
help
Select this to optimize for zSeries machines. This
will enable some optimizations that are not available
on older 31 bit only CPUs.
config MARCH_Z990
bool "IBM eServer zSeries model z890 and z990"
help
Select this enable optimizations for model z890/z990.
This will be slightly faster but does not work on
older machines such as the z900.
endchoice
config PACK_STACK
bool "Pack kernel stack"
help
This option enables the compiler option -mkernel-backchain if it
is available. If the option is available the compiler supports
the new stack layout which dramatically reduces the minimum stack
frame size. With an old compiler a non-leaf function needs a
minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
-mkernel-backchain the minimum size drops to 16 byte on 31 bit
and 24 byte on 64 bit.
Say Y if you are unsure.
config SMALL_STACK
bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
depends on PACK_STACK
help
If you say Y here and the compiler supports the -mkernel-backchain
option the kernel will use a smaller kernel stack size. For 31 bit
the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
instead of 16kb. This allows to run more thread on a system and
reduces the pressure on the memory management for higher order
page allocations.
Say N if you are unsure.
config CHECK_STACK
bool "Detect kernel stack overflow"
help
This option enables the compiler option -mstack-guard and
-mstack-size if they are available. If the compiler supports them
it will emit additional code to each function prolog to trigger
an illegal operation if the kernel stack is about to overflow.
Say N if you are unsure.
config STACK_GUARD
int "Size of the guard area (128-1024)"
range 128 1024
depends on CHECK_STACK
default "256"
help
This allows you to specify the size of the guard area at the lower
end of the kernel stack. If the kernel stack points into the guard
area on function entry an illegal operation is triggered. The size
needs to be a power of 2. Please keep in mind that the size of an
interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
The minimum size for the stack guard should be 256 for 31 bit and
512 for 64 bit.
config WARN_STACK
bool "Emit compiler warnings for function with broken stack usage"
help
This option enables the compiler options -mwarn-framesize and
-mwarn-dynamicstack. If the compiler supports these options it
will generate warnings for function which either use alloca or
create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
Say N if you are unsure.
config WARN_STACK_SIZE
int "Maximum frame size considered safe (128-2048)"
range 128 2048
depends on WARN_STACK
default "256"
help
This allows you to specify the maximum frame size a function may
have without the compiler complaining about it.
source "mm/Kconfig"
comment "I/O subsystem configuration"
config MACHCHK_WARNING
bool "Process warning machine checks"
help
Select this option if you want the machine check handler on IBM S/390 or
zSeries to process warning machine checks (e.g. on power failures).
If unsure, say "Y".
config QDIO
tristate "QDIO support"
---help---
This driver provides the Queued Direct I/O base support for the
IBM S/390 (G5 and G6) and eServer zSeries (z800, z890, z900 and z990).
For details please refer to the documentation provided by IBM at
<http://www10.software.ibm.com/developerworks/opensource/linux390>
To compile this driver as a module, choose M here: the
module will be called qdio.
If unsure, say Y.
config QDIO_PERF_STATS
bool "Performance statistics in /proc"
depends on QDIO
help
Say Y here to get performance statistics in /proc/qdio_perf
If unsure, say N.
config QDIO_DEBUG
bool "Extended debugging information"
depends on QDIO
help
Say Y here to get extended debugging output in /proc/s390dbf/qdio...
Warning: this option reduces the performance of the QDIO module.
If unsure, say N.
comment "Misc"
config PREEMPT
bool "Preemptible Kernel"
help
This option reduces the latency of the kernel when reacting to
real-time or interactive events by allowing a low priority process to
be preempted even if it is in kernel mode executing a system call.
This allows applications to run more reliably even when the system is
under load.
Say N if you are unsure.
config IPL
bool "Builtin IPL record support"
help
If you want to use the produced kernel to IPL directly from a
device, you have to merge a bootsector specific to the device
into the first bytes of the kernel. You will have to select the
IPL device.
choice
prompt "IPL method generated into head.S"
depends on IPL
default IPL_TAPE
help
Select "tape" if you want to IPL the image from a Tape.
Select "vm_reader" if you are running under VM/ESA and want
to IPL the image from the emulated card reader.
config IPL_TAPE
bool "tape"
config IPL_VM
bool "vm_reader"
endchoice
source "fs/Kconfig.binfmt"
config PROCESS_DEBUG
bool "Show crashed user process info"
help
Say Y to print all process fault locations to the console. This is
a debugging option; you probably do not want to set it unless you
are an S390 port maintainer.
config PFAULT
bool "Pseudo page fault support"
help
Select this option, if you want to use PFAULT pseudo page fault
handling under VM. If running native or in LPAR, this option
has no effect. If your VM does not support PFAULT, PAGEEX
pseudo page fault handling will be used.
Note that VM 4.2 supports PFAULT but has a bug in its
implementation that causes some problems.
Everybody who wants to run Linux under VM != VM4.2 should select
this option.
config SHARED_KERNEL
bool "VM shared kernel support"
help
Select this option, if you want to share the text segment of the
Linux kernel between different VM guests. This reduces memory
usage with lots of guests but greatly increases kernel size.
You should only select this option if you know what you are
doing and want to exploit this feature.
config CMM
tristate "Cooperative memory management"
help
Select this option, if you want to enable the kernel interface
to reduce the memory size of the system. This is accomplished
by allocating pages of memory and put them "on hold". This only
makes sense for a system running under VM where the unused pages
will be reused by VM for other guest systems. The interface
allows an external monitor to balance memory of many systems.
Everybody who wants to run Linux under VM should select this
option.
config CMM_PROC
bool "/proc interface to cooperative memory management"
depends on CMM
help
Select this option to enable the /proc interface to the
cooperative memory management.
config CMM_IUCV
bool "IUCV special message interface to cooperative memory management"
depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
help
Select this option to enable the special message interface to
the cooperative memory management.
config VIRT_TIMER
bool "Virtual CPU timer support"
help
This provides a kernel interface for virtual CPU timers.
Default is disabled.
config VIRT_CPU_ACCOUNTING
bool "Base user process accounting on virtual cpu timer"
depends on VIRT_TIMER
help
Select this option to use CPU timer deltas to do user
process accounting.
config APPLDATA_BASE
bool "Linux - VM Monitor Stream, base infrastructure"
depends on PROC_FS && VIRT_TIMER=y
help
This provides a kernel interface for creating and updating z/VM APPLDATA
monitor records. The monitor records are updated at certain time
intervals, once the timer is started.
Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
i.e. enables or disables monitoring on the Linux side.
A custom interval value (in seconds) can be written to
/proc/appldata/interval.
Defaults are 60 seconds interval and timer off.
The /proc entries can also be read from, showing the current settings.
config APPLDATA_MEM
tristate "Monitor memory management statistics"
depends on APPLDATA_BASE
help
This provides memory management related data to the Linux - VM Monitor
Stream, like paging/swapping rate, memory utilisation, etc.
Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
APPLDATA monitor record, i.e. enables or disables monitoring this record
on the z/VM side.
Default is disabled.
The /proc entry can also be read from, showing the current settings.
This can also be compiled as a module, which will be called
appldata_mem.o.
config APPLDATA_OS
tristate "Monitor OS statistics"
depends on APPLDATA_BASE
help
This provides OS related data to the Linux - VM Monitor Stream, like
CPU utilisation, etc.
Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
APPLDATA monitor record, i.e. enables or disables monitoring this record
on the z/VM side.
Default is disabled.
This can also be compiled as a module, which will be called
appldata_os.o.
config APPLDATA_NET_SUM
tristate "Monitor overall network statistics"
depends on APPLDATA_BASE
help
This provides network related data to the Linux - VM Monitor Stream,
currently there is only a total sum of network I/O statistics, no
per-interface data.
Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
APPLDATA monitor record, i.e. enables or disables monitoring this record
on the z/VM side.
Default is disabled.
This can also be compiled as a module, which will be called
appldata_net_sum.o.
config NO_IDLE_HZ
bool "No HZ timer ticks in idle"
help
Switches the regular HZ timer off when the system is going idle.
This helps z/VM to detect that the Linux system is idle. VM can
then "swap-out" this guest which reduces memory usage. It also
reduces the overhead of idle systems.
The HZ timer can be switched on/off via /proc/sys/kernel/hz_timer.
hz_timer=0 means HZ timer is disabled. hz_timer=1 means HZ
timer is active.
config NO_IDLE_HZ_INIT
bool "HZ timer in idle off by default"
depends on NO_IDLE_HZ
help
The HZ timer is switched off in idle by default. That means the
HZ timer is already disabled at boot time.
config KEXEC
bool "kexec system call (EXPERIMENTAL)"
depends on EXPERIMENTAL
help
kexec is a system call that implements the ability to shutdown your
current kernel, and to start another kernel. It is like a reboot
but is independent of hardware/microcode support.
endmenu
source "net/Kconfig"
config PCMCIA
bool
default n
source "drivers/base/Kconfig"
source "drivers/scsi/Kconfig"
source "drivers/s390/Kconfig"
source "drivers/net/Kconfig"
source "fs/Kconfig"
source "arch/s390/oprofile/Kconfig"
source "arch/s390/Kconfig.debug"
source "security/Kconfig"
source "crypto/Kconfig"
source "lib/Kconfig"
