X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fs390%2FKconfig;h=432c55b056a0d7e99960ebe00e39db7a38bcc4e9;hb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;hp=d112120738aed67e52e25c98b6dc1ebd6b76b420;hpb=a2c21200f1c81b08cb55e417b68150bba439b646;p=linux-2.6.git diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index d11212073..432c55b05 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -48,34 +48,6 @@ config ARCH_S390_31 depends on ARCH_S390X = 'n' default y -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 SMP bool "Symmetric multi-processing support" ---help--- @@ -121,7 +93,7 @@ config MATHEMU 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 + on older S/390 machines. Say Y unless you know your machine doesn't need this. config S390_SUPPORT @@ -150,13 +122,112 @@ config BINFMT_ELF32 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. + 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). + zSeries to process warning machine checks (e.g. on power failures). If unsure, say "Y". config QDIO @@ -388,60 +459,7 @@ source "fs/Kconfig" source "arch/s390/oprofile/Kconfig" -menu "Kernel hacking" - -config DEBUG_KERNEL - bool "Kernel debugging" - help - Say Y here if you are developing drivers or trying to debug and - identify kernel problems. - -config MAGIC_SYSRQ - bool "Magic SysRq key" - depends on DEBUG_KERNEL - help - If you say Y here, you will have some control over the system even - if the system crashes for example during kernel debugging (e.g., you - will be able to flush the buffer cache to disk, reboot the system - immediately or dump some status information). This is accomplished - by pressing various keys while holding SysRq (Alt+PrintScreen). It - also works on a serial console (on PC hardware at least), if you - send a BREAK and then within 5 seconds a command keypress. The - keys are documented in . Don't say Y - unless you really know what this hack does. - -config DEBUG_SLAB - bool "Debug memory allocations" - depends on DEBUG_KERNEL - help - Say Y here to have the kernel do limited verification on memory - allocation as well as poisoning memory on free to catch use of freed - memory. - -config KALLSYMS - bool "Load all symbols for debugging/kksymoops" - depends on DEBUG_KERNEL - help - Say Y here to let the kernel print out symbolic crash information and - symbolic stack backtraces. This increases the size of the kernel - somewhat, as all symbols have to be loaded into the kernel image. - -config DEBUG_INFO - bool "Compile the kernel with debug info" - depends on DEBUG_KERNEL - help - If you say Y here the resulting kernel image will include - debugging info resulting in a larger kernel image. - Say Y here only if you plan to use gdb to debug the kernel. - If you don't debug the kernel, you can say N. - -config DEBUG_SPINLOCK_SLEEP - bool "Sleep-inside-spinlock checking" - help - If you say Y here, various routines which may sleep will become very - noisy if they are called with a spinlock held. - -endmenu +source "arch/s390/Kconfig.debug" source "kernel/vserver/Kconfig" @@ -450,4 +468,3 @@ source "security/Kconfig" source "crypto/Kconfig" source "lib/Kconfig" -