If in doubt, say "N".
config JUMP_LABEL
- bool "Optimize trace point call sites"
+ bool "Optimize very unlikely/likely branches"
depends on HAVE_ARCH_JUMP_LABEL
help
+ This option enables a transparent branch optimization that
+ makes certain almost-always-true or almost-always-false branch
+ conditions even cheaper to execute within the kernel.
+
+ Certain performance-sensitive kernel code, such as trace points,
+ scheduler functionality, networking code and KVM have such
+ branches and include support for this optimization technique.
+
If it is detected that the compiler has support for "asm goto",
- the kernel will compile trace point locations with just a
- nop instruction. When trace points are enabled, the nop will
- be converted to a jump to the trace function. This technique
- lowers overhead and stress on the branch prediction of the
- processor.
+ the kernel will compile such branches with just a nop
+ instruction. When the condition flag is toggled to true, the
+ nop will be converted to a jump instruction to execute the
+ conditional block of instructions.
+
+ This technique lowers overhead and stress on the branch prediction
+ of the processor and generally makes the kernel faster. The update
+ of the condition is slower, but those are always very rare.
- On i386, options added to the compiler flags may increase
- the size of the kernel slightly.
+ ( On 32-bit x86, the necessary options added to the compiler
+ flags may increase the size of the kernel slightly. )
config OPTPROBES
def_bool y
config HAVE_OPTPROBES
bool
+
+config HAVE_NMI_WATCHDOG
+ bool
#
# An arch should select this if it provides all these things:
#
config HAVE_CMPXCHG_DOUBLE
bool
+ config ARCH_WANT_OLD_COMPAT_IPC
+ bool
+
source "kernel/gcov/Kconfig"
bool "Flattened Device Tree support"
select OF
select OF_EARLY_FLATTREE
+ select IRQ_DOMAIN
help
Include support for flattened device tree machine descriptions.
config COMPAT
bool
depends on MIPS32_COMPAT
+ select ARCH_WANT_OLD_COMPAT_IPC
default y
config SYSVIPC_COMPAT
select HAVE_HW_BREAKPOINT if PERF_EVENTS && PPC_BOOK3S_64
select HAVE_GENERIC_HARDIRQS
select HAVE_SPARSE_IRQ
+ select SPARSE_IRQ
select IRQ_PER_CPU
+ select IRQ_DOMAIN
select GENERIC_IRQ_SHOW
select GENERIC_IRQ_SHOW_LEVEL
select IRQ_FORCED_THREADING
bool
default y if PPC64
select COMPAT_BINFMT_ELF
+ select ARCH_WANT_OLD_COMPAT_IPC
config SYSVIPC_COMPAT
bool
The same kernel binary can be used as production kernel and dump
capture kernel.
-config PHYP_DUMP
- bool "Hypervisor-assisted dump (EXPERIMENTAL)"
- depends on PPC_PSERIES && EXPERIMENTAL
+config FA_DUMP
+ bool "Firmware-assisted dump"
+ depends on PPC64 && PPC_RTAS && CRASH_DUMP
help
- Hypervisor-assisted dump is meant to be a kdump replacement
- offering robustness and speed not possible without system
- hypervisor assistance.
+ A robust mechanism to get reliable kernel crash dump with
+ assistance from firmware. This approach does not use kexec,
+ instead firmware assists in booting the kdump kernel
+ while preserving memory contents. Firmware-assisted dump
+ is meant to be a kdump replacement offering robustness and
+ speed not possible without system firmware assistance.
If unsure, say "N"
config ISA_DMA_API
bool
- default !PPC_ISERIES || PCI
+ default PCI
menu "Bus options"
config S390
def_bool y
select USE_GENERIC_SMP_HELPERS if SMP
+ select GENERIC_CPU_DEVICES if !SMP
select HAVE_SYSCALL_WRAPPERS
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_TRACE_MCOUNT_TEST
prompt "Kernel support for 31 bit emulation"
depends on 64BIT
select COMPAT_BINFMT_ELF
+ select ARCH_WANT_OLD_COMPAT_IPC
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
select GENERIC_IRQ_SHOW
select USE_GENERIC_SMP_HELPERS if SMP
select GENERIC_PCI_IOMAP
+ select HAVE_NMI_WATCHDOG if SPARC64
config SPARC32
def_bool !64BIT
depends on SPARC64
default y
select COMPAT_BINFMT_ELF
+ select ARCH_WANT_OLD_COMPAT_IPC
config SYSVIPC_COMPAT
bool
select CLKEVT_I8253
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select GENERIC_IOMAP
+ select DCACHE_WORD_ACCESS if !DEBUG_PAGEALLOC
config INSTRUCTION_DECODER
def_bool (KPROBES || PERF_EVENTS)
config ARCH_HAS_CACHE_LINE_SIZE
def_bool y
+config ARCH_HAS_CPU_AUTOPROBE
+ def_bool y
+
config HAVE_SETUP_PER_CPU_AREA
def_bool y
select X86_REBOOTFIXUPS
select OF
select OF_EARLY_FLATTREE
+ select IRQ_DOMAIN
---help---
Select for the Intel CE media processor (CE4100) SOC.
This option compiles in support for the CE4100 SOC for settop
config X86_INTEL_MID
bool
-config X86_MRST
- bool "Moorestown MID platform"
- depends on PCI
- depends on PCI_GOANY
- depends on X86_IO_APIC
- select X86_INTEL_MID
- select SFI
- select DW_APB_TIMER
- select APB_TIMER
- select I2C
- select SPI
- select INTEL_SCU_IPC
- select X86_PLATFORM_DEVICES
- ---help---
- Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
- Internet Device(MID) platform. Moorestown consists of two chips:
- Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
- Unlike standard x86 PCs, Moorestown does not have many legacy devices
- nor standard legacy replacement devices/features. e.g. Moorestown does
- not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
-
config X86_MDFLD
bool "Medfield MID platform"
depends on PCI
select SPI
select INTEL_SCU_IPC
select X86_PLATFORM_DEVICES
+ select MFD_INTEL_MSIC
---help---
Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
Internet Device(MID) platform.
select GPIOLIB
select OF
select OF_PROMTREE
+ select IRQ_DOMAIN
---help---
Add support for detecting the unique features of the OLPC
XO hardware.
Note: You have to set alix.force=1 for boards with Award BIOS.
+config NET5501
+ bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
+ select GPIOLIB
+ ---help---
+ This option enables system support for the Soekris Engineering net5501.
+
+config GEOS
+ bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
+ select GPIOLIB
+ depends on DMI
+ ---help---
+ This option enables system support for the Traverse Technologies GEOS.
+
endif # X86_32
config AMD_NB
config COMPAT
def_bool y
depends on IA32_EMULATION
+ select ARCH_WANT_OLD_COMPAT_IPC
config COMPAT_FOR_U64_ALIGNMENT
def_bool COMPAT
projects / linux-2.6-block.git / commitdiff