default "/lib/modules/$UNAME_RELEASE/.config"
default "/etc/kernel-config"
default "/boot/config-$UNAME_RELEASE"
+ default "$ARCH_DEFCONFIG"
default "arch/$ARCH/defconfig"
menu "General setup"
process and it's parent. Note that this file format is incompatible
with previous v0/v1/v2 file formats, so you will need updated tools
for processing it. A preliminary version of these tools is available
- at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
+ at <http://www.gnu.org/software/acct/>.
config TASKSTATS
bool "Export task/process statistics through netlink (EXPERIMENTAL)"
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
range 12 21
- default 17 if S390 || LOCKDEP
- default 16 if X86_NUMAQ || IA64
- default 15 if SMP
- default 14
+ default 17
help
Select kernel log buffer size as a power of 2.
- Defaults and Examples:
- 17 => 128 KB for S/390
- 16 => 64 KB for x86 NUMAQ or IA-64
- 15 => 32 KB for SMP
- 14 => 16 KB for uniprocessor
+ Examples:
+ 17 => 128 KB
+ 16 => 64 KB
+ 15 => 32 KB
+ 14 => 16 KB
13 => 8 KB
12 => 4 KB
config CGROUP_DEBUG
bool "Example debug cgroup subsystem"
depends on CGROUPS
+ default n
help
This option enables a simple cgroup subsystem that
exports useful debugging information about the cgroups
for instance virtual servers and checkpoint/restart
jobs.
+config CGROUP_FREEZER
+ bool "control group freezer subsystem"
+ depends on CGROUPS
+ help
+ Provides a way to freeze and unfreeze all tasks in a
+ cgroup.
+
+config CGROUP_DEVICE
+ bool "Device controller for cgroups"
+ depends on CGROUPS && EXPERIMENTAL
+ help
+ Provides a cgroup implementing whitelists for devices which
+ a process in the cgroup can mknod or open.
+
config CPUSETS
bool "Cpuset support"
depends on SMP && CGROUPS
Say N if unsure.
+#
+# Architectures with an unreliable sched_clock() should select this:
+#
+config HAVE_UNSTABLE_SCHED_CLOCK
+ bool
+
config GROUP_SCHED
bool "Group CPU scheduler"
- default y
+ depends on EXPERIMENTAL
+ default n
help
This feature lets CPU scheduler recognize task groups and control CPU
bandwidth allocation to such task groups.
config FAIR_GROUP_SCHED
bool "Group scheduling for SCHED_OTHER"
depends on GROUP_SCHED
- default y
+ default GROUP_SCHED
config RT_GROUP_SCHED
bool "Group scheduling for SCHED_RR/FIFO"
depends on EXPERIMENTAL
depends on GROUP_SCHED
default n
+ help
+ This feature lets you explicitly allocate real CPU bandwidth
+ to users or control groups (depending on the "Basis for grouping tasks"
+ setting below. If enabled, it will also make it impossible to
+ schedule realtime tasks for non-root users until you allocate
+ realtime bandwidth for them.
+ See Documentation/scheduler/sched-rt-group.txt for more information.
choice
depends on GROUP_SCHED
infrastructure that works with cgroups
depends on CGROUPS
+config MM_OWNER
+ bool
+
+config CGROUP_MEM_RES_CTLR
+ bool "Memory Resource Controller for Control Groups"
+ depends on CGROUPS && RESOURCE_COUNTERS
+ select MM_OWNER
+ help
+ Provides a memory resource controller that manages both anonymous
+ memory and page cache. (See Documentation/controllers/memory.txt)
+
+ Note that setting this option increases fixed memory overhead
+ associated with each page of memory in the system. By this,
+ 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
+ usage tracking struct at boot. Total amount of this is printed out
+ at boot.
+
+ Only enable when you're ok with these trade offs and really
+ sure you need the memory resource controller. Even when you enable
+ this, you can set "cgroup_disable=memory" at your boot option to
+ disable memory resource controller and you can avoid overheads.
+ (and lose benefits of memory resource contoller)
+
+ This config option also selects MM_OWNER config option, which
+ could in turn add some fork/exit overhead.
+
config SYSFS_DEPRECATED
+ bool
+
+config SYSFS_DEPRECATED_V2
bool "Create deprecated sysfs files"
depends on SYSFS
default y
+ select SYSFS_DEPRECATED
help
This option creates deprecated symlinks such as the
"device"-link, the <subsystem>:<name>-link, and the
If enabled, this option will also move any device structures
that belong to a class, back into the /sys/class hierarchy, in
- order to support older versions of udev.
-
- If you are using a distro that was released in 2006 or later,
- it should be safe to say N here.
+ order to support older versions of udev and some userspace
+ programs.
-config CGROUP_MEM_CONT
- bool "Memory controller for cgroups"
- depends on CGROUPS && RESOURCE_COUNTERS
- help
- Provides a memory controller that manages both page cache and
- RSS memory.
+ If you are using a distro with the most recent userspace
+ packages, it should be safe to say N here.
config PROC_PID_CPUSET
bool "Include legacy /proc/<pid>/cpuset file"
default n
depends on NAMESPACES && EXPERIMENTAL
help
- Suport process id namespaces. This allows having multiple
+ Support process id namespaces. This allows having multiple
process with the same pid as long as they are in different
pid namespaces. This is a building block of containers.
endif
config CC_OPTIMIZE_FOR_SIZE
- bool "Optimize for size (Look out for broken compilers!)"
+ bool "Optimize for size"
default y
- depends on ARM || H8300 || SUPERH || EXPERIMENTAL
help
Enabling this option will pass "-Os" instead of "-O2" to gcc
resulting in a smaller kernel.
- WARNING: some versions of gcc may generate incorrect code with this
- option. If problems are observed, a gcc upgrade may be needed.
-
- If unsure, say N.
+ If unsure, say Y.
config SYSCTL
bool
config UID16
bool "Enable 16-bit UID system calls" if EMBEDDED
- depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
+ depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
default y
help
This enables the legacy 16-bit UID syscall wrappers.
help
Enable support for generating core dumps. Disabling saves about 4k.
+config PCSPKR_PLATFORM
+ bool "Enable PC-Speaker support" if EMBEDDED
+ depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
+ default y
+ help
+ This option allows to disable the internal PC-Speaker
+ support, saving some memory.
+
config COMPAT_BRK
bool "Disable heap randomization"
default y
option replaces shmem and tmpfs with the much simpler ramfs code,
which may be appropriate on small systems without swap.
+config AIO
+ bool "Enable AIO support" if EMBEDDED
+ default y
+ help
+ This option enables POSIX asynchronous I/O which may by used
+ by some high performance threaded applications. Disabling
+ this option saves about 7k.
+
config VM_EVENT_COUNTERS
default y
bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
on EMBEDDED systems. /proc/vmstat will only show page counts
if VM event counters are disabled.
+config PCI_QUIRKS
+ default y
+ bool "Enable PCI quirk workarounds" if EMBEDDED
+ depends on PCI
+ help
+ This enables workarounds for various PCI chipset
+ bugs/quirks. Disable this only if your target machine is
+ unaffected by PCI quirks.
+
config SLUB_DEBUG
default y
bool "Enable SLUB debugging support" if EMBEDDED
- depends on SLUB
+ depends on SLUB && SYSFS
help
SLUB has extensive debug support features. Disabling these can
result in significant savings in code size. This also disables
help
The regular slab allocator that is established and known to work
well in all environments. It organizes cache hot objects in
- per cpu and per node queues. SLAB is the default choice for
- a slab allocator.
+ per cpu and per node queues.
config SLUB
bool "SLUB (Unqueued Allocator)"
instead of managing queues of cached objects (SLAB approach).
Per cpu caching is realized using slabs of objects instead
of queues of objects. SLUB can use memory efficiently
- and has enhanced diagnostics.
+ and has enhanced diagnostics. SLUB is the default choice for
+ a slab allocator.
config SLOB
depends on EMBEDDED
Say Y here to enable the extended profiling support mechanisms used
by profilers such as OProfile.
+#
+# Place an empty function call at each tracepoint site. Can be
+# dynamically changed for a probe function.
+#
+config TRACEPOINTS
+ bool
+
config MARKERS
bool "Activate markers"
+ depends on TRACEPOINTS
help
Place an empty function call at each marker site. Can be
dynamically changed for a probe function.
source "arch/Kconfig"
-config PROC_PAGE_MONITOR
- default y
- depends on PROC_FS && MMU
- bool "Enable /proc page monitoring" if EMBEDDED
- help
- Various /proc files exist to monitor process memory utilization:
- /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
- /proc/kpagecount, and /proc/kpageflags. Disabling these
- interfaces will reduce the size of the kernel by approximately 4kb.
-
endmenu # General setup
+config HAVE_GENERIC_DMA_COHERENT
+ bool
+ default n
+
config SLABINFO
bool
depends on PROC_FS
- depends on SLAB || SLUB
+ depends on SLAB || SLUB_DEBUG
default y
config RT_MUTEXES
If unsure, say Y.
+if MODULES
+
+config MODULE_FORCE_LOAD
+ bool "Forced module loading"
+ default n
+ help
+ Allow loading of modules without version information (ie. modprobe
+ --force). Forced module loading sets the 'F' (forced) taint flag and
+ is usually a really bad idea.
+
config MODULE_UNLOAD
bool "Module unloading"
- depends on MODULES
help
Without this option you will not be able to unload any
modules (note that some modules may not be unloadable
- anyway), which makes your kernel slightly smaller and
- simpler. If unsure, say Y.
+ anyway), which makes your kernel smaller, faster
+ and simpler. If unsure, say Y.
config MODULE_FORCE_UNLOAD
bool "Forced module unloading"
config MODVERSIONS
bool "Module versioning support"
- depends on MODULES
help
Usually, you have to use modules compiled with your kernel.
Saying Y here makes it sometimes possible to use modules
config MODULE_SRCVERSION_ALL
bool "Source checksum for all modules"
- depends on MODULES
help
Modules which contain a MODULE_VERSION get an extra "srcversion"
field inserted into their modinfo section, which contains a
will be created for all modules. If unsure, say N.
config KMOD
- bool "Automatic kernel module loading"
- depends on MODULES
+ def_bool y
+ help
+ This is being removed soon. These days, CONFIG_MODULES
+ implies CONFIG_KMOD, so use that instead.
+
+endif # MODULES
+
+config INIT_ALL_POSSIBLE
+ bool
help
- Normally when you have selected some parts of the kernel to
- be created as kernel modules, you must load them (using the
- "modprobe" command) before you can use them. If you say Y
- here, some parts of the kernel will be able to load modules
- automatically: when a part of the kernel needs a module, it
- runs modprobe with the appropriate arguments, thereby
- loading the module if it is available. If unsure, say Y.
+ Back when each arch used to define their own cpu_online_map and
+ cpu_possible_map, some of them chose to initialize cpu_possible_map
+ with all 1s, and others with all 0s. When they were centralised,
+ it was better to provide this option than to break all the archs
+ and have several arch maintainers persuing me down dark alleys.
config STOP_MACHINE
bool
config PREEMPT_NOTIFIERS
bool
-choice
- prompt "RCU implementation type:"
- default CLASSIC_RCU
- help
- This allows you to choose either the classic RCU implementation
- that is designed for best read-side performance on non-realtime
- systems, or the preemptible RCU implementation for best latency
- on realtime systems. Note that some kernel preemption modes
- will restrict your choice.
-
- Select the default if you are unsure.
-
config CLASSIC_RCU
- bool "Classic RCU"
+ def_bool !PREEMPT_RCU
help
This option selects the classic RCU implementation that is
designed for best read-side performance on non-realtime
- systems.
-
- Say Y if you are unsure.
-
-config PREEMPT_RCU
- bool "Preemptible RCU"
- depends on PREEMPT
- help
- This option reduces the latency of the kernel by making certain
- RCU sections preemptible. Normally RCU code is non-preemptible, if
- this option is selected then read-only RCU sections become
- preemptible. This helps latency, but may expose bugs due to
- now-naive assumptions about each RCU read-side critical section
- remaining on a given CPU through its execution.
-
- Say N if you are unsure.
-
-endchoice
+ systems. Classic RCU is the default. Note that the
+ PREEMPT_RCU symbol is used to select/deselect this option.