config DEFCONFIG_LIST
string
+ depends on !UML
option defconfig_list
default "/lib/modules/$UNAME_RELEASE/.config"
default "/etc/kernel-config"
default "/boot/config-$UNAME_RELEASE"
default "arch/$ARCH/defconfig"
-menu "Code maturity level options"
+menu "General setup"
config EXPERIMENTAL
bool "Prompt for development and/or incomplete code/drivers"
Maximum of each of the number of arguments and environment
variables passed to init from the kernel command line.
-endmenu
-
-menu "General setup"
config LOCALVERSION
string "Local version - append to kernel release"
default y
help
This will try to automatically determine if the current tree is a
- release tree by looking for git tags that
- belong to the current top of tree revision.
+ release tree by looking for git tags that belong to the current
+ top of tree revision.
A string of the format -gxxxxxxxx will be added to the localversion
- if a git based tree is found. The string generated by this will be
+ if a git-based tree is found. The string generated by this will be
appended after any matching localversion* files, and after the value
- set in CONFIG_LOCALVERSION
+ set in CONFIG_LOCALVERSION.
+
+ (The actual string used here is the first eight characters produced
+ by running the command:
- Note: This requires Perl, and a git repository, but not necessarily
- the git or cogito tools to be installed.
+ $ git rev-parse --verify HEAD
+
+ which is done within the script "scripts/setlocalversion".)
config SWAP
bool "Support for paging of anonymous memory (swap)"
section 6.4 of the Linux Programmer's Guide, available from
<http://www.tldp.org/guides.html>.
-config IPC_NS
- bool "IPC Namespaces"
+config SYSVIPC_SYSCTL
+ bool
depends on SYSVIPC
- default n
- help
- Support ipc namespaces. This allows containers, i.e. virtual
- environments, to use ipc namespaces to provide different ipc
- objects for different servers. If unsure, say N.
+ depends on SYSCTL
+ default y
config POSIX_MQUEUE
bool "POSIX Message Queues"
queues every message has a priority which decides about succession
of receiving it by a process. If you want to compile and run
programs written e.g. for Solaris with use of its POSIX message
- queues (functions mq_*) say Y here. To use this feature you will
- also need mqueue library, available from
- <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
+ queues (functions mq_*) say Y here.
POSIX message queues are visible as a filesystem called 'mqueue'
and can be mounted somewhere if you want to do filesystem
Say N if unsure.
-config UTS_NS
- bool "UTS Namespaces"
+config TASK_XACCT
+ bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
+ depends on TASKSTATS
+ help
+ Collect extended task accounting data and send the data
+ to userland for processing over the taskstats interface.
+
+ Say N if unsure.
+
+config TASK_IO_ACCOUNTING
+ bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
+ depends on TASK_XACCT
+ help
+ Collect information on the number of bytes of storage I/O which this
+ task has caused.
+
+ Say N if unsure.
+
+config USER_NS
+ bool "User Namespaces (EXPERIMENTAL)"
default n
+ depends on EXPERIMENTAL
help
- Support uts namespaces. This allows containers, i.e.
- vservers, to use uts namespaces to provide different
- uts info for different servers. If unsure, say N.
+ Support user namespaces. This allows containers, i.e.
+ vservers, to use user namespaces to provide different
+ user info for different servers. If unsure, say N.
+
+config PID_NS
+ bool "PID Namespaces (EXPERIMENTAL)"
+ default n
+ depends on EXPERIMENTAL
+ help
+ Suport 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.
+
+ Unless you want to work with an experimental feature
+ say N here.
config AUDIT
bool "Auditing support"
such as SELinux. To use audit's filesystem watch feature, please
ensure that INOTIFY is configured.
+config AUDIT_TREE
+ def_bool y
+ depends on AUDITSYSCALL && INOTIFY
+
config IKCONFIG
tristate "Kernel .config support"
---help---
This option enables access to the kernel configuration file
through /proc/config.gz.
+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
+ 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
+ 13 => 8 KB
+ 12 => 4 KB
+
+config CGROUPS
+ bool "Control Group support"
+ help
+ This option will let you use process cgroup subsystems
+ such as Cpusets
+
+ Say N if unsure.
+
+config CGROUP_DEBUG
+ bool "Example debug cgroup subsystem"
+ depends on CGROUPS
+ help
+ This option enables a simple cgroup subsystem that
+ exports useful debugging information about the cgroups
+ framework
+
+ Say N if unsure
+
+config CGROUP_NS
+ bool "Namespace cgroup subsystem"
+ depends on CGROUPS
+ help
+ Provides a simple namespace cgroup subsystem to
+ provide hierarchical naming of sets of namespaces,
+ for instance virtual servers and checkpoint/restart
+ jobs.
+
config CPUSETS
bool "Cpuset support"
- depends on SMP
+ depends on SMP && CGROUPS
help
This option will let you create and manage CPUSETs which
allow dynamically partitioning a system into sets of CPUs and
Say N if unsure.
+config FAIR_GROUP_SCHED
+ bool "Fair group CPU scheduler"
+ default y
+ help
+ This feature lets CPU scheduler recognize task groups and control CPU
+ bandwidth allocation to such task groups.
+
+choice
+ depends on FAIR_GROUP_SCHED
+ prompt "Basis for grouping tasks"
+ default FAIR_USER_SCHED
+
+config FAIR_USER_SCHED
+ bool "user id"
+ help
+ This option will choose userid as the basis for grouping
+ tasks, thus providing equal CPU bandwidth to each user.
+
+config FAIR_CGROUP_SCHED
+ bool "Control groups"
+ depends on CGROUPS
+ help
+ This option allows you to create arbitrary task groups
+ using the "cgroup" pseudo filesystem and control
+ the cpu bandwidth allocated to each such task group.
+ Refer to Documentation/cgroups.txt for more information
+ on "cgroup" pseudo filesystem.
+
+endchoice
+
+config CGROUP_CPUACCT
+ bool "Simple CPU accounting cgroup subsystem"
+ depends on CGROUPS
+ help
+ Provides a simple Resource Controller for monitoring the
+ total CPU consumed by the tasks in a cgroup
+
+config SYSFS_DEPRECATED
+ bool "Create deprecated sysfs files"
+ depends on SYSFS
+ default y
+ help
+ This option creates deprecated symlinks such as the
+ "device"-link, the <subsystem>:<name>-link, and the
+ "bus"-link. It may also add deprecated key in the
+ uevent environment.
+ None of these features or values should be used today, as
+ they export driver core implementation details to userspace
+ or export properties which can't be kept stable across kernel
+ releases.
+
+ 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.
+
+config PROC_PID_CPUSET
+ bool "Include legacy /proc/<pid>/cpuset file"
+ depends on CPUSETS
+ default y
+
config RELAY
bool "Kernel->user space relay support (formerly relayfs)"
help
If unsure, say N.
+config BLK_DEV_INITRD
+ bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
+ depends on BROKEN || !FRV
+ help
+ The initial RAM filesystem is a ramfs which is loaded by the
+ boot loader (loadlin or lilo) and that is mounted as root
+ before the normal boot procedure. It is typically used to
+ load modules needed to mount the "real" root file system,
+ etc. See <file:Documentation/initrd.txt> for details.
+
+ If RAM disk support (BLK_DEV_RAM) is also included, this
+ also enables initial RAM disk (initrd) support and adds
+ 15 Kbytes (more on some other architectures) to the kernel size.
+
+ If unsure say Y.
+
+if BLK_DEV_INITRD
+
source "usr/Kconfig"
+endif
+
config CC_OPTIMIZE_FOR_SIZE
bool "Optimize for size (Look out for broken compilers!)"
default y
- depends on ARM || H8300 || EXPERIMENTAL
+ depends on ARM || H8300 || SUPERH || EXPERIMENTAL
help
Enabling this option will pass "-Os" instead of "-O2" to gcc
resulting in a smaller kernel.
If unsure, say N.
-config TASK_XACCT
- bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
- depends on TASKSTATS
- help
- Collect extended task accounting data and send the data
- to userland for processing over the taskstats interface.
-
- Say N if unsure.
-
config SYSCTL
bool
config UID16
bool "Enable 16-bit UID system calls" if EMBEDDED
- depends on ARM || 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 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
default y
help
This enables the legacy 16-bit UID syscall wrappers.
config SYSCTL_SYSCALL
bool "Sysctl syscall support" if EMBEDDED
- default n
+ default y
select SYSCTL
---help---
- Enable the deprecated sysctl system call. sys_sysctl uses
- binary paths that have been found to be a major pain to maintain
- and use. The interface in /proc/sys is now the primary and what
- everyone uses.
+ sys_sysctl uses binary paths that have been found challenging
+ to properly maintain and use. The interface in /proc/sys
+ using paths with ascii names is now the primary path to this
+ information.
- Nothing has been using the binary sysctl interface for some
- time now so nothing should break if you disable sysctl syscall
- support, and your kernel will get marginally smaller.
+ Almost nothing using the binary sysctl interface so if you are
+ trying to save some space it is probably safe to disable this,
+ making your kernel marginally smaller.
- Unless you have an application that uses the sys_sysctl interface
- you should probably say N here.
+ If unsure say Y here.
config KALLSYMS
- bool "Load all symbols for debugging/kksymoops" if EMBEDDED
+ bool "Load all symbols for debugging/ksymoops" if EMBEDDED
default y
help
Say Y here to let the kernel print out symbolic crash information and
support for "fast userspace mutexes". The resulting kernel may not
run glibc-based applications correctly.
+config ANON_INODES
+ bool
+
config EPOLL
bool "Enable eventpoll support" if EMBEDDED
default y
+ select ANON_INODES
help
Disabling this option will cause the kernel to be built without
support for epoll family of system calls.
+config SIGNALFD
+ bool "Enable signalfd() system call" if EMBEDDED
+ select ANON_INODES
+ default y
+ help
+ Enable the signalfd() system call that allows to receive signals
+ on a file descriptor.
+
+ If unsure, say Y.
+
+config TIMERFD
+ bool "Enable timerfd() system call" if EMBEDDED
+ select ANON_INODES
+ depends on BROKEN
+ default y
+ help
+ Enable the timerfd() system call that allows to receive timer
+ events on a file descriptor.
+
+ If unsure, say Y.
+
+config EVENTFD
+ bool "Enable eventfd() system call" if EMBEDDED
+ select ANON_INODES
+ default y
+ help
+ Enable the eventfd() system call that allows to receive both
+ kernel notification (ie. KAIO) or userspace notifications.
+
+ If unsure, say Y.
+
config SHMEM
bool "Use full shmem filesystem" if EMBEDDED
default y
option replaces shmem and tmpfs with the much simpler ramfs code,
which may be appropriate on small systems without swap.
-config SLAB
+config VM_EVENT_COUNTERS
default y
- bool "Use full SLAB allocator" if EMBEDDED
+ bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
help
- Disabling this replaces the advanced SLAB allocator and
- kmalloc support with the drastically simpler SLOB allocator.
- SLOB is more space efficient but does not scale well and is
- more susceptible to fragmentation.
+ VM event counters are needed for event counts to be shown.
+ This option allows the disabling of the VM event counters
+ on EMBEDDED systems. /proc/vmstat will only show page counts
+ if VM event counters are disabled.
-config VM_EVENT_COUNTERS
+config SLUB_DEBUG
default y
- bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
+ bool "Enable SLUB debugging support" if EMBEDDED
+ depends on SLUB
help
- VM event counters are only needed to for event counts to be
- shown. They have no function for the kernel itself. This
- option allows the disabling of the VM event counters.
- /proc/vmstat will only show page counts.
+ SLUB has extensive debug support features. Disabling these can
+ result in significant savings in code size. This also disables
+ SLUB sysfs support. /sys/slab will not exist and there will be
+ no support for cache validation etc.
+
+choice
+ prompt "Choose SLAB allocator"
+ default SLUB
+ help
+ This option allows to select a slab allocator.
+
+config SLAB
+ bool "SLAB"
+ 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.
+
+config SLUB
+ bool "SLUB (Unqueued Allocator)"
+ help
+ SLUB is a slab allocator that minimizes cache line usage
+ 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.
+
+config SLOB
+ depends on EMBEDDED
+ bool "SLOB (Simple Allocator)"
+ help
+ SLOB replaces the SLAB allocator with a drastically simpler
+ allocator. SLOB is more space efficient than SLAB but does not
+ scale well (single lock for all operations) and is also highly
+ susceptible to fragmentation. SLUB can accomplish a higher object
+ density. It is usually better to use SLUB instead of SLOB.
+
+endchoice
endmenu # General setup
+config SLABINFO
+ bool
+ depends on PROC_FS
+ depends on SLAB || SLUB
+ default y
+
config RT_MUTEXES
boolean
select PLIST
default 0 if BASE_FULL
default 1 if !BASE_FULL
-config SLOB
- default !SLAB
- bool
-
-menu "Loadable module support"
-
-config MODULES
+menuconfig MODULES
bool "Enable loadable module support"
help
Kernel modules are small pieces of compiled code which can
depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
help
Need stop_machine() primitive.
-endmenu
-menu "Block layer"
source "block/Kconfig"
-endmenu
+
+config PREEMPT_NOTIFIERS
+ bool
+
+choice
+ prompt "RCU implementation type:"
+ default CLASSIC_RCU
+
+config CLASSIC_RCU
+ bool "Classic 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