default "$ARCH_DEFCONFIG"
default "arch/$ARCH/defconfig"
+config CONSTRUCTORS
+ bool
+ depends on !UML
+ default y
+
menu "General setup"
config EXPERIMENTAL
variables passed to init from the kernel command line.
+config CROSS_COMPILE
+ string "Cross-compiler tool prefix"
+ help
+ Same as running 'make CROSS_COMPILE=prefix-' but stored for
+ default make runs in this kernel build directory. You don't
+ need to set this unless you want the configured kernel build
+ directory to select the cross-compiler automatically.
+
config LOCALVERSION
string "Local version - append to kernel release"
help
config HAVE_KERNEL_LZMA
bool
+config HAVE_KERNEL_LZO
+ bool
+
choice
prompt "Kernel compression mode"
default KERNEL_GZIP
- depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA
+ depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_LZO
help
The linux kernel is a kind of self-extracting executable.
Several compression algorithms are available, which differ
bool "Gzip"
depends on HAVE_KERNEL_GZIP
help
- The old and tried gzip compression. Its compression ratio is
- the poorest among the 3 choices; however its speed (both
- compression and decompression) is the fastest.
+ The old and tried gzip compression. It provides a good balance
+ between compression ratio and decompression speed.
config KERNEL_BZIP2
bool "Bzip2"
two. Compression is slowest. The kernel size is about 33%
smaller with LZMA in comparison to gzip.
+config KERNEL_LZO
+ bool "LZO"
+ depends on HAVE_KERNEL_LZO
+ help
+ Its compression ratio is the poorest among the 4. The kernel
+ size is about about 10% bigger than gzip; however its speed
+ (both compression and decompression) is the fastest.
+
endchoice
config SWAP
If unsure, say Y.
+config POSIX_MQUEUE_SYSCTL
+ bool
+ depends on POSIX_MQUEUE
+ depends on SYSCTL
+ default y
+
config BSD_PROCESS_ACCT
bool "BSD Process Accounting"
help
config AUDITSYSCALL
bool "Enable system-call auditing support"
- depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
+ depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
default y if SECURITY_SELINUX
help
Enable low-overhead system-call auditing infrastructure that
config AUDIT_TREE
def_bool y
- depends on AUDITSYSCALL && INOTIFY
+ depends on AUDITSYSCALL
+ select INOTIFY
menu "RCU Subsystem"
choice
prompt "RCU Implementation"
- 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.
-
- Select this option if you are unsure.
+ default TREE_RCU
config TREE_RCU
bool "Tree-based hierarchical RCU"
help
This option selects the RCU implementation that is
designed for very large SMP system with hundreds or
- thousands of CPUs.
+ thousands of CPUs. It also scales down nicely to
+ smaller systems.
-config PREEMPT_RCU
- bool "Preemptible RCU"
+config TREE_PREEMPT_RCU
+ bool "Preemptable tree-based hierarchical 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.
+ This option selects the RCU implementation that is
+ designed for very large SMP systems with hundreds or
+ thousands of CPUs, but for which real-time response
+ is also required. It also scales down nicely to
+ smaller systems.
+
+config TINY_RCU
+ bool "UP-only small-memory-footprint RCU"
+ depends on !SMP
+ help
+ This option selects the RCU implementation that is
+ designed for UP systems from which real-time response
+ is not required. This option greatly reduces the
+ memory footprint of RCU.
endchoice
config RCU_TRACE
bool "Enable tracing for RCU"
- depends on TREE_RCU || PREEMPT_RCU
+ depends on TREE_RCU || TREE_PREEMPT_RCU
help
This option provides tracing in RCU which presents stats
in debugfs for debugging RCU implementation.
int "Tree-based hierarchical RCU fanout value"
range 2 64 if 64BIT
range 2 32 if !64BIT
- depends on TREE_RCU
+ depends on TREE_RCU || TREE_PREEMPT_RCU
default 64 if 64BIT
default 32 if !64BIT
help
config RCU_FANOUT_EXACT
bool "Disable tree-based hierarchical RCU auto-balancing"
- depends on TREE_RCU
+ depends on TREE_RCU || TREE_PREEMPT_RCU
default n
help
This option forces use of the exact RCU_FANOUT value specified,
Say N if unsure.
-config TREE_RCU_TRACE
- def_bool RCU_TRACE && TREE_RCU
- select DEBUG_FS
+config RCU_FAST_NO_HZ
+ bool "Accelerate last non-dyntick-idle CPU's grace periods"
+ depends on TREE_RCU && NO_HZ && SMP
+ default n
help
- This option provides tracing for the TREE_RCU implementation,
- permitting Makefile to trivially select kernel/rcutree_trace.c.
+ This option causes RCU to attempt to accelerate grace periods
+ in order to allow the final CPU to enter dynticks-idle state
+ more quickly. On the other hand, this option increases the
+ overhead of the dynticks-idle checking, particularly on systems
+ with large numbers of CPUs.
-config PREEMPT_RCU_TRACE
- def_bool RCU_TRACE && PREEMPT_RCU
+ Say Y if energy efficiency is critically important, particularly
+ if you have relatively few CPUs.
+
+ Say N if you are unsure.
+
+config TREE_RCU_TRACE
+ def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
select DEBUG_FS
help
- This option provides tracing for the PREEMPT_RCU implementation,
- permitting Makefile to trivially select kernel/rcupreempt_trace.c.
+ This option provides tracing for the TREE_RCU and
+ TREE_PREEMPT_RCU implementations, permitting Makefile to
+ trivially select kernel/rcutree_trace.c.
endmenu # "RCU Subsystem"
config HAVE_UNSTABLE_SCHED_CLOCK
bool
-config GROUP_SCHED
- bool "Group CPU scheduler"
- depends on EXPERIMENTAL
- default n
- help
- This feature lets CPU scheduler recognize task groups and control CPU
- bandwidth allocation to such task groups.
- In order to create a group from arbitrary set of processes, use
- CONFIG_CGROUPS. (See Control Group support.)
-
-config FAIR_GROUP_SCHED
- bool "Group scheduling for SCHED_OTHER"
- depends on GROUP_SCHED
- 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
- prompt "Basis for grouping tasks"
- default USER_SCHED
-
-config 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 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/cgroups.txt for more
- information on "cgroup" pseudo filesystem.
-
-endchoice
-
menuconfig CGROUPS
boolean "Control Group support"
+ depends on EVENTFD
help
This option adds support for grouping sets of processes together, for
use with process control subsystems such as Cpusets, CFS, memory
config CPUSETS
bool "Cpuset support"
- depends on SMP && CGROUPS
+ depends on CGROUPS
help
This option will let you create and manage CPUSETs which
allow dynamically partitioning a system into sets of CPUs and
select MM_OWNER
help
Provides a memory resource controller that manages both anonymous
- memory and page cache. (See Documentation/controllers/memory.txt)
+ memory and page cache. (See Documentation/cgroups/memory.txt)
Note that setting this option increases fixed memory overhead
associated with each page of memory in the system. By this,
is disabled by boot option, this will be automatically disabled and
there will be no overhead from this. Even when you set this config=y,
if boot option "noswapaccount" is set, swap will not be accounted.
+ Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
+ size is 4096bytes, 512k per 1Gbytes of swap.
+
+menuconfig CGROUP_SCHED
+ bool "Group CPU scheduler"
+ depends on EXPERIMENTAL && CGROUPS
+ default n
+ help
+ This feature lets CPU scheduler recognize task groups and control CPU
+ bandwidth allocation to such task groups. It uses cgroups to group
+ tasks.
+
+if CGROUP_SCHED
+config FAIR_GROUP_SCHED
+ bool "Group scheduling for SCHED_OTHER"
+ depends on CGROUP_SCHED
+ default CGROUP_SCHED
+
+config RT_GROUP_SCHED
+ bool "Group scheduling for SCHED_RR/FIFO"
+ depends on EXPERIMENTAL
+ depends on CGROUP_SCHED
+ default n
+ help
+ This feature lets you explicitly allocate real CPU bandwidth
+ to task groups. 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.
+
+endif #CGROUP_SCHED
+
+config BLK_CGROUP
+ tristate "Block IO controller"
+ depends on CGROUPS && BLOCK
+ default n
+ ---help---
+ Generic block IO controller cgroup interface. This is the common
+ cgroup interface which should be used by various IO controlling
+ policies.
+
+ Currently, CFQ IO scheduler uses it to recognize task groups and
+ control disk bandwidth allocation (proportional time slice allocation)
+ to such task groups.
+
+ This option only enables generic Block IO controller infrastructure.
+ One needs to also enable actual IO controlling logic in CFQ for it
+ to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).
+
+ See Documentation/cgroups/blkio-controller.txt for more information.
+
+config DEBUG_BLK_CGROUP
+ bool "Enable Block IO controller debugging"
+ depends on BLK_CGROUP
+ default n
+ ---help---
+ Enable some debugging help. Currently it exports additional stat
+ files in a cgroup which can be useful for debugging.
endif # CGROUPS
bool
config SYSFS_DEPRECATED_V2
- bool "Create deprecated sysfs layout for older userspace tools"
+ bool "enable deprecated sysfs features to support old userspace tools"
depends on SYSFS
- default y
+ default n
select SYSFS_DEPRECATED
help
This option switches the layout of sysfs to the deprecated
- version.
+ version. Do not use it on recent distributions.
The current sysfs layout features a unified device tree at
/sys/devices/, which is able to express a hierarchy between
config IPC_NS
bool "IPC namespace"
- depends on NAMESPACES && SYSVIPC
+ depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
help
In this namespace tasks work with IPC ids which correspond to
- different IPC objects in different namespaces
+ different IPC objects in different namespaces.
config USER_NS
bool "User namespace (EXPERIMENTAL)"
depends on NAMESPACES && EXPERIMENTAL
help
Support process id namespaces. This allows having multiple
- process with the same pid as long as they are in different
+ processes 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
config SYSCTL_SYSCALL
bool "Sysctl syscall support" if EMBEDDED
+ depends on PROC_SYSCTL
default y
select SYSCTL
---help---
by some high performance threaded applications. Disabling
this option saves about 7k.
+config HAVE_PERF_EVENTS
+ bool
+ help
+ See tools/perf/design.txt for details.
+
+config PERF_USE_VMALLOC
+ bool
+ help
+ See tools/perf/design.txt for details
+
+menu "Kernel Performance Events And Counters"
+
+config PERF_EVENTS
+ bool "Kernel performance events and counters"
+ default y if (PROFILING || PERF_COUNTERS)
+ depends on HAVE_PERF_EVENTS
+ select ANON_INODES
+ help
+ Enable kernel support for various performance events provided
+ by software and hardware.
+
+ Software events are supported either built-in or via the
+ use of generic tracepoints.
+
+ Most modern CPUs support performance events via performance
+ counter registers. These registers count the number of certain
+ types of hw events: such as instructions executed, cachemisses
+ suffered, or branches mis-predicted - without slowing down the
+ kernel or applications. These registers can also trigger interrupts
+ when a threshold number of events have passed - and can thus be
+ used to profile the code that runs on that CPU.
+
+ The Linux Performance Event subsystem provides an abstraction of
+ these software and hardware event capabilities, available via a
+ system call and used by the "perf" utility in tools/perf/. It
+ provides per task and per CPU counters, and it provides event
+ capabilities on top of those.
+
+ Say Y if unsure.
+
+config PERF_COUNTERS
+ bool "Kernel performance counters (old config option)"
+ depends on HAVE_PERF_EVENTS
+ help
+ This config has been obsoleted by the PERF_EVENTS
+ config option - please see that one for details.
+
+ It has no effect on the kernel whether you enable
+ it or not, it is a compatibility placeholder.
+
+ Say N if unsure.
+
+config DEBUG_PERF_USE_VMALLOC
+ default n
+ bool "Debug: use vmalloc to back perf mmap() buffers"
+ depends on PERF_EVENTS && DEBUG_KERNEL
+ select PERF_USE_VMALLOC
+ help
+ Use vmalloc memory to back perf mmap() buffers.
+
+ Mostly useful for debugging the vmalloc code on platforms
+ that don't require it.
+
+ Say N if unsure.
+
+endmenu
+
config VM_EVENT_COUNTERS
default y
bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
Randomizing heap placement makes heap exploits harder, but it
also breaks ancient binaries (including anything libc5 based).
This option changes the bootup default to heap randomization
- disabled, and can be overriden runtime by setting
+ disabled, and can be overridden at runtime by setting
/proc/sys/kernel/randomize_va_space to 2.
On non-ancient distros (post-2000 ones) N is usually a safe choice.
endchoice
+config MMAP_ALLOW_UNINITIALIZED
+ bool "Allow mmapped anonymous memory to be uninitialized"
+ depends on EMBEDDED && !MMU
+ default n
+ help
+ Normally, and according to the Linux spec, anonymous memory obtained
+ from mmap() has it's contents cleared before it is passed to
+ userspace. Enabling this config option allows you to request that
+ mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
+ providing a huge performance boost. If this option is not enabled,
+ then the flag will be ignored.
+
+ This is taken advantage of by uClibc's malloc(), and also by
+ ELF-FDPIC binfmt's brk and stack allocator.
+
+ Because of the obvious security issues, this option should only be
+ enabled on embedded devices where you control what is run in
+ userspace. Since that isn't generally a problem on no-MMU systems,
+ it is normally safe to say Y here.
+
+ See Documentation/nommu-mmap.txt for more information.
+
config PROFILING
- bool "Profiling support (EXPERIMENTAL)"
+ bool "Profiling support"
help
Say Y here to enable the extended profiling support mechanisms used
by profilers such as OProfile.
config TRACEPOINTS
bool
-config MARKERS
- bool "Activate markers"
- depends on TRACEPOINTS
+source "arch/Kconfig"
+
+config SLOW_WORK
+ default n
+ bool
help
- Place an empty function call at each marker site. Can be
- dynamically changed for a probe function.
+ The slow work thread pool provides a number of dynamically allocated
+ threads that can be used by the kernel to perform operations that
+ take a relatively long time.
-source "arch/Kconfig"
+ An example of this would be CacheFiles doing a path lookup followed
+ by a series of mkdirs and a create call, all of which have to touch
+ disk.
+
+ See Documentation/slow-work.txt.
+
+config SLOW_WORK_DEBUG
+ bool "Slow work debugging through debugfs"
+ default n
+ depends on SLOW_WORK && DEBUG_FS
+ help
+ Display the contents of the slow work run queue through debugfs,
+ including items currently executing.
+
+ See Documentation/slow-work.txt.
endmenu # General setup
config RT_MUTEXES
boolean
- select PLIST
config BASE_SMALL
int
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.
+ and have several arch maintainers pursuing me down dark alleys.
config STOP_MACHINE
bool
config PREEMPT_NOTIFIERS
bool
+config PADATA
+ depends on SMP
+ bool
+
+source "kernel/Kconfig.locks"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff