mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-21 08:53:41 +00:00
ebf3f09c63
This patchs adds the CONFIG_AIO option which allows to remove support for asynchronous I/O operations, that are not necessarly used by applications, particularly on embedded devices. As this is a size-reduction option, it depends on CONFIG_EMBEDDED. It allows to save ~7 kilobytes of kernel code/data: text data bss dec hex filename 1115067 119180 217088 1451335 162547 vmlinux 1108025 119048 217088 1444161 160941 vmlinux.new -7042 -132 0 -7174 -1C06 +/- This patch has been originally written by Matt Mackall <mpm@selenic.com>, and is part of the Linux Tiny project. [randy.dunlap@oracle.com: build fix] Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Zach Brown <zach.brown@oracle.com> Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
911 lines
28 KiB
Plaintext
911 lines
28 KiB
Plaintext
config ARCH
|
|
string
|
|
option env="ARCH"
|
|
|
|
config KERNELVERSION
|
|
string
|
|
option env="KERNELVERSION"
|
|
|
|
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 "$ARCH_DEFCONFIG"
|
|
default "arch/$ARCH/defconfig"
|
|
|
|
menu "General setup"
|
|
|
|
config EXPERIMENTAL
|
|
bool "Prompt for development and/or incomplete code/drivers"
|
|
---help---
|
|
Some of the various things that Linux supports (such as network
|
|
drivers, file systems, network protocols, etc.) can be in a state
|
|
of development where the functionality, stability, or the level of
|
|
testing is not yet high enough for general use. This is usually
|
|
known as the "alpha-test" phase among developers. If a feature is
|
|
currently in alpha-test, then the developers usually discourage
|
|
uninformed widespread use of this feature by the general public to
|
|
avoid "Why doesn't this work?" type mail messages. However, active
|
|
testing and use of these systems is welcomed. Just be aware that it
|
|
may not meet the normal level of reliability or it may fail to work
|
|
in some special cases. Detailed bug reports from people familiar
|
|
with the kernel internals are usually welcomed by the developers
|
|
(before submitting bug reports, please read the documents
|
|
<file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
|
|
<file:Documentation/BUG-HUNTING>, and
|
|
<file:Documentation/oops-tracing.txt> in the kernel source).
|
|
|
|
This option will also make obsoleted drivers available. These are
|
|
drivers that have been replaced by something else, and/or are
|
|
scheduled to be removed in a future kernel release.
|
|
|
|
Unless you intend to help test and develop a feature or driver that
|
|
falls into this category, or you have a situation that requires
|
|
using these features, you should probably say N here, which will
|
|
cause the configurator to present you with fewer choices. If
|
|
you say Y here, you will be offered the choice of using features or
|
|
drivers that are currently considered to be in the alpha-test phase.
|
|
|
|
config BROKEN
|
|
bool
|
|
|
|
config BROKEN_ON_SMP
|
|
bool
|
|
depends on BROKEN || !SMP
|
|
default y
|
|
|
|
config LOCK_KERNEL
|
|
bool
|
|
depends on SMP || PREEMPT
|
|
default y
|
|
|
|
config INIT_ENV_ARG_LIMIT
|
|
int
|
|
default 32 if !UML
|
|
default 128 if UML
|
|
help
|
|
Maximum of each of the number of arguments and environment
|
|
variables passed to init from the kernel command line.
|
|
|
|
|
|
config LOCALVERSION
|
|
string "Local version - append to kernel release"
|
|
help
|
|
Append an extra string to the end of your kernel version.
|
|
This will show up when you type uname, for example.
|
|
The string you set here will be appended after the contents of
|
|
any files with a filename matching localversion* in your
|
|
object and source tree, in that order. Your total string can
|
|
be a maximum of 64 characters.
|
|
|
|
config LOCALVERSION_AUTO
|
|
bool "Automatically append version information to the version string"
|
|
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.
|
|
|
|
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
|
|
appended after any matching localversion* files, and after the value
|
|
set in CONFIG_LOCALVERSION.
|
|
|
|
(The actual string used here is the first eight characters produced
|
|
by running the command:
|
|
|
|
$ git rev-parse --verify HEAD
|
|
|
|
which is done within the script "scripts/setlocalversion".)
|
|
|
|
config SWAP
|
|
bool "Support for paging of anonymous memory (swap)"
|
|
depends on MMU && BLOCK
|
|
default y
|
|
help
|
|
This option allows you to choose whether you want to have support
|
|
for so called swap devices or swap files in your kernel that are
|
|
used to provide more virtual memory than the actual RAM present
|
|
in your computer. If unsure say Y.
|
|
|
|
config SYSVIPC
|
|
bool "System V IPC"
|
|
---help---
|
|
Inter Process Communication is a suite of library functions and
|
|
system calls which let processes (running programs) synchronize and
|
|
exchange information. It is generally considered to be a good thing,
|
|
and some programs won't run unless you say Y here. In particular, if
|
|
you want to run the DOS emulator dosemu under Linux (read the
|
|
DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
|
|
you'll need to say Y here.
|
|
|
|
You can find documentation about IPC with "info ipc" and also in
|
|
section 6.4 of the Linux Programmer's Guide, available from
|
|
<http://www.tldp.org/guides.html>.
|
|
|
|
config SYSVIPC_SYSCTL
|
|
bool
|
|
depends on SYSVIPC
|
|
depends on SYSCTL
|
|
default y
|
|
|
|
config POSIX_MQUEUE
|
|
bool "POSIX Message Queues"
|
|
depends on NET && EXPERIMENTAL
|
|
---help---
|
|
POSIX variant of message queues is a part of IPC. In POSIX message
|
|
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.
|
|
|
|
POSIX message queues are visible as a filesystem called 'mqueue'
|
|
and can be mounted somewhere if you want to do filesystem
|
|
operations on message queues.
|
|
|
|
If unsure, say Y.
|
|
|
|
config BSD_PROCESS_ACCT
|
|
bool "BSD Process Accounting"
|
|
help
|
|
If you say Y here, a user level program will be able to instruct the
|
|
kernel (via a special system call) to write process accounting
|
|
information to a file: whenever a process exits, information about
|
|
that process will be appended to the file by the kernel. The
|
|
information includes things such as creation time, owning user,
|
|
command name, memory usage, controlling terminal etc. (the complete
|
|
list is in the struct acct in <file:include/linux/acct.h>). It is
|
|
up to the user level program to do useful things with this
|
|
information. This is generally a good idea, so say Y.
|
|
|
|
config BSD_PROCESS_ACCT_V3
|
|
bool "BSD Process Accounting version 3 file format"
|
|
depends on BSD_PROCESS_ACCT
|
|
default n
|
|
help
|
|
If you say Y here, the process accounting information is written
|
|
in a new file format that also logs the process IDs of each
|
|
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.gnu.org/software/acct/>.
|
|
|
|
config TASKSTATS
|
|
bool "Export task/process statistics through netlink (EXPERIMENTAL)"
|
|
depends on NET
|
|
default n
|
|
help
|
|
Export selected statistics for tasks/processes through the
|
|
generic netlink interface. Unlike BSD process accounting, the
|
|
statistics are available during the lifetime of tasks/processes as
|
|
responses to commands. Like BSD accounting, they are sent to user
|
|
space on task exit.
|
|
|
|
Say N if unsure.
|
|
|
|
config TASK_DELAY_ACCT
|
|
bool "Enable per-task delay accounting (EXPERIMENTAL)"
|
|
depends on TASKSTATS
|
|
help
|
|
Collect information on time spent by a task waiting for system
|
|
resources like cpu, synchronous block I/O completion and swapping
|
|
in pages. Such statistics can help in setting a task's priorities
|
|
relative to other tasks for cpu, io, rss limits etc.
|
|
|
|
Say N if unsure.
|
|
|
|
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 AUDIT
|
|
bool "Auditing support"
|
|
depends on NET
|
|
help
|
|
Enable auditing infrastructure that can be used with another
|
|
kernel subsystem, such as SELinux (which requires this for
|
|
logging of avc messages output). Does not do system-call
|
|
auditing without CONFIG_AUDITSYSCALL.
|
|
|
|
config AUDITSYSCALL
|
|
bool "Enable system-call auditing support"
|
|
depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
|
|
default y if SECURITY_SELINUX
|
|
help
|
|
Enable low-overhead system-call auditing infrastructure that
|
|
can be used independently or with another kernel subsystem,
|
|
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 the complete Linux kernel ".config" file
|
|
contents to be saved in the kernel. It provides documentation
|
|
of which kernel options are used in a running kernel or in an
|
|
on-disk kernel. This information can be extracted from the kernel
|
|
image file with the script scripts/extract-ikconfig and used as
|
|
input to rebuild the current kernel or to build another kernel.
|
|
It can also be extracted from a running kernel by reading
|
|
/proc/config.gz if enabled (below).
|
|
|
|
config IKCONFIG_PROC
|
|
bool "Enable access to .config through /proc/config.gz"
|
|
depends on IKCONFIG && PROC_FS
|
|
---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
|
|
help
|
|
Select kernel log buffer size as a power of 2.
|
|
Examples:
|
|
17 => 128 KB
|
|
16 => 64 KB
|
|
15 => 32 KB
|
|
14 => 16 KB
|
|
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
|
|
default n
|
|
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 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
|
|
help
|
|
This option will let you create and manage CPUSETs which
|
|
allow dynamically partitioning a system into sets of CPUs and
|
|
Memory Nodes and assigning tasks to run only within those sets.
|
|
This is primarily useful on large SMP or NUMA systems.
|
|
|
|
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"
|
|
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 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/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.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 RESOURCE_COUNTERS
|
|
bool "Resource counters"
|
|
help
|
|
This option enables controller independent resource accounting
|
|
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 page cache and
|
|
RSS memory.
|
|
|
|
Note that setting this option increases fixed memory overhead
|
|
associated with each page of memory in the system by 4/8 bytes
|
|
and also increases cache misses because struct page on many 64bit
|
|
systems will not fit into a single cache line anymore.
|
|
|
|
Only enable when you're ok with these trade offs and really
|
|
sure you need the memory resource controller.
|
|
|
|
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
|
|
"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 and some userspace
|
|
programs.
|
|
|
|
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"
|
|
depends on CPUSETS
|
|
default y
|
|
|
|
config RELAY
|
|
bool "Kernel->user space relay support (formerly relayfs)"
|
|
help
|
|
This option enables support for relay interface support in
|
|
certain file systems (such as debugfs).
|
|
It is designed to provide an efficient mechanism for tools and
|
|
facilities to relay large amounts of data from kernel space to
|
|
user space.
|
|
|
|
If unsure, say N.
|
|
|
|
config NAMESPACES
|
|
bool "Namespaces support" if EMBEDDED
|
|
default !EMBEDDED
|
|
help
|
|
Provides the way to make tasks work with different objects using
|
|
the same id. For example same IPC id may refer to different objects
|
|
or same user id or pid may refer to different tasks when used in
|
|
different namespaces.
|
|
|
|
config UTS_NS
|
|
bool "UTS namespace"
|
|
depends on NAMESPACES
|
|
help
|
|
In this namespace tasks see different info provided with the
|
|
uname() system call
|
|
|
|
config IPC_NS
|
|
bool "IPC namespace"
|
|
depends on NAMESPACES && SYSVIPC
|
|
help
|
|
In this namespace tasks work with IPC ids which correspond to
|
|
different IPC objects in different namespaces
|
|
|
|
config USER_NS
|
|
bool "User namespace (EXPERIMENTAL)"
|
|
depends on NAMESPACES && EXPERIMENTAL
|
|
help
|
|
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 NAMESPACES && EXPERIMENTAL
|
|
help
|
|
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.
|
|
|
|
Unless you want to work with an experimental feature
|
|
say N here.
|
|
|
|
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"
|
|
default y
|
|
help
|
|
Enabling this option will pass "-Os" instead of "-O2" to gcc
|
|
resulting in a smaller kernel.
|
|
|
|
If unsure, say Y.
|
|
|
|
config SYSCTL
|
|
bool
|
|
|
|
menuconfig EMBEDDED
|
|
bool "Configure standard kernel features (for small systems)"
|
|
help
|
|
This option allows certain base kernel options and settings
|
|
to be disabled or tweaked. This is for specialized
|
|
environments which can tolerate a "non-standard" kernel.
|
|
Only use this if you really know what you are doing.
|
|
|
|
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 && 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 y
|
|
select SYSCTL
|
|
---help---
|
|
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.
|
|
|
|
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.
|
|
|
|
If unsure say Y here.
|
|
|
|
config KALLSYMS
|
|
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
|
|
symbolic stack backtraces. This increases the size of the kernel
|
|
somewhat, as all symbols have to be loaded into the kernel image.
|
|
|
|
config KALLSYMS_ALL
|
|
bool "Include all symbols in kallsyms"
|
|
depends on DEBUG_KERNEL && KALLSYMS
|
|
help
|
|
Normally kallsyms only contains the symbols of functions, for nicer
|
|
OOPS messages. Some debuggers can use kallsyms for other
|
|
symbols too: say Y here to include all symbols, if you need them
|
|
and you don't care about adding 300k to the size of your kernel.
|
|
|
|
Say N.
|
|
|
|
config KALLSYMS_EXTRA_PASS
|
|
bool "Do an extra kallsyms pass"
|
|
depends on KALLSYMS
|
|
help
|
|
If kallsyms is not working correctly, the build will fail with
|
|
inconsistent kallsyms data. If that occurs, log a bug report and
|
|
turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
|
|
Always say N here unless you find a bug in kallsyms, which must be
|
|
reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
|
|
you wait for kallsyms to be fixed.
|
|
|
|
|
|
config HOTPLUG
|
|
bool "Support for hot-pluggable devices" if EMBEDDED
|
|
default y
|
|
help
|
|
This option is provided for the case where no hotplug or uevent
|
|
capabilities is wanted by the kernel. You should only consider
|
|
disabling this option for embedded systems that do not use modules, a
|
|
dynamic /dev tree, or dynamic device discovery. Just say Y.
|
|
|
|
config PRINTK
|
|
default y
|
|
bool "Enable support for printk" if EMBEDDED
|
|
help
|
|
This option enables normal printk support. Removing it
|
|
eliminates most of the message strings from the kernel image
|
|
and makes the kernel more or less silent. As this makes it
|
|
very difficult to diagnose system problems, saying N here is
|
|
strongly discouraged.
|
|
|
|
config BUG
|
|
bool "BUG() support" if EMBEDDED
|
|
default y
|
|
help
|
|
Disabling this option eliminates support for BUG and WARN, reducing
|
|
the size of your kernel image and potentially quietly ignoring
|
|
numerous fatal conditions. You should only consider disabling this
|
|
option for embedded systems with no facilities for reporting errors.
|
|
Just say Y.
|
|
|
|
config ELF_CORE
|
|
default y
|
|
bool "Enable ELF core dumps" if EMBEDDED
|
|
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
|
|
help
|
|
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
|
|
/proc/sys/kernel/randomize_va_space to 2.
|
|
|
|
On non-ancient distros (post-2000 ones) N is usually a safe choice.
|
|
|
|
config BASE_FULL
|
|
default y
|
|
bool "Enable full-sized data structures for core" if EMBEDDED
|
|
help
|
|
Disabling this option reduces the size of miscellaneous core
|
|
kernel data structures. This saves memory on small machines,
|
|
but may reduce performance.
|
|
|
|
config FUTEX
|
|
bool "Enable futex support" if EMBEDDED
|
|
default y
|
|
select RT_MUTEXES
|
|
help
|
|
Disabling this option will cause the kernel to be built without
|
|
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
|
|
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
|
|
depends on MMU
|
|
help
|
|
The shmem is an internal filesystem used to manage shared memory.
|
|
It is backed by swap and manages resource limits. It is also exported
|
|
to userspace as tmpfs if TMPFS is enabled. Disabling this
|
|
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
|
|
help
|
|
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 SLUB_DEBUG
|
|
default y
|
|
bool "Enable SLUB debugging support" if EMBEDDED
|
|
depends on SLUB && SYSFS
|
|
help
|
|
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 stock allocator with a drastically simpler
|
|
allocator. SLOB is generally more space efficient but
|
|
does not perform as well on large systems.
|
|
|
|
endchoice
|
|
|
|
config PROFILING
|
|
bool "Profiling support (EXPERIMENTAL)"
|
|
help
|
|
Say Y here to enable the extended profiling support mechanisms used
|
|
by profilers such as OProfile.
|
|
|
|
config MARKERS
|
|
bool "Activate markers"
|
|
help
|
|
Place an empty function call at each marker site. Can be
|
|
dynamically changed for a probe function.
|
|
|
|
source "arch/Kconfig"
|
|
|
|
endmenu # General setup
|
|
|
|
config HAVE_GENERIC_DMA_COHERENT
|
|
bool
|
|
default n
|
|
|
|
config SLABINFO
|
|
bool
|
|
depends on PROC_FS
|
|
depends on SLAB || SLUB_DEBUG
|
|
default y
|
|
|
|
config RT_MUTEXES
|
|
boolean
|
|
select PLIST
|
|
|
|
config TINY_SHMEM
|
|
default !SHMEM
|
|
bool
|
|
|
|
config BASE_SMALL
|
|
int
|
|
default 0 if BASE_FULL
|
|
default 1 if !BASE_FULL
|
|
|
|
menuconfig MODULES
|
|
bool "Enable loadable module support"
|
|
help
|
|
Kernel modules are small pieces of compiled code which can
|
|
be inserted in the running kernel, rather than being
|
|
permanently built into the kernel. You use the "modprobe"
|
|
tool to add (and sometimes remove) them. If you say Y here,
|
|
many parts of the kernel can be built as modules (by
|
|
answering M instead of Y where indicated): this is most
|
|
useful for infrequently used options which are not required
|
|
for booting. For more information, see the man pages for
|
|
modprobe, lsmod, modinfo, insmod and rmmod.
|
|
|
|
If you say Y here, you will need to run "make
|
|
modules_install" to put the modules under /lib/modules/
|
|
where modprobe can find them (you may need to be root to do
|
|
this).
|
|
|
|
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"
|
|
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 smaller, faster
|
|
and simpler. If unsure, say Y.
|
|
|
|
config MODULE_FORCE_UNLOAD
|
|
bool "Forced module unloading"
|
|
depends on MODULE_UNLOAD && EXPERIMENTAL
|
|
help
|
|
This option allows you to force a module to unload, even if the
|
|
kernel believes it is unsafe: the kernel will remove the module
|
|
without waiting for anyone to stop using it (using the -f option to
|
|
rmmod). This is mainly for kernel developers and desperate users.
|
|
If unsure, say N.
|
|
|
|
config MODVERSIONS
|
|
bool "Module versioning support"
|
|
help
|
|
Usually, you have to use modules compiled with your kernel.
|
|
Saying Y here makes it sometimes possible to use modules
|
|
compiled for different kernels, by adding enough information
|
|
to the modules to (hopefully) spot any changes which would
|
|
make them incompatible with the kernel you are running. If
|
|
unsure, say N.
|
|
|
|
config MODULE_SRCVERSION_ALL
|
|
bool "Source checksum for all modules"
|
|
help
|
|
Modules which contain a MODULE_VERSION get an extra "srcversion"
|
|
field inserted into their modinfo section, which contains a
|
|
sum of the source files which made it. This helps maintainers
|
|
see exactly which source was used to build a module (since
|
|
others sometimes change the module source without updating
|
|
the version). With this option, such a "srcversion" field
|
|
will be created for all modules. If unsure, say N.
|
|
|
|
config KMOD
|
|
def_bool y
|
|
help
|
|
This is being removed soon. These days, CONFIG_MODULES
|
|
implies CONFIG_KMOD, so use that instead.
|
|
|
|
endif # MODULES
|
|
|
|
config STOP_MACHINE
|
|
bool
|
|
default y
|
|
depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
|
|
help
|
|
Need stop_machine() primitive.
|
|
|
|
source "block/Kconfig"
|
|
|
|
config PREEMPT_NOTIFIERS
|
|
bool
|
|
|
|
config 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. Classic RCU is the default. Note that the
|
|
PREEMPT_RCU symbol is used to select/deselect this option.
|