7 option env="KERNELVERSION"
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
16 default "$ARCH_DEFCONFIG"
17 default "arch/$ARCH/defconfig"
22 bool "Prompt for development and/or incomplete code/drivers"
24 Some of the various things that Linux supports (such as network
25 drivers, file systems, network protocols, etc.) can be in a state
26 of development where the functionality, stability, or the level of
27 testing is not yet high enough for general use. This is usually
28 known as the "alpha-test" phase among developers. If a feature is
29 currently in alpha-test, then the developers usually discourage
30 uninformed widespread use of this feature by the general public to
31 avoid "Why doesn't this work?" type mail messages. However, active
32 testing and use of these systems is welcomed. Just be aware that it
33 may not meet the normal level of reliability or it may fail to work
34 in some special cases. Detailed bug reports from people familiar
35 with the kernel internals are usually welcomed by the developers
36 (before submitting bug reports, please read the documents
37 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
38 <file:Documentation/BUG-HUNTING>, and
39 <file:Documentation/oops-tracing.txt> in the kernel source).
41 This option will also make obsoleted drivers available. These are
42 drivers that have been replaced by something else, and/or are
43 scheduled to be removed in a future kernel release.
45 Unless you intend to help test and develop a feature or driver that
46 falls into this category, or you have a situation that requires
47 using these features, you should probably say N here, which will
48 cause the configurator to present you with fewer choices. If
49 you say Y here, you will be offered the choice of using features or
50 drivers that are currently considered to be in the alpha-test phase.
57 depends on BROKEN || !SMP
62 depends on SMP || PREEMPT
65 config INIT_ENV_ARG_LIMIT
70 Maximum of each of the number of arguments and environment
71 variables passed to init from the kernel command line.
75 string "Local version - append to kernel release"
77 Append an extra string to the end of your kernel version.
78 This will show up when you type uname, for example.
79 The string you set here will be appended after the contents of
80 any files with a filename matching localversion* in your
81 object and source tree, in that order. Your total string can
82 be a maximum of 64 characters.
84 config LOCALVERSION_AUTO
85 bool "Automatically append version information to the version string"
88 This will try to automatically determine if the current tree is a
89 release tree by looking for git tags that belong to the current
92 A string of the format -gxxxxxxxx will be added to the localversion
93 if a git-based tree is found. The string generated by this will be
94 appended after any matching localversion* files, and after the value
95 set in CONFIG_LOCALVERSION.
97 (The actual string used here is the first eight characters produced
98 by running the command:
100 $ git rev-parse --verify HEAD
102 which is done within the script "scripts/setlocalversion".)
105 bool "Support for paging of anonymous memory (swap)"
106 depends on MMU && BLOCK
109 This option allows you to choose whether you want to have support
110 for so called swap devices or swap files in your kernel that are
111 used to provide more virtual memory than the actual RAM present
112 in your computer. If unsure say Y.
117 Inter Process Communication is a suite of library functions and
118 system calls which let processes (running programs) synchronize and
119 exchange information. It is generally considered to be a good thing,
120 and some programs won't run unless you say Y here. In particular, if
121 you want to run the DOS emulator dosemu under Linux (read the
122 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
123 you'll need to say Y here.
125 You can find documentation about IPC with "info ipc" and also in
126 section 6.4 of the Linux Programmer's Guide, available from
127 <http://www.tldp.org/guides.html>.
129 config SYSVIPC_SYSCTL
136 bool "POSIX Message Queues"
137 depends on NET && EXPERIMENTAL
139 POSIX variant of message queues is a part of IPC. In POSIX message
140 queues every message has a priority which decides about succession
141 of receiving it by a process. If you want to compile and run
142 programs written e.g. for Solaris with use of its POSIX message
143 queues (functions mq_*) say Y here.
145 POSIX message queues are visible as a filesystem called 'mqueue'
146 and can be mounted somewhere if you want to do filesystem
147 operations on message queues.
151 config BSD_PROCESS_ACCT
152 bool "BSD Process Accounting"
154 If you say Y here, a user level program will be able to instruct the
155 kernel (via a special system call) to write process accounting
156 information to a file: whenever a process exits, information about
157 that process will be appended to the file by the kernel. The
158 information includes things such as creation time, owning user,
159 command name, memory usage, controlling terminal etc. (the complete
160 list is in the struct acct in <file:include/linux/acct.h>). It is
161 up to the user level program to do useful things with this
162 information. This is generally a good idea, so say Y.
164 config BSD_PROCESS_ACCT_V3
165 bool "BSD Process Accounting version 3 file format"
166 depends on BSD_PROCESS_ACCT
169 If you say Y here, the process accounting information is written
170 in a new file format that also logs the process IDs of each
171 process and it's parent. Note that this file format is incompatible
172 with previous v0/v1/v2 file formats, so you will need updated tools
173 for processing it. A preliminary version of these tools is available
174 at <http://www.gnu.org/software/acct/>.
177 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
181 Export selected statistics for tasks/processes through the
182 generic netlink interface. Unlike BSD process accounting, the
183 statistics are available during the lifetime of tasks/processes as
184 responses to commands. Like BSD accounting, they are sent to user
189 config TASK_DELAY_ACCT
190 bool "Enable per-task delay accounting (EXPERIMENTAL)"
193 Collect information on time spent by a task waiting for system
194 resources like cpu, synchronous block I/O completion and swapping
195 in pages. Such statistics can help in setting a task's priorities
196 relative to other tasks for cpu, io, rss limits etc.
201 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
204 Collect extended task accounting data and send the data
205 to userland for processing over the taskstats interface.
209 config TASK_IO_ACCOUNTING
210 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
211 depends on TASK_XACCT
213 Collect information on the number of bytes of storage I/O which this
219 bool "Auditing support"
222 Enable auditing infrastructure that can be used with another
223 kernel subsystem, such as SELinux (which requires this for
224 logging of avc messages output). Does not do system-call
225 auditing without CONFIG_AUDITSYSCALL.
228 bool "Enable system-call auditing support"
229 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
230 default y if SECURITY_SELINUX
232 Enable low-overhead system-call auditing infrastructure that
233 can be used independently or with another kernel subsystem,
234 such as SELinux. To use audit's filesystem watch feature, please
235 ensure that INOTIFY is configured.
239 depends on AUDITSYSCALL && INOTIFY
244 prompt "RCU Implementation"
250 This option selects the classic RCU implementation that is
251 designed for best read-side performance on non-realtime
254 Select this option if you are unsure.
257 bool "Tree-based hierarchical RCU"
259 This option selects the RCU implementation that is
260 designed for very large SMP system with hundreds or
264 bool "Preemptible RCU"
267 This option reduces the latency of the kernel by making certain
268 RCU sections preemptible. Normally RCU code is non-preemptible, if
269 this option is selected then read-only RCU sections become
270 preemptible. This helps latency, but may expose bugs due to
271 now-naive assumptions about each RCU read-side critical section
272 remaining on a given CPU through its execution.
277 bool "Enable tracing for RCU"
278 depends on TREE_RCU || PREEMPT_RCU
280 This option provides tracing in RCU which presents stats
281 in debugfs for debugging RCU implementation.
283 Say Y here if you want to enable RCU tracing
284 Say N if you are unsure.
287 int "Tree-based hierarchical RCU fanout value"
294 This option controls the fanout of hierarchical implementations
295 of RCU, allowing RCU to work efficiently on machines with
296 large numbers of CPUs. This value must be at least the cube
297 root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
298 systems and up to 262,144 for 64-bit systems.
300 Select a specific number if testing RCU itself.
301 Take the default if unsure.
303 config RCU_FANOUT_EXACT
304 bool "Disable tree-based hierarchical RCU auto-balancing"
308 This option forces use of the exact RCU_FANOUT value specified,
309 regardless of imbalances in the hierarchy. This is useful for
310 testing RCU itself, and might one day be useful on systems with
311 strong NUMA behavior.
313 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
317 config TREE_RCU_TRACE
318 def_bool RCU_TRACE && TREE_RCU
321 This option provides tracing for the TREE_RCU implementation,
322 permitting Makefile to trivially select kernel/rcutree_trace.c.
324 config PREEMPT_RCU_TRACE
325 def_bool RCU_TRACE && PREEMPT_RCU
328 This option provides tracing for the PREEMPT_RCU implementation,
329 permitting Makefile to trivially select kernel/rcupreempt_trace.c.
331 endmenu # "RCU Subsystem"
334 tristate "Kernel .config support"
336 This option enables the complete Linux kernel ".config" file
337 contents to be saved in the kernel. It provides documentation
338 of which kernel options are used in a running kernel or in an
339 on-disk kernel. This information can be extracted from the kernel
340 image file with the script scripts/extract-ikconfig and used as
341 input to rebuild the current kernel or to build another kernel.
342 It can also be extracted from a running kernel by reading
343 /proc/config.gz if enabled (below).
346 bool "Enable access to .config through /proc/config.gz"
347 depends on IKCONFIG && PROC_FS
349 This option enables access to the kernel configuration file
350 through /proc/config.gz.
353 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
357 Select kernel log buffer size as a power of 2.
367 # Architectures with an unreliable sched_clock() should select this:
369 config HAVE_UNSTABLE_SCHED_CLOCK
373 bool "Group CPU scheduler"
374 depends on EXPERIMENTAL
377 This feature lets CPU scheduler recognize task groups and control CPU
378 bandwidth allocation to such task groups.
379 In order to create a group from arbitrary set of processes, use
380 CONFIG_CGROUPS. (See Control Group support.)
382 config FAIR_GROUP_SCHED
383 bool "Group scheduling for SCHED_OTHER"
384 depends on GROUP_SCHED
387 config RT_GROUP_SCHED
388 bool "Group scheduling for SCHED_RR/FIFO"
389 depends on EXPERIMENTAL
390 depends on GROUP_SCHED
393 This feature lets you explicitly allocate real CPU bandwidth
394 to users or control groups (depending on the "Basis for grouping tasks"
395 setting below. If enabled, it will also make it impossible to
396 schedule realtime tasks for non-root users until you allocate
397 realtime bandwidth for them.
398 See Documentation/scheduler/sched-rt-group.txt for more information.
401 depends on GROUP_SCHED
402 prompt "Basis for grouping tasks"
408 This option will choose userid as the basis for grouping
409 tasks, thus providing equal CPU bandwidth to each user.
412 bool "Control groups"
415 This option allows you to create arbitrary task groups
416 using the "cgroup" pseudo filesystem and control
417 the cpu bandwidth allocated to each such task group.
418 Refer to Documentation/cgroups/cgroups.txt for more
419 information on "cgroup" pseudo filesystem.
424 boolean "Control Group support"
426 This option adds support for grouping sets of processes together, for
427 use with process control subsystems such as Cpusets, CFS, memory
428 controls or device isolation.
430 - Documentation/scheduler/sched-design-CFS.txt (CFS)
431 - Documentation/cgroups/ (features for grouping, isolation
432 and resource control)
439 bool "Example debug cgroup subsystem"
443 This option enables a simple cgroup subsystem that
444 exports useful debugging information about the cgroups
450 bool "Namespace cgroup subsystem"
453 Provides a simple namespace cgroup subsystem to
454 provide hierarchical naming of sets of namespaces,
455 for instance virtual servers and checkpoint/restart
458 config CGROUP_FREEZER
459 bool "Freezer cgroup subsystem"
462 Provides a way to freeze and unfreeze all tasks in a
466 bool "Device controller for cgroups"
467 depends on CGROUPS && EXPERIMENTAL
469 Provides a cgroup implementing whitelists for devices which
470 a process in the cgroup can mknod or open.
473 bool "Cpuset support"
474 depends on SMP && CGROUPS
476 This option will let you create and manage CPUSETs which
477 allow dynamically partitioning a system into sets of CPUs and
478 Memory Nodes and assigning tasks to run only within those sets.
479 This is primarily useful on large SMP or NUMA systems.
483 config PROC_PID_CPUSET
484 bool "Include legacy /proc/<pid>/cpuset file"
488 config CGROUP_CPUACCT
489 bool "Simple CPU accounting cgroup subsystem"
492 Provides a simple Resource Controller for monitoring the
493 total CPU consumed by the tasks in a cgroup.
495 config RESOURCE_COUNTERS
496 bool "Resource counters"
498 This option enables controller independent resource accounting
499 infrastructure that works with cgroups.
502 config CGROUP_MEM_RES_CTLR
503 bool "Memory Resource Controller for Control Groups"
504 depends on CGROUPS && RESOURCE_COUNTERS
507 Provides a memory resource controller that manages both anonymous
508 memory and page cache. (See Documentation/controllers/memory.txt)
510 Note that setting this option increases fixed memory overhead
511 associated with each page of memory in the system. By this,
512 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
513 usage tracking struct at boot. Total amount of this is printed out
516 Only enable when you're ok with these trade offs and really
517 sure you need the memory resource controller. Even when you enable
518 this, you can set "cgroup_disable=memory" at your boot option to
519 disable memory resource controller and you can avoid overheads.
520 (and lose benefits of memory resource controller)
522 This config option also selects MM_OWNER config option, which
523 could in turn add some fork/exit overhead.
525 config CGROUP_MEM_RES_CTLR_SWAP
526 bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
527 depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
529 Add swap management feature to memory resource controller. When you
530 enable this, you can limit mem+swap usage per cgroup. In other words,
531 when you disable this, memory resource controller has no cares to
532 usage of swap...a process can exhaust all of the swap. This extension
533 is useful when you want to avoid exhaustion swap but this itself
534 adds more overheads and consumes memory for remembering information.
535 Especially if you use 32bit system or small memory system, please
536 be careful about enabling this. When memory resource controller
537 is disabled by boot option, this will be automatically disabled and
538 there will be no overhead from this. Even when you set this config=y,
539 if boot option "noswapaccount" is set, swap will not be accounted.
546 config SYSFS_DEPRECATED
549 config SYSFS_DEPRECATED_V2
550 bool "Create deprecated sysfs layout for older userspace tools"
553 select SYSFS_DEPRECATED
555 This option switches the layout of sysfs to the deprecated
558 The current sysfs layout features a unified device tree at
559 /sys/devices/, which is able to express a hierarchy between
560 class devices. If the deprecated option is set to Y, the
561 unified device tree is split into a bus device tree at
562 /sys/devices/ and several individual class device trees at
563 /sys/class/. The class and bus devices will be connected by
564 "<subsystem>:<name>" and the "device" links. The "block"
565 class devices, will not show up in /sys/class/block/. Some
566 subsystems will suppress the creation of some devices which
567 depend on the unified device tree.
569 This option is not a pure compatibility option that can
570 be safely enabled on newer distributions. It will change the
571 layout of sysfs to the non-extensible deprecated version,
572 and disable some features, which can not be exported without
573 confusing older userspace tools. Since 2007/2008 all major
574 distributions do not enable this option, and ship no tools which
575 depend on the deprecated layout or this option.
577 If you are using a new kernel on an older distribution, or use
578 older userspace tools, you might need to say Y here. Do not say Y,
579 if the original kernel, that came with your distribution, has
580 this option set to N.
583 bool "Kernel->user space relay support (formerly relayfs)"
585 This option enables support for relay interface support in
586 certain file systems (such as debugfs).
587 It is designed to provide an efficient mechanism for tools and
588 facilities to relay large amounts of data from kernel space to
594 bool "Namespaces support" if EMBEDDED
597 Provides the way to make tasks work with different objects using
598 the same id. For example same IPC id may refer to different objects
599 or same user id or pid may refer to different tasks when used in
600 different namespaces.
604 depends on NAMESPACES
606 In this namespace tasks see different info provided with the
611 depends on NAMESPACES && SYSVIPC
613 In this namespace tasks work with IPC ids which correspond to
614 different IPC objects in different namespaces
617 bool "User namespace (EXPERIMENTAL)"
618 depends on NAMESPACES && EXPERIMENTAL
620 This allows containers, i.e. vservers, to use user namespaces
621 to provide different user info for different servers.
625 bool "PID Namespaces (EXPERIMENTAL)"
627 depends on NAMESPACES && EXPERIMENTAL
629 Support process id namespaces. This allows having multiple
630 process with the same pid as long as they are in different
631 pid namespaces. This is a building block of containers.
633 Unless you want to work with an experimental feature
637 bool "Network namespace"
639 depends on NAMESPACES && EXPERIMENTAL && NET
641 Allow user space to create what appear to be multiple instances
642 of the network stack.
644 config BLK_DEV_INITRD
645 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
646 depends on BROKEN || !FRV
648 The initial RAM filesystem is a ramfs which is loaded by the
649 boot loader (loadlin or lilo) and that is mounted as root
650 before the normal boot procedure. It is typically used to
651 load modules needed to mount the "real" root file system,
652 etc. See <file:Documentation/initrd.txt> for details.
654 If RAM disk support (BLK_DEV_RAM) is also included, this
655 also enables initial RAM disk (initrd) support and adds
656 15 Kbytes (more on some other architectures) to the kernel size.
666 config CC_OPTIMIZE_FOR_SIZE
667 bool "Optimize for size"
670 Enabling this option will pass "-Os" instead of "-O2" to gcc
671 resulting in a smaller kernel.
682 bool "Configure standard kernel features (for small systems)"
684 This option allows certain base kernel options and settings
685 to be disabled or tweaked. This is for specialized
686 environments which can tolerate a "non-standard" kernel.
687 Only use this if you really know what you are doing.
690 bool "Enable 16-bit UID system calls" if EMBEDDED
691 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
694 This enables the legacy 16-bit UID syscall wrappers.
696 config SYSCTL_SYSCALL
697 bool "Sysctl syscall support" if EMBEDDED
701 sys_sysctl uses binary paths that have been found challenging
702 to properly maintain and use. The interface in /proc/sys
703 using paths with ascii names is now the primary path to this
706 Almost nothing using the binary sysctl interface so if you are
707 trying to save some space it is probably safe to disable this,
708 making your kernel marginally smaller.
710 If unsure say Y here.
713 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
716 Say Y here to let the kernel print out symbolic crash information and
717 symbolic stack backtraces. This increases the size of the kernel
718 somewhat, as all symbols have to be loaded into the kernel image.
721 bool "Include all symbols in kallsyms"
722 depends on DEBUG_KERNEL && KALLSYMS
724 Normally kallsyms only contains the symbols of functions, for nicer
725 OOPS messages. Some debuggers can use kallsyms for other
726 symbols too: say Y here to include all symbols, if you need them
727 and you don't care about adding 300k to the size of your kernel.
731 config KALLSYMS_EXTRA_PASS
732 bool "Do an extra kallsyms pass"
735 If kallsyms is not working correctly, the build will fail with
736 inconsistent kallsyms data. If that occurs, log a bug report and
737 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
738 Always say N here unless you find a bug in kallsyms, which must be
739 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
740 you wait for kallsyms to be fixed.
744 bool "Support for hot-pluggable devices" if EMBEDDED
747 This option is provided for the case where no hotplug or uevent
748 capabilities is wanted by the kernel. You should only consider
749 disabling this option for embedded systems that do not use modules, a
750 dynamic /dev tree, or dynamic device discovery. Just say Y.
754 bool "Enable support for printk" if EMBEDDED
756 This option enables normal printk support. Removing it
757 eliminates most of the message strings from the kernel image
758 and makes the kernel more or less silent. As this makes it
759 very difficult to diagnose system problems, saying N here is
760 strongly discouraged.
763 bool "BUG() support" if EMBEDDED
766 Disabling this option eliminates support for BUG and WARN, reducing
767 the size of your kernel image and potentially quietly ignoring
768 numerous fatal conditions. You should only consider disabling this
769 option for embedded systems with no facilities for reporting errors.
774 bool "Enable ELF core dumps" if EMBEDDED
776 Enable support for generating core dumps. Disabling saves about 4k.
778 config PCSPKR_PLATFORM
779 bool "Enable PC-Speaker support" if EMBEDDED
780 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
783 This option allows to disable the internal PC-Speaker
784 support, saving some memory.
788 bool "Enable full-sized data structures for core" if EMBEDDED
790 Disabling this option reduces the size of miscellaneous core
791 kernel data structures. This saves memory on small machines,
792 but may reduce performance.
795 bool "Enable futex support" if EMBEDDED
799 Disabling this option will cause the kernel to be built without
800 support for "fast userspace mutexes". The resulting kernel may not
801 run glibc-based applications correctly.
804 bool "Enable eventpoll support" if EMBEDDED
808 Disabling this option will cause the kernel to be built without
809 support for epoll family of system calls.
812 bool "Enable signalfd() system call" if EMBEDDED
816 Enable the signalfd() system call that allows to receive signals
817 on a file descriptor.
822 bool "Enable timerfd() system call" if EMBEDDED
826 Enable the timerfd() system call that allows to receive timer
827 events on a file descriptor.
832 bool "Enable eventfd() system call" if EMBEDDED
836 Enable the eventfd() system call that allows to receive both
837 kernel notification (ie. KAIO) or userspace notifications.
842 bool "Use full shmem filesystem" if EMBEDDED
846 The shmem is an internal filesystem used to manage shared memory.
847 It is backed by swap and manages resource limits. It is also exported
848 to userspace as tmpfs if TMPFS is enabled. Disabling this
849 option replaces shmem and tmpfs with the much simpler ramfs code,
850 which may be appropriate on small systems without swap.
853 bool "Enable AIO support" if EMBEDDED
856 This option enables POSIX asynchronous I/O which may by used
857 by some high performance threaded applications. Disabling
858 this option saves about 7k.
860 config VM_EVENT_COUNTERS
862 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
864 VM event counters are needed for event counts to be shown.
865 This option allows the disabling of the VM event counters
866 on EMBEDDED systems. /proc/vmstat will only show page counts
867 if VM event counters are disabled.
871 bool "Enable PCI quirk workarounds" if EMBEDDED
874 This enables workarounds for various PCI chipset
875 bugs/quirks. Disable this only if your target machine is
876 unaffected by PCI quirks.
880 bool "Enable SLUB debugging support" if EMBEDDED
881 depends on SLUB && SYSFS
883 SLUB has extensive debug support features. Disabling these can
884 result in significant savings in code size. This also disables
885 SLUB sysfs support. /sys/slab will not exist and there will be
886 no support for cache validation etc.
889 bool "Disable heap randomization"
892 Randomizing heap placement makes heap exploits harder, but it
893 also breaks ancient binaries (including anything libc5 based).
894 This option changes the bootup default to heap randomization
895 disabled, and can be overriden runtime by setting
896 /proc/sys/kernel/randomize_va_space to 2.
898 On non-ancient distros (post-2000 ones) N is usually a safe choice.
901 prompt "Choose SLAB allocator"
904 This option allows to select a slab allocator.
909 The regular slab allocator that is established and known to work
910 well in all environments. It organizes cache hot objects in
911 per cpu and per node queues.
914 bool "SLUB (Unqueued Allocator)"
916 SLUB is a slab allocator that minimizes cache line usage
917 instead of managing queues of cached objects (SLAB approach).
918 Per cpu caching is realized using slabs of objects instead
919 of queues of objects. SLUB can use memory efficiently
920 and has enhanced diagnostics. SLUB is the default choice for
925 bool "SLOB (Simple Allocator)"
927 SLOB replaces the stock allocator with a drastically simpler
928 allocator. SLOB is generally more space efficient but
929 does not perform as well on large systems.
934 bool "Profiling support (EXPERIMENTAL)"
936 Say Y here to enable the extended profiling support mechanisms used
937 by profilers such as OProfile.
940 # Place an empty function call at each tracepoint site. Can be
941 # dynamically changed for a probe function.
947 bool "Activate markers"
948 depends on TRACEPOINTS
950 Place an empty function call at each marker site. Can be
951 dynamically changed for a probe function.
953 source "arch/Kconfig"
955 endmenu # General setup
957 config HAVE_GENERIC_DMA_COHERENT
964 depends on SLAB || SLUB_DEBUG
973 default 0 if BASE_FULL
974 default 1 if !BASE_FULL
977 bool "Enable loadable module support"
979 Kernel modules are small pieces of compiled code which can
980 be inserted in the running kernel, rather than being
981 permanently built into the kernel. You use the "modprobe"
982 tool to add (and sometimes remove) them. If you say Y here,
983 many parts of the kernel can be built as modules (by
984 answering M instead of Y where indicated): this is most
985 useful for infrequently used options which are not required
986 for booting. For more information, see the man pages for
987 modprobe, lsmod, modinfo, insmod and rmmod.
989 If you say Y here, you will need to run "make
990 modules_install" to put the modules under /lib/modules/
991 where modprobe can find them (you may need to be root to do
998 config MODULE_FORCE_LOAD
999 bool "Forced module loading"
1002 Allow loading of modules without version information (ie. modprobe
1003 --force). Forced module loading sets the 'F' (forced) taint flag and
1004 is usually a really bad idea.
1006 config MODULE_UNLOAD
1007 bool "Module unloading"
1009 Without this option you will not be able to unload any
1010 modules (note that some modules may not be unloadable
1011 anyway), which makes your kernel smaller, faster
1012 and simpler. If unsure, say Y.
1014 config MODULE_FORCE_UNLOAD
1015 bool "Forced module unloading"
1016 depends on MODULE_UNLOAD && EXPERIMENTAL
1018 This option allows you to force a module to unload, even if the
1019 kernel believes it is unsafe: the kernel will remove the module
1020 without waiting for anyone to stop using it (using the -f option to
1021 rmmod). This is mainly for kernel developers and desperate users.
1025 bool "Module versioning support"
1027 Usually, you have to use modules compiled with your kernel.
1028 Saying Y here makes it sometimes possible to use modules
1029 compiled for different kernels, by adding enough information
1030 to the modules to (hopefully) spot any changes which would
1031 make them incompatible with the kernel you are running. If
1034 config MODULE_SRCVERSION_ALL
1035 bool "Source checksum for all modules"
1037 Modules which contain a MODULE_VERSION get an extra "srcversion"
1038 field inserted into their modinfo section, which contains a
1039 sum of the source files which made it. This helps maintainers
1040 see exactly which source was used to build a module (since
1041 others sometimes change the module source without updating
1042 the version). With this option, such a "srcversion" field
1043 will be created for all modules. If unsure, say N.
1047 config INIT_ALL_POSSIBLE
1050 Back when each arch used to define their own cpu_online_map and
1051 cpu_possible_map, some of them chose to initialize cpu_possible_map
1052 with all 1s, and others with all 0s. When they were centralised,
1053 it was better to provide this option than to break all the archs
1054 and have several arch maintainers persuing me down dark alleys.
1059 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1061 Need stop_machine() primitive.
1063 source "block/Kconfig"
1065 config PREEMPT_NOTIFIERS
projects / linux-2.6 / blob