| blob | 95ac2657b0f452d71590746a493d6b8960068006 |
1 config ARCH
2 string
3 option env="ARCH"
5 config KERNELVERSION
6 string
7 option env="KERNELVERSION"
9 config DEFCONFIG_LIST
10 string
11 depends on !UML
12 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
16 default "arch/$ARCH/defconfig"
18 menu "General setup"
20 config EXPERIMENTAL
21 bool "Prompt for development and/or incomplete code/drivers"
22 ---help---
23 Some of the various things that Linux supports (such as network
24 drivers, file systems, network protocols, etc.) can be in a state
25 of development where the functionality, stability, or the level of
26 testing is not yet high enough for general use. This is usually
27 known as the "alpha-test" phase among developers. If a feature is
28 currently in alpha-test, then the developers usually discourage
29 uninformed widespread use of this feature by the general public to
30 avoid "Why doesn't this work?" type mail messages. However, active
31 testing and use of these systems is welcomed. Just be aware that it
32 may not meet the normal level of reliability or it may fail to work
33 in some special cases. Detailed bug reports from people familiar
34 with the kernel internals are usually welcomed by the developers
35 (before submitting bug reports, please read the documents
36 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
37 <file:Documentation/BUG-HUNTING>, and
38 <file:Documentation/oops-tracing.txt> in the kernel source).
40 This option will also make obsoleted drivers available. These are
41 drivers that have been replaced by something else, and/or are
42 scheduled to be removed in a future kernel release.
44 Unless you intend to help test and develop a feature or driver that
45 falls into this category, or you have a situation that requires
46 using these features, you should probably say N here, which will
47 cause the configurator to present you with fewer choices. If
48 you say Y here, you will be offered the choice of using features or
49 drivers that are currently considered to be in the alpha-test phase.
51 config BROKEN
52 bool
54 config BROKEN_ON_SMP
55 bool
56 depends on BROKEN || !SMP
57 default y
59 config LOCK_KERNEL
60 bool
61 depends on SMP || PREEMPT
62 default y
64 config INIT_ENV_ARG_LIMIT
65 int
66 default 32 if !UML
67 default 128 if UML
68 help
69 Maximum of each of the number of arguments and environment
70 variables passed to init from the kernel command line.
73 config LOCALVERSION
74 string "Local version - append to kernel release"
75 help
76 Append an extra string to the end of your kernel version.
77 This will show up when you type uname, for example.
78 The string you set here will be appended after the contents of
79 any files with a filename matching localversion* in your
80 object and source tree, in that order. Your total string can
81 be a maximum of 64 characters.
83 config LOCALVERSION_AUTO
84 bool "Automatically append version information to the version string"
85 default y
86 help
87 This will try to automatically determine if the current tree is a
88 release tree by looking for git tags that belong to the current
89 top of tree revision.
91 A string of the format -gxxxxxxxx will be added to the localversion
92 if a git-based tree is found. The string generated by this will be
93 appended after any matching localversion* files, and after the value
94 set in CONFIG_LOCALVERSION.
96 (The actual string used here is the first eight characters produced
97 by running the command:
99 $ git rev-parse --verify HEAD
101 which is done within the script "scripts/setlocalversion".)
103 config SWAP
104 bool "Support for paging of anonymous memory (swap)"
105 depends on MMU && BLOCK
106 default y
107 help
108 This option allows you to choose whether you want to have support
109 for so called swap devices or swap files in your kernel that are
110 used to provide more virtual memory than the actual RAM present
111 in your computer. If unsure say Y.
113 config SYSVIPC
114 bool "System V IPC"
115 ---help---
116 Inter Process Communication is a suite of library functions and
117 system calls which let processes (running programs) synchronize and
118 exchange information. It is generally considered to be a good thing,
119 and some programs won't run unless you say Y here. In particular, if
120 you want to run the DOS emulator dosemu under Linux (read the
121 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
122 you'll need to say Y here.
124 You can find documentation about IPC with "info ipc" and also in
125 section 6.4 of the Linux Programmer's Guide, available from
126 <http://www.tldp.org/guides.html>.
128 config SYSVIPC_SYSCTL
129 bool
130 depends on SYSVIPC
131 depends on SYSCTL
132 default y
134 config POSIX_MQUEUE
135 bool "POSIX Message Queues"
136 depends on NET && EXPERIMENTAL
137 ---help---
138 POSIX variant of message queues is a part of IPC. In POSIX message
139 queues every message has a priority which decides about succession
140 of receiving it by a process. If you want to compile and run
141 programs written e.g. for Solaris with use of its POSIX message
142 queues (functions mq_*) say Y here.
144 POSIX message queues are visible as a filesystem called 'mqueue'
145 and can be mounted somewhere if you want to do filesystem
146 operations on message queues.
148 If unsure, say Y.
150 config BSD_PROCESS_ACCT
151 bool "BSD Process Accounting"
152 help
153 If you say Y here, a user level program will be able to instruct the
154 kernel (via a special system call) to write process accounting
155 information to a file: whenever a process exits, information about
156 that process will be appended to the file by the kernel. The
157 information includes things such as creation time, owning user,
158 command name, memory usage, controlling terminal etc. (the complete
159 list is in the struct acct in <file:include/linux/acct.h>). It is
160 up to the user level program to do useful things with this
161 information. This is generally a good idea, so say Y.
163 config BSD_PROCESS_ACCT_V3
164 bool "BSD Process Accounting version 3 file format"
165 depends on BSD_PROCESS_ACCT
166 default n
167 help
168 If you say Y here, the process accounting information is written
169 in a new file format that also logs the process IDs of each
170 process and it's parent. Note that this file format is incompatible
171 with previous v0/v1/v2 file formats, so you will need updated tools
172 for processing it. A preliminary version of these tools is available
173 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
175 config TASKSTATS
176 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
177 depends on NET
178 default n
179 help
180 Export selected statistics for tasks/processes through the
181 generic netlink interface. Unlike BSD process accounting, the
182 statistics are available during the lifetime of tasks/processes as
183 responses to commands. Like BSD accounting, they are sent to user
184 space on task exit.
186 Say N if unsure.
188 config TASK_DELAY_ACCT
189 bool "Enable per-task delay accounting (EXPERIMENTAL)"
190 depends on TASKSTATS
191 help
192 Collect information on time spent by a task waiting for system
193 resources like cpu, synchronous block I/O completion and swapping
194 in pages. Such statistics can help in setting a task's priorities
195 relative to other tasks for cpu, io, rss limits etc.
197 Say N if unsure.
199 config TASK_XACCT
200 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
201 depends on TASKSTATS
202 help
203 Collect extended task accounting data and send the data
204 to userland for processing over the taskstats interface.
206 Say N if unsure.
208 config TASK_IO_ACCOUNTING
209 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
210 depends on TASK_XACCT
211 help
212 Collect information on the number of bytes of storage I/O which this
213 task has caused.
215 Say N if unsure.
217 config USER_NS
218 bool "User Namespaces (EXPERIMENTAL)"
219 default n
220 depends on EXPERIMENTAL
221 help
222 Support user namespaces. This allows containers, i.e.
223 vservers, to use user namespaces to provide different
224 user info for different servers. If unsure, say N.
226 config PID_NS
227 bool "PID Namespaces (EXPERIMENTAL)"
228 default n
229 depends on EXPERIMENTAL
230 help
231 Suport process id namespaces. This allows having multiple
232 process with the same pid as long as they are in different
233 pid namespaces. This is a building block of containers.
235 Unless you want to work with an experimental feature
236 say N here.
238 config AUDIT
239 bool "Auditing support"
240 depends on NET
241 help
242 Enable auditing infrastructure that can be used with another
243 kernel subsystem, such as SELinux (which requires this for
244 logging of avc messages output). Does not do system-call
245 auditing without CONFIG_AUDITSYSCALL.
247 config AUDITSYSCALL
248 bool "Enable system-call auditing support"
249 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
250 default y if SECURITY_SELINUX
251 help
252 Enable low-overhead system-call auditing infrastructure that
253 can be used independently or with another kernel subsystem,
254 such as SELinux. To use audit's filesystem watch feature, please
255 ensure that INOTIFY is configured.
257 config AUDIT_TREE
258 def_bool y
259 depends on AUDITSYSCALL && INOTIFY
261 config IKCONFIG
262 tristate "Kernel .config support"
263 ---help---
264 This option enables the complete Linux kernel ".config" file
265 contents to be saved in the kernel. It provides documentation
266 of which kernel options are used in a running kernel or in an
267 on-disk kernel. This information can be extracted from the kernel
268 image file with the script scripts/extract-ikconfig and used as
269 input to rebuild the current kernel or to build another kernel.
270 It can also be extracted from a running kernel by reading
271 /proc/config.gz if enabled (below).
273 config IKCONFIG_PROC
274 bool "Enable access to .config through /proc/config.gz"
275 depends on IKCONFIG && PROC_FS
276 ---help---
277 This option enables access to the kernel configuration file
278 through /proc/config.gz.
280 config LOG_BUF_SHIFT
281 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
282 range 12 21
283 default 17 if S390 || LOCKDEP
284 default 16 if X86_NUMAQ || IA64
285 default 15 if SMP
286 default 14
287 help
288 Select kernel log buffer size as a power of 2.
289 Defaults and Examples:
290 17 => 128 KB for S/390
291 16 => 64 KB for x86 NUMAQ or IA-64
292 15 => 32 KB for SMP
293 14 => 16 KB for uniprocessor
294 13 => 8 KB
295 12 => 4 KB
297 config CGROUPS
298 bool "Control Group support"
299 help
300 This option will let you use process cgroup subsystems
301 such as Cpusets
303 Say N if unsure.
305 config CGROUP_DEBUG
306 bool "Example debug cgroup subsystem"
307 depends on CGROUPS
308 help
309 This option enables a simple cgroup subsystem that
310 exports useful debugging information about the cgroups
311 framework
313 Say N if unsure
315 config CGROUP_NS
316 bool "Namespace cgroup subsystem"
317 depends on CGROUPS
318 help
319 Provides a simple namespace cgroup subsystem to
320 provide hierarchical naming of sets of namespaces,
321 for instance virtual servers and checkpoint/restart
322 jobs.
324 config CPUSETS
325 bool "Cpuset support"
326 depends on SMP && CGROUPS
327 help
328 This option will let you create and manage CPUSETs which
329 allow dynamically partitioning a system into sets of CPUs and
330 Memory Nodes and assigning tasks to run only within those sets.
331 This is primarily useful on large SMP or NUMA systems.
333 Say N if unsure.
335 config FAIR_GROUP_SCHED
336 bool "Fair group CPU scheduler"
337 default y
338 help
339 This feature lets CPU scheduler recognize task groups and control CPU
340 bandwidth allocation to such task groups.
342 choice
343 depends on FAIR_GROUP_SCHED
344 prompt "Basis for grouping tasks"
345 default FAIR_USER_SCHED
347 config FAIR_USER_SCHED
348 bool "user id"
349 help
350 This option will choose userid as the basis for grouping
351 tasks, thus providing equal CPU bandwidth to each user.
353 config FAIR_CGROUP_SCHED
354 bool "Control groups"
355 depends on CGROUPS
356 help
357 This option allows you to create arbitrary task groups
358 using the "cgroup" pseudo filesystem and control
359 the cpu bandwidth allocated to each such task group.
360 Refer to Documentation/cgroups.txt for more information
361 on "cgroup" pseudo filesystem.
363 endchoice
365 config CGROUP_CPUACCT
366 bool "Simple CPU accounting cgroup subsystem"
367 depends on CGROUPS
368 help
369 Provides a simple Resource Controller for monitoring the
370 total CPU consumed by the tasks in a cgroup
372 config RESOURCE_COUNTERS
373 bool "Resource counters"
374 help
375 This option enables controller independent resource accounting
376 infrastructure that works with cgroups
377 depends on CGROUPS
379 config SYSFS_DEPRECATED
380 bool "Create deprecated sysfs files"
381 depends on SYSFS
382 default y
383 help
384 This option creates deprecated symlinks such as the
385 "device"-link, the <subsystem>:<name>-link, and the
386 "bus"-link. It may also add deprecated key in the
387 uevent environment.
388 None of these features or values should be used today, as
389 they export driver core implementation details to userspace
390 or export properties which can't be kept stable across kernel
391 releases.
393 If enabled, this option will also move any device structures
394 that belong to a class, back into the /sys/class hierarchy, in
395 order to support older versions of udev.
397 If you are using a distro that was released in 2006 or later,
398 it should be safe to say N here.
400 config CGROUP_MEM_CONT
401 bool "Memory controller for cgroups"
402 depends on CGROUPS && RESOURCE_COUNTERS
403 help
404 Provides a memory controller that manages both page cache and
405 RSS memory.
407 config PROC_PID_CPUSET
408 bool "Include legacy /proc/<pid>/cpuset file"
409 depends on CPUSETS
410 default y
412 config RELAY
413 bool "Kernel->user space relay support (formerly relayfs)"
414 help
415 This option enables support for relay interface support in
416 certain file systems (such as debugfs).
417 It is designed to provide an efficient mechanism for tools and
418 facilities to relay large amounts of data from kernel space to
419 user space.
421 If unsure, say N.
423 config BLK_DEV_INITRD
424 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
425 depends on BROKEN || !FRV
426 help
427 The initial RAM filesystem is a ramfs which is loaded by the
428 boot loader (loadlin or lilo) and that is mounted as root
429 before the normal boot procedure. It is typically used to
430 load modules needed to mount the "real" root file system,
431 etc. See <file:Documentation/initrd.txt> for details.
433 If RAM disk support (BLK_DEV_RAM) is also included, this
434 also enables initial RAM disk (initrd) support and adds
435 15 Kbytes (more on some other architectures) to the kernel size.
437 If unsure say Y.
439 if BLK_DEV_INITRD
441 source "usr/Kconfig"
443 endif
445 config CC_OPTIMIZE_FOR_SIZE
446 bool "Optimize for size (Look out for broken compilers!)"
447 default y
448 depends on ARM || H8300 || SUPERH || EXPERIMENTAL
449 help
450 Enabling this option will pass "-Os" instead of "-O2" to gcc
451 resulting in a smaller kernel.
453 WARNING: some versions of gcc may generate incorrect code with this
454 option. If problems are observed, a gcc upgrade may be needed.
456 If unsure, say N.
458 config SYSCTL
459 bool
461 menuconfig EMBEDDED
462 bool "Configure standard kernel features (for small systems)"
463 help
464 This option allows certain base kernel options and settings
465 to be disabled or tweaked. This is for specialized
466 environments which can tolerate a "non-standard" kernel.
467 Only use this if you really know what you are doing.
469 config UID16
470 bool "Enable 16-bit UID system calls" if EMBEDDED
471 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
472 default y
473 help
474 This enables the legacy 16-bit UID syscall wrappers.
476 config SYSCTL_SYSCALL
477 bool "Sysctl syscall support" if EMBEDDED
478 default y
479 select SYSCTL
480 ---help---
481 sys_sysctl uses binary paths that have been found challenging
482 to properly maintain and use. The interface in /proc/sys
483 using paths with ascii names is now the primary path to this
484 information.
486 Almost nothing using the binary sysctl interface so if you are
487 trying to save some space it is probably safe to disable this,
488 making your kernel marginally smaller.
490 If unsure say Y here.
492 config KALLSYMS
493 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
494 default y
495 help
496 Say Y here to let the kernel print out symbolic crash information and
497 symbolic stack backtraces. This increases the size of the kernel
498 somewhat, as all symbols have to be loaded into the kernel image.
500 config KALLSYMS_ALL
501 bool "Include all symbols in kallsyms"
502 depends on DEBUG_KERNEL && KALLSYMS
503 help
504 Normally kallsyms only contains the symbols of functions, for nicer
505 OOPS messages. Some debuggers can use kallsyms for other
506 symbols too: say Y here to include all symbols, if you need them
507 and you don't care about adding 300k to the size of your kernel.
509 Say N.
511 config KALLSYMS_EXTRA_PASS
512 bool "Do an extra kallsyms pass"
513 depends on KALLSYMS
514 help
515 If kallsyms is not working correctly, the build will fail with
516 inconsistent kallsyms data. If that occurs, log a bug report and
517 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
518 Always say N here unless you find a bug in kallsyms, which must be
519 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
520 you wait for kallsyms to be fixed.
523 config HOTPLUG
524 bool "Support for hot-pluggable devices" if EMBEDDED
525 default y
526 help
527 This option is provided for the case where no hotplug or uevent
528 capabilities is wanted by the kernel. You should only consider
529 disabling this option for embedded systems that do not use modules, a
530 dynamic /dev tree, or dynamic device discovery. Just say Y.
532 config PRINTK
533 default y
534 bool "Enable support for printk" if EMBEDDED
535 help
536 This option enables normal printk support. Removing it
537 eliminates most of the message strings from the kernel image
538 and makes the kernel more or less silent. As this makes it
539 very difficult to diagnose system problems, saying N here is
540 strongly discouraged.
542 config BUG
543 bool "BUG() support" if EMBEDDED
544 default y
545 help
546 Disabling this option eliminates support for BUG and WARN, reducing
547 the size of your kernel image and potentially quietly ignoring
548 numerous fatal conditions. You should only consider disabling this
549 option for embedded systems with no facilities for reporting errors.
550 Just say Y.
552 config ELF_CORE
553 default y
554 bool "Enable ELF core dumps" if EMBEDDED
555 help
556 Enable support for generating core dumps. Disabling saves about 4k.
558 config COMPAT_BRK
559 bool "Disable heap randomization"
560 default y
561 help
562 Randomizing heap placement makes heap exploits harder, but it
563 also breaks ancient binaries (including anything libc5 based).
564 This option changes the bootup default to heap randomization
565 disabled, and can be overriden runtime by setting
566 /proc/sys/kernel/randomize_va_space to 2.
568 On non-ancient distros (post-2000 ones) Y is usually a safe choice.
570 config BASE_FULL
571 default y
572 bool "Enable full-sized data structures for core" if EMBEDDED
573 help
574 Disabling this option reduces the size of miscellaneous core
575 kernel data structures. This saves memory on small machines,
576 but may reduce performance.
578 config FUTEX
579 bool "Enable futex support" if EMBEDDED
580 default y
581 select RT_MUTEXES
582 help
583 Disabling this option will cause the kernel to be built without
584 support for "fast userspace mutexes". The resulting kernel may not
585 run glibc-based applications correctly.
587 config ANON_INODES
588 bool
590 config EPOLL
591 bool "Enable eventpoll support" if EMBEDDED
592 default y
593 select ANON_INODES
594 help
595 Disabling this option will cause the kernel to be built without
596 support for epoll family of system calls.
598 config SIGNALFD
599 bool "Enable signalfd() system call" if EMBEDDED
600 select ANON_INODES
601 default y
602 help
603 Enable the signalfd() system call that allows to receive signals
604 on a file descriptor.
606 If unsure, say Y.
608 config TIMERFD
609 bool "Enable timerfd() system call" if EMBEDDED
610 select ANON_INODES
611 default y
612 help
613 Enable the timerfd() system call that allows to receive timer
614 events on a file descriptor.
616 If unsure, say Y.
618 config EVENTFD
619 bool "Enable eventfd() system call" if EMBEDDED
620 select ANON_INODES
621 default y
622 help
623 Enable the eventfd() system call that allows to receive both
624 kernel notification (ie. KAIO) or userspace notifications.
626 If unsure, say Y.
628 config SHMEM
629 bool "Use full shmem filesystem" if EMBEDDED
630 default y
631 depends on MMU
632 help
633 The shmem is an internal filesystem used to manage shared memory.
634 It is backed by swap and manages resource limits. It is also exported
635 to userspace as tmpfs if TMPFS is enabled. Disabling this
636 option replaces shmem and tmpfs with the much simpler ramfs code,
637 which may be appropriate on small systems without swap.
639 config VM_EVENT_COUNTERS
640 default y
641 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
642 help
643 VM event counters are needed for event counts to be shown.
644 This option allows the disabling of the VM event counters
645 on EMBEDDED systems. /proc/vmstat will only show page counts
646 if VM event counters are disabled.
648 config SLUB_DEBUG
649 default y
650 bool "Enable SLUB debugging support" if EMBEDDED
651 depends on SLUB
652 help
653 SLUB has extensive debug support features. Disabling these can
654 result in significant savings in code size. This also disables
655 SLUB sysfs support. /sys/slab will not exist and there will be
656 no support for cache validation etc.
658 choice
659 prompt "Choose SLAB allocator"
660 default SLUB
661 help
662 This option allows to select a slab allocator.
664 config SLAB
665 bool "SLAB"
666 help
667 The regular slab allocator that is established and known to work
668 well in all environments. It organizes cache hot objects in
669 per cpu and per node queues. SLAB is the default choice for
670 a slab allocator.
672 config SLUB
673 bool "SLUB (Unqueued Allocator)"
674 help
675 SLUB is a slab allocator that minimizes cache line usage
676 instead of managing queues of cached objects (SLAB approach).
677 Per cpu caching is realized using slabs of objects instead
678 of queues of objects. SLUB can use memory efficiently
679 and has enhanced diagnostics.
681 config SLOB
682 depends on EMBEDDED
683 bool "SLOB (Simple Allocator)"
684 help
685 SLOB replaces the stock allocator with a drastically simpler
686 allocator. SLOB is generally more space efficient but
687 does not perform as well on large systems.
689 endchoice
691 config PROFILING
692 bool "Profiling support (EXPERIMENTAL)"
693 help
694 Say Y here to enable the extended profiling support mechanisms used
695 by profilers such as OProfile.
697 config MARKERS
698 bool "Activate markers"
699 help
700 Place an empty function call at each marker site. Can be
701 dynamically changed for a probe function.
703 source "arch/Kconfig"
705 config PROC_PAGE_MONITOR
706 default y
707 depends on PROC_FS && MMU
708 bool "Enable /proc page monitoring" if EMBEDDED
709 help
710 Various /proc files exist to monitor process memory utilization:
711 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
712 /proc/kpagecount, and /proc/kpageflags. Disabling these
713 interfaces will reduce the size of the kernel by approximately 4kb.
715 endmenu # General setup
717 config SLABINFO
718 bool
719 depends on PROC_FS
720 depends on SLAB || SLUB
721 default y
723 config RT_MUTEXES
724 boolean
725 select PLIST
727 config TINY_SHMEM
728 default !SHMEM
729 bool
731 config BASE_SMALL
732 int
733 default 0 if BASE_FULL
734 default 1 if !BASE_FULL
736 menuconfig MODULES
737 bool "Enable loadable module support"
738 help
739 Kernel modules are small pieces of compiled code which can
740 be inserted in the running kernel, rather than being
741 permanently built into the kernel. You use the "modprobe"
742 tool to add (and sometimes remove) them. If you say Y here,
743 many parts of the kernel can be built as modules (by
744 answering M instead of Y where indicated): this is most
745 useful for infrequently used options which are not required
746 for booting. For more information, see the man pages for
747 modprobe, lsmod, modinfo, insmod and rmmod.
749 If you say Y here, you will need to run "make
750 modules_install" to put the modules under /lib/modules/
751 where modprobe can find them (you may need to be root to do
752 this).
754 If unsure, say Y.
756 config MODULE_UNLOAD
757 bool "Module unloading"
758 depends on MODULES
759 help
760 Without this option you will not be able to unload any
761 modules (note that some modules may not be unloadable
762 anyway), which makes your kernel slightly smaller and
763 simpler. If unsure, say Y.
765 config MODULE_FORCE_UNLOAD
766 bool "Forced module unloading"
767 depends on MODULE_UNLOAD && EXPERIMENTAL
768 help
769 This option allows you to force a module to unload, even if the
770 kernel believes it is unsafe: the kernel will remove the module
771 without waiting for anyone to stop using it (using the -f option to
772 rmmod). This is mainly for kernel developers and desperate users.
773 If unsure, say N.
775 config MODVERSIONS
776 bool "Module versioning support"
777 depends on MODULES
778 help
779 Usually, you have to use modules compiled with your kernel.
780 Saying Y here makes it sometimes possible to use modules
781 compiled for different kernels, by adding enough information
782 to the modules to (hopefully) spot any changes which would
783 make them incompatible with the kernel you are running. If
784 unsure, say N.
786 config MODULE_SRCVERSION_ALL
787 bool "Source checksum for all modules"
788 depends on MODULES
789 help
790 Modules which contain a MODULE_VERSION get an extra "srcversion"
791 field inserted into their modinfo section, which contains a
792 sum of the source files which made it. This helps maintainers
793 see exactly which source was used to build a module (since
794 others sometimes change the module source without updating
795 the version). With this option, such a "srcversion" field
796 will be created for all modules. If unsure, say N.
798 config KMOD
799 bool "Automatic kernel module loading"
800 depends on MODULES
801 help
802 Normally when you have selected some parts of the kernel to
803 be created as kernel modules, you must load them (using the
804 "modprobe" command) before you can use them. If you say Y
805 here, some parts of the kernel will be able to load modules
806 automatically: when a part of the kernel needs a module, it
807 runs modprobe with the appropriate arguments, thereby
808 loading the module if it is available. If unsure, say Y.
810 config STOP_MACHINE
811 bool
812 default y
813 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
814 help
815 Need stop_machine() primitive.
817 source "block/Kconfig"
819 config PREEMPT_NOTIFIERS
820 bool
822 choice
823 prompt "RCU implementation type:"
824 default CLASSIC_RCU
825 help
826 This allows you to choose either the classic RCU implementation
827 that is designed for best read-side performance on non-realtime
828 systems, or the preemptible RCU implementation for best latency
829 on realtime systems. Note that some kernel preemption modes
830 will restrict your choice.
832 Select the default if you are unsure.
834 config CLASSIC_RCU
835 bool "Classic RCU"
836 help
837 This option selects the classic RCU implementation that is
838 designed for best read-side performance on non-realtime
839 systems.
841 Say Y if you are unsure.
843 config PREEMPT_RCU
844 bool "Preemptible RCU"
845 depends on PREEMPT
846 help
847 This option reduces the latency of the kernel by making certain
848 RCU sections preemptible. Normally RCU code is non-preemptible, if
849 this option is selected then read-only RCU sections become
850 preemptible. This helps latency, but may expose bugs due to
851 now-naive assumptions about each RCU read-side critical section
852 remaining on a given CPU through its execution.
854 Say N if you are unsure.
856 endchoice