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1 config ARCH
2 string
3 option env="ARCH"
4
5 config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
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 "$ARCH_DEFCONFIG"
17 default "arch/$ARCH/defconfig"
18
19 menu "General setup"
20
21 config EXPERIMENTAL
22 bool "Prompt for development and/or incomplete code/drivers"
23 ---help---
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).
40
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42 drivers that have been replaced by something else, and/or are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.
44
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.
51
52 config BROKEN
53 bool
54
55 config BROKEN_ON_SMP
56 bool
57 depends on BROKEN || !SMP
58 default y
59
60 config LOCK_KERNEL
61 bool
62 depends on SMP || PREEMPT
63 default y
64
65 config INIT_ENV_ARG_LIMIT
66 int
67 default 32 if !UML
68 default 128 if UML
69 help
70 Maximum of each of the number of arguments and environment
71 variables passed to init from the kernel command line.
72
73
74 config LOCALVERSION
75 string "Local version - append to kernel release"
76 help
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.
83
84 config LOCALVERSION_AUTO
85 bool "Automatically append version information to the version string"
86 default y
87 help
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
90 top of tree revision.
91
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.
96
97 (The actual string used here is the first eight characters produced
98 by running the command:
99
100 $ git rev-parse --verify HEAD
101
102 which is done within the script "scripts/setlocalversion".)
103
104 config SWAP
105 bool "Support for paging of anonymous memory (swap)"
106 depends on MMU && BLOCK
107 default y
108 help
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.
113
114 config SYSVIPC
115 bool "System V IPC"
116 ---help---
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.
124
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>.
128
129 config SYSVIPC_SYSCTL
130 bool
131 depends on SYSVIPC
132 depends on SYSCTL
133 default y
134
135 config POSIX_MQUEUE
136 bool "POSIX Message Queues"
137 depends on NET && EXPERIMENTAL
138 ---help---
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.
144
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.
148
149 If unsure, say Y.
150
151 config BSD_PROCESS_ACCT
152 bool "BSD Process Accounting"
153 help
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.
163
164 config BSD_PROCESS_ACCT_V3
165 bool "BSD Process Accounting version 3 file format"
166 depends on BSD_PROCESS_ACCT
167 default n
168 help
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.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
175
176 config TASKSTATS
177 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
178 depends on NET
179 default n
180 help
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
185 space on task exit.
186
187 Say N if unsure.
188
189 config TASK_DELAY_ACCT
190 bool "Enable per-task delay accounting (EXPERIMENTAL)"
191 depends on TASKSTATS
192 help
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.
197
198 Say N if unsure.
199
200 config TASK_XACCT
201 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
202 depends on TASKSTATS
203 help
204 Collect extended task accounting data and send the data
205 to userland for processing over the taskstats interface.
206
207 Say N if unsure.
208
209 config TASK_IO_ACCOUNTING
210 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
211 depends on TASK_XACCT
212 help
213 Collect information on the number of bytes of storage I/O which this
214 task has caused.
215
216 Say N if unsure.
217
218 config AUDIT
219 bool "Auditing support"
220 depends on NET
221 help
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.
226
227 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
231 help
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.
236
237 config AUDIT_TREE
238 def_bool y
239 depends on AUDITSYSCALL && INOTIFY
240
241 config IKCONFIG
242 tristate "Kernel .config support"
243 ---help---
244 This option enables the complete Linux kernel ".config" file
245 contents to be saved in the kernel. It provides documentation
246 of which kernel options are used in a running kernel or in an
247 on-disk kernel. This information can be extracted from the kernel
248 image file with the script scripts/extract-ikconfig and used as
249 input to rebuild the current kernel or to build another kernel.
250 It can also be extracted from a running kernel by reading
251 /proc/config.gz if enabled (below).
252
253 config IKCONFIG_PROC
254 bool "Enable access to .config through /proc/config.gz"
255 depends on IKCONFIG && PROC_FS
256 ---help---
257 This option enables access to the kernel configuration file
258 through /proc/config.gz.
259
260 config LOG_BUF_SHIFT
261 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
262 range 12 21
263 default 17
264 help
265 Select kernel log buffer size as a power of 2.
266 Examples:
267 17 => 128 KB
268 16 => 64 KB
269 15 => 32 KB
270 14 => 16 KB
271 13 => 8 KB
272 12 => 4 KB
273
274 config CGROUPS
275 bool "Control Group support"
276 help
277 This option will let you use process cgroup subsystems
278 such as Cpusets
279
280 Say N if unsure.
281
282 config CGROUP_DEBUG
283 bool "Example debug cgroup subsystem"
284 depends on CGROUPS
285 default n
286 help
287 This option enables a simple cgroup subsystem that
288 exports useful debugging information about the cgroups
289 framework
290
291 Say N if unsure
292
293 config CGROUP_NS
294 bool "Namespace cgroup subsystem"
295 depends on CGROUPS
296 help
297 Provides a simple namespace cgroup subsystem to
298 provide hierarchical naming of sets of namespaces,
299 for instance virtual servers and checkpoint/restart
300 jobs.
301
302 config CGROUP_DEVICE
303 bool "Device controller for cgroups"
304 depends on CGROUPS && EXPERIMENTAL
305 help
306 Provides a cgroup implementing whitelists for devices which
307 a process in the cgroup can mknod or open.
308
309 config CPUSETS
310 bool "Cpuset support"
311 depends on SMP && CGROUPS
312 help
313 This option will let you create and manage CPUSETs which
314 allow dynamically partitioning a system into sets of CPUs and
315 Memory Nodes and assigning tasks to run only within those sets.
316 This is primarily useful on large SMP or NUMA systems.
317
318 Say N if unsure.
319
320 #
321 # Architectures with an unreliable sched_clock() should select this:
322 #
323 config HAVE_UNSTABLE_SCHED_CLOCK
324 bool
325
326 config GROUP_SCHED
327 bool "Group CPU scheduler"
328 depends on EXPERIMENTAL
329 default n
330 help
331 This feature lets CPU scheduler recognize task groups and control CPU
332 bandwidth allocation to such task groups.
333
334 config FAIR_GROUP_SCHED
335 bool "Group scheduling for SCHED_OTHER"
336 depends on GROUP_SCHED
337 default GROUP_SCHED
338
339 config RT_GROUP_SCHED
340 bool "Group scheduling for SCHED_RR/FIFO"
341 depends on EXPERIMENTAL
342 depends on GROUP_SCHED
343 default n
344 help
345 This feature lets you explicitly allocate real CPU bandwidth
346 to users or control groups (depending on the "Basis for grouping tasks"
347 setting below. If enabled, it will also make it impossible to
348 schedule realtime tasks for non-root users until you allocate
349 realtime bandwidth for them.
350 See Documentation/sched-rt-group.txt for more information.
351
352 choice
353 depends on GROUP_SCHED
354 prompt "Basis for grouping tasks"
355 default USER_SCHED
356
357 config USER_SCHED
358 bool "user id"
359 help
360 This option will choose userid as the basis for grouping
361 tasks, thus providing equal CPU bandwidth to each user.
362
363 config CGROUP_SCHED
364 bool "Control groups"
365 depends on CGROUPS
366 help
367 This option allows you to create arbitrary task groups
368 using the "cgroup" pseudo filesystem and control
369 the cpu bandwidth allocated to each such task group.
370 Refer to Documentation/cgroups.txt for more information
371 on "cgroup" pseudo filesystem.
372
373 endchoice
374
375 config CGROUP_CPUACCT
376 bool "Simple CPU accounting cgroup subsystem"
377 depends on CGROUPS
378 help
379 Provides a simple Resource Controller for monitoring the
380 total CPU consumed by the tasks in a cgroup
381
382 config RESOURCE_COUNTERS
383 bool "Resource counters"
384 help
385 This option enables controller independent resource accounting
386 infrastructure that works with cgroups
387 depends on CGROUPS
388
389 config MM_OWNER
390 bool
391
392 config CGROUP_MEM_RES_CTLR
393 bool "Memory Resource Controller for Control Groups"
394 depends on CGROUPS && RESOURCE_COUNTERS
395 select MM_OWNER
396 help
397 Provides a memory resource controller that manages both page cache and
398 RSS memory.
399
400 Note that setting this option increases fixed memory overhead
401 associated with each page of memory in the system by 4/8 bytes
402 and also increases cache misses because struct page on many 64bit
403 systems will not fit into a single cache line anymore.
404
405 Only enable when you're ok with these trade offs and really
406 sure you need the memory resource controller.
407
408 This config option also selects MM_OWNER config option, which
409 could in turn add some fork/exit overhead.
410
411 config SYSFS_DEPRECATED
412 bool
413
414 config SYSFS_DEPRECATED_V2
415 bool "Create deprecated sysfs files"
416 depends on SYSFS
417 default y
418 select SYSFS_DEPRECATED
419 help
420 This option creates deprecated symlinks such as the
421 "device"-link, the <subsystem>:<name>-link, and the
422 "bus"-link. It may also add deprecated key in the
423 uevent environment.
424 None of these features or values should be used today, as
425 they export driver core implementation details to userspace
426 or export properties which can't be kept stable across kernel
427 releases.
428
429 If enabled, this option will also move any device structures
430 that belong to a class, back into the /sys/class hierarchy, in
431 order to support older versions of udev and some userspace
432 programs.
433
434 If you are using a distro with the most recent userspace
435 packages, it should be safe to say N here.
436
437 config PROC_PID_CPUSET
438 bool "Include legacy /proc/<pid>/cpuset file"
439 depends on CPUSETS
440 default y
441
442 config RELAY
443 bool "Kernel->user space relay support (formerly relayfs)"
444 help
445 This option enables support for relay interface support in
446 certain file systems (such as debugfs).
447 It is designed to provide an efficient mechanism for tools and
448 facilities to relay large amounts of data from kernel space to
449 user space.
450
451 If unsure, say N.
452
453 config NAMESPACES
454 bool "Namespaces support" if EMBEDDED
455 default !EMBEDDED
456 help
457 Provides the way to make tasks work with different objects using
458 the same id. For example same IPC id may refer to different objects
459 or same user id or pid may refer to different tasks when used in
460 different namespaces.
461
462 config UTS_NS
463 bool "UTS namespace"
464 depends on NAMESPACES
465 help
466 In this namespace tasks see different info provided with the
467 uname() system call
468
469 config IPC_NS
470 bool "IPC namespace"
471 depends on NAMESPACES && SYSVIPC
472 help
473 In this namespace tasks work with IPC ids which correspond to
474 different IPC objects in different namespaces
475
476 config USER_NS
477 bool "User namespace (EXPERIMENTAL)"
478 depends on NAMESPACES && EXPERIMENTAL
479 help
480 This allows containers, i.e. vservers, to use user namespaces
481 to provide different user info for different servers.
482 If unsure, say N.
483
484 config PID_NS
485 bool "PID Namespaces (EXPERIMENTAL)"
486 default n
487 depends on NAMESPACES && EXPERIMENTAL
488 help
489 Suport process id namespaces. This allows having multiple
490 process with the same pid as long as they are in different
491 pid namespaces. This is a building block of containers.
492
493 Unless you want to work with an experimental feature
494 say N here.
495
496 config BLK_DEV_INITRD
497 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
498 depends on BROKEN || !FRV
499 help
500 The initial RAM filesystem is a ramfs which is loaded by the
501 boot loader (loadlin or lilo) and that is mounted as root
502 before the normal boot procedure. It is typically used to
503 load modules needed to mount the "real" root file system,
504 etc. See <file:Documentation/initrd.txt> for details.
505
506 If RAM disk support (BLK_DEV_RAM) is also included, this
507 also enables initial RAM disk (initrd) support and adds
508 15 Kbytes (more on some other architectures) to the kernel size.
509
510 If unsure say Y.
511
512 if BLK_DEV_INITRD
513
514 source "usr/Kconfig"
515
516 endif
517
518 config CC_OPTIMIZE_FOR_SIZE
519 bool "Optimize for size"
520 default y
521 help
522 Enabling this option will pass "-Os" instead of "-O2" to gcc
523 resulting in a smaller kernel.
524
525 If unsure, say N.
526
527 config SYSCTL
528 bool
529
530 menuconfig EMBEDDED
531 bool "Configure standard kernel features (for small systems)"
532 help
533 This option allows certain base kernel options and settings
534 to be disabled or tweaked. This is for specialized
535 environments which can tolerate a "non-standard" kernel.
536 Only use this if you really know what you are doing.
537
538 config UID16
539 bool "Enable 16-bit UID system calls" if EMBEDDED
540 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
541 default y
542 help
543 This enables the legacy 16-bit UID syscall wrappers.
544
545 config SYSCTL_SYSCALL
546 bool "Sysctl syscall support" if EMBEDDED
547 default y
548 select SYSCTL
549 ---help---
550 sys_sysctl uses binary paths that have been found challenging
551 to properly maintain and use. The interface in /proc/sys
552 using paths with ascii names is now the primary path to this
553 information.
554
555 Almost nothing using the binary sysctl interface so if you are
556 trying to save some space it is probably safe to disable this,
557 making your kernel marginally smaller.
558
559 If unsure say Y here.
560
561 config SYSCTL_SYSCALL_CHECK
562 bool "Sysctl checks" if EMBEDDED
563 depends on SYSCTL_SYSCALL
564 default y
565 ---help---
566 sys_sysctl uses binary paths that have been found challenging
567 to properly maintain and use. This enables checks that help
568 you to keep things correct.
569
570 If unsure say Y here.
571
572 config KALLSYMS
573 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
574 default y
575 help
576 Say Y here to let the kernel print out symbolic crash information and
577 symbolic stack backtraces. This increases the size of the kernel
578 somewhat, as all symbols have to be loaded into the kernel image.
579
580 config KALLSYMS_ALL
581 bool "Include all symbols in kallsyms"
582 depends on DEBUG_KERNEL && KALLSYMS
583 help
584 Normally kallsyms only contains the symbols of functions, for nicer
585 OOPS messages. Some debuggers can use kallsyms for other
586 symbols too: say Y here to include all symbols, if you need them
587 and you don't care about adding 300k to the size of your kernel.
588
589 Say N.
590
591 config KALLSYMS_EXTRA_PASS
592 bool "Do an extra kallsyms pass"
593 depends on KALLSYMS
594 help
595 If kallsyms is not working correctly, the build will fail with
596 inconsistent kallsyms data. If that occurs, log a bug report and
597 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
598 Always say N here unless you find a bug in kallsyms, which must be
599 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
600 you wait for kallsyms to be fixed.
601
602
603 config HOTPLUG
604 bool "Support for hot-pluggable devices" if EMBEDDED
605 default y
606 help
607 This option is provided for the case where no hotplug or uevent
608 capabilities is wanted by the kernel. You should only consider
609 disabling this option for embedded systems that do not use modules, a
610 dynamic /dev tree, or dynamic device discovery. Just say Y.
611
612 config PRINTK
613 default y
614 bool "Enable support for printk" if EMBEDDED
615 help
616 This option enables normal printk support. Removing it
617 eliminates most of the message strings from the kernel image
618 and makes the kernel more or less silent. As this makes it
619 very difficult to diagnose system problems, saying N here is
620 strongly discouraged.
621
622 config BUG
623 bool "BUG() support" if EMBEDDED
624 default y
625 help
626 Disabling this option eliminates support for BUG and WARN, reducing
627 the size of your kernel image and potentially quietly ignoring
628 numerous fatal conditions. You should only consider disabling this
629 option for embedded systems with no facilities for reporting errors.
630 Just say Y.
631
632 config ELF_CORE
633 default y
634 bool "Enable ELF core dumps" if EMBEDDED
635 help
636 Enable support for generating core dumps. Disabling saves about 4k.
637
638 config PCSPKR_PLATFORM
639 bool "Enable PC-Speaker support" if EMBEDDED
640 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
641 default y
642 help
643 This option allows to disable the internal PC-Speaker
644 support, saving some memory.
645
646 config COMPAT_BRK
647 bool "Disable heap randomization"
648 default y
649 help
650 Randomizing heap placement makes heap exploits harder, but it
651 also breaks ancient binaries (including anything libc5 based).
652 This option changes the bootup default to heap randomization
653 disabled, and can be overriden runtime by setting
654 /proc/sys/kernel/randomize_va_space to 2.
655
656 On non-ancient distros (post-2000 ones) N is usually a safe choice.
657
658 config BASE_FULL
659 default y
660 bool "Enable full-sized data structures for core" if EMBEDDED
661 help
662 Disabling this option reduces the size of miscellaneous core
663 kernel data structures. This saves memory on small machines,
664 but may reduce performance.
665
666 config FUTEX
667 bool "Enable futex support" if EMBEDDED
668 default y
669 select RT_MUTEXES
670 help
671 Disabling this option will cause the kernel to be built without
672 support for "fast userspace mutexes". The resulting kernel may not
673 run glibc-based applications correctly.
674
675 config ANON_INODES
676 bool
677
678 config EPOLL
679 bool "Enable eventpoll support" if EMBEDDED
680 default y
681 select ANON_INODES
682 help
683 Disabling this option will cause the kernel to be built without
684 support for epoll family of system calls.
685
686 config SIGNALFD
687 bool "Enable signalfd() system call" if EMBEDDED
688 select ANON_INODES
689 default y
690 help
691 Enable the signalfd() system call that allows to receive signals
692 on a file descriptor.
693
694 If unsure, say Y.
695
696 config TIMERFD
697 bool "Enable timerfd() system call" if EMBEDDED
698 select ANON_INODES
699 default y
700 help
701 Enable the timerfd() system call that allows to receive timer
702 events on a file descriptor.
703
704 If unsure, say Y.
705
706 config EVENTFD
707 bool "Enable eventfd() system call" if EMBEDDED
708 select ANON_INODES
709 default y
710 help
711 Enable the eventfd() system call that allows to receive both
712 kernel notification (ie. KAIO) or userspace notifications.
713
714 If unsure, say Y.
715
716 config SHMEM
717 bool "Use full shmem filesystem" if EMBEDDED
718 default y
719 depends on MMU
720 help
721 The shmem is an internal filesystem used to manage shared memory.
722 It is backed by swap and manages resource limits. It is also exported
723 to userspace as tmpfs if TMPFS is enabled. Disabling this
724 option replaces shmem and tmpfs with the much simpler ramfs code,
725 which may be appropriate on small systems without swap.
726
727 config VM_EVENT_COUNTERS
728 default y
729 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
730 help
731 VM event counters are needed for event counts to be shown.
732 This option allows the disabling of the VM event counters
733 on EMBEDDED systems. /proc/vmstat will only show page counts
734 if VM event counters are disabled.
735
736 config SLUB_DEBUG
737 default y
738 bool "Enable SLUB debugging support" if EMBEDDED
739 depends on SLUB && SYSFS
740 help
741 SLUB has extensive debug support features. Disabling these can
742 result in significant savings in code size. This also disables
743 SLUB sysfs support. /sys/slab will not exist and there will be
744 no support for cache validation etc.
745
746 choice
747 prompt "Choose SLAB allocator"
748 default SLUB
749 help
750 This option allows to select a slab allocator.
751
752 config SLAB
753 bool "SLAB"
754 help
755 The regular slab allocator that is established and known to work
756 well in all environments. It organizes cache hot objects in
757 per cpu and per node queues. SLAB is the default choice for
758 a slab allocator.
759
760 config SLUB
761 bool "SLUB (Unqueued Allocator)"
762 help
763 SLUB is a slab allocator that minimizes cache line usage
764 instead of managing queues of cached objects (SLAB approach).
765 Per cpu caching is realized using slabs of objects instead
766 of queues of objects. SLUB can use memory efficiently
767 and has enhanced diagnostics.
768
769 config SLOB
770 depends on EMBEDDED
771 bool "SLOB (Simple Allocator)"
772 help
773 SLOB replaces the stock allocator with a drastically simpler
774 allocator. SLOB is generally more space efficient but
775 does not perform as well on large systems.
776
777 endchoice
778
779 config PROFILING
780 bool "Profiling support (EXPERIMENTAL)"
781 help
782 Say Y here to enable the extended profiling support mechanisms used
783 by profilers such as OProfile.
784
785 config MARKERS
786 bool "Activate markers"
787 help
788 Place an empty function call at each marker site. Can be
789 dynamically changed for a probe function.
790
791 source "arch/Kconfig"
792
793 config PROC_PAGE_MONITOR
794 default y
795 depends on PROC_FS && MMU
796 bool "Enable /proc page monitoring" if EMBEDDED
797 help
798 Various /proc files exist to monitor process memory utilization:
799 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
800 /proc/kpagecount, and /proc/kpageflags. Disabling these
801 interfaces will reduce the size of the kernel by approximately 4kb.
802
803 endmenu # General setup
804
805 config SLABINFO
806 bool
807 depends on PROC_FS
808 depends on SLAB || SLUB_DEBUG
809 default y
810
811 config RT_MUTEXES
812 boolean
813 select PLIST
814
815 config TINY_SHMEM
816 default !SHMEM
817 bool
818
819 config BASE_SMALL
820 int
821 default 0 if BASE_FULL
822 default 1 if !BASE_FULL
823
824 menuconfig MODULES
825 bool "Enable loadable module support"
826 help
827 Kernel modules are small pieces of compiled code which can
828 be inserted in the running kernel, rather than being
829 permanently built into the kernel. You use the "modprobe"
830 tool to add (and sometimes remove) them. If you say Y here,
831 many parts of the kernel can be built as modules (by
832 answering M instead of Y where indicated): this is most
833 useful for infrequently used options which are not required
834 for booting. For more information, see the man pages for
835 modprobe, lsmod, modinfo, insmod and rmmod.
836
837 If you say Y here, you will need to run "make
838 modules_install" to put the modules under /lib/modules/
839 where modprobe can find them (you may need to be root to do
840 this).
841
842 If unsure, say Y.
843
844 config MODULE_FORCE_LOAD
845 bool "Forced module loading"
846 depends on MODULES
847 default n
848 help
849 Allow loading of modules without version information (ie. modprobe
850 --force). Forced module loading sets the 'F' (forced) taint flag and
851 is usually a really bad idea.
852
853 config MODULE_UNLOAD
854 bool "Module unloading"
855 depends on MODULES
856 help
857 Without this option you will not be able to unload any
858 modules (note that some modules may not be unloadable
859 anyway), which makes your kernel slightly smaller and
860 simpler. If unsure, say Y.
861
862 config MODULE_FORCE_UNLOAD
863 bool "Forced module unloading"
864 depends on MODULE_UNLOAD && EXPERIMENTAL
865 help
866 This option allows you to force a module to unload, even if the
867 kernel believes it is unsafe: the kernel will remove the module
868 without waiting for anyone to stop using it (using the -f option to
869 rmmod). This is mainly for kernel developers and desperate users.
870 If unsure, say N.
871
872 config MODVERSIONS
873 bool "Module versioning support"
874 depends on MODULES
875 help
876 Usually, you have to use modules compiled with your kernel.
877 Saying Y here makes it sometimes possible to use modules
878 compiled for different kernels, by adding enough information
879 to the modules to (hopefully) spot any changes which would
880 make them incompatible with the kernel you are running. If
881 unsure, say N.
882
883 config MODULE_SRCVERSION_ALL
884 bool "Source checksum for all modules"
885 depends on MODULES
886 help
887 Modules which contain a MODULE_VERSION get an extra "srcversion"
888 field inserted into their modinfo section, which contains a
889 sum of the source files which made it. This helps maintainers
890 see exactly which source was used to build a module (since
891 others sometimes change the module source without updating
892 the version). With this option, such a "srcversion" field
893 will be created for all modules. If unsure, say N.
894
895 config KMOD
896 bool "Automatic kernel module loading"
897 depends on MODULES
898 help
899 Normally when you have selected some parts of the kernel to
900 be created as kernel modules, you must load them (using the
901 "modprobe" command) before you can use them. If you say Y
902 here, some parts of the kernel will be able to load modules
903 automatically: when a part of the kernel needs a module, it
904 runs modprobe with the appropriate arguments, thereby
905 loading the module if it is available. If unsure, say Y.
906
907 config STOP_MACHINE
908 bool
909 default y
910 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
911 help
912 Need stop_machine() primitive.
913
914 source "block/Kconfig"
915
916 config PREEMPT_NOTIFIERS
917 bool
918
919 config CLASSIC_RCU
920 def_bool !PREEMPT_RCU
921 help
922 This option selects the classic RCU implementation that is
923 designed for best read-side performance on non-realtime
924 systems. Classic RCU is the default. Note that the
925 PREEMPT_RCU symbol is used to select/deselect this option.