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Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670ea2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Al Boldiff0cfc62007-07-31 00:39:23 -070019menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
21config 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42 drivers that have been replaced by something else, and/or are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
Linus Torvalds1da177e2005-04-16 15:20:36 -070052config BROKEN
53 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55config BROKEN_ON_SMP
56 bool
57 depends on BROKEN || !SMP
58 default y
59
60config LOCK_KERNEL
61 bool
62 depends on SMP || PREEMPT
63 default y
64
65config INIT_ENV_ARG_LIMIT
66 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070067 default 32 if !UML
68 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080070 Maximum of each of the number of arguments and environment
71 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74config 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
Ryan Andersonaaebf432005-07-31 04:57:49 -040084config 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
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020089 release tree by looking for git tags that belong to the current
90 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040091
92 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020093 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040094 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020095 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -040096
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020097 (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".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400103
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800104config HAVE_KERNEL_GZIP
105 bool
106
107config HAVE_KERNEL_BZIP2
108 bool
109
110config HAVE_KERNEL_LZMA
111 bool
112
Alain Knaff30d65db2009-01-04 22:46:17 +0100113choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800114 prompt "Kernel compression mode"
115 default KERNEL_GZIP
116 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA
117 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100118 The linux kernel is a kind of self-extracting executable.
119 Several compression algorithms are available, which differ
120 in efficiency, compression and decompression speed.
121 Compression speed is only relevant when building a kernel.
122 Decompression speed is relevant at each boot.
123
124 If you have any problems with bzip2 or lzma compressed
125 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
126 version of this functionality (bzip2 only), for 2.4, was
127 supplied by Christian Ludwig)
128
129 High compression options are mostly useful for users, who
130 are low on disk space (embedded systems), but for whom ram
131 size matters less.
132
133 If in doubt, select 'gzip'
134
135config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800136 bool "Gzip"
137 depends on HAVE_KERNEL_GZIP
138 help
139 The old and tried gzip compression. Its compression ratio is
140 the poorest among the 3 choices; however its speed (both
141 compression and decompression) is the fastest.
Alain Knaff30d65db2009-01-04 22:46:17 +0100142
143config KERNEL_BZIP2
144 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800145 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100146 help
147 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800148 Decompression speed is slowest among the three. The kernel
149 size is about 10% smaller with bzip2, in comparison to gzip.
150 Bzip2 uses a large amount of memory. For modern kernels you
151 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100152
153config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800154 bool "LZMA"
155 depends on HAVE_KERNEL_LZMA
156 help
157 The most recent compression algorithm.
158 Its ratio is best, decompression speed is between the other
159 two. Compression is slowest. The kernel size is about 33%
160 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100161
162endchoice
163
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164config SWAP
165 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200166 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 default y
168 help
169 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100170 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 used to provide more virtual memory than the actual RAM present
172 in your computer. If unsure say Y.
173
174config SYSVIPC
175 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 ---help---
177 Inter Process Communication is a suite of library functions and
178 system calls which let processes (running programs) synchronize and
179 exchange information. It is generally considered to be a good thing,
180 and some programs won't run unless you say Y here. In particular, if
181 you want to run the DOS emulator dosemu under Linux (read the
182 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
183 you'll need to say Y here.
184
185 You can find documentation about IPC with "info ipc" and also in
186 section 6.4 of the Linux Programmer's Guide, available from
187 <http://www.tldp.org/guides.html>.
188
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800189config SYSVIPC_SYSCTL
190 bool
191 depends on SYSVIPC
192 depends on SYSCTL
193 default y
194
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195config POSIX_MQUEUE
196 bool "POSIX Message Queues"
197 depends on NET && EXPERIMENTAL
198 ---help---
199 POSIX variant of message queues is a part of IPC. In POSIX message
200 queues every message has a priority which decides about succession
201 of receiving it by a process. If you want to compile and run
202 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200203 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
205 POSIX message queues are visible as a filesystem called 'mqueue'
206 and can be mounted somewhere if you want to do filesystem
207 operations on message queues.
208
209 If unsure, say Y.
210
211config BSD_PROCESS_ACCT
212 bool "BSD Process Accounting"
213 help
214 If you say Y here, a user level program will be able to instruct the
215 kernel (via a special system call) to write process accounting
216 information to a file: whenever a process exits, information about
217 that process will be appended to the file by the kernel. The
218 information includes things such as creation time, owning user,
219 command name, memory usage, controlling terminal etc. (the complete
220 list is in the struct acct in <file:include/linux/acct.h>). It is
221 up to the user level program to do useful things with this
222 information. This is generally a good idea, so say Y.
223
224config BSD_PROCESS_ACCT_V3
225 bool "BSD Process Accounting version 3 file format"
226 depends on BSD_PROCESS_ACCT
227 default n
228 help
229 If you say Y here, the process accounting information is written
230 in a new file format that also logs the process IDs of each
231 process and it's parent. Note that this file format is incompatible
232 with previous v0/v1/v2 file formats, so you will need updated tools
233 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300234 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
Shailabh Nagarc7572492006-07-14 00:24:40 -0700236config TASKSTATS
237 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
238 depends on NET
239 default n
240 help
241 Export selected statistics for tasks/processes through the
242 generic netlink interface. Unlike BSD process accounting, the
243 statistics are available during the lifetime of tasks/processes as
244 responses to commands. Like BSD accounting, they are sent to user
245 space on task exit.
246
247 Say N if unsure.
248
Shailabh Nagarca74e922006-07-14 00:24:36 -0700249config TASK_DELAY_ACCT
250 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700251 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700252 help
253 Collect information on time spent by a task waiting for system
254 resources like cpu, synchronous block I/O completion and swapping
255 in pages. Such statistics can help in setting a task's priorities
256 relative to other tasks for cpu, io, rss limits etc.
257
258 Say N if unsure.
259
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800260config TASK_XACCT
261 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
262 depends on TASKSTATS
263 help
264 Collect extended task accounting data and send the data
265 to userland for processing over the taskstats interface.
266
267 Say N if unsure.
268
269config TASK_IO_ACCOUNTING
270 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
271 depends on TASK_XACCT
272 help
273 Collect information on the number of bytes of storage I/O which this
274 task has caused.
275
276 Say N if unsure.
277
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278config AUDIT
279 bool "Auditing support"
Chris Wright804a6a42005-05-11 10:52:45 +0100280 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 help
282 Enable auditing infrastructure that can be used with another
283 kernel subsystem, such as SELinux (which requires this for
284 logging of avc messages output). Does not do system-call
285 auditing without CONFIG_AUDITSYSCALL.
286
287config AUDITSYSCALL
288 bool "Enable system-call auditing support"
Yuichi Nakamura1322b9d2007-11-10 19:21:34 +0900289 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 default y if SECURITY_SELINUX
291 help
292 Enable low-overhead system-call auditing infrastructure that
293 can be used independently or with another kernel subsystem,
Amy Griffisf368c07d2006-04-07 16:55:56 -0400294 such as SELinux. To use audit's filesystem watch feature, please
295 ensure that INOTIFY is configured.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
Al Viro74c3cbe2007-07-22 08:04:18 -0400297config AUDIT_TREE
298 def_bool y
299 depends on AUDITSYSCALL && INOTIFY
300
Mike Travisc903ff82009-01-15 12:28:29 -0800301menu "RCU Subsystem"
302
303choice
304 prompt "RCU Implementation"
305 default CLASSIC_RCU
306
307config CLASSIC_RCU
308 bool "Classic RCU"
309 help
310 This option selects the classic RCU implementation that is
311 designed for best read-side performance on non-realtime
312 systems.
313
314 Select this option if you are unsure.
315
316config TREE_RCU
317 bool "Tree-based hierarchical RCU"
318 help
319 This option selects the RCU implementation that is
320 designed for very large SMP system with hundreds or
321 thousands of CPUs.
322
323config PREEMPT_RCU
324 bool "Preemptible RCU"
325 depends on PREEMPT
326 help
327 This option reduces the latency of the kernel by making certain
328 RCU sections preemptible. Normally RCU code is non-preemptible, if
329 this option is selected then read-only RCU sections become
330 preemptible. This helps latency, but may expose bugs due to
331 now-naive assumptions about each RCU read-side critical section
332 remaining on a given CPU through its execution.
333
334endchoice
335
336config RCU_TRACE
337 bool "Enable tracing for RCU"
338 depends on TREE_RCU || PREEMPT_RCU
339 help
340 This option provides tracing in RCU which presents stats
341 in debugfs for debugging RCU implementation.
342
343 Say Y here if you want to enable RCU tracing
344 Say N if you are unsure.
345
346config RCU_FANOUT
347 int "Tree-based hierarchical RCU fanout value"
348 range 2 64 if 64BIT
349 range 2 32 if !64BIT
350 depends on TREE_RCU
351 default 64 if 64BIT
352 default 32 if !64BIT
353 help
354 This option controls the fanout of hierarchical implementations
355 of RCU, allowing RCU to work efficiently on machines with
356 large numbers of CPUs. This value must be at least the cube
357 root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
358 systems and up to 262,144 for 64-bit systems.
359
360 Select a specific number if testing RCU itself.
361 Take the default if unsure.
362
363config RCU_FANOUT_EXACT
364 bool "Disable tree-based hierarchical RCU auto-balancing"
365 depends on TREE_RCU
366 default n
367 help
368 This option forces use of the exact RCU_FANOUT value specified,
369 regardless of imbalances in the hierarchy. This is useful for
370 testing RCU itself, and might one day be useful on systems with
371 strong NUMA behavior.
372
373 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
374
375 Say N if unsure.
376
377config TREE_RCU_TRACE
378 def_bool RCU_TRACE && TREE_RCU
379 select DEBUG_FS
380 help
381 This option provides tracing for the TREE_RCU implementation,
382 permitting Makefile to trivially select kernel/rcutree_trace.c.
383
384config PREEMPT_RCU_TRACE
385 def_bool RCU_TRACE && PREEMPT_RCU
386 select DEBUG_FS
387 help
388 This option provides tracing for the PREEMPT_RCU implementation,
389 permitting Makefile to trivially select kernel/rcupreempt_trace.c.
390
391endmenu # "RCU Subsystem"
392
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700394 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 ---help---
396 This option enables the complete Linux kernel ".config" file
397 contents to be saved in the kernel. It provides documentation
398 of which kernel options are used in a running kernel or in an
399 on-disk kernel. This information can be extracted from the kernel
400 image file with the script scripts/extract-ikconfig and used as
401 input to rebuild the current kernel or to build another kernel.
402 It can also be extracted from a running kernel by reading
403 /proc/config.gz if enabled (below).
404
405config IKCONFIG_PROC
406 bool "Enable access to .config through /proc/config.gz"
407 depends on IKCONFIG && PROC_FS
408 ---help---
409 This option enables access to the kernel configuration file
410 through /proc/config.gz.
411
Alistair John Strachan794543a2007-05-08 00:31:15 -0700412config LOG_BUF_SHIFT
413 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
414 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700415 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700416 help
417 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700418 Examples:
419 17 => 128 KB
420 16 => 64 KB
421 15 => 32 KB
422 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700423 13 => 8 KB
424 12 => 4 KB
425
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800426#
427# Architectures with an unreliable sched_clock() should select this:
428#
429config HAVE_UNSTABLE_SCHED_CLOCK
430 bool
431
432config GROUP_SCHED
433 bool "Group CPU scheduler"
434 depends on EXPERIMENTAL
435 default n
436 help
437 This feature lets CPU scheduler recognize task groups and control CPU
438 bandwidth allocation to such task groups.
439 In order to create a group from arbitrary set of processes, use
440 CONFIG_CGROUPS. (See Control Group support.)
441
442config FAIR_GROUP_SCHED
443 bool "Group scheduling for SCHED_OTHER"
444 depends on GROUP_SCHED
445 default GROUP_SCHED
446
447config RT_GROUP_SCHED
448 bool "Group scheduling for SCHED_RR/FIFO"
449 depends on EXPERIMENTAL
450 depends on GROUP_SCHED
451 default n
452 help
453 This feature lets you explicitly allocate real CPU bandwidth
454 to users or control groups (depending on the "Basis for grouping tasks"
455 setting below. If enabled, it will also make it impossible to
456 schedule realtime tasks for non-root users until you allocate
457 realtime bandwidth for them.
458 See Documentation/scheduler/sched-rt-group.txt for more information.
459
460choice
461 depends on GROUP_SCHED
462 prompt "Basis for grouping tasks"
463 default USER_SCHED
464
465config USER_SCHED
466 bool "user id"
467 help
468 This option will choose userid as the basis for grouping
469 tasks, thus providing equal CPU bandwidth to each user.
470
471config CGROUP_SCHED
472 bool "Control groups"
473 depends on CGROUPS
474 help
475 This option allows you to create arbitrary task groups
476 using the "cgroup" pseudo filesystem and control
477 the cpu bandwidth allocated to each such task group.
Li Zefan45ce80f2009-01-15 13:50:59 -0800478 Refer to Documentation/cgroups/cgroups.txt for more
479 information on "cgroup" pseudo filesystem.
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800480
481endchoice
482
Li Zefan23964d22009-01-15 13:50:58 -0800483menuconfig CGROUPS
484 boolean "Control Group support"
Paul Menageddbcc7e2007-10-18 23:39:30 -0700485 help
Li Zefan23964d22009-01-15 13:50:58 -0800486 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800487 use with process control subsystems such as Cpusets, CFS, memory
488 controls or device isolation.
489 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800490 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800491 - Documentation/cgroups/ (features for grouping, isolation
492 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700493
494 Say N if unsure.
495
Li Zefan23964d22009-01-15 13:50:58 -0800496if CGROUPS
497
Paul Menage006cb992007-10-18 23:39:43 -0700498config CGROUP_DEBUG
499 bool "Example debug cgroup subsystem"
500 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700501 default n
Paul Menage006cb992007-10-18 23:39:43 -0700502 help
503 This option enables a simple cgroup subsystem that
504 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800505 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700506
Li Zefan23964d22009-01-15 13:50:58 -0800507 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700508
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700509config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800510 bool "Namespace cgroup subsystem"
511 depends on CGROUPS
512 help
513 Provides a simple namespace cgroup subsystem to
514 provide hierarchical naming of sets of namespaces,
515 for instance virtual servers and checkpoint/restart
516 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700517
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700518config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800519 bool "Freezer cgroup subsystem"
520 depends on CGROUPS
521 help
522 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700523 cgroup.
524
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700525config CGROUP_DEVICE
526 bool "Device controller for cgroups"
527 depends on CGROUPS && EXPERIMENTAL
528 help
529 Provides a cgroup implementing whitelists for devices which
530 a process in the cgroup can mknod or open.
531
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532config CPUSETS
533 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700534 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700536 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 allow dynamically partitioning a system into sets of CPUs and
538 Memory Nodes and assigning tasks to run only within those sets.
539 This is primarily useful on large SMP or NUMA systems.
540
541 Say N if unsure.
542
Li Zefan23964d22009-01-15 13:50:58 -0800543config PROC_PID_CPUSET
544 bool "Include legacy /proc/<pid>/cpuset file"
545 depends on CPUSETS
546 default y
547
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100548config CGROUP_CPUACCT
549 bool "Simple CPU accounting cgroup subsystem"
550 depends on CGROUPS
551 help
552 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800553 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100554
Pavel Emelianove552b662008-02-07 00:13:49 -0800555config RESOURCE_COUNTERS
556 bool "Resource counters"
557 help
558 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800559 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800560 depends on CGROUPS
561
Balbir Singh00f0b822008-03-04 14:28:39 -0800562config CGROUP_MEM_RES_CTLR
563 bool "Memory Resource Controller for Control Groups"
564 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700565 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800566 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700567 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100568 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800569
570 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700571 associated with each page of memory in the system. By this,
572 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
573 usage tracking struct at boot. Total amount of this is printed out
574 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800575
576 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700577 sure you need the memory resource controller. Even when you enable
578 this, you can set "cgroup_disable=memory" at your boot option to
579 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800580 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800581
Balbir Singhcf475ad2008-04-29 01:00:16 -0700582 This config option also selects MM_OWNER config option, which
583 could in turn add some fork/exit overhead.
584
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800585config CGROUP_MEM_RES_CTLR_SWAP
586 bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
587 depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
588 help
589 Add swap management feature to memory resource controller. When you
590 enable this, you can limit mem+swap usage per cgroup. In other words,
591 when you disable this, memory resource controller has no cares to
592 usage of swap...a process can exhaust all of the swap. This extension
593 is useful when you want to avoid exhaustion swap but this itself
594 adds more overheads and consumes memory for remembering information.
595 Especially if you use 32bit system or small memory system, please
596 be careful about enabling this. When memory resource controller
597 is disabled by boot option, this will be automatically disabled and
598 there will be no overhead from this. Even when you set this config=y,
599 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700600 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
601 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800602
Li Zefan23964d22009-01-15 13:50:58 -0800603endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800604
Li Zefan23964d22009-01-15 13:50:58 -0800605config MM_OWNER
606 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800607
Kay Sievers88a22c92006-09-14 11:23:28 +0200608config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100609 bool
610
611config SYSFS_DEPRECATED_V2
Kay Sieversfce3e802008-11-01 14:03:00 +0100612 bool "Create deprecated sysfs layout for older userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800613 depends on SYSFS
Kay Sievers88a22c92006-09-14 11:23:28 +0200614 default y
Ingo Molnard47846c2008-03-04 14:54:47 +0100615 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200616 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100617 This option switches the layout of sysfs to the deprecated
618 version.
Kay Sievers88a22c92006-09-14 11:23:28 +0200619
Kay Sieversfce3e802008-11-01 14:03:00 +0100620 The current sysfs layout features a unified device tree at
621 /sys/devices/, which is able to express a hierarchy between
622 class devices. If the deprecated option is set to Y, the
623 unified device tree is split into a bus device tree at
624 /sys/devices/ and several individual class device trees at
625 /sys/class/. The class and bus devices will be connected by
626 "<subsystem>:<name>" and the "device" links. The "block"
627 class devices, will not show up in /sys/class/block/. Some
628 subsystems will suppress the creation of some devices which
629 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200630
Kay Sieversfce3e802008-11-01 14:03:00 +0100631 This option is not a pure compatibility option that can
632 be safely enabled on newer distributions. It will change the
633 layout of sysfs to the non-extensible deprecated version,
634 and disable some features, which can not be exported without
635 confusing older userspace tools. Since 2007/2008 all major
636 distributions do not enable this option, and ship no tools which
637 depend on the deprecated layout or this option.
638
639 If you are using a new kernel on an older distribution, or use
640 older userspace tools, you might need to say Y here. Do not say Y,
641 if the original kernel, that came with your distribution, has
642 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200643
Jens Axboeb86ff982006-03-23 19:56:55 +0100644config RELAY
645 bool "Kernel->user space relay support (formerly relayfs)"
646 help
647 This option enables support for relay interface support in
648 certain file systems (such as debugfs).
649 It is designed to provide an efficient mechanism for tools and
650 facilities to relay large amounts of data from kernel space to
651 user space.
652
653 If unsure, say N.
654
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800655config NAMESPACES
656 bool "Namespaces support" if EMBEDDED
657 default !EMBEDDED
658 help
659 Provides the way to make tasks work with different objects using
660 the same id. For example same IPC id may refer to different objects
661 or same user id or pid may refer to different tasks when used in
662 different namespaces.
663
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800664config UTS_NS
665 bool "UTS namespace"
666 depends on NAMESPACES
667 help
668 In this namespace tasks see different info provided with the
669 uname() system call
670
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800671config IPC_NS
672 bool "IPC namespace"
673 depends on NAMESPACES && SYSVIPC
674 help
675 In this namespace tasks work with IPC ids which correspond to
676 different IPC objects in different namespaces
677
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800678config USER_NS
679 bool "User namespace (EXPERIMENTAL)"
680 depends on NAMESPACES && EXPERIMENTAL
681 help
682 This allows containers, i.e. vservers, to use user namespaces
683 to provide different user info for different servers.
684 If unsure, say N.
685
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800686config PID_NS
687 bool "PID Namespaces (EXPERIMENTAL)"
688 default n
689 depends on NAMESPACES && EXPERIMENTAL
690 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300691 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100692 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800693 pid namespaces. This is a building block of containers.
694
695 Unless you want to work with an experimental feature
696 say N here.
697
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800698config NET_NS
699 bool "Network namespace"
700 default n
701 depends on NAMESPACES && EXPERIMENTAL && NET
702 help
703 Allow user space to create what appear to be multiple instances
704 of the network stack.
705
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800706config BLK_DEV_INITRD
707 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
708 depends on BROKEN || !FRV
709 help
710 The initial RAM filesystem is a ramfs which is loaded by the
711 boot loader (loadlin or lilo) and that is mounted as root
712 before the normal boot procedure. It is typically used to
713 load modules needed to mount the "real" root file system,
714 etc. See <file:Documentation/initrd.txt> for details.
715
716 If RAM disk support (BLK_DEV_RAM) is also included, this
717 also enables initial RAM disk (initrd) support and adds
718 15 Kbytes (more on some other architectures) to the kernel size.
719
720 If unsure say Y.
721
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800722if BLK_DEV_INITRD
723
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200724source "usr/Kconfig"
725
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800726endif
727
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800728config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200729 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800730 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800731 help
732 Enabling this option will pass "-Os" instead of "-O2" to gcc
733 resulting in a smaller kernel.
734
jkacur775a7222008-07-16 00:31:16 +0200735 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800736
Randy Dunlap08470622006-09-30 23:28:13 -0700737config SYSCTL
738 bool
739
Randy Dunlapb943c462009-03-10 12:55:46 -0700740config ANON_INODES
741 bool
742
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743menuconfig EMBEDDED
744 bool "Configure standard kernel features (for small systems)"
745 help
746 This option allows certain base kernel options and settings
747 to be disabled or tweaked. This is for specialized
748 environments which can tolerate a "non-standard" kernel.
749 Only use this if you really know what you are doing.
750
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700751config UID16
752 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700753 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700754 default y
755 help
756 This enables the legacy 16-bit UID syscall wrappers.
757
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700758config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700759 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800760 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700761 select SYSCTL
762 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800763 sys_sysctl uses binary paths that have been found challenging
764 to properly maintain and use. The interface in /proc/sys
765 using paths with ascii names is now the primary path to this
766 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700767
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800768 Almost nothing using the binary sysctl interface so if you are
769 trying to save some space it is probably safe to disable this,
770 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700771
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800772 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700773
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100775 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 default y
777 help
778 Say Y here to let the kernel print out symbolic crash information and
779 symbolic stack backtraces. This increases the size of the kernel
780 somewhat, as all symbols have to be loaded into the kernel image.
781
782config KALLSYMS_ALL
783 bool "Include all symbols in kallsyms"
784 depends on DEBUG_KERNEL && KALLSYMS
785 help
786 Normally kallsyms only contains the symbols of functions, for nicer
787 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200788 symbols too: say Y here to include all symbols, if you need them
789 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
791 Say N.
792
793config KALLSYMS_EXTRA_PASS
794 bool "Do an extra kallsyms pass"
795 depends on KALLSYMS
796 help
797 If kallsyms is not working correctly, the build will fail with
798 inconsistent kallsyms data. If that occurs, log a bug report and
799 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
800 Always say N here unless you find a bug in kallsyms, which must be
801 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
802 you wait for kallsyms to be fixed.
803
Matt Mackalld59745c2005-05-01 08:59:02 -0700804
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800805config HOTPLUG
806 bool "Support for hot-pluggable devices" if EMBEDDED
807 default y
808 help
809 This option is provided for the case where no hotplug or uevent
810 capabilities is wanted by the kernel. You should only consider
811 disabling this option for embedded systems that do not use modules, a
812 dynamic /dev tree, or dynamic device discovery. Just say Y.
813
Matt Mackalld59745c2005-05-01 08:59:02 -0700814config PRINTK
815 default y
816 bool "Enable support for printk" if EMBEDDED
817 help
818 This option enables normal printk support. Removing it
819 eliminates most of the message strings from the kernel image
820 and makes the kernel more or less silent. As this makes it
821 very difficult to diagnose system problems, saying N here is
822 strongly discouraged.
823
Matt Mackallc8538a72005-05-01 08:59:01 -0700824config BUG
825 bool "BUG() support" if EMBEDDED
826 default y
827 help
828 Disabling this option eliminates support for BUG and WARN, reducing
829 the size of your kernel image and potentially quietly ignoring
830 numerous fatal conditions. You should only consider disabling this
831 option for embedded systems with no facilities for reporting errors.
832 Just say Y.
833
Matt Mackall708e9a72006-01-08 01:05:25 -0800834config ELF_CORE
835 default y
836 bool "Enable ELF core dumps" if EMBEDDED
837 help
838 Enable support for generating core dumps. Disabling saves about 4k.
839
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200840config PCSPKR_PLATFORM
841 bool "Enable PC-Speaker support" if EMBEDDED
842 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
843 default y
844 help
845 This option allows to disable the internal PC-Speaker
846 support, saving some memory.
847
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848config BASE_FULL
849 default y
850 bool "Enable full-sized data structures for core" if EMBEDDED
851 help
852 Disabling this option reduces the size of miscellaneous core
853 kernel data structures. This saves memory on small machines,
854 but may reduce performance.
855
856config FUTEX
857 bool "Enable futex support" if EMBEDDED
858 default y
Ingo Molnar23f78d42006-06-27 02:54:53 -0700859 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 help
861 Disabling this option will cause the kernel to be built without
862 support for "fast userspace mutexes". The resulting kernel may not
863 run glibc-based applications correctly.
864
865config EPOLL
866 bool "Enable eventpoll support" if EMBEDDED
867 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700868 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 help
870 Disabling this option will cause the kernel to be built without
871 support for epoll family of system calls.
872
Davide Libenzifba2afa2007-05-10 22:23:13 -0700873config SIGNALFD
874 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700875 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700876 default y
877 help
878 Enable the signalfd() system call that allows to receive signals
879 on a file descriptor.
880
881 If unsure, say Y.
882
Davide Libenzib215e282007-05-10 22:23:16 -0700883config TIMERFD
884 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700885 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700886 default y
887 help
888 Enable the timerfd() system call that allows to receive timer
889 events on a file descriptor.
890
891 If unsure, say Y.
892
Davide Libenzie1ad7462007-05-10 22:23:19 -0700893config EVENTFD
894 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700895 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700896 default y
897 help
898 Enable the eventfd() system call that allows to receive both
899 kernel notification (ie. KAIO) or userspace notifications.
900
901 If unsure, say Y.
902
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903config SHMEM
904 bool "Use full shmem filesystem" if EMBEDDED
905 default y
906 depends on MMU
907 help
908 The shmem is an internal filesystem used to manage shared memory.
909 It is backed by swap and manages resource limits. It is also exported
910 to userspace as tmpfs if TMPFS is enabled. Disabling this
911 option replaces shmem and tmpfs with the much simpler ramfs code,
912 which may be appropriate on small systems without swap.
913
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700914config AIO
915 bool "Enable AIO support" if EMBEDDED
916 default y
917 help
918 This option enables POSIX asynchronous I/O which may by used
919 by some high performance threaded applications. Disabling
920 this option saves about 7k.
921
Thomas Gleixner0793a612008-12-04 20:12:29 +0100922config HAVE_PERF_COUNTERS
923 bool
924
925menu "Performance Counters"
926
927config PERF_COUNTERS
928 bool "Kernel Performance Counters"
929 depends on HAVE_PERF_COUNTERS
930 default y
Ingo Molnar4c59e462008-12-08 19:38:33 +0100931 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +0100932 help
933 Enable kernel support for performance counter hardware.
934
935 Performance counters are special hardware registers available
936 on most modern CPUs. These registers count the number of certain
937 types of hw events: such as instructions executed, cachemisses
938 suffered, or branches mis-predicted - without slowing down the
939 kernel or applications. These registers can also trigger interrupts
940 when a threshold number of events have passed - and can thus be
941 used to profile the code that runs on that CPU.
942
943 The Linux Performance Counter subsystem provides an abstraction of
944 these hardware capabilities, available via a system call. It
945 provides per task and per CPU counters, and it provides event
946 capabilities on top of those.
947
948 Say Y if unsure.
949
Peter Zijlstrae077df42009-03-19 20:26:17 +0100950config EVENT_PROFILE
951 bool "Tracepoint profile sources"
952 depends on PERF_COUNTERS && EVENT_TRACER
953 default y
954
Thomas Gleixner0793a612008-12-04 20:12:29 +0100955endmenu
956
Christoph Lameterf8891e52006-06-30 01:55:45 -0700957config VM_EVENT_COUNTERS
958 default y
959 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
960 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -0800961 VM event counters are needed for event counts to be shown.
962 This option allows the disabling of the VM event counters
963 on EMBEDDED systems. /proc/vmstat will only show page counts
964 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -0700965
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200966config PCI_QUIRKS
967 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +0200968 bool "Enable PCI quirk workarounds" if EMBEDDED
969 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200970 help
971 This enables workarounds for various PCI chipset
972 bugs/quirks. Disable this only if your target machine is
973 unaffected by PCI quirks.
974
Christoph Lameter41ecc552007-05-09 02:32:44 -0700975config SLUB_DEBUG
976 default y
977 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -0700978 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -0700979 help
980 SLUB has extensive debug support features. Disabling these can
981 result in significant savings in code size. This also disables
982 SLUB sysfs support. /sys/slab will not exist and there will be
983 no support for cache validation etc.
984
Randy Dunlapb943c462009-03-10 12:55:46 -0700985config COMPAT_BRK
986 bool "Disable heap randomization"
987 default y
988 help
989 Randomizing heap placement makes heap exploits harder, but it
990 also breaks ancient binaries (including anything libc5 based).
991 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +0100992 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -0700993 /proc/sys/kernel/randomize_va_space to 2.
994
995 On non-ancient distros (post-2000 ones) N is usually a safe choice.
996
Christoph Lameter81819f02007-05-06 14:49:36 -0700997choice
998 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -0700999 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001000 help
1001 This option allows to select a slab allocator.
1002
1003config SLAB
1004 bool "SLAB"
1005 help
1006 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001007 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001008 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001009
1010config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001011 bool "SLUB (Unqueued Allocator)"
1012 help
1013 SLUB is a slab allocator that minimizes cache line usage
1014 instead of managing queues of cached objects (SLAB approach).
1015 Per cpu caching is realized using slabs of objects instead
1016 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001017 and has enhanced diagnostics. SLUB is the default choice for
1018 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001019
1020config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001021 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001022 bool "SLOB (Simple Allocator)"
1023 help
Matt Mackall37291452008-02-04 22:29:38 -08001024 SLOB replaces the stock allocator with a drastically simpler
1025 allocator. SLOB is generally more space efficient but
1026 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001027
1028endchoice
1029
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001030config PROFILING
1031 bool "Profiling support (EXPERIMENTAL)"
1032 help
1033 Say Y here to enable the extended profiling support mechanisms used
1034 by profilers such as OProfile.
1035
Ingo Molnar5f87f112008-07-23 14:15:22 +02001036#
1037# Place an empty function call at each tracepoint site. Can be
1038# dynamically changed for a probe function.
1039#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001040config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001041 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001042
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001043config MARKERS
1044 bool "Activate markers"
Frederic Weisbecker91f73f92009-02-20 17:34:06 +01001045 select TRACEPOINTS
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001046 help
1047 Place an empty function call at each marker site. Can be
1048 dynamically changed for a probe function.
1049
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001050source "arch/Kconfig"
1051
David Howells07fe7cb2009-04-03 16:42:35 +01001052config SLOW_WORK
1053 default n
1054 bool "Enable slow work thread pool"
1055 help
1056 The slow work thread pool provides a number of dynamically allocated
1057 threads that can be used by the kernel to perform operations that
1058 take a relatively long time.
1059
1060 An example of this would be CacheFiles doing a path lookup followed
1061 by a series of mkdirs and a create call, all of which have to touch
1062 disk.
1063
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064endmenu # General setup
1065
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001066config HAVE_GENERIC_DMA_COHERENT
1067 bool
1068 default n
1069
Linus Torvalds158a9622008-01-02 13:04:48 -08001070config SLABINFO
1071 bool
1072 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001073 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001074 default y
1075
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001076config RT_MUTEXES
1077 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001078
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079config BASE_SMALL
1080 int
1081 default 0 if BASE_FULL
1082 default 1 if !BASE_FULL
1083
Jan Engelhardt66da5732007-07-15 23:39:29 -07001084menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085 bool "Enable loadable module support"
1086 help
1087 Kernel modules are small pieces of compiled code which can
1088 be inserted in the running kernel, rather than being
1089 permanently built into the kernel. You use the "modprobe"
1090 tool to add (and sometimes remove) them. If you say Y here,
1091 many parts of the kernel can be built as modules (by
1092 answering M instead of Y where indicated): this is most
1093 useful for infrequently used options which are not required
1094 for booting. For more information, see the man pages for
1095 modprobe, lsmod, modinfo, insmod and rmmod.
1096
1097 If you say Y here, you will need to run "make
1098 modules_install" to put the modules under /lib/modules/
1099 where modprobe can find them (you may need to be root to do
1100 this).
1101
1102 If unsure, say Y.
1103
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001104if MODULES
1105
Linus Torvalds826e4502008-05-04 17:04:16 -07001106config MODULE_FORCE_LOAD
1107 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001108 default n
1109 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001110 Allow loading of modules without version information (ie. modprobe
1111 --force). Forced module loading sets the 'F' (forced) taint flag and
1112 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001113
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114config MODULE_UNLOAD
1115 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116 help
1117 Without this option you will not be able to unload any
1118 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001119 anyway), which makes your kernel smaller, faster
1120 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121
1122config MODULE_FORCE_UNLOAD
1123 bool "Forced module unloading"
1124 depends on MODULE_UNLOAD && EXPERIMENTAL
1125 help
1126 This option allows you to force a module to unload, even if the
1127 kernel believes it is unsafe: the kernel will remove the module
1128 without waiting for anyone to stop using it (using the -f option to
1129 rmmod). This is mainly for kernel developers and desperate users.
1130 If unsure, say N.
1131
Linus Torvalds1da177e2005-04-16 15:20:36 -07001132config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001133 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 help
1135 Usually, you have to use modules compiled with your kernel.
1136 Saying Y here makes it sometimes possible to use modules
1137 compiled for different kernels, by adding enough information
1138 to the modules to (hopefully) spot any changes which would
1139 make them incompatible with the kernel you are running. If
1140 unsure, say N.
1141
1142config MODULE_SRCVERSION_ALL
1143 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 help
1145 Modules which contain a MODULE_VERSION get an extra "srcversion"
1146 field inserted into their modinfo section, which contains a
1147 sum of the source files which made it. This helps maintainers
1148 see exactly which source was used to build a module (since
1149 others sometimes change the module source without updating
1150 the version). With this option, such a "srcversion" field
1151 will be created for all modules. If unsure, say N.
1152
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001153endif # MODULES
1154
Rusty Russell98a79d62008-12-13 21:19:41 +10301155config INIT_ALL_POSSIBLE
1156 bool
1157 help
1158 Back when each arch used to define their own cpu_online_map and
1159 cpu_possible_map, some of them chose to initialize cpu_possible_map
1160 with all 1s, and others with all 0s. When they were centralised,
1161 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001162 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301163
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164config STOP_MACHINE
1165 bool
1166 default y
1167 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1168 help
1169 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001170
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001171source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001172
1173config PREEMPT_NOTIFIERS
1174 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001175