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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' Giarrussob2670eac2006-10-19 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
Peter Oberparleiterb99b87f72009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
22 default y
23
Al Boldiff0cfc62007-07-31 00:39:23 -070024menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26config EXPERIMENTAL
27 bool "Prompt for development and/or incomplete code/drivers"
28 ---help---
29 Some of the various things that Linux supports (such as network
30 drivers, file systems, network protocols, etc.) can be in a state
31 of development where the functionality, stability, or the level of
32 testing is not yet high enough for general use. This is usually
33 known as the "alpha-test" phase among developers. If a feature is
34 currently in alpha-test, then the developers usually discourage
35 uninformed widespread use of this feature by the general public to
36 avoid "Why doesn't this work?" type mail messages. However, active
37 testing and use of these systems is welcomed. Just be aware that it
38 may not meet the normal level of reliability or it may fail to work
39 in some special cases. Detailed bug reports from people familiar
40 with the kernel internals are usually welcomed by the developers
41 (before submitting bug reports, please read the documents
42 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
43 <file:Documentation/BUG-HUNTING>, and
44 <file:Documentation/oops-tracing.txt> in the kernel source).
45
46 This option will also make obsoleted drivers available. These are
47 drivers that have been replaced by something else, and/or are
48 scheduled to be removed in a future kernel release.
49
50 Unless you intend to help test and develop a feature or driver that
51 falls into this category, or you have a situation that requires
52 using these features, you should probably say N here, which will
53 cause the configurator to present you with fewer choices. If
54 you say Y here, you will be offered the choice of using features or
55 drivers that are currently considered to be in the alpha-test phase.
56
Linus Torvalds1da177e2005-04-16 15:20:36 -070057config BROKEN
58 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60config BROKEN_ON_SMP
61 bool
62 depends on BROKEN || !SMP
63 default y
64
65config LOCK_KERNEL
66 bool
67 depends on SMP || PREEMPT
68 default y
69
70config INIT_ENV_ARG_LIMIT
71 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070072 default 32 if !UML
73 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 help
Randy Dunlap34ad92c22005-10-30 15:01:46 -080075 Maximum of each of the number of arguments and environment
76 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
79config LOCALVERSION
80 string "Local version - append to kernel release"
81 help
82 Append an extra string to the end of your kernel version.
83 This will show up when you type uname, for example.
84 The string you set here will be appended after the contents of
85 any files with a filename matching localversion* in your
86 object and source tree, in that order. Your total string can
87 be a maximum of 64 characters.
88
Ryan Andersonaaebf432005-07-31 04:57:49 -040089config LOCALVERSION_AUTO
90 bool "Automatically append version information to the version string"
91 default y
92 help
93 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020094 release tree by looking for git tags that belong to the current
95 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040096
97 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020098 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040099 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200100 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400101
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200102 (The actual string used here is the first eight characters produced
103 by running the command:
104
105 $ git rev-parse --verify HEAD
106
107 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400108
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800109config HAVE_KERNEL_GZIP
110 bool
111
112config HAVE_KERNEL_BZIP2
113 bool
114
115config HAVE_KERNEL_LZMA
116 bool
117
Alain Knaff30d65db2009-01-04 22:46:17 +0100118choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800119 prompt "Kernel compression mode"
120 default KERNEL_GZIP
121 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA
122 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100123 The linux kernel is a kind of self-extracting executable.
124 Several compression algorithms are available, which differ
125 in efficiency, compression and decompression speed.
126 Compression speed is only relevant when building a kernel.
127 Decompression speed is relevant at each boot.
128
129 If you have any problems with bzip2 or lzma compressed
130 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
131 version of this functionality (bzip2 only), for 2.4, was
132 supplied by Christian Ludwig)
133
134 High compression options are mostly useful for users, who
135 are low on disk space (embedded systems), but for whom ram
136 size matters less.
137
138 If in doubt, select 'gzip'
139
140config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800141 bool "Gzip"
142 depends on HAVE_KERNEL_GZIP
143 help
144 The old and tried gzip compression. Its compression ratio is
145 the poorest among the 3 choices; however its speed (both
146 compression and decompression) is the fastest.
Alain Knaff30d65db2009-01-04 22:46:17 +0100147
148config KERNEL_BZIP2
149 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800150 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100151 help
152 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800153 Decompression speed is slowest among the three. The kernel
154 size is about 10% smaller with bzip2, in comparison to gzip.
155 Bzip2 uses a large amount of memory. For modern kernels you
156 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100157
158config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800159 bool "LZMA"
160 depends on HAVE_KERNEL_LZMA
161 help
162 The most recent compression algorithm.
163 Its ratio is best, decompression speed is between the other
164 two. Compression is slowest. The kernel size is about 33%
165 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100166
167endchoice
168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169config SWAP
170 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200171 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 default y
173 help
174 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100175 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 used to provide more virtual memory than the actual RAM present
177 in your computer. If unsure say Y.
178
179config SYSVIPC
180 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 ---help---
182 Inter Process Communication is a suite of library functions and
183 system calls which let processes (running programs) synchronize and
184 exchange information. It is generally considered to be a good thing,
185 and some programs won't run unless you say Y here. In particular, if
186 you want to run the DOS emulator dosemu under Linux (read the
187 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
188 you'll need to say Y here.
189
190 You can find documentation about IPC with "info ipc" and also in
191 section 6.4 of the Linux Programmer's Guide, available from
192 <http://www.tldp.org/guides.html>.
193
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800194config SYSVIPC_SYSCTL
195 bool
196 depends on SYSVIPC
197 depends on SYSCTL
198 default y
199
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200config POSIX_MQUEUE
201 bool "POSIX Message Queues"
202 depends on NET && EXPERIMENTAL
203 ---help---
204 POSIX variant of message queues is a part of IPC. In POSIX message
205 queues every message has a priority which decides about succession
206 of receiving it by a process. If you want to compile and run
207 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200208 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210 POSIX message queues are visible as a filesystem called 'mqueue'
211 and can be mounted somewhere if you want to do filesystem
212 operations on message queues.
213
214 If unsure, say Y.
215
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700216config POSIX_MQUEUE_SYSCTL
217 bool
218 depends on POSIX_MQUEUE
219 depends on SYSCTL
220 default y
221
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222config BSD_PROCESS_ACCT
223 bool "BSD Process Accounting"
224 help
225 If you say Y here, a user level program will be able to instruct the
226 kernel (via a special system call) to write process accounting
227 information to a file: whenever a process exits, information about
228 that process will be appended to the file by the kernel. The
229 information includes things such as creation time, owning user,
230 command name, memory usage, controlling terminal etc. (the complete
231 list is in the struct acct in <file:include/linux/acct.h>). It is
232 up to the user level program to do useful things with this
233 information. This is generally a good idea, so say Y.
234
235config BSD_PROCESS_ACCT_V3
236 bool "BSD Process Accounting version 3 file format"
237 depends on BSD_PROCESS_ACCT
238 default n
239 help
240 If you say Y here, the process accounting information is written
241 in a new file format that also logs the process IDs of each
242 process and it's parent. Note that this file format is incompatible
243 with previous v0/v1/v2 file formats, so you will need updated tools
244 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300245 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
Shailabh Nagarc7572492006-07-14 00:24:40 -0700247config TASKSTATS
248 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
249 depends on NET
250 default n
251 help
252 Export selected statistics for tasks/processes through the
253 generic netlink interface. Unlike BSD process accounting, the
254 statistics are available during the lifetime of tasks/processes as
255 responses to commands. Like BSD accounting, they are sent to user
256 space on task exit.
257
258 Say N if unsure.
259
Shailabh Nagarca74e922006-07-14 00:24:36 -0700260config TASK_DELAY_ACCT
261 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700262 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700263 help
264 Collect information on time spent by a task waiting for system
265 resources like cpu, synchronous block I/O completion and swapping
266 in pages. Such statistics can help in setting a task's priorities
267 relative to other tasks for cpu, io, rss limits etc.
268
269 Say N if unsure.
270
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800271config TASK_XACCT
272 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
273 depends on TASKSTATS
274 help
275 Collect extended task accounting data and send the data
276 to userland for processing over the taskstats interface.
277
278 Say N if unsure.
279
280config TASK_IO_ACCOUNTING
281 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
282 depends on TASK_XACCT
283 help
284 Collect information on the number of bytes of storage I/O which this
285 task has caused.
286
287 Say N if unsure.
288
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289config AUDIT
290 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100291 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 help
293 Enable auditing infrastructure that can be used with another
294 kernel subsystem, such as SELinux (which requires this for
295 logging of avc messages output). Does not do system-call
296 auditing without CONFIG_AUDITSYSCALL.
297
298config AUDITSYSCALL
299 bool "Enable system-call auditing support"
Yuichi Nakamura1322b9d2007-11-10 19:21:34 +0900300 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 default y if SECURITY_SELINUX
302 help
303 Enable low-overhead system-call auditing infrastructure that
304 can be used independently or with another kernel subsystem,
Amy Griffisf368c07d2006-04-07 16:55:56 -0400305 such as SELinux. To use audit's filesystem watch feature, please
306 ensure that INOTIFY is configured.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
Al Viro74c3cbe2007-07-22 08:04:18 -0400308config AUDIT_TREE
309 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400310 depends on AUDITSYSCALL
311 select INOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400312
Mike Travisc903ff82009-01-15 12:28:29 -0800313menu "RCU Subsystem"
314
315choice
316 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700317 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800318
Mike Travisc903ff82009-01-15 12:28:29 -0800319config TREE_RCU
320 bool "Tree-based hierarchical RCU"
321 help
322 This option selects the RCU implementation that is
323 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700324 thousands of CPUs. It also scales down nicely to
325 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800326
327config PREEMPT_RCU
328 bool "Preemptible RCU"
329 depends on PREEMPT
330 help
331 This option reduces the latency of the kernel by making certain
332 RCU sections preemptible. Normally RCU code is non-preemptible, if
333 this option is selected then read-only RCU sections become
334 preemptible. This helps latency, but may expose bugs due to
335 now-naive assumptions about each RCU read-side critical section
336 remaining on a given CPU through its execution.
337
338endchoice
339
340config RCU_TRACE
341 bool "Enable tracing for RCU"
342 depends on TREE_RCU || PREEMPT_RCU
343 help
344 This option provides tracing in RCU which presents stats
345 in debugfs for debugging RCU implementation.
346
347 Say Y here if you want to enable RCU tracing
348 Say N if you are unsure.
349
350config RCU_FANOUT
351 int "Tree-based hierarchical RCU fanout value"
352 range 2 64 if 64BIT
353 range 2 32 if !64BIT
354 depends on TREE_RCU
355 default 64 if 64BIT
356 default 32 if !64BIT
357 help
358 This option controls the fanout of hierarchical implementations
359 of RCU, allowing RCU to work efficiently on machines with
360 large numbers of CPUs. This value must be at least the cube
361 root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
362 systems and up to 262,144 for 64-bit systems.
363
364 Select a specific number if testing RCU itself.
365 Take the default if unsure.
366
367config RCU_FANOUT_EXACT
368 bool "Disable tree-based hierarchical RCU auto-balancing"
369 depends on TREE_RCU
370 default n
371 help
372 This option forces use of the exact RCU_FANOUT value specified,
373 regardless of imbalances in the hierarchy. This is useful for
374 testing RCU itself, and might one day be useful on systems with
375 strong NUMA behavior.
376
377 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
378
379 Say N if unsure.
380
381config TREE_RCU_TRACE
382 def_bool RCU_TRACE && TREE_RCU
383 select DEBUG_FS
384 help
385 This option provides tracing for the TREE_RCU implementation,
386 permitting Makefile to trivially select kernel/rcutree_trace.c.
387
388config PREEMPT_RCU_TRACE
389 def_bool RCU_TRACE && PREEMPT_RCU
390 select DEBUG_FS
391 help
392 This option provides tracing for the PREEMPT_RCU implementation,
393 permitting Makefile to trivially select kernel/rcupreempt_trace.c.
394
395endmenu # "RCU Subsystem"
396
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700398 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 ---help---
400 This option enables the complete Linux kernel ".config" file
401 contents to be saved in the kernel. It provides documentation
402 of which kernel options are used in a running kernel or in an
403 on-disk kernel. This information can be extracted from the kernel
404 image file with the script scripts/extract-ikconfig and used as
405 input to rebuild the current kernel or to build another kernel.
406 It can also be extracted from a running kernel by reading
407 /proc/config.gz if enabled (below).
408
409config IKCONFIG_PROC
410 bool "Enable access to .config through /proc/config.gz"
411 depends on IKCONFIG && PROC_FS
412 ---help---
413 This option enables access to the kernel configuration file
414 through /proc/config.gz.
415
Alistair John Strachan794543a2007-05-08 00:31:15 -0700416config LOG_BUF_SHIFT
417 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
418 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700419 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700420 help
421 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700422 Examples:
423 17 => 128 KB
424 16 => 64 KB
425 15 => 32 KB
426 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700427 13 => 8 KB
428 12 => 4 KB
429
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800430#
431# Architectures with an unreliable sched_clock() should select this:
432#
433config HAVE_UNSTABLE_SCHED_CLOCK
434 bool
435
436config GROUP_SCHED
437 bool "Group CPU scheduler"
438 depends on EXPERIMENTAL
439 default n
440 help
441 This feature lets CPU scheduler recognize task groups and control CPU
442 bandwidth allocation to such task groups.
443 In order to create a group from arbitrary set of processes, use
444 CONFIG_CGROUPS. (See Control Group support.)
445
446config FAIR_GROUP_SCHED
447 bool "Group scheduling for SCHED_OTHER"
448 depends on GROUP_SCHED
449 default GROUP_SCHED
450
451config RT_GROUP_SCHED
452 bool "Group scheduling for SCHED_RR/FIFO"
453 depends on EXPERIMENTAL
454 depends on GROUP_SCHED
455 default n
456 help
457 This feature lets you explicitly allocate real CPU bandwidth
458 to users or control groups (depending on the "Basis for grouping tasks"
459 setting below. If enabled, it will also make it impossible to
460 schedule realtime tasks for non-root users until you allocate
461 realtime bandwidth for them.
462 See Documentation/scheduler/sched-rt-group.txt for more information.
463
464choice
465 depends on GROUP_SCHED
466 prompt "Basis for grouping tasks"
467 default USER_SCHED
468
469config USER_SCHED
470 bool "user id"
471 help
472 This option will choose userid as the basis for grouping
473 tasks, thus providing equal CPU bandwidth to each user.
474
475config CGROUP_SCHED
476 bool "Control groups"
477 depends on CGROUPS
478 help
479 This option allows you to create arbitrary task groups
480 using the "cgroup" pseudo filesystem and control
481 the cpu bandwidth allocated to each such task group.
Li Zefan45ce80f2009-01-15 13:50:59 -0800482 Refer to Documentation/cgroups/cgroups.txt for more
483 information on "cgroup" pseudo filesystem.
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800484
485endchoice
486
Li Zefan23964d22009-01-15 13:50:58 -0800487menuconfig CGROUPS
488 boolean "Control Group support"
Paul Menageddbcc7e2007-10-18 23:39:30 -0700489 help
Li Zefan23964d22009-01-15 13:50:58 -0800490 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800491 use with process control subsystems such as Cpusets, CFS, memory
492 controls or device isolation.
493 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800494 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800495 - Documentation/cgroups/ (features for grouping, isolation
496 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700497
498 Say N if unsure.
499
Li Zefan23964d22009-01-15 13:50:58 -0800500if CGROUPS
501
Paul Menage006cb992007-10-18 23:39:43 -0700502config CGROUP_DEBUG
503 bool "Example debug cgroup subsystem"
504 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700505 default n
Paul Menage006cb992007-10-18 23:39:43 -0700506 help
507 This option enables a simple cgroup subsystem that
508 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800509 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700510
Li Zefan23964d22009-01-15 13:50:58 -0800511 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700512
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700513config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800514 bool "Namespace cgroup subsystem"
515 depends on CGROUPS
516 help
517 Provides a simple namespace cgroup subsystem to
518 provide hierarchical naming of sets of namespaces,
519 for instance virtual servers and checkpoint/restart
520 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700521
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700522config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800523 bool "Freezer cgroup subsystem"
524 depends on CGROUPS
525 help
526 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700527 cgroup.
528
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700529config CGROUP_DEVICE
530 bool "Device controller for cgroups"
531 depends on CGROUPS && EXPERIMENTAL
532 help
533 Provides a cgroup implementing whitelists for devices which
534 a process in the cgroup can mknod or open.
535
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536config CPUSETS
537 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700538 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700540 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 allow dynamically partitioning a system into sets of CPUs and
542 Memory Nodes and assigning tasks to run only within those sets.
543 This is primarily useful on large SMP or NUMA systems.
544
545 Say N if unsure.
546
Li Zefan23964d22009-01-15 13:50:58 -0800547config PROC_PID_CPUSET
548 bool "Include legacy /proc/<pid>/cpuset file"
549 depends on CPUSETS
550 default y
551
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100552config CGROUP_CPUACCT
553 bool "Simple CPU accounting cgroup subsystem"
554 depends on CGROUPS
555 help
556 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800557 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100558
Pavel Emelianove552b662008-02-07 00:13:49 -0800559config RESOURCE_COUNTERS
560 bool "Resource counters"
561 help
562 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800563 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800564 depends on CGROUPS
565
Balbir Singh00f0b822008-03-04 14:28:39 -0800566config CGROUP_MEM_RES_CTLR
567 bool "Memory Resource Controller for Control Groups"
568 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700569 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800570 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700571 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100572 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800573
574 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700575 associated with each page of memory in the system. By this,
576 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
577 usage tracking struct at boot. Total amount of this is printed out
578 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800579
580 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700581 sure you need the memory resource controller. Even when you enable
582 this, you can set "cgroup_disable=memory" at your boot option to
583 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800584 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800585
Balbir Singhcf475ad2008-04-29 01:00:16 -0700586 This config option also selects MM_OWNER config option, which
587 could in turn add some fork/exit overhead.
588
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800589config CGROUP_MEM_RES_CTLR_SWAP
590 bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
591 depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
592 help
593 Add swap management feature to memory resource controller. When you
594 enable this, you can limit mem+swap usage per cgroup. In other words,
595 when you disable this, memory resource controller has no cares to
596 usage of swap...a process can exhaust all of the swap. This extension
597 is useful when you want to avoid exhaustion swap but this itself
598 adds more overheads and consumes memory for remembering information.
599 Especially if you use 32bit system or small memory system, please
600 be careful about enabling this. When memory resource controller
601 is disabled by boot option, this will be automatically disabled and
602 there will be no overhead from this. Even when you set this config=y,
603 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700604 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
605 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800606
Li Zefan23964d22009-01-15 13:50:58 -0800607endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800608
Li Zefan23964d22009-01-15 13:50:58 -0800609config MM_OWNER
610 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800611
Kay Sievers88a22c92006-09-14 11:23:28 +0200612config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100613 bool
614
615config SYSFS_DEPRECATED_V2
Kay Sieversf6ee6492009-04-16 19:56:37 +0200616 bool "remove sysfs features which may confuse old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800617 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200618 default n
Ingo Molnard47846c2008-03-04 14:54:47 +0100619 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200620 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100621 This option switches the layout of sysfs to the deprecated
Kay Sieversf6ee6492009-04-16 19:56:37 +0200622 version. Do not use it on recent distributions.
Kay Sievers88a22c92006-09-14 11:23:28 +0200623
Kay Sieversfce3e802008-11-01 14:03:00 +0100624 The current sysfs layout features a unified device tree at
625 /sys/devices/, which is able to express a hierarchy between
626 class devices. If the deprecated option is set to Y, the
627 unified device tree is split into a bus device tree at
628 /sys/devices/ and several individual class device trees at
629 /sys/class/. The class and bus devices will be connected by
630 "<subsystem>:<name>" and the "device" links. The "block"
631 class devices, will not show up in /sys/class/block/. Some
632 subsystems will suppress the creation of some devices which
633 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200634
Kay Sieversfce3e802008-11-01 14:03:00 +0100635 This option is not a pure compatibility option that can
636 be safely enabled on newer distributions. It will change the
637 layout of sysfs to the non-extensible deprecated version,
638 and disable some features, which can not be exported without
639 confusing older userspace tools. Since 2007/2008 all major
640 distributions do not enable this option, and ship no tools which
641 depend on the deprecated layout or this option.
642
643 If you are using a new kernel on an older distribution, or use
644 older userspace tools, you might need to say Y here. Do not say Y,
645 if the original kernel, that came with your distribution, has
646 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200647
Jens Axboeb86ff9812006-03-23 19:56:55 +0100648config RELAY
649 bool "Kernel->user space relay support (formerly relayfs)"
650 help
651 This option enables support for relay interface support in
652 certain file systems (such as debugfs).
653 It is designed to provide an efficient mechanism for tools and
654 facilities to relay large amounts of data from kernel space to
655 user space.
656
657 If unsure, say N.
658
Pavel Emelyanovc5289a692008-02-08 04:18:19 -0800659config NAMESPACES
660 bool "Namespaces support" if EMBEDDED
661 default !EMBEDDED
662 help
663 Provides the way to make tasks work with different objects using
664 the same id. For example same IPC id may refer to different objects
665 or same user id or pid may refer to different tasks when used in
666 different namespaces.
667
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800668config UTS_NS
669 bool "UTS namespace"
670 depends on NAMESPACES
671 help
672 In this namespace tasks see different info provided with the
673 uname() system call
674
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800675config IPC_NS
676 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700677 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800678 help
679 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700680 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800681
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800682config USER_NS
683 bool "User namespace (EXPERIMENTAL)"
684 depends on NAMESPACES && EXPERIMENTAL
685 help
686 This allows containers, i.e. vservers, to use user namespaces
687 to provide different user info for different servers.
688 If unsure, say N.
689
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800690config PID_NS
691 bool "PID Namespaces (EXPERIMENTAL)"
692 default n
693 depends on NAMESPACES && EXPERIMENTAL
694 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300695 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100696 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800697 pid namespaces. This is a building block of containers.
698
699 Unless you want to work with an experimental feature
700 say N here.
701
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800702config NET_NS
703 bool "Network namespace"
704 default n
705 depends on NAMESPACES && EXPERIMENTAL && NET
706 help
707 Allow user space to create what appear to be multiple instances
708 of the network stack.
709
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800710config BLK_DEV_INITRD
711 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
712 depends on BROKEN || !FRV
713 help
714 The initial RAM filesystem is a ramfs which is loaded by the
715 boot loader (loadlin or lilo) and that is mounted as root
716 before the normal boot procedure. It is typically used to
717 load modules needed to mount the "real" root file system,
718 etc. See <file:Documentation/initrd.txt> for details.
719
720 If RAM disk support (BLK_DEV_RAM) is also included, this
721 also enables initial RAM disk (initrd) support and adds
722 15 Kbytes (more on some other architectures) to the kernel size.
723
724 If unsure say Y.
725
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800726if BLK_DEV_INITRD
727
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200728source "usr/Kconfig"
729
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800730endif
731
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800732config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200733 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800734 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800735 help
736 Enabling this option will pass "-Os" instead of "-O2" to gcc
737 resulting in a smaller kernel.
738
jkacur775a7222008-07-16 00:31:16 +0200739 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800740
Randy Dunlap08470622006-09-30 23:28:13 -0700741config SYSCTL
742 bool
743
Randy Dunlapb943c462009-03-10 12:55:46 -0700744config ANON_INODES
745 bool
746
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747menuconfig EMBEDDED
748 bool "Configure standard kernel features (for small systems)"
749 help
750 This option allows certain base kernel options and settings
751 to be disabled or tweaked. This is for specialized
752 environments which can tolerate a "non-standard" kernel.
753 Only use this if you really know what you are doing.
754
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700755config UID16
756 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700757 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 -0700758 default y
759 help
760 This enables the legacy 16-bit UID syscall wrappers.
761
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700762config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700763 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800764 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700765 select SYSCTL
766 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800767 sys_sysctl uses binary paths that have been found challenging
768 to properly maintain and use. The interface in /proc/sys
769 using paths with ascii names is now the primary path to this
770 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700771
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800772 Almost nothing using the binary sysctl interface so if you are
773 trying to save some space it is probably safe to disable this,
774 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700775
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800776 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700777
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100779 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 default y
781 help
782 Say Y here to let the kernel print out symbolic crash information and
783 symbolic stack backtraces. This increases the size of the kernel
784 somewhat, as all symbols have to be loaded into the kernel image.
785
786config KALLSYMS_ALL
787 bool "Include all symbols in kallsyms"
788 depends on DEBUG_KERNEL && KALLSYMS
789 help
790 Normally kallsyms only contains the symbols of functions, for nicer
791 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200792 symbols too: say Y here to include all symbols, if you need them
793 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794
795 Say N.
796
797config KALLSYMS_EXTRA_PASS
798 bool "Do an extra kallsyms pass"
799 depends on KALLSYMS
800 help
801 If kallsyms is not working correctly, the build will fail with
802 inconsistent kallsyms data. If that occurs, log a bug report and
803 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
804 Always say N here unless you find a bug in kallsyms, which must be
805 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
806 you wait for kallsyms to be fixed.
807
Matt Mackalld59745c2005-05-01 08:59:02 -0700808
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800809config HOTPLUG
810 bool "Support for hot-pluggable devices" if EMBEDDED
811 default y
812 help
813 This option is provided for the case where no hotplug or uevent
814 capabilities is wanted by the kernel. You should only consider
815 disabling this option for embedded systems that do not use modules, a
816 dynamic /dev tree, or dynamic device discovery. Just say Y.
817
Matt Mackalld59745c2005-05-01 08:59:02 -0700818config PRINTK
819 default y
820 bool "Enable support for printk" if EMBEDDED
821 help
822 This option enables normal printk support. Removing it
823 eliminates most of the message strings from the kernel image
824 and makes the kernel more or less silent. As this makes it
825 very difficult to diagnose system problems, saying N here is
826 strongly discouraged.
827
Matt Mackallc8538a72005-05-01 08:59:01 -0700828config BUG
829 bool "BUG() support" if EMBEDDED
830 default y
831 help
832 Disabling this option eliminates support for BUG and WARN, reducing
833 the size of your kernel image and potentially quietly ignoring
834 numerous fatal conditions. You should only consider disabling this
835 option for embedded systems with no facilities for reporting errors.
836 Just say Y.
837
Matt Mackall708e9a72006-01-08 01:05:25 -0800838config ELF_CORE
839 default y
840 bool "Enable ELF core dumps" if EMBEDDED
841 help
842 Enable support for generating core dumps. Disabling saves about 4k.
843
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200844config PCSPKR_PLATFORM
845 bool "Enable PC-Speaker support" if EMBEDDED
846 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
847 default y
848 help
849 This option allows to disable the internal PC-Speaker
850 support, saving some memory.
851
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852config BASE_FULL
853 default y
854 bool "Enable full-sized data structures for core" if EMBEDDED
855 help
856 Disabling this option reduces the size of miscellaneous core
857 kernel data structures. This saves memory on small machines,
858 but may reduce performance.
859
860config FUTEX
861 bool "Enable futex support" if EMBEDDED
862 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700863 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 help
865 Disabling this option will cause the kernel to be built without
866 support for "fast userspace mutexes". The resulting kernel may not
867 run glibc-based applications correctly.
868
869config EPOLL
870 bool "Enable eventpoll support" if EMBEDDED
871 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700872 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 help
874 Disabling this option will cause the kernel to be built without
875 support for epoll family of system calls.
876
Davide Libenzifba2afa2007-05-10 22:23:13 -0700877config SIGNALFD
878 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700879 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700880 default y
881 help
882 Enable the signalfd() system call that allows to receive signals
883 on a file descriptor.
884
885 If unsure, say Y.
886
Davide Libenzib215e282007-05-10 22:23:16 -0700887config TIMERFD
888 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700889 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700890 default y
891 help
892 Enable the timerfd() system call that allows to receive timer
893 events on a file descriptor.
894
895 If unsure, say Y.
896
Davide Libenzie1ad7462007-05-10 22:23:19 -0700897config EVENTFD
898 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700899 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700900 default y
901 help
902 Enable the eventfd() system call that allows to receive both
903 kernel notification (ie. KAIO) or userspace notifications.
904
905 If unsure, say Y.
906
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907config SHMEM
908 bool "Use full shmem filesystem" if EMBEDDED
909 default y
910 depends on MMU
911 help
912 The shmem is an internal filesystem used to manage shared memory.
913 It is backed by swap and manages resource limits. It is also exported
914 to userspace as tmpfs if TMPFS is enabled. Disabling this
915 option replaces shmem and tmpfs with the much simpler ramfs code,
916 which may be appropriate on small systems without swap.
917
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700918config AIO
919 bool "Enable AIO support" if EMBEDDED
920 default y
921 help
922 This option enables POSIX asynchronous I/O which may by used
923 by some high performance threaded applications. Disabling
924 this option saves about 7k.
925
Thomas Gleixner0793a612008-12-04 20:12:29 +0100926config HAVE_PERF_COUNTERS
927 bool
Mike Frysinger018df722009-06-12 13:17:43 -0400928 help
929 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100930
931menu "Performance Counters"
932
933config PERF_COUNTERS
934 bool "Kernel Performance Counters"
935 depends on HAVE_PERF_COUNTERS
Ingo Molnar4c59e462008-12-08 19:38:33 +0100936 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +0100937 help
938 Enable kernel support for performance counter hardware.
939
940 Performance counters are special hardware registers available
941 on most modern CPUs. These registers count the number of certain
942 types of hw events: such as instructions executed, cachemisses
943 suffered, or branches mis-predicted - without slowing down the
944 kernel or applications. These registers can also trigger interrupts
945 when a threshold number of events have passed - and can thus be
946 used to profile the code that runs on that CPU.
947
948 The Linux Performance Counter subsystem provides an abstraction of
949 these hardware capabilities, available via a system call. It
950 provides per task and per CPU counters, and it provides event
951 capabilities on top of those.
952
953 Say Y if unsure.
954
Peter Zijlstrae077df42009-03-19 20:26:17 +0100955config EVENT_PROFILE
956 bool "Tracepoint profile sources"
957 depends on PERF_COUNTERS && EVENT_TRACER
958 default y
959
Thomas Gleixner0793a612008-12-04 20:12:29 +0100960endmenu
961
Christoph Lameterf8891e52006-06-30 01:55:45 -0700962config VM_EVENT_COUNTERS
963 default y
964 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
965 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -0800966 VM event counters are needed for event counts to be shown.
967 This option allows the disabling of the VM event counters
968 on EMBEDDED systems. /proc/vmstat will only show page counts
969 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -0700970
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200971config PCI_QUIRKS
972 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +0200973 bool "Enable PCI quirk workarounds" if EMBEDDED
974 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200975 help
976 This enables workarounds for various PCI chipset
977 bugs/quirks. Disable this only if your target machine is
978 unaffected by PCI quirks.
979
Christoph Lameter41ecc552007-05-09 02:32:44 -0700980config SLUB_DEBUG
981 default y
982 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -0700983 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -0700984 help
985 SLUB has extensive debug support features. Disabling these can
986 result in significant savings in code size. This also disables
987 SLUB sysfs support. /sys/slab will not exist and there will be
988 no support for cache validation etc.
989
Randy Dunlapa9eb5222009-06-05 15:02:47 -0700990config STRIP_ASM_SYMS
991 bool "Strip assembler-generated symbols during link"
992 default n
993 help
994 Strip internal assembler-generated symbols during a link (symbols
995 that look like '.Lxxx') so they don't pollute the output of
996 get_wchan() and suchlike.
997
Randy Dunlapb943c462009-03-10 12:55:46 -0700998config COMPAT_BRK
999 bool "Disable heap randomization"
1000 default y
1001 help
1002 Randomizing heap placement makes heap exploits harder, but it
1003 also breaks ancient binaries (including anything libc5 based).
1004 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001005 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001006 /proc/sys/kernel/randomize_va_space to 2.
1007
1008 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1009
Christoph Lameter81819f02007-05-06 14:49:36 -07001010choice
1011 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001012 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001013 help
1014 This option allows to select a slab allocator.
1015
1016config SLAB
1017 bool "SLAB"
1018 help
1019 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001020 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001021 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001022
1023config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001024 bool "SLUB (Unqueued Allocator)"
1025 help
1026 SLUB is a slab allocator that minimizes cache line usage
1027 instead of managing queues of cached objects (SLAB approach).
1028 Per cpu caching is realized using slabs of objects instead
1029 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001030 and has enhanced diagnostics. SLUB is the default choice for
1031 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001032
1033config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001034 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001035 bool "SLOB (Simple Allocator)"
1036 help
Matt Mackall37291452008-02-04 22:29:38 -08001037 SLOB replaces the stock allocator with a drastically simpler
1038 allocator. SLOB is generally more space efficient but
1039 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001040
1041endchoice
1042
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001043config PROFILING
1044 bool "Profiling support (EXPERIMENTAL)"
1045 help
1046 Say Y here to enable the extended profiling support mechanisms used
1047 by profilers such as OProfile.
1048
Ingo Molnar5f87f112008-07-23 14:15:22 +02001049#
1050# Place an empty function call at each tracepoint site. Can be
1051# dynamically changed for a probe function.
1052#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001053config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001054 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001055
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001056config MARKERS
1057 bool "Activate markers"
Frederic Weisbecker91f73f92009-02-20 17:34:06 +01001058 select TRACEPOINTS
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001059 help
1060 Place an empty function call at each marker site. Can be
1061 dynamically changed for a probe function.
1062
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001063source "arch/Kconfig"
1064
David Howells07fe7cb2009-04-03 16:42:35 +01001065config SLOW_WORK
1066 default n
David Howells1c2d0082009-04-06 15:47:25 +01001067 bool
David Howells07fe7cb2009-04-03 16:42:35 +01001068 help
1069 The slow work thread pool provides a number of dynamically allocated
1070 threads that can be used by the kernel to perform operations that
1071 take a relatively long time.
1072
1073 An example of this would be CacheFiles doing a path lookup followed
1074 by a series of mkdirs and a create call, all of which have to touch
1075 disk.
1076
David Howells1c2d0082009-04-06 15:47:25 +01001077 See Documentation/slow-work.txt.
1078
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079endmenu # General setup
1080
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001081config HAVE_GENERIC_DMA_COHERENT
1082 bool
1083 default n
1084
Linus Torvalds158a9622008-01-02 13:04:48 -08001085config SLABINFO
1086 bool
1087 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001088 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001089 default y
1090
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001091config RT_MUTEXES
1092 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001093
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094config BASE_SMALL
1095 int
1096 default 0 if BASE_FULL
1097 default 1 if !BASE_FULL
1098
Jan Engelhardt66da5732007-07-15 23:39:29 -07001099menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001100 bool "Enable loadable module support"
1101 help
1102 Kernel modules are small pieces of compiled code which can
1103 be inserted in the running kernel, rather than being
1104 permanently built into the kernel. You use the "modprobe"
1105 tool to add (and sometimes remove) them. If you say Y here,
1106 many parts of the kernel can be built as modules (by
1107 answering M instead of Y where indicated): this is most
1108 useful for infrequently used options which are not required
1109 for booting. For more information, see the man pages for
1110 modprobe, lsmod, modinfo, insmod and rmmod.
1111
1112 If you say Y here, you will need to run "make
1113 modules_install" to put the modules under /lib/modules/
1114 where modprobe can find them (you may need to be root to do
1115 this).
1116
1117 If unsure, say Y.
1118
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001119if MODULES
1120
Linus Torvalds826e4502008-05-04 17:04:16 -07001121config MODULE_FORCE_LOAD
1122 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001123 default n
1124 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001125 Allow loading of modules without version information (ie. modprobe
1126 --force). Forced module loading sets the 'F' (forced) taint flag and
1127 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001128
Linus Torvalds1da177e2005-04-16 15:20:36 -07001129config MODULE_UNLOAD
1130 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131 help
1132 Without this option you will not be able to unload any
1133 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001134 anyway), which makes your kernel smaller, faster
1135 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136
1137config MODULE_FORCE_UNLOAD
1138 bool "Forced module unloading"
1139 depends on MODULE_UNLOAD && EXPERIMENTAL
1140 help
1141 This option allows you to force a module to unload, even if the
1142 kernel believes it is unsafe: the kernel will remove the module
1143 without waiting for anyone to stop using it (using the -f option to
1144 rmmod). This is mainly for kernel developers and desperate users.
1145 If unsure, say N.
1146
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001148 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 help
1150 Usually, you have to use modules compiled with your kernel.
1151 Saying Y here makes it sometimes possible to use modules
1152 compiled for different kernels, by adding enough information
1153 to the modules to (hopefully) spot any changes which would
1154 make them incompatible with the kernel you are running. If
1155 unsure, say N.
1156
1157config MODULE_SRCVERSION_ALL
1158 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159 help
1160 Modules which contain a MODULE_VERSION get an extra "srcversion"
1161 field inserted into their modinfo section, which contains a
1162 sum of the source files which made it. This helps maintainers
1163 see exactly which source was used to build a module (since
1164 others sometimes change the module source without updating
1165 the version). With this option, such a "srcversion" field
1166 will be created for all modules. If unsure, say N.
1167
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001168endif # MODULES
1169
Rusty Russell98a79d62008-12-13 21:19:41 +10301170config INIT_ALL_POSSIBLE
1171 bool
1172 help
1173 Back when each arch used to define their own cpu_online_map and
1174 cpu_possible_map, some of them chose to initialize cpu_possible_map
1175 with all 1s, and others with all 0s. When they were centralised,
1176 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001177 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301178
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179config STOP_MACHINE
1180 bool
1181 default y
1182 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1183 help
1184 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001185
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001186source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001187
1188config PREEMPT_NOTIFIERS
1189 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001190