blob: 706728be312f5506a8d3fd20b51d33bf9186144e [file] [log] [blame]
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47 drivers that have been replaced by something else, and/or are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
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700327config TREE_PREEMPT_RCU
328 bool "Preemptable tree-based hierarchical RCU"
329 depends on PREEMPT
330 help
331 This option selects the RCU implementation that is
332 designed for very large SMP systems with hundreds or
333 thousands of CPUs, but for which real-time response
334 is also required.
335
Mike Travisc903ff82009-01-15 12:28:29 -0800336endchoice
337
338config RCU_TRACE
339 bool "Enable tracing for RCU"
Paul E. McKenney6b3ef482009-08-22 13:56:53 -0700340 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800341 help
342 This option provides tracing in RCU which presents stats
343 in debugfs for debugging RCU implementation.
344
345 Say Y here if you want to enable RCU tracing
346 Say N if you are unsure.
347
348config RCU_FANOUT
349 int "Tree-based hierarchical RCU fanout value"
350 range 2 64 if 64BIT
351 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700352 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800353 default 64 if 64BIT
354 default 32 if !64BIT
355 help
356 This option controls the fanout of hierarchical implementations
357 of RCU, allowing RCU to work efficiently on machines with
358 large numbers of CPUs. This value must be at least the cube
359 root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
360 systems and up to 262,144 for 64-bit systems.
361
362 Select a specific number if testing RCU itself.
363 Take the default if unsure.
364
365config RCU_FANOUT_EXACT
366 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700367 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800368 default n
369 help
370 This option forces use of the exact RCU_FANOUT value specified,
371 regardless of imbalances in the hierarchy. This is useful for
372 testing RCU itself, and might one day be useful on systems with
373 strong NUMA behavior.
374
375 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
376
377 Say N if unsure.
378
379config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700380 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800381 select DEBUG_FS
382 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700383 This option provides tracing for the TREE_RCU and
384 TREE_PREEMPT_RCU implementations, permitting Makefile to
385 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800386
Mike Travisc903ff82009-01-15 12:28:29 -0800387endmenu # "RCU Subsystem"
388
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700390 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 ---help---
392 This option enables the complete Linux kernel ".config" file
393 contents to be saved in the kernel. It provides documentation
394 of which kernel options are used in a running kernel or in an
395 on-disk kernel. This information can be extracted from the kernel
396 image file with the script scripts/extract-ikconfig and used as
397 input to rebuild the current kernel or to build another kernel.
398 It can also be extracted from a running kernel by reading
399 /proc/config.gz if enabled (below).
400
401config IKCONFIG_PROC
402 bool "Enable access to .config through /proc/config.gz"
403 depends on IKCONFIG && PROC_FS
404 ---help---
405 This option enables access to the kernel configuration file
406 through /proc/config.gz.
407
Alistair John Strachan794543a2007-05-08 00:31:15 -0700408config LOG_BUF_SHIFT
409 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
410 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700411 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700412 help
413 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700414 Examples:
415 17 => 128 KB
416 16 => 64 KB
417 15 => 32 KB
418 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700419 13 => 8 KB
420 12 => 4 KB
421
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800422#
423# Architectures with an unreliable sched_clock() should select this:
424#
425config HAVE_UNSTABLE_SCHED_CLOCK
426 bool
427
428config GROUP_SCHED
429 bool "Group CPU scheduler"
430 depends on EXPERIMENTAL
431 default n
432 help
433 This feature lets CPU scheduler recognize task groups and control CPU
434 bandwidth allocation to such task groups.
435 In order to create a group from arbitrary set of processes, use
436 CONFIG_CGROUPS. (See Control Group support.)
437
438config FAIR_GROUP_SCHED
439 bool "Group scheduling for SCHED_OTHER"
440 depends on GROUP_SCHED
441 default GROUP_SCHED
442
443config RT_GROUP_SCHED
444 bool "Group scheduling for SCHED_RR/FIFO"
445 depends on EXPERIMENTAL
446 depends on GROUP_SCHED
447 default n
448 help
449 This feature lets you explicitly allocate real CPU bandwidth
450 to users or control groups (depending on the "Basis for grouping tasks"
451 setting below. If enabled, it will also make it impossible to
452 schedule realtime tasks for non-root users until you allocate
453 realtime bandwidth for them.
454 See Documentation/scheduler/sched-rt-group.txt for more information.
455
456choice
457 depends on GROUP_SCHED
458 prompt "Basis for grouping tasks"
459 default USER_SCHED
460
461config USER_SCHED
462 bool "user id"
463 help
464 This option will choose userid as the basis for grouping
465 tasks, thus providing equal CPU bandwidth to each user.
466
467config CGROUP_SCHED
468 bool "Control groups"
469 depends on CGROUPS
470 help
471 This option allows you to create arbitrary task groups
472 using the "cgroup" pseudo filesystem and control
473 the cpu bandwidth allocated to each such task group.
Li Zefan45ce80f2009-01-15 13:50:59 -0800474 Refer to Documentation/cgroups/cgroups.txt for more
475 information on "cgroup" pseudo filesystem.
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800476
477endchoice
478
Li Zefan23964d22009-01-15 13:50:58 -0800479menuconfig CGROUPS
480 boolean "Control Group support"
Paul Menageddbcc7e2007-10-18 23:39:30 -0700481 help
Li Zefan23964d22009-01-15 13:50:58 -0800482 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800483 use with process control subsystems such as Cpusets, CFS, memory
484 controls or device isolation.
485 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800486 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800487 - Documentation/cgroups/ (features for grouping, isolation
488 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700489
490 Say N if unsure.
491
Li Zefan23964d22009-01-15 13:50:58 -0800492if CGROUPS
493
Paul Menage006cb992007-10-18 23:39:43 -0700494config CGROUP_DEBUG
495 bool "Example debug cgroup subsystem"
496 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700497 default n
Paul Menage006cb992007-10-18 23:39:43 -0700498 help
499 This option enables a simple cgroup subsystem that
500 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800501 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700502
Li Zefan23964d22009-01-15 13:50:58 -0800503 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700504
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700505config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800506 bool "Namespace cgroup subsystem"
507 depends on CGROUPS
508 help
509 Provides a simple namespace cgroup subsystem to
510 provide hierarchical naming of sets of namespaces,
511 for instance virtual servers and checkpoint/restart
512 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700513
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700514config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800515 bool "Freezer cgroup subsystem"
516 depends on CGROUPS
517 help
518 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700519 cgroup.
520
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700521config CGROUP_DEVICE
522 bool "Device controller for cgroups"
523 depends on CGROUPS && EXPERIMENTAL
524 help
525 Provides a cgroup implementing whitelists for devices which
526 a process in the cgroup can mknod or open.
527
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528config CPUSETS
529 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700530 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700532 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 allow dynamically partitioning a system into sets of CPUs and
534 Memory Nodes and assigning tasks to run only within those sets.
535 This is primarily useful on large SMP or NUMA systems.
536
537 Say N if unsure.
538
Li Zefan23964d22009-01-15 13:50:58 -0800539config PROC_PID_CPUSET
540 bool "Include legacy /proc/<pid>/cpuset file"
541 depends on CPUSETS
542 default y
543
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100544config CGROUP_CPUACCT
545 bool "Simple CPU accounting cgroup subsystem"
546 depends on CGROUPS
547 help
548 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800549 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100550
Pavel Emelianove552b662008-02-07 00:13:49 -0800551config RESOURCE_COUNTERS
552 bool "Resource counters"
553 help
554 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800555 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800556 depends on CGROUPS
557
Balbir Singh00f0b822008-03-04 14:28:39 -0800558config CGROUP_MEM_RES_CTLR
559 bool "Memory Resource Controller for Control Groups"
560 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700561 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800562 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700563 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100564 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800565
566 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700567 associated with each page of memory in the system. By this,
568 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
569 usage tracking struct at boot. Total amount of this is printed out
570 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800571
572 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700573 sure you need the memory resource controller. Even when you enable
574 this, you can set "cgroup_disable=memory" at your boot option to
575 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800576 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800577
Balbir Singhcf475ad2008-04-29 01:00:16 -0700578 This config option also selects MM_OWNER config option, which
579 could in turn add some fork/exit overhead.
580
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800581config CGROUP_MEM_RES_CTLR_SWAP
582 bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
583 depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
584 help
585 Add swap management feature to memory resource controller. When you
586 enable this, you can limit mem+swap usage per cgroup. In other words,
587 when you disable this, memory resource controller has no cares to
588 usage of swap...a process can exhaust all of the swap. This extension
589 is useful when you want to avoid exhaustion swap but this itself
590 adds more overheads and consumes memory for remembering information.
591 Especially if you use 32bit system or small memory system, please
592 be careful about enabling this. When memory resource controller
593 is disabled by boot option, this will be automatically disabled and
594 there will be no overhead from this. Even when you set this config=y,
595 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700596 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
597 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800598
Li Zefan23964d22009-01-15 13:50:58 -0800599endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800600
Li Zefan23964d22009-01-15 13:50:58 -0800601config MM_OWNER
602 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800603
Kay Sievers88a22c92006-09-14 11:23:28 +0200604config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100605 bool
606
607config SYSFS_DEPRECATED_V2
Kay Sieversf6ee6492009-04-16 19:56:37 +0200608 bool "remove sysfs features which may confuse old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800609 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200610 default n
Ingo Molnard47846c2008-03-04 14:54:47 +0100611 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200612 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100613 This option switches the layout of sysfs to the deprecated
Kay Sieversf6ee6492009-04-16 19:56:37 +0200614 version. Do not use it on recent distributions.
Kay Sievers88a22c92006-09-14 11:23:28 +0200615
Kay Sieversfce3e802008-11-01 14:03:00 +0100616 The current sysfs layout features a unified device tree at
617 /sys/devices/, which is able to express a hierarchy between
618 class devices. If the deprecated option is set to Y, the
619 unified device tree is split into a bus device tree at
620 /sys/devices/ and several individual class device trees at
621 /sys/class/. The class and bus devices will be connected by
622 "<subsystem>:<name>" and the "device" links. The "block"
623 class devices, will not show up in /sys/class/block/. Some
624 subsystems will suppress the creation of some devices which
625 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200626
Kay Sieversfce3e802008-11-01 14:03:00 +0100627 This option is not a pure compatibility option that can
628 be safely enabled on newer distributions. It will change the
629 layout of sysfs to the non-extensible deprecated version,
630 and disable some features, which can not be exported without
631 confusing older userspace tools. Since 2007/2008 all major
632 distributions do not enable this option, and ship no tools which
633 depend on the deprecated layout or this option.
634
635 If you are using a new kernel on an older distribution, or use
636 older userspace tools, you might need to say Y here. Do not say Y,
637 if the original kernel, that came with your distribution, has
638 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200639
Jens Axboeb86ff9812006-03-23 19:56:55 +0100640config RELAY
641 bool "Kernel->user space relay support (formerly relayfs)"
642 help
643 This option enables support for relay interface support in
644 certain file systems (such as debugfs).
645 It is designed to provide an efficient mechanism for tools and
646 facilities to relay large amounts of data from kernel space to
647 user space.
648
649 If unsure, say N.
650
Pavel Emelyanovc5289a692008-02-08 04:18:19 -0800651config NAMESPACES
652 bool "Namespaces support" if EMBEDDED
653 default !EMBEDDED
654 help
655 Provides the way to make tasks work with different objects using
656 the same id. For example same IPC id may refer to different objects
657 or same user id or pid may refer to different tasks when used in
658 different namespaces.
659
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800660config UTS_NS
661 bool "UTS namespace"
662 depends on NAMESPACES
663 help
664 In this namespace tasks see different info provided with the
665 uname() system call
666
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800667config IPC_NS
668 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700669 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800670 help
671 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700672 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800673
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800674config USER_NS
675 bool "User namespace (EXPERIMENTAL)"
676 depends on NAMESPACES && EXPERIMENTAL
677 help
678 This allows containers, i.e. vservers, to use user namespaces
679 to provide different user info for different servers.
680 If unsure, say N.
681
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800682config PID_NS
683 bool "PID Namespaces (EXPERIMENTAL)"
684 default n
685 depends on NAMESPACES && EXPERIMENTAL
686 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300687 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100688 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800689 pid namespaces. This is a building block of containers.
690
691 Unless you want to work with an experimental feature
692 say N here.
693
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800694config NET_NS
695 bool "Network namespace"
696 default n
697 depends on NAMESPACES && EXPERIMENTAL && NET
698 help
699 Allow user space to create what appear to be multiple instances
700 of the network stack.
701
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800702config BLK_DEV_INITRD
703 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
704 depends on BROKEN || !FRV
705 help
706 The initial RAM filesystem is a ramfs which is loaded by the
707 boot loader (loadlin or lilo) and that is mounted as root
708 before the normal boot procedure. It is typically used to
709 load modules needed to mount the "real" root file system,
710 etc. See <file:Documentation/initrd.txt> for details.
711
712 If RAM disk support (BLK_DEV_RAM) is also included, this
713 also enables initial RAM disk (initrd) support and adds
714 15 Kbytes (more on some other architectures) to the kernel size.
715
716 If unsure say Y.
717
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800718if BLK_DEV_INITRD
719
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200720source "usr/Kconfig"
721
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800722endif
723
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800724config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200725 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800726 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800727 help
728 Enabling this option will pass "-Os" instead of "-O2" to gcc
729 resulting in a smaller kernel.
730
jkacur775a7222008-07-16 00:31:16 +0200731 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800732
Randy Dunlap08470622006-09-30 23:28:13 -0700733config SYSCTL
734 bool
735
Randy Dunlapb943c462009-03-10 12:55:46 -0700736config ANON_INODES
737 bool
738
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739menuconfig EMBEDDED
740 bool "Configure standard kernel features (for small systems)"
741 help
742 This option allows certain base kernel options and settings
743 to be disabled or tweaked. This is for specialized
744 environments which can tolerate a "non-standard" kernel.
745 Only use this if you really know what you are doing.
746
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700747config UID16
748 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700749 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 -0700750 default y
751 help
752 This enables the legacy 16-bit UID syscall wrappers.
753
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700754config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700755 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800756 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700757 select SYSCTL
758 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800759 sys_sysctl uses binary paths that have been found challenging
760 to properly maintain and use. The interface in /proc/sys
761 using paths with ascii names is now the primary path to this
762 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700763
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800764 Almost nothing using the binary sysctl interface so if you are
765 trying to save some space it is probably safe to disable this,
766 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700767
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800768 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700769
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100771 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 default y
773 help
774 Say Y here to let the kernel print out symbolic crash information and
775 symbolic stack backtraces. This increases the size of the kernel
776 somewhat, as all symbols have to be loaded into the kernel image.
777
778config KALLSYMS_ALL
779 bool "Include all symbols in kallsyms"
780 depends on DEBUG_KERNEL && KALLSYMS
781 help
782 Normally kallsyms only contains the symbols of functions, for nicer
783 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200784 symbols too: say Y here to include all symbols, if you need them
785 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
787 Say N.
788
789config KALLSYMS_EXTRA_PASS
790 bool "Do an extra kallsyms pass"
791 depends on KALLSYMS
792 help
793 If kallsyms is not working correctly, the build will fail with
794 inconsistent kallsyms data. If that occurs, log a bug report and
795 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
796 Always say N here unless you find a bug in kallsyms, which must be
797 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
798 you wait for kallsyms to be fixed.
799
Matt Mackalld59745c2005-05-01 08:59:02 -0700800
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800801config HOTPLUG
802 bool "Support for hot-pluggable devices" if EMBEDDED
803 default y
804 help
805 This option is provided for the case where no hotplug or uevent
806 capabilities is wanted by the kernel. You should only consider
807 disabling this option for embedded systems that do not use modules, a
808 dynamic /dev tree, or dynamic device discovery. Just say Y.
809
Matt Mackalld59745c2005-05-01 08:59:02 -0700810config PRINTK
811 default y
812 bool "Enable support for printk" if EMBEDDED
813 help
814 This option enables normal printk support. Removing it
815 eliminates most of the message strings from the kernel image
816 and makes the kernel more or less silent. As this makes it
817 very difficult to diagnose system problems, saying N here is
818 strongly discouraged.
819
Matt Mackallc8538a72005-05-01 08:59:01 -0700820config BUG
821 bool "BUG() support" if EMBEDDED
822 default y
823 help
824 Disabling this option eliminates support for BUG and WARN, reducing
825 the size of your kernel image and potentially quietly ignoring
826 numerous fatal conditions. You should only consider disabling this
827 option for embedded systems with no facilities for reporting errors.
828 Just say Y.
829
Matt Mackall708e9a72006-01-08 01:05:25 -0800830config ELF_CORE
831 default y
832 bool "Enable ELF core dumps" if EMBEDDED
833 help
834 Enable support for generating core dumps. Disabling saves about 4k.
835
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200836config PCSPKR_PLATFORM
837 bool "Enable PC-Speaker support" if EMBEDDED
838 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
839 default y
840 help
841 This option allows to disable the internal PC-Speaker
842 support, saving some memory.
843
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844config BASE_FULL
845 default y
846 bool "Enable full-sized data structures for core" if EMBEDDED
847 help
848 Disabling this option reduces the size of miscellaneous core
849 kernel data structures. This saves memory on small machines,
850 but may reduce performance.
851
852config FUTEX
853 bool "Enable futex support" if EMBEDDED
854 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700855 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 help
857 Disabling this option will cause the kernel to be built without
858 support for "fast userspace mutexes". The resulting kernel may not
859 run glibc-based applications correctly.
860
861config EPOLL
862 bool "Enable eventpoll support" if EMBEDDED
863 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700864 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 help
866 Disabling this option will cause the kernel to be built without
867 support for epoll family of system calls.
868
Davide Libenzifba2afa2007-05-10 22:23:13 -0700869config SIGNALFD
870 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700871 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700872 default y
873 help
874 Enable the signalfd() system call that allows to receive signals
875 on a file descriptor.
876
877 If unsure, say Y.
878
Davide Libenzib215e282007-05-10 22:23:16 -0700879config TIMERFD
880 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700881 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700882 default y
883 help
884 Enable the timerfd() system call that allows to receive timer
885 events on a file descriptor.
886
887 If unsure, say Y.
888
Davide Libenzie1ad7462007-05-10 22:23:19 -0700889config EVENTFD
890 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700891 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700892 default y
893 help
894 Enable the eventfd() system call that allows to receive both
895 kernel notification (ie. KAIO) or userspace notifications.
896
897 If unsure, say Y.
898
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899config SHMEM
900 bool "Use full shmem filesystem" if EMBEDDED
901 default y
902 depends on MMU
903 help
904 The shmem is an internal filesystem used to manage shared memory.
905 It is backed by swap and manages resource limits. It is also exported
906 to userspace as tmpfs if TMPFS is enabled. Disabling this
907 option replaces shmem and tmpfs with the much simpler ramfs code,
908 which may be appropriate on small systems without swap.
909
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700910config AIO
911 bool "Enable AIO support" if EMBEDDED
912 default y
913 help
914 This option enables POSIX asynchronous I/O which may by used
915 by some high performance threaded applications. Disabling
916 this option saves about 7k.
917
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200918config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +0100919 bool
Mike Frysinger018df722009-06-12 13:17:43 -0400920 help
921 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100922
Ingo Molnar57c0c152009-09-21 12:20:38 +0200923menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +0100924
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200925config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +0200926 bool "Kernel performance events and counters"
927 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200928 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +0100929 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +0100930 help
Ingo Molnar57c0c152009-09-21 12:20:38 +0200931 Enable kernel support for various performance events provided
932 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100933
Ingo Molnar57c0c152009-09-21 12:20:38 +0200934 Software events are supported either build-in or via the
935 use of generic tracepoints.
936
937 Most modern CPUs support performance events via performance
938 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +0100939 types of hw events: such as instructions executed, cachemisses
940 suffered, or branches mis-predicted - without slowing down the
941 kernel or applications. These registers can also trigger interrupts
942 when a threshold number of events have passed - and can thus be
943 used to profile the code that runs on that CPU.
944
Ingo Molnar57c0c152009-09-21 12:20:38 +0200945 The Linux Performance Event subsystem provides an abstraction of
946 these software and hardware cevent apabilities, available via a
947 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +0100948 provides per task and per CPU counters, and it provides event
949 capabilities on top of those.
950
951 Say Y if unsure.
952
Peter Zijlstrae077df42009-03-19 20:26:17 +0100953config EVENT_PROFILE
Peter Zijlstra470a1392009-07-29 10:50:09 +0200954 bool "Tracepoint profiling sources"
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200955 depends on PERF_EVENTS && EVENT_TRACING
Peter Zijlstrae077df42009-03-19 20:26:17 +0100956 default y
Peter Zijlstra470a1392009-07-29 10:50:09 +0200957 help
Ingo Molnar57c0c152009-09-21 12:20:38 +0200958 Allow the use of tracepoints as software performance events.
Peter Zijlstra470a1392009-07-29 10:50:09 +0200959
Ingo Molnar57c0c152009-09-21 12:20:38 +0200960 When this is enabled, you can create perf events based on
Peter Zijlstra470a1392009-07-29 10:50:09 +0200961 tracepoints using PERF_TYPE_TRACEPOINT and the tracepoint ID
962 found in debugfs://tracing/events/*/*/id. (The -e/--events
963 option to the perf tool can parse and interpret symbolic
964 tracepoints, in the subsystem:tracepoint_name format.)
Peter Zijlstrae077df42009-03-19 20:26:17 +0100965
Ingo Molnar57c0c152009-09-21 12:20:38 +0200966config PERF_COUNTERS
967 bool "Kernel performance counters (old config option)"
968 depends on HAVE_PERF_EVENTS
969 help
970 This config has been obsoleted by the PERF_EVENTS
971 config option - please see that one for details.
972
973 It has no effect on the kernel whether you enable
974 it or not, it is a compatibility placeholder.
975
976 Say N if unsure.
977
Thomas Gleixner0793a612008-12-04 20:12:29 +0100978endmenu
979
Christoph Lameterf8891e52006-06-30 01:55:45 -0700980config VM_EVENT_COUNTERS
981 default y
982 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
983 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -0800984 VM event counters are needed for event counts to be shown.
985 This option allows the disabling of the VM event counters
986 on EMBEDDED systems. /proc/vmstat will only show page counts
987 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -0700988
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200989config PCI_QUIRKS
990 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +0200991 bool "Enable PCI quirk workarounds" if EMBEDDED
992 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200993 help
994 This enables workarounds for various PCI chipset
995 bugs/quirks. Disable this only if your target machine is
996 unaffected by PCI quirks.
997
Christoph Lameter41ecc552007-05-09 02:32:44 -0700998config SLUB_DEBUG
999 default y
1000 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -07001001 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001002 help
1003 SLUB has extensive debug support features. Disabling these can
1004 result in significant savings in code size. This also disables
1005 SLUB sysfs support. /sys/slab will not exist and there will be
1006 no support for cache validation etc.
1007
Randy Dunlapa9eb5222009-06-05 15:02:47 -07001008config STRIP_ASM_SYMS
1009 bool "Strip assembler-generated symbols during link"
1010 default n
1011 help
1012 Strip internal assembler-generated symbols during a link (symbols
1013 that look like '.Lxxx') so they don't pollute the output of
1014 get_wchan() and suchlike.
1015
Randy Dunlapb943c462009-03-10 12:55:46 -07001016config COMPAT_BRK
1017 bool "Disable heap randomization"
1018 default y
1019 help
1020 Randomizing heap placement makes heap exploits harder, but it
1021 also breaks ancient binaries (including anything libc5 based).
1022 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001023 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001024 /proc/sys/kernel/randomize_va_space to 2.
1025
1026 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1027
Christoph Lameter81819f02007-05-06 14:49:36 -07001028choice
1029 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001030 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001031 help
1032 This option allows to select a slab allocator.
1033
1034config SLAB
1035 bool "SLAB"
1036 help
1037 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001038 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001039 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001040
1041config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001042 bool "SLUB (Unqueued Allocator)"
1043 help
1044 SLUB is a slab allocator that minimizes cache line usage
1045 instead of managing queues of cached objects (SLAB approach).
1046 Per cpu caching is realized using slabs of objects instead
1047 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001048 and has enhanced diagnostics. SLUB is the default choice for
1049 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001050
1051config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001052 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001053 bool "SLOB (Simple Allocator)"
1054 help
Matt Mackall37291452008-02-04 22:29:38 -08001055 SLOB replaces the stock allocator with a drastically simpler
1056 allocator. SLOB is generally more space efficient but
1057 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001058
1059endchoice
1060
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001061config PROFILING
1062 bool "Profiling support (EXPERIMENTAL)"
1063 help
1064 Say Y here to enable the extended profiling support mechanisms used
1065 by profilers such as OProfile.
1066
Ingo Molnar5f87f112008-07-23 14:15:22 +02001067#
1068# Place an empty function call at each tracepoint site. Can be
1069# dynamically changed for a probe function.
1070#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001071config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001072 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001073
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001074config MARKERS
1075 bool "Activate markers"
Frederic Weisbecker91f73f92009-02-20 17:34:06 +01001076 select TRACEPOINTS
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001077 help
1078 Place an empty function call at each marker site. Can be
1079 dynamically changed for a probe function.
1080
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001081source "arch/Kconfig"
1082
David Howells07fe7cb2009-04-03 16:42:35 +01001083config SLOW_WORK
1084 default n
David Howells1c2d0082009-04-06 15:47:25 +01001085 bool
David Howells07fe7cb2009-04-03 16:42:35 +01001086 help
1087 The slow work thread pool provides a number of dynamically allocated
1088 threads that can be used by the kernel to perform operations that
1089 take a relatively long time.
1090
1091 An example of this would be CacheFiles doing a path lookup followed
1092 by a series of mkdirs and a create call, all of which have to touch
1093 disk.
1094
David Howells1c2d0082009-04-06 15:47:25 +01001095 See Documentation/slow-work.txt.
1096
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097endmenu # General setup
1098
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001099config HAVE_GENERIC_DMA_COHERENT
1100 bool
1101 default n
1102
Linus Torvalds158a9622008-01-02 13:04:48 -08001103config SLABINFO
1104 bool
1105 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001106 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001107 default y
1108
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001109config RT_MUTEXES
1110 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001111
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112config BASE_SMALL
1113 int
1114 default 0 if BASE_FULL
1115 default 1 if !BASE_FULL
1116
Jan Engelhardt66da5732007-07-15 23:39:29 -07001117menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118 bool "Enable loadable module support"
1119 help
1120 Kernel modules are small pieces of compiled code which can
1121 be inserted in the running kernel, rather than being
1122 permanently built into the kernel. You use the "modprobe"
1123 tool to add (and sometimes remove) them. If you say Y here,
1124 many parts of the kernel can be built as modules (by
1125 answering M instead of Y where indicated): this is most
1126 useful for infrequently used options which are not required
1127 for booting. For more information, see the man pages for
1128 modprobe, lsmod, modinfo, insmod and rmmod.
1129
1130 If you say Y here, you will need to run "make
1131 modules_install" to put the modules under /lib/modules/
1132 where modprobe can find them (you may need to be root to do
1133 this).
1134
1135 If unsure, say Y.
1136
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001137if MODULES
1138
Linus Torvalds826e4502008-05-04 17:04:16 -07001139config MODULE_FORCE_LOAD
1140 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001141 default n
1142 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001143 Allow loading of modules without version information (ie. modprobe
1144 --force). Forced module loading sets the 'F' (forced) taint flag and
1145 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001146
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147config MODULE_UNLOAD
1148 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 help
1150 Without this option you will not be able to unload any
1151 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001152 anyway), which makes your kernel smaller, faster
1153 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154
1155config MODULE_FORCE_UNLOAD
1156 bool "Forced module unloading"
1157 depends on MODULE_UNLOAD && EXPERIMENTAL
1158 help
1159 This option allows you to force a module to unload, even if the
1160 kernel believes it is unsafe: the kernel will remove the module
1161 without waiting for anyone to stop using it (using the -f option to
1162 rmmod). This is mainly for kernel developers and desperate users.
1163 If unsure, say N.
1164
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001166 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 help
1168 Usually, you have to use modules compiled with your kernel.
1169 Saying Y here makes it sometimes possible to use modules
1170 compiled for different kernels, by adding enough information
1171 to the modules to (hopefully) spot any changes which would
1172 make them incompatible with the kernel you are running. If
1173 unsure, say N.
1174
1175config MODULE_SRCVERSION_ALL
1176 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 help
1178 Modules which contain a MODULE_VERSION get an extra "srcversion"
1179 field inserted into their modinfo section, which contains a
1180 sum of the source files which made it. This helps maintainers
1181 see exactly which source was used to build a module (since
1182 others sometimes change the module source without updating
1183 the version). With this option, such a "srcversion" field
1184 will be created for all modules. If unsure, say N.
1185
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001186endif # MODULES
1187
Rusty Russell98a79d62008-12-13 21:19:41 +10301188config INIT_ALL_POSSIBLE
1189 bool
1190 help
1191 Back when each arch used to define their own cpu_online_map and
1192 cpu_possible_map, some of them chose to initialize cpu_possible_map
1193 with all 1s, and others with all 0s. When they were centralised,
1194 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001195 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301196
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197config STOP_MACHINE
1198 bool
1199 default y
1200 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1201 help
1202 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001203
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001204source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001205
1206config PREEMPT_NOTIFIERS
1207 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001208