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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 Oberparleiterb99b87f2009-06-17 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47 drivers that have been replaced by something else, and/or are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 Dunlap34ad92c2005-10-30 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"
Kumar Gala022382a2009-10-16 07:21:37 +0000300 depends on AUDIT && (X86 || PPC || 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
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700334 is also required. It also scales down nicely to
335 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700336
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700337config TINY_RCU
338 bool "UP-only small-memory-footprint RCU"
339 depends on !SMP
340 help
341 This option selects the RCU implementation that is
342 designed for UP systems from which real-time response
343 is not required. This option greatly reduces the
344 memory footprint of RCU.
345
Mike Travisc903ff82009-01-15 12:28:29 -0800346endchoice
347
348config RCU_TRACE
349 bool "Enable tracing for RCU"
Paul E. McKenney6b3ef482009-08-22 13:56:53 -0700350 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800351 help
352 This option provides tracing in RCU which presents stats
353 in debugfs for debugging RCU implementation.
354
355 Say Y here if you want to enable RCU tracing
356 Say N if you are unsure.
357
358config RCU_FANOUT
359 int "Tree-based hierarchical RCU fanout value"
360 range 2 64 if 64BIT
361 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700362 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800363 default 64 if 64BIT
364 default 32 if !64BIT
365 help
366 This option controls the fanout of hierarchical implementations
367 of RCU, allowing RCU to work efficiently on machines with
368 large numbers of CPUs. This value must be at least the cube
369 root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
370 systems and up to 262,144 for 64-bit systems.
371
372 Select a specific number if testing RCU itself.
373 Take the default if unsure.
374
375config RCU_FANOUT_EXACT
376 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700377 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800378 default n
379 help
380 This option forces use of the exact RCU_FANOUT value specified,
381 regardless of imbalances in the hierarchy. This is useful for
382 testing RCU itself, and might one day be useful on systems with
383 strong NUMA behavior.
384
385 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
386
387 Say N if unsure.
388
389config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700390 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800391 select DEBUG_FS
392 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700393 This option provides tracing for the TREE_RCU and
394 TREE_PREEMPT_RCU implementations, permitting Makefile to
395 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800396
Mike Travisc903ff82009-01-15 12:28:29 -0800397endmenu # "RCU Subsystem"
398
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700400 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 ---help---
402 This option enables the complete Linux kernel ".config" file
403 contents to be saved in the kernel. It provides documentation
404 of which kernel options are used in a running kernel or in an
405 on-disk kernel. This information can be extracted from the kernel
406 image file with the script scripts/extract-ikconfig and used as
407 input to rebuild the current kernel or to build another kernel.
408 It can also be extracted from a running kernel by reading
409 /proc/config.gz if enabled (below).
410
411config IKCONFIG_PROC
412 bool "Enable access to .config through /proc/config.gz"
413 depends on IKCONFIG && PROC_FS
414 ---help---
415 This option enables access to the kernel configuration file
416 through /proc/config.gz.
417
Alistair John Strachan794543a2007-05-08 00:31:15 -0700418config LOG_BUF_SHIFT
419 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
420 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700421 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700422 help
423 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700424 Examples:
425 17 => 128 KB
426 16 => 64 KB
427 15 => 32 KB
428 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700429 13 => 8 KB
430 12 => 4 KB
431
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800432#
433# Architectures with an unreliable sched_clock() should select this:
434#
435config HAVE_UNSTABLE_SCHED_CLOCK
436 bool
437
438config GROUP_SCHED
439 bool "Group CPU scheduler"
440 depends on EXPERIMENTAL
441 default n
442 help
443 This feature lets CPU scheduler recognize task groups and control CPU
444 bandwidth allocation to such task groups.
445 In order to create a group from arbitrary set of processes, use
446 CONFIG_CGROUPS. (See Control Group support.)
447
448config FAIR_GROUP_SCHED
449 bool "Group scheduling for SCHED_OTHER"
450 depends on GROUP_SCHED
451 default GROUP_SCHED
452
453config RT_GROUP_SCHED
454 bool "Group scheduling for SCHED_RR/FIFO"
455 depends on EXPERIMENTAL
456 depends on GROUP_SCHED
457 default n
458 help
459 This feature lets you explicitly allocate real CPU bandwidth
460 to users or control groups (depending on the "Basis for grouping tasks"
461 setting below. If enabled, it will also make it impossible to
462 schedule realtime tasks for non-root users until you allocate
463 realtime bandwidth for them.
464 See Documentation/scheduler/sched-rt-group.txt for more information.
465
466choice
467 depends on GROUP_SCHED
468 prompt "Basis for grouping tasks"
469 default USER_SCHED
470
471config USER_SCHED
472 bool "user id"
473 help
474 This option will choose userid as the basis for grouping
475 tasks, thus providing equal CPU bandwidth to each user.
476
477config CGROUP_SCHED
478 bool "Control groups"
479 depends on CGROUPS
480 help
481 This option allows you to create arbitrary task groups
482 using the "cgroup" pseudo filesystem and control
483 the cpu bandwidth allocated to each such task group.
Li Zefan45ce80f2009-01-15 13:50:59 -0800484 Refer to Documentation/cgroups/cgroups.txt for more
485 information on "cgroup" pseudo filesystem.
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800486
487endchoice
488
Li Zefan23964d22009-01-15 13:50:58 -0800489menuconfig CGROUPS
490 boolean "Control Group support"
Paul Menageddbcc7e2007-10-18 23:39:30 -0700491 help
Li Zefan23964d22009-01-15 13:50:58 -0800492 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800493 use with process control subsystems such as Cpusets, CFS, memory
494 controls or device isolation.
495 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800496 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800497 - Documentation/cgroups/ (features for grouping, isolation
498 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700499
500 Say N if unsure.
501
Li Zefan23964d22009-01-15 13:50:58 -0800502if CGROUPS
503
Paul Menage006cb992007-10-18 23:39:43 -0700504config CGROUP_DEBUG
505 bool "Example debug cgroup subsystem"
506 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700507 default n
Paul Menage006cb992007-10-18 23:39:43 -0700508 help
509 This option enables a simple cgroup subsystem that
510 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800511 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700512
Li Zefan23964d22009-01-15 13:50:58 -0800513 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700514
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700515config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800516 bool "Namespace cgroup subsystem"
517 depends on CGROUPS
518 help
519 Provides a simple namespace cgroup subsystem to
520 provide hierarchical naming of sets of namespaces,
521 for instance virtual servers and checkpoint/restart
522 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700523
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700524config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800525 bool "Freezer cgroup subsystem"
526 depends on CGROUPS
527 help
528 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700529 cgroup.
530
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700531config CGROUP_DEVICE
532 bool "Device controller for cgroups"
533 depends on CGROUPS && EXPERIMENTAL
534 help
535 Provides a cgroup implementing whitelists for devices which
536 a process in the cgroup can mknod or open.
537
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538config CPUSETS
539 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700540 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700542 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 allow dynamically partitioning a system into sets of CPUs and
544 Memory Nodes and assigning tasks to run only within those sets.
545 This is primarily useful on large SMP or NUMA systems.
546
547 Say N if unsure.
548
Li Zefan23964d22009-01-15 13:50:58 -0800549config PROC_PID_CPUSET
550 bool "Include legacy /proc/<pid>/cpuset file"
551 depends on CPUSETS
552 default y
553
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100554config CGROUP_CPUACCT
555 bool "Simple CPU accounting cgroup subsystem"
556 depends on CGROUPS
557 help
558 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800559 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100560
Pavel Emelianove552b662008-02-07 00:13:49 -0800561config RESOURCE_COUNTERS
562 bool "Resource counters"
563 help
564 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800565 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800566 depends on CGROUPS
567
Balbir Singh00f0b822008-03-04 14:28:39 -0800568config CGROUP_MEM_RES_CTLR
569 bool "Memory Resource Controller for Control Groups"
570 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700571 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800572 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700573 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100574 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800575
576 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700577 associated with each page of memory in the system. By this,
578 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
579 usage tracking struct at boot. Total amount of this is printed out
580 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800581
582 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700583 sure you need the memory resource controller. Even when you enable
584 this, you can set "cgroup_disable=memory" at your boot option to
585 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800586 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800587
Balbir Singhcf475ad2008-04-29 01:00:16 -0700588 This config option also selects MM_OWNER config option, which
589 could in turn add some fork/exit overhead.
590
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800591config CGROUP_MEM_RES_CTLR_SWAP
592 bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
593 depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
594 help
595 Add swap management feature to memory resource controller. When you
596 enable this, you can limit mem+swap usage per cgroup. In other words,
597 when you disable this, memory resource controller has no cares to
598 usage of swap...a process can exhaust all of the swap. This extension
599 is useful when you want to avoid exhaustion swap but this itself
600 adds more overheads and consumes memory for remembering information.
601 Especially if you use 32bit system or small memory system, please
602 be careful about enabling this. When memory resource controller
603 is disabled by boot option, this will be automatically disabled and
604 there will be no overhead from this. Even when you set this config=y,
605 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700606 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
607 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800608
Li Zefan23964d22009-01-15 13:50:58 -0800609endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800610
Li Zefan23964d22009-01-15 13:50:58 -0800611config MM_OWNER
612 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800613
Kay Sievers88a22c92006-09-14 11:23:28 +0200614config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100615 bool
616
617config SYSFS_DEPRECATED_V2
Uwe Kleine-König9e9868a2009-12-03 19:58:00 +0100618 bool "enable deprecated sysfs features to support old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800619 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200620 default n
Ingo Molnard47846c2008-03-04 14:54:47 +0100621 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200622 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100623 This option switches the layout of sysfs to the deprecated
Kay Sieversf6ee6492009-04-16 19:56:37 +0200624 version. Do not use it on recent distributions.
Kay Sievers88a22c92006-09-14 11:23:28 +0200625
Kay Sieversfce3e802008-11-01 14:03:00 +0100626 The current sysfs layout features a unified device tree at
627 /sys/devices/, which is able to express a hierarchy between
628 class devices. If the deprecated option is set to Y, the
629 unified device tree is split into a bus device tree at
630 /sys/devices/ and several individual class device trees at
631 /sys/class/. The class and bus devices will be connected by
632 "<subsystem>:<name>" and the "device" links. The "block"
633 class devices, will not show up in /sys/class/block/. Some
634 subsystems will suppress the creation of some devices which
635 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200636
Kay Sieversfce3e802008-11-01 14:03:00 +0100637 This option is not a pure compatibility option that can
638 be safely enabled on newer distributions. It will change the
639 layout of sysfs to the non-extensible deprecated version,
640 and disable some features, which can not be exported without
641 confusing older userspace tools. Since 2007/2008 all major
642 distributions do not enable this option, and ship no tools which
643 depend on the deprecated layout or this option.
644
645 If you are using a new kernel on an older distribution, or use
646 older userspace tools, you might need to say Y here. Do not say Y,
647 if the original kernel, that came with your distribution, has
648 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200649
Jens Axboeb86ff9812006-03-23 19:56:55 +0100650config RELAY
651 bool "Kernel->user space relay support (formerly relayfs)"
652 help
653 This option enables support for relay interface support in
654 certain file systems (such as debugfs).
655 It is designed to provide an efficient mechanism for tools and
656 facilities to relay large amounts of data from kernel space to
657 user space.
658
659 If unsure, say N.
660
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800661config NAMESPACES
662 bool "Namespaces support" if EMBEDDED
663 default !EMBEDDED
664 help
665 Provides the way to make tasks work with different objects using
666 the same id. For example same IPC id may refer to different objects
667 or same user id or pid may refer to different tasks when used in
668 different namespaces.
669
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800670config UTS_NS
671 bool "UTS namespace"
672 depends on NAMESPACES
673 help
674 In this namespace tasks see different info provided with the
675 uname() system call
676
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800677config IPC_NS
678 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700679 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800680 help
681 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700682 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800683
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800684config USER_NS
685 bool "User namespace (EXPERIMENTAL)"
686 depends on NAMESPACES && EXPERIMENTAL
687 help
688 This allows containers, i.e. vservers, to use user namespaces
689 to provide different user info for different servers.
690 If unsure, say N.
691
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800692config PID_NS
693 bool "PID Namespaces (EXPERIMENTAL)"
694 default n
695 depends on NAMESPACES && EXPERIMENTAL
696 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300697 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100698 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800699 pid namespaces. This is a building block of containers.
700
701 Unless you want to work with an experimental feature
702 say N here.
703
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800704config NET_NS
705 bool "Network namespace"
706 default n
707 depends on NAMESPACES && EXPERIMENTAL && NET
708 help
709 Allow user space to create what appear to be multiple instances
710 of the network stack.
711
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800712config BLK_DEV_INITRD
713 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
714 depends on BROKEN || !FRV
715 help
716 The initial RAM filesystem is a ramfs which is loaded by the
717 boot loader (loadlin or lilo) and that is mounted as root
718 before the normal boot procedure. It is typically used to
719 load modules needed to mount the "real" root file system,
720 etc. See <file:Documentation/initrd.txt> for details.
721
722 If RAM disk support (BLK_DEV_RAM) is also included, this
723 also enables initial RAM disk (initrd) support and adds
724 15 Kbytes (more on some other architectures) to the kernel size.
725
726 If unsure say Y.
727
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800728if BLK_DEV_INITRD
729
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200730source "usr/Kconfig"
731
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800732endif
733
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800734config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200735 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800736 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800737 help
738 Enabling this option will pass "-Os" instead of "-O2" to gcc
739 resulting in a smaller kernel.
740
jkacur775a7222008-07-16 00:31:16 +0200741 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800742
Randy Dunlap08470622006-09-30 23:28:13 -0700743config SYSCTL
744 bool
745
Randy Dunlapb943c462009-03-10 12:55:46 -0700746config ANON_INODES
747 bool
748
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749menuconfig EMBEDDED
750 bool "Configure standard kernel features (for small systems)"
751 help
752 This option allows certain base kernel options and settings
753 to be disabled or tweaked. This is for specialized
754 environments which can tolerate a "non-standard" kernel.
755 Only use this if you really know what you are doing.
756
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700757config UID16
758 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700759 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 -0700760 default y
761 help
762 This enables the legacy 16-bit UID syscall wrappers.
763
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700764config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700765 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman26a70342009-11-05 05:26:41 -0800766 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800767 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700768 select SYSCTL
769 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800770 sys_sysctl uses binary paths that have been found challenging
771 to properly maintain and use. The interface in /proc/sys
772 using paths with ascii names is now the primary path to this
773 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700774
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800775 Almost nothing using the binary sysctl interface so if you are
776 trying to save some space it is probably safe to disable this,
777 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700778
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800779 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700780
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100782 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 default y
784 help
785 Say Y here to let the kernel print out symbolic crash information and
786 symbolic stack backtraces. This increases the size of the kernel
787 somewhat, as all symbols have to be loaded into the kernel image.
788
789config KALLSYMS_ALL
790 bool "Include all symbols in kallsyms"
791 depends on DEBUG_KERNEL && KALLSYMS
792 help
793 Normally kallsyms only contains the symbols of functions, for nicer
794 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200795 symbols too: say Y here to include all symbols, if you need them
796 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797
798 Say N.
799
800config KALLSYMS_EXTRA_PASS
801 bool "Do an extra kallsyms pass"
802 depends on KALLSYMS
803 help
804 If kallsyms is not working correctly, the build will fail with
805 inconsistent kallsyms data. If that occurs, log a bug report and
806 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
807 Always say N here unless you find a bug in kallsyms, which must be
808 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
809 you wait for kallsyms to be fixed.
810
Matt Mackalld59745c2005-05-01 08:59:02 -0700811
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800812config HOTPLUG
813 bool "Support for hot-pluggable devices" if EMBEDDED
814 default y
815 help
816 This option is provided for the case where no hotplug or uevent
817 capabilities is wanted by the kernel. You should only consider
818 disabling this option for embedded systems that do not use modules, a
819 dynamic /dev tree, or dynamic device discovery. Just say Y.
820
Matt Mackalld59745c2005-05-01 08:59:02 -0700821config PRINTK
822 default y
823 bool "Enable support for printk" if EMBEDDED
824 help
825 This option enables normal printk support. Removing it
826 eliminates most of the message strings from the kernel image
827 and makes the kernel more or less silent. As this makes it
828 very difficult to diagnose system problems, saying N here is
829 strongly discouraged.
830
Matt Mackallc8538a72005-05-01 08:59:01 -0700831config BUG
832 bool "BUG() support" if EMBEDDED
833 default y
834 help
835 Disabling this option eliminates support for BUG and WARN, reducing
836 the size of your kernel image and potentially quietly ignoring
837 numerous fatal conditions. You should only consider disabling this
838 option for embedded systems with no facilities for reporting errors.
839 Just say Y.
840
Matt Mackall708e9a72006-01-08 01:05:25 -0800841config ELF_CORE
842 default y
843 bool "Enable ELF core dumps" if EMBEDDED
844 help
845 Enable support for generating core dumps. Disabling saves about 4k.
846
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200847config PCSPKR_PLATFORM
848 bool "Enable PC-Speaker support" if EMBEDDED
849 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
850 default y
851 help
852 This option allows to disable the internal PC-Speaker
853 support, saving some memory.
854
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855config BASE_FULL
856 default y
857 bool "Enable full-sized data structures for core" if EMBEDDED
858 help
859 Disabling this option reduces the size of miscellaneous core
860 kernel data structures. This saves memory on small machines,
861 but may reduce performance.
862
863config FUTEX
864 bool "Enable futex support" if EMBEDDED
865 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700866 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 help
868 Disabling this option will cause the kernel to be built without
869 support for "fast userspace mutexes". The resulting kernel may not
870 run glibc-based applications correctly.
871
872config EPOLL
873 bool "Enable eventpoll support" if EMBEDDED
874 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700875 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 help
877 Disabling this option will cause the kernel to be built without
878 support for epoll family of system calls.
879
Davide Libenzifba2afa2007-05-10 22:23:13 -0700880config SIGNALFD
881 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700882 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700883 default y
884 help
885 Enable the signalfd() system call that allows to receive signals
886 on a file descriptor.
887
888 If unsure, say Y.
889
Davide Libenzib215e282007-05-10 22:23:16 -0700890config TIMERFD
891 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700892 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700893 default y
894 help
895 Enable the timerfd() system call that allows to receive timer
896 events on a file descriptor.
897
898 If unsure, say Y.
899
Davide Libenzie1ad7462007-05-10 22:23:19 -0700900config EVENTFD
901 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700902 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700903 default y
904 help
905 Enable the eventfd() system call that allows to receive both
906 kernel notification (ie. KAIO) or userspace notifications.
907
908 If unsure, say Y.
909
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910config SHMEM
911 bool "Use full shmem filesystem" if EMBEDDED
912 default y
913 depends on MMU
914 help
915 The shmem is an internal filesystem used to manage shared memory.
916 It is backed by swap and manages resource limits. It is also exported
917 to userspace as tmpfs if TMPFS is enabled. Disabling this
918 option replaces shmem and tmpfs with the much simpler ramfs code,
919 which may be appropriate on small systems without swap.
920
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700921config AIO
922 bool "Enable AIO support" if EMBEDDED
923 default y
924 help
925 This option enables POSIX asynchronous I/O which may by used
926 by some high performance threaded applications. Disabling
927 this option saves about 7k.
928
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200929config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +0100930 bool
Mike Frysinger018df722009-06-12 13:17:43 -0400931 help
932 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100933
Peter Zijlstra906010b2009-09-21 16:08:49 +0200934config PERF_USE_VMALLOC
935 bool
936 help
937 See tools/perf/design.txt for details
938
Ingo Molnar57c0c152009-09-21 12:20:38 +0200939menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +0100940
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200941config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +0200942 bool "Kernel performance events and counters"
943 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200944 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +0100945 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +0100946 help
Ingo Molnar57c0c152009-09-21 12:20:38 +0200947 Enable kernel support for various performance events provided
948 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100949
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -0200950 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +0200951 use of generic tracepoints.
952
953 Most modern CPUs support performance events via performance
954 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +0100955 types of hw events: such as instructions executed, cachemisses
956 suffered, or branches mis-predicted - without slowing down the
957 kernel or applications. These registers can also trigger interrupts
958 when a threshold number of events have passed - and can thus be
959 used to profile the code that runs on that CPU.
960
Ingo Molnar57c0c152009-09-21 12:20:38 +0200961 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -0200962 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +0200963 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +0100964 provides per task and per CPU counters, and it provides event
965 capabilities on top of those.
966
967 Say Y if unsure.
968
Peter Zijlstrae077df42009-03-19 20:26:17 +0100969config EVENT_PROFILE
Peter Zijlstra470a1392009-07-29 10:50:09 +0200970 bool "Tracepoint profiling sources"
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200971 depends on PERF_EVENTS && EVENT_TRACING
Peter Zijlstrae077df42009-03-19 20:26:17 +0100972 default y
Peter Zijlstra470a1392009-07-29 10:50:09 +0200973 help
Ingo Molnar57c0c152009-09-21 12:20:38 +0200974 Allow the use of tracepoints as software performance events.
Peter Zijlstra470a1392009-07-29 10:50:09 +0200975
Ingo Molnar57c0c152009-09-21 12:20:38 +0200976 When this is enabled, you can create perf events based on
Peter Zijlstra470a1392009-07-29 10:50:09 +0200977 tracepoints using PERF_TYPE_TRACEPOINT and the tracepoint ID
978 found in debugfs://tracing/events/*/*/id. (The -e/--events
979 option to the perf tool can parse and interpret symbolic
980 tracepoints, in the subsystem:tracepoint_name format.)
Peter Zijlstrae077df42009-03-19 20:26:17 +0100981
Ingo Molnar57c0c152009-09-21 12:20:38 +0200982config PERF_COUNTERS
983 bool "Kernel performance counters (old config option)"
984 depends on HAVE_PERF_EVENTS
985 help
986 This config has been obsoleted by the PERF_EVENTS
987 config option - please see that one for details.
988
989 It has no effect on the kernel whether you enable
990 it or not, it is a compatibility placeholder.
991
992 Say N if unsure.
993
Peter Zijlstra906010b2009-09-21 16:08:49 +0200994config DEBUG_PERF_USE_VMALLOC
995 default n
996 bool "Debug: use vmalloc to back perf mmap() buffers"
997 depends on PERF_EVENTS && DEBUG_KERNEL
998 select PERF_USE_VMALLOC
999 help
1000 Use vmalloc memory to back perf mmap() buffers.
1001
1002 Mostly useful for debugging the vmalloc code on platforms
1003 that don't require it.
1004
1005 Say N if unsure.
1006
Thomas Gleixner0793a612008-12-04 20:12:29 +01001007endmenu
1008
Christoph Lameterf8891e52006-06-30 01:55:45 -07001009config VM_EVENT_COUNTERS
1010 default y
1011 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
1012 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001013 VM event counters are needed for event counts to be shown.
1014 This option allows the disabling of the VM event counters
1015 on EMBEDDED systems. /proc/vmstat will only show page counts
1016 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001017
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001018config PCI_QUIRKS
1019 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001020 bool "Enable PCI quirk workarounds" if EMBEDDED
1021 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001022 help
1023 This enables workarounds for various PCI chipset
1024 bugs/quirks. Disable this only if your target machine is
1025 unaffected by PCI quirks.
1026
Christoph Lameter41ecc552007-05-09 02:32:44 -07001027config SLUB_DEBUG
1028 default y
1029 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -07001030 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001031 help
1032 SLUB has extensive debug support features. Disabling these can
1033 result in significant savings in code size. This also disables
1034 SLUB sysfs support. /sys/slab will not exist and there will be
1035 no support for cache validation etc.
1036
Randy Dunlapb943c462009-03-10 12:55:46 -07001037config COMPAT_BRK
1038 bool "Disable heap randomization"
1039 default y
1040 help
1041 Randomizing heap placement makes heap exploits harder, but it
1042 also breaks ancient binaries (including anything libc5 based).
1043 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001044 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001045 /proc/sys/kernel/randomize_va_space to 2.
1046
1047 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1048
Christoph Lameter81819f02007-05-06 14:49:36 -07001049choice
1050 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001051 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001052 help
1053 This option allows to select a slab allocator.
1054
1055config SLAB
1056 bool "SLAB"
1057 help
1058 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001059 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001060 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001061
1062config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001063 bool "SLUB (Unqueued Allocator)"
1064 help
1065 SLUB is a slab allocator that minimizes cache line usage
1066 instead of managing queues of cached objects (SLAB approach).
1067 Per cpu caching is realized using slabs of objects instead
1068 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001069 and has enhanced diagnostics. SLUB is the default choice for
1070 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001071
1072config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001073 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001074 bool "SLOB (Simple Allocator)"
1075 help
Matt Mackall37291452008-02-04 22:29:38 -08001076 SLOB replaces the stock allocator with a drastically simpler
1077 allocator. SLOB is generally more space efficient but
1078 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001079
1080endchoice
1081
Jie Zhangea637632009-12-14 18:00:02 -08001082config MMAP_ALLOW_UNINITIALIZED
1083 bool "Allow mmapped anonymous memory to be uninitialized"
1084 depends on EMBEDDED && !MMU
1085 default n
1086 help
1087 Normally, and according to the Linux spec, anonymous memory obtained
1088 from mmap() has it's contents cleared before it is passed to
1089 userspace. Enabling this config option allows you to request that
1090 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1091 providing a huge performance boost. If this option is not enabled,
1092 then the flag will be ignored.
1093
1094 This is taken advantage of by uClibc's malloc(), and also by
1095 ELF-FDPIC binfmt's brk and stack allocator.
1096
1097 Because of the obvious security issues, this option should only be
1098 enabled on embedded devices where you control what is run in
1099 userspace. Since that isn't generally a problem on no-MMU systems,
1100 it is normally safe to say Y here.
1101
1102 See Documentation/nommu-mmap.txt for more information.
1103
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001104config PROFILING
1105 bool "Profiling support (EXPERIMENTAL)"
1106 help
1107 Say Y here to enable the extended profiling support mechanisms used
1108 by profilers such as OProfile.
1109
Ingo Molnar5f87f112008-07-23 14:15:22 +02001110#
1111# Place an empty function call at each tracepoint site. Can be
1112# dynamically changed for a probe function.
1113#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001114config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001115 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001116
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001117source "arch/Kconfig"
1118
David Howells07fe7cb2009-04-03 16:42:35 +01001119config SLOW_WORK
1120 default n
David Howells1c2d0082009-04-06 15:47:25 +01001121 bool
David Howells07fe7cb2009-04-03 16:42:35 +01001122 help
1123 The slow work thread pool provides a number of dynamically allocated
1124 threads that can be used by the kernel to perform operations that
1125 take a relatively long time.
1126
1127 An example of this would be CacheFiles doing a path lookup followed
1128 by a series of mkdirs and a create call, all of which have to touch
1129 disk.
1130
David Howells1c2d0082009-04-06 15:47:25 +01001131 See Documentation/slow-work.txt.
1132
David Howellsf13a48b2009-12-01 15:36:11 +00001133config SLOW_WORK_DEBUG
1134 bool "Slow work debugging through debugfs"
David Howells8fba10a2009-11-19 18:10:51 +00001135 default n
David Howellsf13a48b2009-12-01 15:36:11 +00001136 depends on SLOW_WORK && DEBUG_FS
David Howells8fba10a2009-11-19 18:10:51 +00001137 help
David Howellsf13a48b2009-12-01 15:36:11 +00001138 Display the contents of the slow work run queue through debugfs,
David Howells8fba10a2009-11-19 18:10:51 +00001139 including items currently executing.
1140
1141 See Documentation/slow-work.txt.
1142
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143endmenu # General setup
1144
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001145config HAVE_GENERIC_DMA_COHERENT
1146 bool
1147 default n
1148
Linus Torvalds158a9622008-01-02 13:04:48 -08001149config SLABINFO
1150 bool
1151 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001152 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001153 default y
1154
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001155config RT_MUTEXES
1156 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001157
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158config BASE_SMALL
1159 int
1160 default 0 if BASE_FULL
1161 default 1 if !BASE_FULL
1162
Jan Engelhardt66da5732007-07-15 23:39:29 -07001163menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 bool "Enable loadable module support"
1165 help
1166 Kernel modules are small pieces of compiled code which can
1167 be inserted in the running kernel, rather than being
1168 permanently built into the kernel. You use the "modprobe"
1169 tool to add (and sometimes remove) them. If you say Y here,
1170 many parts of the kernel can be built as modules (by
1171 answering M instead of Y where indicated): this is most
1172 useful for infrequently used options which are not required
1173 for booting. For more information, see the man pages for
1174 modprobe, lsmod, modinfo, insmod and rmmod.
1175
1176 If you say Y here, you will need to run "make
1177 modules_install" to put the modules under /lib/modules/
1178 where modprobe can find them (you may need to be root to do
1179 this).
1180
1181 If unsure, say Y.
1182
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001183if MODULES
1184
Linus Torvalds826e4502008-05-04 17:04:16 -07001185config MODULE_FORCE_LOAD
1186 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001187 default n
1188 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001189 Allow loading of modules without version information (ie. modprobe
1190 --force). Forced module loading sets the 'F' (forced) taint flag and
1191 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001192
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193config MODULE_UNLOAD
1194 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 help
1196 Without this option you will not be able to unload any
1197 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001198 anyway), which makes your kernel smaller, faster
1199 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200
1201config MODULE_FORCE_UNLOAD
1202 bool "Forced module unloading"
1203 depends on MODULE_UNLOAD && EXPERIMENTAL
1204 help
1205 This option allows you to force a module to unload, even if the
1206 kernel believes it is unsafe: the kernel will remove the module
1207 without waiting for anyone to stop using it (using the -f option to
1208 rmmod). This is mainly for kernel developers and desperate users.
1209 If unsure, say N.
1210
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001212 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213 help
1214 Usually, you have to use modules compiled with your kernel.
1215 Saying Y here makes it sometimes possible to use modules
1216 compiled for different kernels, by adding enough information
1217 to the modules to (hopefully) spot any changes which would
1218 make them incompatible with the kernel you are running. If
1219 unsure, say N.
1220
1221config MODULE_SRCVERSION_ALL
1222 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223 help
1224 Modules which contain a MODULE_VERSION get an extra "srcversion"
1225 field inserted into their modinfo section, which contains a
1226 sum of the source files which made it. This helps maintainers
1227 see exactly which source was used to build a module (since
1228 others sometimes change the module source without updating
1229 the version). With this option, such a "srcversion" field
1230 will be created for all modules. If unsure, say N.
1231
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001232endif # MODULES
1233
Rusty Russell98a79d62008-12-13 21:19:41 +10301234config INIT_ALL_POSSIBLE
1235 bool
1236 help
1237 Back when each arch used to define their own cpu_online_map and
1238 cpu_possible_map, some of them chose to initialize cpu_possible_map
1239 with all 1s, and others with all 0s. When they were centralised,
1240 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001241 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301242
Linus Torvalds1da177e2005-04-16 15:20:36 -07001243config STOP_MACHINE
1244 bool
1245 default y
1246 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1247 help
1248 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001249
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001250source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001251
1252config PREEMPT_NOTIFIERS
1253 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001254
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001255source "kernel/Kconfig.locks"