blob: 2c5aa3407d6b7bd28415e318a6a8e72994929a38 [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 Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070022
Peter Zijlstrae360adb2010-10-14 14:01:34 +080023config HAVE_IRQ_WORK
24 bool
25
26config IRQ_WORK
27 bool
28 depends on HAVE_IRQ_WORK
29
David Daney1dbdc6f2012-04-19 14:59:57 -070030config BUILDTIME_EXTABLE_SORT
31 bool
32
Al Boldiff0cfc62007-07-31 00:39:23 -070033menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35config EXPERIMENTAL
36 bool "Prompt for development and/or incomplete code/drivers"
37 ---help---
38 Some of the various things that Linux supports (such as network
39 drivers, file systems, network protocols, etc.) can be in a state
40 of development where the functionality, stability, or the level of
41 testing is not yet high enough for general use. This is usually
42 known as the "alpha-test" phase among developers. If a feature is
43 currently in alpha-test, then the developers usually discourage
44 uninformed widespread use of this feature by the general public to
45 avoid "Why doesn't this work?" type mail messages. However, active
46 testing and use of these systems is welcomed. Just be aware that it
47 may not meet the normal level of reliability or it may fail to work
48 in some special cases. Detailed bug reports from people familiar
49 with the kernel internals are usually welcomed by the developers
50 (before submitting bug reports, please read the documents
51 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
52 <file:Documentation/BUG-HUNTING>, and
53 <file:Documentation/oops-tracing.txt> in the kernel source).
54
55 This option will also make obsoleted drivers available. These are
56 drivers that have been replaced by something else, and/or are
57 scheduled to be removed in a future kernel release.
58
59 Unless you intend to help test and develop a feature or driver that
60 falls into this category, or you have a situation that requires
61 using these features, you should probably say N here, which will
62 cause the configurator to present you with fewer choices. If
63 you say Y here, you will be offered the choice of using features or
64 drivers that are currently considered to be in the alpha-test phase.
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066config BROKEN
67 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69config BROKEN_ON_SMP
70 bool
71 depends on BROKEN || !SMP
72 default y
73
Linus Torvalds1da177e2005-04-16 15:20:36 -070074config INIT_ENV_ARG_LIMIT
75 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070076 default 32 if !UML
77 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080079 Maximum of each of the number of arguments and environment
80 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
Roland McGrath84336462009-12-21 16:24:06 -080083config CROSS_COMPILE
84 string "Cross-compiler tool prefix"
85 help
86 Same as running 'make CROSS_COMPILE=prefix-' but stored for
87 default make runs in this kernel build directory. You don't
88 need to set this unless you want the configured kernel build
89 directory to select the cross-compiler automatically.
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091config LOCALVERSION
92 string "Local version - append to kernel release"
93 help
94 Append an extra string to the end of your kernel version.
95 This will show up when you type uname, for example.
96 The string you set here will be appended after the contents of
97 any files with a filename matching localversion* in your
98 object and source tree, in that order. Your total string can
99 be a maximum of 64 characters.
100
Ryan Andersonaaebf432005-07-31 04:57:49 -0400101config LOCALVERSION_AUTO
102 bool "Automatically append version information to the version string"
103 default y
104 help
105 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200106 release tree by looking for git tags that belong to the current
107 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400108
109 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200110 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400111 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200112 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400113
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200114 (The actual string used here is the first eight characters produced
115 by running the command:
116
117 $ git rev-parse --verify HEAD
118
119 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400120
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800121config HAVE_KERNEL_GZIP
122 bool
123
124config HAVE_KERNEL_BZIP2
125 bool
126
127config HAVE_KERNEL_LZMA
128 bool
129
Lasse Collin3ebe1242011-01-12 17:01:23 -0800130config HAVE_KERNEL_XZ
131 bool
132
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800133config HAVE_KERNEL_LZO
134 bool
135
Alain Knaff30d65db2009-01-04 22:46:17 +0100136choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800137 prompt "Kernel compression mode"
138 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800139 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800140 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100141 The linux kernel is a kind of self-extracting executable.
142 Several compression algorithms are available, which differ
143 in efficiency, compression and decompression speed.
144 Compression speed is only relevant when building a kernel.
145 Decompression speed is relevant at each boot.
146
147 If you have any problems with bzip2 or lzma compressed
148 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
149 version of this functionality (bzip2 only), for 2.4, was
150 supplied by Christian Ludwig)
151
152 High compression options are mostly useful for users, who
153 are low on disk space (embedded systems), but for whom ram
154 size matters less.
155
156 If in doubt, select 'gzip'
157
158config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800159 bool "Gzip"
160 depends on HAVE_KERNEL_GZIP
161 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800162 The old and tried gzip compression. It provides a good balance
163 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100164
165config KERNEL_BZIP2
166 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800167 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100168 help
169 Its compression ratio and speed is intermediate.
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700170 Decompression speed is slowest among the choices. The kernel
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800171 size is about 10% smaller with bzip2, in comparison to gzip.
172 Bzip2 uses a large amount of memory. For modern kernels you
173 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100174
175config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800176 bool "LZMA"
177 depends on HAVE_KERNEL_LZMA
178 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700179 This compression algorithm's ratio is best. Decompression speed
180 is between gzip and bzip2. Compression is slowest.
181 The kernel size is about 33% smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100182
Lasse Collin3ebe1242011-01-12 17:01:23 -0800183config KERNEL_XZ
184 bool "XZ"
185 depends on HAVE_KERNEL_XZ
186 help
187 XZ uses the LZMA2 algorithm and instruction set specific
188 BCJ filters which can improve compression ratio of executable
189 code. The size of the kernel is about 30% smaller with XZ in
190 comparison to gzip. On architectures for which there is a BCJ
191 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
192 will create a few percent smaller kernel than plain LZMA.
193
194 The speed is about the same as with LZMA: The decompression
195 speed of XZ is better than that of bzip2 but worse than gzip
196 and LZO. Compression is slow.
197
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800198config KERNEL_LZO
199 bool "LZO"
200 depends on HAVE_KERNEL_LZO
201 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700202 Its compression ratio is the poorest among the choices. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200203 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800204 (both compression and decompression) is the fastest.
205
Alain Knaff30d65db2009-01-04 22:46:17 +0100206endchoice
207
Josh Triplettbd5dc172011-06-15 15:08:28 -0700208config DEFAULT_HOSTNAME
209 string "Default hostname"
210 default "(none)"
211 help
212 This option determines the default system hostname before userspace
213 calls sethostname(2). The kernel traditionally uses "(none)" here,
214 but you may wish to use a different default here to make a minimal
215 system more usable with less configuration.
216
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217config SWAP
218 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200219 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 default y
221 help
222 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100223 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 used to provide more virtual memory than the actual RAM present
225 in your computer. If unsure say Y.
226
227config SYSVIPC
228 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 ---help---
230 Inter Process Communication is a suite of library functions and
231 system calls which let processes (running programs) synchronize and
232 exchange information. It is generally considered to be a good thing,
233 and some programs won't run unless you say Y here. In particular, if
234 you want to run the DOS emulator dosemu under Linux (read the
235 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
236 you'll need to say Y here.
237
238 You can find documentation about IPC with "info ipc" and also in
239 section 6.4 of the Linux Programmer's Guide, available from
240 <http://www.tldp.org/guides.html>.
241
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800242config SYSVIPC_SYSCTL
243 bool
244 depends on SYSVIPC
245 depends on SYSCTL
246 default y
247
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248config POSIX_MQUEUE
249 bool "POSIX Message Queues"
250 depends on NET && EXPERIMENTAL
251 ---help---
252 POSIX variant of message queues is a part of IPC. In POSIX message
253 queues every message has a priority which decides about succession
254 of receiving it by a process. If you want to compile and run
255 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200256 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 POSIX message queues are visible as a filesystem called 'mqueue'
259 and can be mounted somewhere if you want to do filesystem
260 operations on message queues.
261
262 If unsure, say Y.
263
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700264config POSIX_MQUEUE_SYSCTL
265 bool
266 depends on POSIX_MQUEUE
267 depends on SYSCTL
268 default y
269
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530270config FHANDLE
271 bool "open by fhandle syscalls"
272 select EXPORTFS
273 help
274 If you say Y here, a user level program will be able to map
275 file names to handle and then later use the handle for
276 different file system operations. This is useful in implementing
277 userspace file servers, which now track files using handles instead
278 of names. The handle would remain the same even if file names
279 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
280 syscalls.
281
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282config AUDIT
283 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100284 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 help
286 Enable auditing infrastructure that can be used with another
287 kernel subsystem, such as SELinux (which requires this for
288 logging of avc messages output). Does not do system-call
289 auditing without CONFIG_AUDITSYSCALL.
290
291config AUDITSYSCALL
292 bool "Enable system-call auditing support"
Will Deacon8f827a12012-07-06 15:48:16 +0100293 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 default y if SECURITY_SELINUX
295 help
296 Enable low-overhead system-call auditing infrastructure that
297 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500298 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299
Eric Paris939a67f2009-12-17 20:12:06 -0500300config AUDIT_WATCH
301 def_bool y
302 depends on AUDITSYSCALL
303 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304
Al Viro74c3cbe2007-07-22 08:04:18 -0400305config AUDIT_TREE
306 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400307 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500308 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400309
Eric Paris633b4542012-01-03 14:23:08 -0500310config AUDIT_LOGINUID_IMMUTABLE
311 bool "Make audit loginuid immutable"
312 depends on AUDIT
313 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800314 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500315 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
316 but should instead only allow setting its loginuid if it was never
317 previously set. On systems which use systemd or a similar central
318 process to restart login services this should be set to true. On older
319 systems in which an admin would typically have to directly stop and
320 start processes this should be set to false. Setting this to true allows
321 one to drop potentially dangerous capabilites from the login tasks,
322 but may not be backwards compatible with older init systems.
323
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000324source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200325source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000326
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200327menu "CPU/Task time and stats accounting"
328
329config VIRT_CPU_ACCOUNTING
330 bool "Deterministic task and CPU time accounting"
331 depends on HAVE_VIRT_CPU_ACCOUNTING
332 default y if PPC64
333 help
334 Select this option to enable more accurate task and CPU time
335 accounting. This is done by reading a CPU counter on each
336 kernel entry and exit and on transitions within the kernel
337 between system, softirq and hardirq state, so there is a
338 small performance impact. In the case of s390 or IBM POWER > 5,
339 this also enables accounting of stolen time on logically-partitioned
340 systems.
341
342config BSD_PROCESS_ACCT
343 bool "BSD Process Accounting"
344 help
345 If you say Y here, a user level program will be able to instruct the
346 kernel (via a special system call) to write process accounting
347 information to a file: whenever a process exits, information about
348 that process will be appended to the file by the kernel. The
349 information includes things such as creation time, owning user,
350 command name, memory usage, controlling terminal etc. (the complete
351 list is in the struct acct in <file:include/linux/acct.h>). It is
352 up to the user level program to do useful things with this
353 information. This is generally a good idea, so say Y.
354
355config BSD_PROCESS_ACCT_V3
356 bool "BSD Process Accounting version 3 file format"
357 depends on BSD_PROCESS_ACCT
358 default n
359 help
360 If you say Y here, the process accounting information is written
361 in a new file format that also logs the process IDs of each
362 process and it's parent. Note that this file format is incompatible
363 with previous v0/v1/v2 file formats, so you will need updated tools
364 for processing it. A preliminary version of these tools is available
365 at <http://www.gnu.org/software/acct/>.
366
367config TASKSTATS
368 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
369 depends on NET
370 default n
371 help
372 Export selected statistics for tasks/processes through the
373 generic netlink interface. Unlike BSD process accounting, the
374 statistics are available during the lifetime of tasks/processes as
375 responses to commands. Like BSD accounting, they are sent to user
376 space on task exit.
377
378 Say N if unsure.
379
380config TASK_DELAY_ACCT
381 bool "Enable per-task delay accounting (EXPERIMENTAL)"
382 depends on TASKSTATS
383 help
384 Collect information on time spent by a task waiting for system
385 resources like cpu, synchronous block I/O completion and swapping
386 in pages. Such statistics can help in setting a task's priorities
387 relative to other tasks for cpu, io, rss limits etc.
388
389 Say N if unsure.
390
391config TASK_XACCT
392 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
393 depends on TASKSTATS
394 help
395 Collect extended task accounting data and send the data
396 to userland for processing over the taskstats interface.
397
398 Say N if unsure.
399
400config TASK_IO_ACCOUNTING
401 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
402 depends on TASK_XACCT
403 help
404 Collect information on the number of bytes of storage I/O which this
405 task has caused.
406
407 Say N if unsure.
408
409endmenu # "CPU/Task time and stats accounting"
410
Mike Travisc903ff82009-01-15 12:28:29 -0800411menu "RCU Subsystem"
412
413choice
414 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700415 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800416
Mike Travisc903ff82009-01-15 12:28:29 -0800417config TREE_RCU
418 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700419 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800420 help
421 This option selects the RCU implementation that is
422 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700423 thousands of CPUs. It also scales down nicely to
424 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800425
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700426config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700427 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700428 depends on PREEMPT && SMP
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700429 help
430 This option selects the RCU implementation that is
431 designed for very large SMP systems with hundreds or
432 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700433 is also required. It also scales down nicely to
434 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700435
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700436config TINY_RCU
437 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700438 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700439 help
440 This option selects the RCU implementation that is
441 designed for UP systems from which real-time response
442 is not required. This option greatly reduces the
443 memory footprint of RCU.
444
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700445config TINY_PREEMPT_RCU
446 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700447 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700448 help
449 This option selects the RCU implementation that is designed
450 for real-time UP systems. This option greatly reduces the
451 memory footprint of RCU.
452
Mike Travisc903ff82009-01-15 12:28:29 -0800453endchoice
454
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700455config PREEMPT_RCU
456 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
457 help
458 This option enables preemptible-RCU code that is common between
459 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
460
Mike Travisc903ff82009-01-15 12:28:29 -0800461config RCU_FANOUT
462 int "Tree-based hierarchical RCU fanout value"
463 range 2 64 if 64BIT
464 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700465 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800466 default 64 if 64BIT
467 default 32 if !64BIT
468 help
469 This option controls the fanout of hierarchical implementations
470 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700471 large numbers of CPUs. This value must be at least the fourth
472 root of NR_CPUS, which allows NR_CPUS to be insanely large.
473 The default value of RCU_FANOUT should be used for production
474 systems, but if you are stress-testing the RCU implementation
475 itself, small RCU_FANOUT values allow you to test large-system
476 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800477
478 Select a specific number if testing RCU itself.
479 Take the default if unsure.
480
Paul E. McKenney8932a632012-04-19 12:20:14 -0700481config RCU_FANOUT_LEAF
482 int "Tree-based hierarchical RCU leaf-level fanout value"
483 range 2 RCU_FANOUT if 64BIT
484 range 2 RCU_FANOUT if !64BIT
485 depends on TREE_RCU || TREE_PREEMPT_RCU
486 default 16
487 help
488 This option controls the leaf-level fanout of hierarchical
489 implementations of RCU, and allows trading off cache misses
490 against lock contention. Systems that synchronize their
491 scheduling-clock interrupts for energy-efficiency reasons will
492 want the default because the smaller leaf-level fanout keeps
493 lock contention levels acceptably low. Very large systems
494 (hundreds or thousands of CPUs) will instead want to set this
495 value to the maximum value possible in order to reduce the
496 number of cache misses incurred during RCU's grace-period
497 initialization. These systems tend to run CPU-bound, and thus
498 are not helped by synchronized interrupts, and thus tend to
499 skew them, which reduces lock contention enough that large
500 leaf-level fanouts work well.
501
502 Select a specific number if testing RCU itself.
503
504 Select the maximum permissible value for large systems.
505
506 Take the default if unsure.
507
Mike Travisc903ff82009-01-15 12:28:29 -0800508config RCU_FANOUT_EXACT
509 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700510 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800511 default n
512 help
513 This option forces use of the exact RCU_FANOUT value specified,
514 regardless of imbalances in the hierarchy. This is useful for
515 testing RCU itself, and might one day be useful on systems with
516 strong NUMA behavior.
517
518 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
519
520 Say N if unsure.
521
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800522config RCU_FAST_NO_HZ
523 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700524 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800525 default n
526 help
527 This option causes RCU to attempt to accelerate grace periods
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700528 in order to allow CPUs to enter dynticks-idle state more
529 quickly. On the other hand, this option increases the overhead
530 of the dynticks-idle checking, particularly on systems with
531 large numbers of CPUs.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800532
533 Say Y if energy efficiency is critically important, particularly
534 if you have relatively few CPUs.
535
536 Say N if you are unsure.
537
Mike Travisc903ff82009-01-15 12:28:29 -0800538config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700539 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800540 select DEBUG_FS
541 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700542 This option provides tracing for the TREE_RCU and
543 TREE_PREEMPT_RCU implementations, permitting Makefile to
544 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800545
Paul E. McKenney24278d12010-09-27 17:25:23 -0700546config RCU_BOOST
547 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800548 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700549 default n
550 help
551 This option boosts the priority of preempted RCU readers that
552 block the current preemptible RCU grace period for too long.
553 This option also prevents heavy loads from blocking RCU
554 callback invocation for all flavors of RCU.
555
556 Say Y here if you are working with real-time apps or heavy loads
557 Say N here if you are unsure.
558
559config RCU_BOOST_PRIO
560 int "Real-time priority to boost RCU readers to"
561 range 1 99
562 depends on RCU_BOOST
563 default 1
564 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700565 This option specifies the real-time priority to which long-term
566 preempted RCU readers are to be boosted. If you are working
567 with a real-time application that has one or more CPU-bound
568 threads running at a real-time priority level, you should set
569 RCU_BOOST_PRIO to a priority higher then the highest-priority
570 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
571 of 1 is appropriate in the common case, which is real-time
572 applications that do not have any CPU-bound threads.
573
574 Some real-time applications might not have a single real-time
575 thread that saturates a given CPU, but instead might have
576 multiple real-time threads that, taken together, fully utilize
577 that CPU. In this case, you should set RCU_BOOST_PRIO to
578 a priority higher than the lowest-priority thread that is
579 conspiring to prevent the CPU from running any non-real-time
580 tasks. For example, if one thread at priority 10 and another
581 thread at priority 5 are between themselves fully consuming
582 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
583 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700584
585 Specify the real-time priority, or take the default if unsure.
586
587config RCU_BOOST_DELAY
588 int "Milliseconds to delay boosting after RCU grace-period start"
589 range 0 3000
590 depends on RCU_BOOST
591 default 500
592 help
593 This option specifies the time to wait after the beginning of
594 a given grace period before priority-boosting preempted RCU
595 readers blocking that grace period. Note that any RCU reader
596 blocking an expedited RCU grace period is boosted immediately.
597
598 Accept the default if unsure.
599
Mike Travisc903ff82009-01-15 12:28:29 -0800600endmenu # "RCU Subsystem"
601
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700603 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 ---help---
605 This option enables the complete Linux kernel ".config" file
606 contents to be saved in the kernel. It provides documentation
607 of which kernel options are used in a running kernel or in an
608 on-disk kernel. This information can be extracted from the kernel
609 image file with the script scripts/extract-ikconfig and used as
610 input to rebuild the current kernel or to build another kernel.
611 It can also be extracted from a running kernel by reading
612 /proc/config.gz if enabled (below).
613
614config IKCONFIG_PROC
615 bool "Enable access to .config through /proc/config.gz"
616 depends on IKCONFIG && PROC_FS
617 ---help---
618 This option enables access to the kernel configuration file
619 through /proc/config.gz.
620
Alistair John Strachan794543a2007-05-08 00:31:15 -0700621config LOG_BUF_SHIFT
622 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
623 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700624 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700625 help
626 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700627 Examples:
628 17 => 128 KB
629 16 => 64 KB
630 15 => 32 KB
631 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700632 13 => 8 KB
633 12 => 4 KB
634
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800635#
636# Architectures with an unreliable sched_clock() should select this:
637#
638config HAVE_UNSTABLE_SCHED_CLOCK
639 bool
640
Li Zefan23964d22009-01-15 13:50:58 -0800641menuconfig CGROUPS
642 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800643 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700644 help
Li Zefan23964d22009-01-15 13:50:58 -0800645 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800646 use with process control subsystems such as Cpusets, CFS, memory
647 controls or device isolation.
648 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800649 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800650 - Documentation/cgroups/ (features for grouping, isolation
651 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700652
653 Say N if unsure.
654
Li Zefan23964d22009-01-15 13:50:58 -0800655if CGROUPS
656
Paul Menage006cb992007-10-18 23:39:43 -0700657config CGROUP_DEBUG
658 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700659 default n
Paul Menage006cb992007-10-18 23:39:43 -0700660 help
661 This option enables a simple cgroup subsystem that
662 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800663 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700664
Li Zefan23964d22009-01-15 13:50:58 -0800665 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700666
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700667config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800668 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800669 help
670 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700671 cgroup.
672
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700673config CGROUP_DEVICE
674 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700675 help
676 Provides a cgroup implementing whitelists for devices which
677 a process in the cgroup can mknod or open.
678
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679config CPUSETS
680 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700682 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 allow dynamically partitioning a system into sets of CPUs and
684 Memory Nodes and assigning tasks to run only within those sets.
685 This is primarily useful on large SMP or NUMA systems.
686
687 Say N if unsure.
688
Li Zefan23964d22009-01-15 13:50:58 -0800689config PROC_PID_CPUSET
690 bool "Include legacy /proc/<pid>/cpuset file"
691 depends on CPUSETS
692 default y
693
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100694config CGROUP_CPUACCT
695 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100696 help
697 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800698 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100699
Pavel Emelianove552b662008-02-07 00:13:49 -0800700config RESOURCE_COUNTERS
701 bool "Resource counters"
702 help
703 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800704 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800705
Andrew Mortonc255a452012-07-31 16:43:02 -0700706config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800707 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700708 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700709 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800710 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700711 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100712 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800713
714 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700715 associated with each page of memory in the system. By this,
716 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
717 usage tracking struct at boot. Total amount of this is printed out
718 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800719
720 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700721 sure you need the memory resource controller. Even when you enable
722 this, you can set "cgroup_disable=memory" at your boot option to
723 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800724 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800725
Balbir Singhcf475ad2008-04-29 01:00:16 -0700726 This config option also selects MM_OWNER config option, which
727 could in turn add some fork/exit overhead.
728
Andrew Mortonc255a452012-07-31 16:43:02 -0700729config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700730 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700731 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800732 help
733 Add swap management feature to memory resource controller. When you
734 enable this, you can limit mem+swap usage per cgroup. In other words,
735 when you disable this, memory resource controller has no cares to
736 usage of swap...a process can exhaust all of the swap. This extension
737 is useful when you want to avoid exhaustion swap but this itself
738 adds more overheads and consumes memory for remembering information.
739 Especially if you use 32bit system or small memory system, please
740 be careful about enabling this. When memory resource controller
741 is disabled by boot option, this will be automatically disabled and
742 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700743 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700744 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
745 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700746config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800747 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700748 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800749 default y
750 help
751 Memory Resource Controller Swap Extension comes with its price in
752 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700753 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800754 and let the user enable it by swapaccount boot command line
755 parameter should have this option unselected.
756 For those who want to have the feature enabled by default should
757 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700758 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700759config MEMCG_KMEM
Glauber Costae5671df2011-12-11 21:47:01 +0000760 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
Andrew Mortonc255a452012-07-31 16:43:02 -0700761 depends on MEMCG && EXPERIMENTAL
Glauber Costae5671df2011-12-11 21:47:01 +0000762 default n
763 help
764 The Kernel Memory extension for Memory Resource Controller can limit
765 the amount of memory used by kernel objects in the system. Those are
766 fundamentally different from the entities handled by the standard
767 Memory Controller, which are page-based, and can be swapped. Users of
768 the kmem extension can use it to guarantee that no group of processes
769 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800770
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700771config CGROUP_HUGETLB
772 bool "HugeTLB Resource Controller for Control Groups"
773 depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL
774 default n
775 help
776 Provides a cgroup Resource Controller for HugeTLB pages.
777 When you enable this, you can put a per cgroup limit on HugeTLB usage.
778 The limit is enforced during page fault. Since HugeTLB doesn't
779 support page reclaim, enforcing the limit at page fault time implies
780 that, the application will get SIGBUS signal if it tries to access
781 HugeTLB pages beyond its limit. This requires the application to know
782 beforehand how much HugeTLB pages it would require for its use. The
783 control group is tracked in the third page lru pointer. This means
784 that we cannot use the controller with huge page less than 3 pages.
785
Stephane Eraniane5d13672011-02-14 11:20:01 +0200786config CGROUP_PERF
787 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
788 depends on PERF_EVENTS && CGROUPS
789 help
790 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800791 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200792 designated cpu.
793
794 Say N if unsure.
795
Dhaval Giani7c941432010-01-20 13:26:18 +0100796menuconfig CGROUP_SCHED
797 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100798 default n
799 help
800 This feature lets CPU scheduler recognize task groups and control CPU
801 bandwidth allocation to such task groups. It uses cgroups to group
802 tasks.
803
804if CGROUP_SCHED
805config FAIR_GROUP_SCHED
806 bool "Group scheduling for SCHED_OTHER"
807 depends on CGROUP_SCHED
808 default CGROUP_SCHED
809
Paul Turnerab84d312011-07-21 09:43:28 -0700810config CFS_BANDWIDTH
811 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
812 depends on EXPERIMENTAL
813 depends on FAIR_GROUP_SCHED
814 default n
815 help
816 This option allows users to define CPU bandwidth rates (limits) for
817 tasks running within the fair group scheduler. Groups with no limit
818 set are considered to be unconstrained and will run with no
819 restriction.
820 See tip/Documentation/scheduler/sched-bwc.txt for more information.
821
Dhaval Giani7c941432010-01-20 13:26:18 +0100822config RT_GROUP_SCHED
823 bool "Group scheduling for SCHED_RR/FIFO"
824 depends on EXPERIMENTAL
825 depends on CGROUP_SCHED
826 default n
827 help
828 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800829 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100830 schedule realtime tasks for non-root users until you allocate
831 realtime bandwidth for them.
832 See Documentation/scheduler/sched-rt-group.txt for more information.
833
834endif #CGROUP_SCHED
835
Vivek Goyalafc24d42010-04-26 19:27:56 +0200836config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800837 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700838 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200839 default n
840 ---help---
841 Generic block IO controller cgroup interface. This is the common
842 cgroup interface which should be used by various IO controlling
843 policies.
844
845 Currently, CFQ IO scheduler uses it to recognize task groups and
846 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400847 to such task groups. It is also used by bio throttling logic in
848 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200849
850 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400851 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000852 enabling proportional weight division of disk bandwidth in CFQ, set
853 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000854 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200855
856 See Documentation/cgroups/blkio-controller.txt for more information.
857
858config DEBUG_BLK_CGROUP
859 bool "Enable Block IO controller debugging"
860 depends on BLK_CGROUP
861 default n
862 ---help---
863 Enable some debugging help. Currently it exports additional stat
864 files in a cgroup which can be useful for debugging.
865
Li Zefan23964d22009-01-15 13:50:58 -0800866endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800867
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800868config CHECKPOINT_RESTORE
869 bool "Checkpoint/restore support" if EXPERT
870 default n
871 help
872 Enables additional kernel features in a sake of checkpoint/restore.
873 In particular it adds auxiliary prctl codes to setup process text,
874 data and heap segment sizes, and a few additional /proc filesystem
875 entries.
876
877 If unsure, say N here.
878
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700879menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800880 bool "Namespaces support" if EXPERT
881 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800882 help
883 Provides the way to make tasks work with different objects using
884 the same id. For example same IPC id may refer to different objects
885 or same user id or pid may refer to different tasks when used in
886 different namespaces.
887
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700888if NAMESPACES
889
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800890config UTS_NS
891 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700892 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800893 help
894 In this namespace tasks see different info provided with the
895 uname() system call
896
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800897config IPC_NS
898 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700899 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700900 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800901 help
902 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700903 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800904
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800905config USER_NS
906 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700907 depends on EXPERIMENTAL
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700908 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -0800909 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700910
Eric W. Biederman5673a942011-11-17 10:23:55 -0800911 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800912 help
913 This allows containers, i.e. vservers, to use user namespaces
914 to provide different user info for different servers.
915 If unsure, say N.
916
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800917config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700918 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700919 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800920 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300921 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100922 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800923 pid namespaces. This is a building block of containers.
924
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800925config NET_NS
926 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700927 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700928 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800929 help
930 Allow user space to create what appear to be multiple instances
931 of the network stack.
932
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700933endif # NAMESPACES
934
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700935config UIDGID_CONVERTED
936 # True if all of the selected software conmponents are known
937 # to have uid_t and gid_t converted to kuid_t and kgid_t
938 # where appropriate and are otherwise safe to use with
939 # the user namespace.
940 bool
941 default y
942
943 # List of kernel pieces that need user namespace work
944 # Features
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700945 depends on SYSVIPC = n
946 depends on IMA = n
947 depends on EVM = n
948 depends on KEYS = n
949 depends on AUDIT = n
950 depends on AUDITSYSCALL = n
951 depends on TASKSTATS = n
952 depends on TRACING = n
953 depends on FS_POSIX_ACL = n
954 depends on QUOTA = n
955 depends on QUOTACTL = n
956 depends on DEBUG_CREDENTIALS = n
957 depends on BSD_PROCESS_ACCT = n
958 depends on DRM = n
959 depends on PROC_EVENTS = n
960
961 # Networking
962 depends on NET = n
963 depends on NET_9P = n
964 depends on IPX = n
965 depends on PHONET = n
966 depends on NET_CLS_FLOW = n
967 depends on NETFILTER_XT_MATCH_OWNER = n
968 depends on NETFILTER_XT_MATCH_RECENT = n
969 depends on NETFILTER_XT_TARGET_LOG = n
970 depends on NETFILTER_NETLINK_LOG = n
971 depends on INET = n
972 depends on IPV6 = n
973 depends on IP_SCTP = n
974 depends on AF_RXRPC = n
975 depends on LLC2 = n
976 depends on NET_KEY = n
977 depends on INET_DIAG = n
978 depends on DNS_RESOLVER = n
979 depends on AX25 = n
980 depends on ATALK = n
981
982 # Filesystems
983 depends on USB_DEVICEFS = n
984 depends on USB_GADGETFS = n
985 depends on USB_FUNCTIONFS = n
986 depends on DEVTMPFS = n
987 depends on XENFS = n
988
989 depends on 9P_FS = n
990 depends on ADFS_FS = n
991 depends on AFFS_FS = n
992 depends on AFS_FS = n
993 depends on AUTOFS4_FS = n
994 depends on BEFS_FS = n
995 depends on BFS_FS = n
996 depends on BTRFS_FS = n
997 depends on CEPH_FS = n
998 depends on CIFS = n
999 depends on CODA_FS = n
1000 depends on CONFIGFS_FS = n
1001 depends on CRAMFS = n
1002 depends on DEBUG_FS = n
1003 depends on ECRYPT_FS = n
1004 depends on EFS_FS = n
1005 depends on EXOFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001006 depends on FAT_FS = n
1007 depends on FUSE_FS = n
1008 depends on GFS2_FS = n
1009 depends on HFS_FS = n
1010 depends on HFSPLUS_FS = n
1011 depends on HPFS_FS = n
1012 depends on HUGETLBFS = n
1013 depends on ISO9660_FS = n
1014 depends on JFFS2_FS = n
1015 depends on JFS_FS = n
1016 depends on LOGFS = n
1017 depends on MINIX_FS = n
1018 depends on NCP_FS = n
1019 depends on NFSD = n
1020 depends on NFS_FS = n
1021 depends on NILFS2_FS = n
1022 depends on NTFS_FS = n
1023 depends on OCFS2_FS = n
1024 depends on OMFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001025 depends on QNX4FS_FS = n
1026 depends on QNX6FS_FS = n
1027 depends on REISERFS_FS = n
1028 depends on SQUASHFS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001029 depends on SYSV_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001030 depends on UBIFS_FS = n
1031 depends on UDF_FS = n
1032 depends on UFS_FS = n
1033 depends on VXFS_FS = n
1034 depends on XFS_FS = n
1035
1036 depends on !UML || HOSTFS = n
1037
1038 # The rare drivers that won't build
1039 depends on AIRO = n
1040 depends on AIRO_CS = n
1041 depends on TUN = n
1042 depends on INFINIBAND_QIB = n
1043 depends on BLK_DEV_LOOP = n
1044 depends on ANDROID_BINDER_IPC = n
1045
1046 # Security modules
1047 depends on SECURITY_TOMOYO = n
1048 depends on SECURITY_APPARMOR = n
1049
Eric W. Biederman5673a942011-11-17 10:23:55 -08001050config UIDGID_STRICT_TYPE_CHECKS
1051 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001052 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001053 default n
1054 help
1055 While the nececessary conversions are being added to all subsystems this option allows
1056 the code to continue to build for unconverted subsystems.
1057
1058 Say Y here if you want the strict type checking enabled
1059
Mike Galbraith5091faa2010-11-30 14:18:03 +01001060config SCHED_AUTOGROUP
1061 bool "Automatic process group scheduling"
1062 select EVENTFD
1063 select CGROUPS
1064 select CGROUP_SCHED
1065 select FAIR_GROUP_SCHED
1066 help
1067 This option optimizes the scheduler for common desktop workloads by
1068 automatically creating and populating task groups. This separation
1069 of workloads isolates aggressive CPU burners (like build jobs) from
1070 desktop applications. Task group autogeneration is currently based
1071 upon task session.
1072
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001073config MM_OWNER
1074 bool
1075
1076config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001077 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001078 depends on SYSFS
1079 default n
1080 help
1081 This option adds code that switches the layout of the "block" class
1082 devices, to not show up in /sys/class/block/, but only in
1083 /sys/block/.
1084
1085 This switch is only active when the sysfs.deprecated=1 boot option is
1086 passed or the SYSFS_DEPRECATED_V2 option is set.
1087
1088 This option allows new kernels to run on old distributions and tools,
1089 which might get confused by /sys/class/block/. Since 2007/2008 all
1090 major distributions and tools handle this just fine.
1091
1092 Recent distributions and userspace tools after 2009/2010 depend on
1093 the existence of /sys/class/block/, and will not work with this
1094 option enabled.
1095
1096 Only if you are using a new kernel on an old distribution, you might
1097 need to say Y here.
1098
1099config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001100 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001101 default n
1102 depends on SYSFS
1103 depends on SYSFS_DEPRECATED
1104 help
1105 Enable deprecated sysfs by default.
1106
1107 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1108 option.
1109
1110 Only if you are using a new kernel on an old distribution, you might
1111 need to say Y here. Even then, odds are you would not need it
1112 enabled, you can always pass the boot option if absolutely necessary.
1113
1114config RELAY
1115 bool "Kernel->user space relay support (formerly relayfs)"
1116 help
1117 This option enables support for relay interface support in
1118 certain file systems (such as debugfs).
1119 It is designed to provide an efficient mechanism for tools and
1120 facilities to relay large amounts of data from kernel space to
1121 user space.
1122
1123 If unsure, say N.
1124
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001125config BLK_DEV_INITRD
1126 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1127 depends on BROKEN || !FRV
1128 help
1129 The initial RAM filesystem is a ramfs which is loaded by the
1130 boot loader (loadlin or lilo) and that is mounted as root
1131 before the normal boot procedure. It is typically used to
1132 load modules needed to mount the "real" root file system,
1133 etc. See <file:Documentation/initrd.txt> for details.
1134
1135 If RAM disk support (BLK_DEV_RAM) is also included, this
1136 also enables initial RAM disk (initrd) support and adds
1137 15 Kbytes (more on some other architectures) to the kernel size.
1138
1139 If unsure say Y.
1140
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001141if BLK_DEV_INITRD
1142
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001143source "usr/Kconfig"
1144
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001145endif
1146
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001147config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001148 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001149 help
1150 Enabling this option will pass "-Os" instead of "-O2" to gcc
1151 resulting in a smaller kernel.
1152
jkacur775a7222008-07-16 00:31:16 +02001153 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001154
Randy Dunlap08470622006-09-30 23:28:13 -07001155config SYSCTL
1156 bool
1157
Randy Dunlapb943c462009-03-10 12:55:46 -07001158config ANON_INODES
1159 bool
1160
David Rientjes6a108a12011-01-20 14:44:16 -08001161menuconfig EXPERT
1162 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001163 # Unhide debug options, to make the on-by-default options visible
1164 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165 help
1166 This option allows certain base kernel options and settings
1167 to be disabled or tweaked. This is for specialized
1168 environments which can tolerate a "non-standard" kernel.
1169 Only use this if you really know what you are doing.
1170
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001171config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001172 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -07001173 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 -07001174 default y
1175 help
1176 This enables the legacy 16-bit UID syscall wrappers.
1177
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001178config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001179 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001180 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001181 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001182 select SYSCTL
1183 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001184 sys_sysctl uses binary paths that have been found challenging
1185 to properly maintain and use. The interface in /proc/sys
1186 using paths with ascii names is now the primary path to this
1187 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001188
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001189 Almost nothing using the binary sysctl interface so if you are
1190 trying to save some space it is probably safe to disable this,
1191 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001192
WANG Congc736de62011-11-02 13:39:25 -07001193 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001194
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001196 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197 default y
1198 help
1199 Say Y here to let the kernel print out symbolic crash information and
1200 symbolic stack backtraces. This increases the size of the kernel
1201 somewhat, as all symbols have to be loaded into the kernel image.
1202
1203config KALLSYMS_ALL
1204 bool "Include all symbols in kallsyms"
1205 depends on DEBUG_KERNEL && KALLSYMS
1206 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001207 Normally kallsyms only contains the symbols of functions for nicer
1208 OOPS messages and backtraces (i.e., symbols from the text and inittext
1209 sections). This is sufficient for most cases. And only in very rare
1210 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1211 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001213 This option makes sure that all symbols are loaded into the kernel
1214 image (i.e., symbols from all sections) in cost of increased kernel
1215 size (depending on the kernel configuration, it may be 300KiB or
1216 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001218 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001219
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001220config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -08001221 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001222 default y
1223 help
1224 This option is provided for the case where no hotplug or uevent
1225 capabilities is wanted by the kernel. You should only consider
1226 disabling this option for embedded systems that do not use modules, a
1227 dynamic /dev tree, or dynamic device discovery. Just say Y.
1228
Matt Mackalld59745c2005-05-01 08:59:02 -07001229config PRINTK
1230 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001231 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001232 help
1233 This option enables normal printk support. Removing it
1234 eliminates most of the message strings from the kernel image
1235 and makes the kernel more or less silent. As this makes it
1236 very difficult to diagnose system problems, saying N here is
1237 strongly discouraged.
1238
Matt Mackallc8538a72005-05-01 08:59:01 -07001239config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001240 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001241 default y
1242 help
1243 Disabling this option eliminates support for BUG and WARN, reducing
1244 the size of your kernel image and potentially quietly ignoring
1245 numerous fatal conditions. You should only consider disabling this
1246 option for embedded systems with no facilities for reporting errors.
1247 Just say Y.
1248
Matt Mackall708e9a72006-01-08 01:05:25 -08001249config ELF_CORE
1250 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001251 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001252 help
1253 Enable support for generating core dumps. Disabling saves about 4k.
1254
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001255
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001256config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001257 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001258 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001259 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001260 default y
1261 help
1262 This option allows to disable the internal PC-Speaker
1263 support, saving some memory.
1264
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001265config HAVE_PCSPKR_PLATFORM
1266 bool
1267
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268config BASE_FULL
1269 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001270 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271 help
1272 Disabling this option reduces the size of miscellaneous core
1273 kernel data structures. This saves memory on small machines,
1274 but may reduce performance.
1275
1276config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001277 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001279 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280 help
1281 Disabling this option will cause the kernel to be built without
1282 support for "fast userspace mutexes". The resulting kernel may not
1283 run glibc-based applications correctly.
1284
1285config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001286 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001288 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289 help
1290 Disabling this option will cause the kernel to be built without
1291 support for epoll family of system calls.
1292
Davide Libenzifba2afa2007-05-10 22:23:13 -07001293config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001294 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001295 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001296 default y
1297 help
1298 Enable the signalfd() system call that allows to receive signals
1299 on a file descriptor.
1300
1301 If unsure, say Y.
1302
Davide Libenzib215e282007-05-10 22:23:16 -07001303config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001304 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001305 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001306 default y
1307 help
1308 Enable the timerfd() system call that allows to receive timer
1309 events on a file descriptor.
1310
1311 If unsure, say Y.
1312
Davide Libenzie1ad7462007-05-10 22:23:19 -07001313config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001314 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001315 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001316 default y
1317 help
1318 Enable the eventfd() system call that allows to receive both
1319 kernel notification (ie. KAIO) or userspace notifications.
1320
1321 If unsure, say Y.
1322
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001324 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 default y
1326 depends on MMU
1327 help
1328 The shmem is an internal filesystem used to manage shared memory.
1329 It is backed by swap and manages resource limits. It is also exported
1330 to userspace as tmpfs if TMPFS is enabled. Disabling this
1331 option replaces shmem and tmpfs with the much simpler ramfs code,
1332 which may be appropriate on small systems without swap.
1333
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001334config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001335 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001336 default y
1337 help
1338 This option enables POSIX asynchronous I/O which may by used
1339 by some high performance threaded applications. Disabling
1340 this option saves about 7k.
1341
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001342config EMBEDDED
1343 bool "Embedded system"
1344 select EXPERT
1345 help
1346 This option should be enabled if compiling the kernel for
1347 an embedded system so certain expert options are available
1348 for configuration.
1349
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001350config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001351 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001352 help
1353 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001354
Peter Zijlstra906010b2009-09-21 16:08:49 +02001355config PERF_USE_VMALLOC
1356 bool
1357 help
1358 See tools/perf/design.txt for details
1359
Ingo Molnar57c0c152009-09-21 12:20:38 +02001360menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001361
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001362config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001363 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001364 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001365 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001366 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001367 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001368 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001369 Enable kernel support for various performance events provided
1370 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001371
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001372 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001373 use of generic tracepoints.
1374
1375 Most modern CPUs support performance events via performance
1376 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001377 types of hw events: such as instructions executed, cachemisses
1378 suffered, or branches mis-predicted - without slowing down the
1379 kernel or applications. These registers can also trigger interrupts
1380 when a threshold number of events have passed - and can thus be
1381 used to profile the code that runs on that CPU.
1382
Ingo Molnar57c0c152009-09-21 12:20:38 +02001383 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001384 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001385 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001386 provides per task and per CPU counters, and it provides event
1387 capabilities on top of those.
1388
1389 Say Y if unsure.
1390
Peter Zijlstra906010b2009-09-21 16:08:49 +02001391config DEBUG_PERF_USE_VMALLOC
1392 default n
1393 bool "Debug: use vmalloc to back perf mmap() buffers"
1394 depends on PERF_EVENTS && DEBUG_KERNEL
1395 select PERF_USE_VMALLOC
1396 help
1397 Use vmalloc memory to back perf mmap() buffers.
1398
1399 Mostly useful for debugging the vmalloc code on platforms
1400 that don't require it.
1401
1402 Say N if unsure.
1403
Thomas Gleixner0793a612008-12-04 20:12:29 +01001404endmenu
1405
Christoph Lameterf8891e52006-06-30 01:55:45 -07001406config VM_EVENT_COUNTERS
1407 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001408 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001409 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001410 VM event counters are needed for event counts to be shown.
1411 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001412 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001413 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001414
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001415config PCI_QUIRKS
1416 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001417 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001418 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001419 help
1420 This enables workarounds for various PCI chipset
1421 bugs/quirks. Disable this only if your target machine is
1422 unaffected by PCI quirks.
1423
Christoph Lameter41ecc552007-05-09 02:32:44 -07001424config SLUB_DEBUG
1425 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001426 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001427 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001428 help
1429 SLUB has extensive debug support features. Disabling these can
1430 result in significant savings in code size. This also disables
1431 SLUB sysfs support. /sys/slab will not exist and there will be
1432 no support for cache validation etc.
1433
Randy Dunlapb943c462009-03-10 12:55:46 -07001434config COMPAT_BRK
1435 bool "Disable heap randomization"
1436 default y
1437 help
1438 Randomizing heap placement makes heap exploits harder, but it
1439 also breaks ancient binaries (including anything libc5 based).
1440 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001441 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001442 /proc/sys/kernel/randomize_va_space to 2.
1443
1444 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1445
Christoph Lameter81819f02007-05-06 14:49:36 -07001446choice
1447 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001448 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001449 help
1450 This option allows to select a slab allocator.
1451
1452config SLAB
1453 bool "SLAB"
1454 help
1455 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001456 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001457 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001458
1459config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001460 bool "SLUB (Unqueued Allocator)"
1461 help
1462 SLUB is a slab allocator that minimizes cache line usage
1463 instead of managing queues of cached objects (SLAB approach).
1464 Per cpu caching is realized using slabs of objects instead
1465 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001466 and has enhanced diagnostics. SLUB is the default choice for
1467 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001468
1469config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001470 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001471 bool "SLOB (Simple Allocator)"
1472 help
Matt Mackall37291452008-02-04 22:29:38 -08001473 SLOB replaces the stock allocator with a drastically simpler
1474 allocator. SLOB is generally more space efficient but
1475 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001476
1477endchoice
1478
Jie Zhangea637632009-12-14 18:00:02 -08001479config MMAP_ALLOW_UNINITIALIZED
1480 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001481 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001482 default n
1483 help
1484 Normally, and according to the Linux spec, anonymous memory obtained
1485 from mmap() has it's contents cleared before it is passed to
1486 userspace. Enabling this config option allows you to request that
1487 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1488 providing a huge performance boost. If this option is not enabled,
1489 then the flag will be ignored.
1490
1491 This is taken advantage of by uClibc's malloc(), and also by
1492 ELF-FDPIC binfmt's brk and stack allocator.
1493
1494 Because of the obvious security issues, this option should only be
1495 enabled on embedded devices where you control what is run in
1496 userspace. Since that isn't generally a problem on no-MMU systems,
1497 it is normally safe to say Y here.
1498
1499 See Documentation/nommu-mmap.txt for more information.
1500
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001501config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001502 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001503 help
1504 Say Y here to enable the extended profiling support mechanisms used
1505 by profilers such as OProfile.
1506
Ingo Molnar5f87f112008-07-23 14:15:22 +02001507#
1508# Place an empty function call at each tracepoint site. Can be
1509# dynamically changed for a probe function.
1510#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001511config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001512 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001513
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001514source "arch/Kconfig"
1515
Linus Torvalds1da177e2005-04-16 15:20:36 -07001516endmenu # General setup
1517
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001518config HAVE_GENERIC_DMA_COHERENT
1519 bool
1520 default n
1521
Linus Torvalds158a9622008-01-02 13:04:48 -08001522config SLABINFO
1523 bool
1524 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001525 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001526 default y
1527
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001528config RT_MUTEXES
1529 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001530
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531config BASE_SMALL
1532 int
1533 default 0 if BASE_FULL
1534 default 1 if !BASE_FULL
1535
Jan Engelhardt66da5732007-07-15 23:39:29 -07001536menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001537 bool "Enable loadable module support"
1538 help
1539 Kernel modules are small pieces of compiled code which can
1540 be inserted in the running kernel, rather than being
1541 permanently built into the kernel. You use the "modprobe"
1542 tool to add (and sometimes remove) them. If you say Y here,
1543 many parts of the kernel can be built as modules (by
1544 answering M instead of Y where indicated): this is most
1545 useful for infrequently used options which are not required
1546 for booting. For more information, see the man pages for
1547 modprobe, lsmod, modinfo, insmod and rmmod.
1548
1549 If you say Y here, you will need to run "make
1550 modules_install" to put the modules under /lib/modules/
1551 where modprobe can find them (you may need to be root to do
1552 this).
1553
1554 If unsure, say Y.
1555
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001556if MODULES
1557
Linus Torvalds826e4502008-05-04 17:04:16 -07001558config MODULE_FORCE_LOAD
1559 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001560 default n
1561 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001562 Allow loading of modules without version information (ie. modprobe
1563 --force). Forced module loading sets the 'F' (forced) taint flag and
1564 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001565
Linus Torvalds1da177e2005-04-16 15:20:36 -07001566config MODULE_UNLOAD
1567 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001568 help
1569 Without this option you will not be able to unload any
1570 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001571 anyway), which makes your kernel smaller, faster
1572 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001573
1574config MODULE_FORCE_UNLOAD
1575 bool "Forced module unloading"
1576 depends on MODULE_UNLOAD && EXPERIMENTAL
1577 help
1578 This option allows you to force a module to unload, even if the
1579 kernel believes it is unsafe: the kernel will remove the module
1580 without waiting for anyone to stop using it (using the -f option to
1581 rmmod). This is mainly for kernel developers and desperate users.
1582 If unsure, say N.
1583
Linus Torvalds1da177e2005-04-16 15:20:36 -07001584config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001585 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586 help
1587 Usually, you have to use modules compiled with your kernel.
1588 Saying Y here makes it sometimes possible to use modules
1589 compiled for different kernels, by adding enough information
1590 to the modules to (hopefully) spot any changes which would
1591 make them incompatible with the kernel you are running. If
1592 unsure, say N.
1593
1594config MODULE_SRCVERSION_ALL
1595 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596 help
1597 Modules which contain a MODULE_VERSION get an extra "srcversion"
1598 field inserted into their modinfo section, which contains a
1599 sum of the source files which made it. This helps maintainers
1600 see exactly which source was used to build a module (since
1601 others sometimes change the module source without updating
1602 the version). With this option, such a "srcversion" field
1603 will be created for all modules. If unsure, say N.
1604
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001605endif # MODULES
1606
Rusty Russell98a79d62008-12-13 21:19:41 +10301607config INIT_ALL_POSSIBLE
1608 bool
1609 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301610 Back when each arch used to define their own cpu_online_mask and
1611 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301612 with all 1s, and others with all 0s. When they were centralised,
1613 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001614 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301615
Linus Torvalds1da177e2005-04-16 15:20:36 -07001616config STOP_MACHINE
1617 bool
1618 default y
1619 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1620 help
1621 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001622
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001623source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001624
1625config PREEMPT_NOTIFIERS
1626 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001627
Steffen Klassert16295be2010-01-06 19:47:10 +11001628config PADATA
1629 depends on SMP
1630 bool
1631
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001632source "kernel/Kconfig.locks"