blob: 79383d3aa5dc5f7fe64abdcaf7d511144ca016e5 [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 IRQ_WORK
24 bool
Peter Zijlstrae360adb2010-10-14 14:01:34 +080025
David Daney1dbdc6f2012-04-19 14:59:57 -070026config BUILDTIME_EXTABLE_SORT
27 bool
28
Al Boldiff0cfc62007-07-31 00:39:23 -070029menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Linus Torvalds1da177e2005-04-16 15:20:36 -070031config BROKEN
32 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34config BROKEN_ON_SMP
35 bool
36 depends on BROKEN || !SMP
37 default y
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039config INIT_ENV_ARG_LIMIT
40 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070041 default 32 if !UML
42 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080044 Maximum of each of the number of arguments and environment
45 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Roland McGrath84336462009-12-21 16:24:06 -080048config CROSS_COMPILE
49 string "Cross-compiler tool prefix"
50 help
51 Same as running 'make CROSS_COMPILE=prefix-' but stored for
52 default make runs in this kernel build directory. You don't
53 need to set this unless you want the configured kernel build
54 directory to select the cross-compiler automatically.
55
Jiri Slaby4bb16672013-05-22 10:56:24 +020056config COMPILE_TEST
57 bool "Compile also drivers which will not load"
58 default n
59 help
60 Some drivers can be compiled on a different platform than they are
61 intended to be run on. Despite they cannot be loaded there (or even
62 when they load they cannot be used due to missing HW support),
63 developers still, opposing to distributors, might want to build such
64 drivers to compile-test them.
65
66 If you are a developer and want to build everything available, say Y
67 here. If you are a user/distributor, say N here to exclude useless
68 drivers to be distributed.
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070config LOCALVERSION
71 string "Local version - append to kernel release"
72 help
73 Append an extra string to the end of your kernel version.
74 This will show up when you type uname, for example.
75 The string you set here will be appended after the contents of
76 any files with a filename matching localversion* in your
77 object and source tree, in that order. Your total string can
78 be a maximum of 64 characters.
79
Ryan Andersonaaebf432005-07-31 04:57:49 -040080config LOCALVERSION_AUTO
81 bool "Automatically append version information to the version string"
82 default y
83 help
84 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020085 release tree by looking for git tags that belong to the current
86 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040087
88 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020089 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040090 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020091 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -040092
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020093 (The actual string used here is the first eight characters produced
94 by running the command:
95
96 $ git rev-parse --verify HEAD
97
98 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -040099
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800100config HAVE_KERNEL_GZIP
101 bool
102
103config HAVE_KERNEL_BZIP2
104 bool
105
106config HAVE_KERNEL_LZMA
107 bool
108
Lasse Collin3ebe1242011-01-12 17:01:23 -0800109config HAVE_KERNEL_XZ
110 bool
111
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800112config HAVE_KERNEL_LZO
113 bool
114
Kyungsik Leee76e1fd2013-07-08 16:01:46 -0700115config HAVE_KERNEL_LZ4
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
H. Peter Anvin2d3c6272013-11-14 21:43:47 -0800121 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800122 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
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800144 The old and tried gzip compression. It provides a good balance
145 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100146
147config KERNEL_BZIP2
148 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800149 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100150 help
151 Its compression ratio and speed is intermediate.
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700152 Decompression speed is slowest among the choices. The kernel
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800153 size is about 10% smaller with bzip2, in comparison to gzip.
154 Bzip2 uses a large amount of memory. For modern kernels you
155 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100156
157config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800158 bool "LZMA"
159 depends on HAVE_KERNEL_LZMA
160 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700161 This compression algorithm's ratio is best. Decompression speed
162 is between gzip and bzip2. Compression is slowest.
163 The kernel size is about 33% smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100164
Lasse Collin3ebe1242011-01-12 17:01:23 -0800165config KERNEL_XZ
166 bool "XZ"
167 depends on HAVE_KERNEL_XZ
168 help
169 XZ uses the LZMA2 algorithm and instruction set specific
170 BCJ filters which can improve compression ratio of executable
171 code. The size of the kernel is about 30% smaller with XZ in
172 comparison to gzip. On architectures for which there is a BCJ
173 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
174 will create a few percent smaller kernel than plain LZMA.
175
176 The speed is about the same as with LZMA: The decompression
177 speed of XZ is better than that of bzip2 but worse than gzip
178 and LZO. Compression is slow.
179
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800180config KERNEL_LZO
181 bool "LZO"
182 depends on HAVE_KERNEL_LZO
183 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700184 Its compression ratio is the poorest among the choices. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200185 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800186 (both compression and decompression) is the fastest.
187
Kyungsik Leee76e1fd2013-07-08 16:01:46 -0700188config KERNEL_LZ4
189 bool "LZ4"
190 depends on HAVE_KERNEL_LZ4
191 help
192 LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
193 A preliminary version of LZ4 de/compression tool is available at
194 <https://code.google.com/p/lz4/>.
195
196 Its compression ratio is worse than LZO. The size of the kernel
197 is about 8% bigger than LZO. But the decompression speed is
198 faster than LZO.
199
Alain Knaff30d65db2009-01-04 22:46:17 +0100200endchoice
201
Josh Triplettbd5dc172011-06-15 15:08:28 -0700202config DEFAULT_HOSTNAME
203 string "Default hostname"
204 default "(none)"
205 help
206 This option determines the default system hostname before userspace
207 calls sethostname(2). The kernel traditionally uses "(none)" here,
208 but you may wish to use a different default here to make a minimal
209 system more usable with less configuration.
210
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211config SWAP
212 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200213 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 default y
215 help
216 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100217 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 used to provide more virtual memory than the actual RAM present
219 in your computer. If unsure say Y.
220
221config SYSVIPC
222 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 ---help---
224 Inter Process Communication is a suite of library functions and
225 system calls which let processes (running programs) synchronize and
226 exchange information. It is generally considered to be a good thing,
227 and some programs won't run unless you say Y here. In particular, if
228 you want to run the DOS emulator dosemu under Linux (read the
229 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
230 you'll need to say Y here.
231
232 You can find documentation about IPC with "info ipc" and also in
233 section 6.4 of the Linux Programmer's Guide, available from
234 <http://www.tldp.org/guides.html>.
235
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800236config SYSVIPC_SYSCTL
237 bool
238 depends on SYSVIPC
239 depends on SYSCTL
240 default y
241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242config POSIX_MQUEUE
243 bool "POSIX Message Queues"
Kees Cook19c92392012-10-02 11:19:29 -0700244 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 ---help---
246 POSIX variant of message queues is a part of IPC. In POSIX message
247 queues every message has a priority which decides about succession
248 of receiving it by a process. If you want to compile and run
249 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200250 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 POSIX message queues are visible as a filesystem called 'mqueue'
253 and can be mounted somewhere if you want to do filesystem
254 operations on message queues.
255
256 If unsure, say Y.
257
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700258config POSIX_MQUEUE_SYSCTL
259 bool
260 depends on POSIX_MQUEUE
261 depends on SYSCTL
262 default y
263
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530264config FHANDLE
265 bool "open by fhandle syscalls"
266 select EXPORTFS
267 help
268 If you say Y here, a user level program will be able to map
269 file names to handle and then later use the handle for
270 different file system operations. This is useful in implementing
271 userspace file servers, which now track files using handles instead
272 of names. The handle would remain the same even if file names
273 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
274 syscalls.
275
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276config AUDIT
277 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100278 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 help
280 Enable auditing infrastructure that can be used with another
281 kernel subsystem, such as SELinux (which requires this for
282 logging of avc messages output). Does not do system-call
283 auditing without CONFIG_AUDITSYSCALL.
284
285config AUDITSYSCALL
286 bool "Enable system-call auditing support"
Helge Deller527973c2013-10-15 19:25:46 +0200287 depends on AUDIT && (X86 || PARISC || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 default y if SECURITY_SELINUX
289 help
290 Enable low-overhead system-call auditing infrastructure that
291 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500292 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
Eric Paris939a67f2009-12-17 20:12:06 -0500294config AUDIT_WATCH
295 def_bool y
296 depends on AUDITSYSCALL
297 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298
Al Viro74c3cbe2007-07-22 08:04:18 -0400299config AUDIT_TREE
300 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400301 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500302 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400303
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000304source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200305source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000306
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200307menu "CPU/Task time and stats accounting"
308
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200309config VIRT_CPU_ACCOUNTING
310 bool
311
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200312choice
313 prompt "Cputime accounting"
314 default TICK_CPU_ACCOUNTING if !PPC64
Stephen Rothwell02fc8d32013-02-08 14:19:38 +1100315 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200316
317# Kind of a stub config for the pure tick based cputime accounting
318config TICK_CPU_ACCOUNTING
319 bool "Simple tick based cputime accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200320 depends on !S390 && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200321 help
322 This is the basic tick based cputime accounting that maintains
323 statistics about user, system and idle time spent on per jiffies
324 granularity.
325
326 If unsure, say Y.
327
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200328config VIRT_CPU_ACCOUNTING_NATIVE
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200329 bool "Deterministic task and CPU time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200330 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200331 select VIRT_CPU_ACCOUNTING
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200332 help
333 Select this option to enable more accurate task and CPU time
334 accounting. This is done by reading a CPU counter on each
335 kernel entry and exit and on transitions within the kernel
336 between system, softirq and hardirq state, so there is a
337 small performance impact. In the case of s390 or IBM POWER > 5,
338 this also enables accounting of stolen time on logically-partitioned
339 systems.
340
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200341config VIRT_CPU_ACCOUNTING_GEN
342 bool "Full dynticks CPU time accounting"
Kevin Hilmanff3fb252013-09-16 15:28:19 -0700343 depends on HAVE_CONTEXT_TRACKING
Kevin Hilman554b0002013-09-16 15:28:21 -0700344 depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200345 select VIRT_CPU_ACCOUNTING
346 select CONTEXT_TRACKING
347 help
348 Select this option to enable task and CPU time accounting on full
349 dynticks systems. This accounting is implemented by watching every
350 kernel-user boundaries using the context tracking subsystem.
351 The accounting is thus performed at the expense of some significant
352 overhead.
353
354 For now this is only useful if you are working on the full
355 dynticks subsystem development.
356
357 If unsure, say N.
358
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200359config IRQ_TIME_ACCOUNTING
360 bool "Fine granularity task level IRQ time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200361 depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200362 help
363 Select this option to enable fine granularity task irq time
364 accounting. This is done by reading a timestamp on each
365 transitions between softirq and hardirq state, so there can be a
366 small performance impact.
367
368 If in doubt, say N here.
369
370endchoice
371
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200372config BSD_PROCESS_ACCT
373 bool "BSD Process Accounting"
374 help
375 If you say Y here, a user level program will be able to instruct the
376 kernel (via a special system call) to write process accounting
377 information to a file: whenever a process exits, information about
378 that process will be appended to the file by the kernel. The
379 information includes things such as creation time, owning user,
380 command name, memory usage, controlling terminal etc. (the complete
381 list is in the struct acct in <file:include/linux/acct.h>). It is
382 up to the user level program to do useful things with this
383 information. This is generally a good idea, so say Y.
384
385config BSD_PROCESS_ACCT_V3
386 bool "BSD Process Accounting version 3 file format"
387 depends on BSD_PROCESS_ACCT
388 default n
389 help
390 If you say Y here, the process accounting information is written
391 in a new file format that also logs the process IDs of each
392 process and it's parent. Note that this file format is incompatible
393 with previous v0/v1/v2 file formats, so you will need updated tools
394 for processing it. A preliminary version of these tools is available
395 at <http://www.gnu.org/software/acct/>.
396
397config TASKSTATS
Kees Cook19c92392012-10-02 11:19:29 -0700398 bool "Export task/process statistics through netlink"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200399 depends on NET
400 default n
401 help
402 Export selected statistics for tasks/processes through the
403 generic netlink interface. Unlike BSD process accounting, the
404 statistics are available during the lifetime of tasks/processes as
405 responses to commands. Like BSD accounting, they are sent to user
406 space on task exit.
407
408 Say N if unsure.
409
410config TASK_DELAY_ACCT
Kees Cook19c92392012-10-02 11:19:29 -0700411 bool "Enable per-task delay accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200412 depends on TASKSTATS
413 help
414 Collect information on time spent by a task waiting for system
415 resources like cpu, synchronous block I/O completion and swapping
416 in pages. Such statistics can help in setting a task's priorities
417 relative to other tasks for cpu, io, rss limits etc.
418
419 Say N if unsure.
420
421config TASK_XACCT
Kees Cook19c92392012-10-02 11:19:29 -0700422 bool "Enable extended accounting over taskstats"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200423 depends on TASKSTATS
424 help
425 Collect extended task accounting data and send the data
426 to userland for processing over the taskstats interface.
427
428 Say N if unsure.
429
430config TASK_IO_ACCOUNTING
Kees Cook19c92392012-10-02 11:19:29 -0700431 bool "Enable per-task storage I/O accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200432 depends on TASK_XACCT
433 help
434 Collect information on the number of bytes of storage I/O which this
435 task has caused.
436
437 Say N if unsure.
438
439endmenu # "CPU/Task time and stats accounting"
440
Mike Travisc903ff82009-01-15 12:28:29 -0800441menu "RCU Subsystem"
442
443choice
444 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700445 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800446
Mike Travisc903ff82009-01-15 12:28:29 -0800447config TREE_RCU
448 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700449 depends on !PREEMPT && SMP
Steven Rostedt016a8d52013-05-28 17:32:53 -0400450 select IRQ_WORK
Mike Travisc903ff82009-01-15 12:28:29 -0800451 help
452 This option selects the RCU implementation that is
453 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700454 thousands of CPUs. It also scales down nicely to
455 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800456
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700457config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700458 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800459 depends on PREEMPT
James Hogan53614712013-07-25 15:34:25 +0100460 select IRQ_WORK
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700461 help
462 This option selects the RCU implementation that is
463 designed for very large SMP systems with hundreds or
464 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700465 is also required. It also scales down nicely to
466 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700467
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800468 Select this option if you are unsure.
469
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700470config TINY_RCU
471 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700472 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700473 help
474 This option selects the RCU implementation that is
475 designed for UP systems from which real-time response
476 is not required. This option greatly reduces the
477 memory footprint of RCU.
478
Mike Travisc903ff82009-01-15 12:28:29 -0800479endchoice
480
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700481config PREEMPT_RCU
Paul E. McKenney127781d2013-03-27 08:44:00 -0700482 def_bool TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700483 help
484 This option enables preemptible-RCU code that is common between
485 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
486
Paul E. McKenney6bfc09e2012-10-19 12:49:17 -0700487config RCU_STALL_COMMON
488 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
489 help
490 This option enables RCU CPU stall code that is common between
491 the TINY and TREE variants of RCU. The purpose is to allow
492 the tiny variants to disable RCU CPU stall warnings, while
493 making these warnings mandatory for the tree variants.
494
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100495config CONTEXT_TRACKING
496 bool
497
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200498config RCU_USER_QS
499 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100500 depends on HAVE_CONTEXT_TRACKING && SMP
501 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200502 help
503 This option sets hooks on kernel / userspace boundaries and
504 puts RCU in extended quiescent state when the CPU runs in
505 userspace. It means that when a CPU runs in userspace, it is
506 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700507 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200508
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200509 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100510 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700511 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200512
513 If unsure say N
514
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100515config CONTEXT_TRACKING_FORCE
516 bool "Force context tracking"
517 depends on CONTEXT_TRACKING
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200518 default y if !NO_HZ_FULL
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200519 help
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200520 The major pre-requirement for full dynticks to work is to
521 support the context tracking subsystem. But there are also
522 other dependencies to provide in order to make the full
523 dynticks working.
524
525 This option stands for testing when an arch implements the
526 context tracking backend but doesn't yet fullfill all the
527 requirements to make the full dynticks feature working.
528 Without the full dynticks, there is no way to test the support
529 for context tracking and the subsystems that rely on it: RCU
530 userspace extended quiescent state and tickless cputime
531 accounting. This option copes with the absence of the full
532 dynticks subsystem by forcing the context tracking on all
533 CPUs in the system.
534
535 Say Y only if you're working on the developpement of an
536 architecture backend for the context tracking.
537
538 Say N otherwise, this option brings an overhead that you
539 don't want in production.
540
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200541
Mike Travisc903ff82009-01-15 12:28:29 -0800542config RCU_FANOUT
543 int "Tree-based hierarchical RCU fanout value"
544 range 2 64 if 64BIT
545 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700546 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800547 default 64 if 64BIT
548 default 32 if !64BIT
549 help
550 This option controls the fanout of hierarchical implementations
551 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700552 large numbers of CPUs. This value must be at least the fourth
553 root of NR_CPUS, which allows NR_CPUS to be insanely large.
554 The default value of RCU_FANOUT should be used for production
555 systems, but if you are stress-testing the RCU implementation
556 itself, small RCU_FANOUT values allow you to test large-system
557 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800558
559 Select a specific number if testing RCU itself.
560 Take the default if unsure.
561
Paul E. McKenney8932a632012-04-19 12:20:14 -0700562config RCU_FANOUT_LEAF
563 int "Tree-based hierarchical RCU leaf-level fanout value"
564 range 2 RCU_FANOUT if 64BIT
565 range 2 RCU_FANOUT if !64BIT
566 depends on TREE_RCU || TREE_PREEMPT_RCU
567 default 16
568 help
569 This option controls the leaf-level fanout of hierarchical
570 implementations of RCU, and allows trading off cache misses
571 against lock contention. Systems that synchronize their
572 scheduling-clock interrupts for energy-efficiency reasons will
573 want the default because the smaller leaf-level fanout keeps
574 lock contention levels acceptably low. Very large systems
575 (hundreds or thousands of CPUs) will instead want to set this
576 value to the maximum value possible in order to reduce the
577 number of cache misses incurred during RCU's grace-period
578 initialization. These systems tend to run CPU-bound, and thus
579 are not helped by synchronized interrupts, and thus tend to
580 skew them, which reduces lock contention enough that large
581 leaf-level fanouts work well.
582
583 Select a specific number if testing RCU itself.
584
585 Select the maximum permissible value for large systems.
586
587 Take the default if unsure.
588
Mike Travisc903ff82009-01-15 12:28:29 -0800589config RCU_FANOUT_EXACT
590 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700591 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800592 default n
593 help
594 This option forces use of the exact RCU_FANOUT value specified,
595 regardless of imbalances in the hierarchy. This is useful for
596 testing RCU itself, and might one day be useful on systems with
597 strong NUMA behavior.
598
599 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
600
601 Say N if unsure.
602
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800603config RCU_FAST_NO_HZ
604 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Frederic Weisbecker3451d022011-08-10 23:21:01 +0200605 depends on NO_HZ_COMMON && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800606 default n
607 help
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800608 This option permits CPUs to enter dynticks-idle state even if
609 they have RCU callbacks queued, and prevents RCU from waking
610 these CPUs up more than roughly once every four jiffies (by
611 default, you can adjust this using the rcutree.rcu_idle_gp_delay
612 parameter), thus improving energy efficiency. On the other
613 hand, this option increases the duration of RCU grace periods,
614 for example, slowing down synchronize_rcu().
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800615
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800616 Say Y if energy efficiency is critically important, and you
617 don't care about increased grace-period durations.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800618
619 Say N if you are unsure.
620
Mike Travisc903ff82009-01-15 12:28:29 -0800621config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700622 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800623 select DEBUG_FS
624 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700625 This option provides tracing for the TREE_RCU and
626 TREE_PREEMPT_RCU implementations, permitting Makefile to
627 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800628
Paul E. McKenney24278d12010-09-27 17:25:23 -0700629config RCU_BOOST
630 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800631 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700632 default n
633 help
634 This option boosts the priority of preempted RCU readers that
635 block the current preemptible RCU grace period for too long.
636 This option also prevents heavy loads from blocking RCU
637 callback invocation for all flavors of RCU.
638
639 Say Y here if you are working with real-time apps or heavy loads
640 Say N here if you are unsure.
641
642config RCU_BOOST_PRIO
643 int "Real-time priority to boost RCU readers to"
644 range 1 99
645 depends on RCU_BOOST
646 default 1
647 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700648 This option specifies the real-time priority to which long-term
649 preempted RCU readers are to be boosted. If you are working
650 with a real-time application that has one or more CPU-bound
651 threads running at a real-time priority level, you should set
652 RCU_BOOST_PRIO to a priority higher then the highest-priority
653 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
654 of 1 is appropriate in the common case, which is real-time
655 applications that do not have any CPU-bound threads.
656
657 Some real-time applications might not have a single real-time
658 thread that saturates a given CPU, but instead might have
659 multiple real-time threads that, taken together, fully utilize
660 that CPU. In this case, you should set RCU_BOOST_PRIO to
661 a priority higher than the lowest-priority thread that is
662 conspiring to prevent the CPU from running any non-real-time
663 tasks. For example, if one thread at priority 10 and another
664 thread at priority 5 are between themselves fully consuming
665 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
666 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700667
668 Specify the real-time priority, or take the default if unsure.
669
670config RCU_BOOST_DELAY
671 int "Milliseconds to delay boosting after RCU grace-period start"
672 range 0 3000
673 depends on RCU_BOOST
674 default 500
675 help
676 This option specifies the time to wait after the beginning of
677 a given grace period before priority-boosting preempted RCU
678 readers blocking that grace period. Note that any RCU reader
679 blocking an expedited RCU grace period is boosted immediately.
680
681 Accept the default if unsure.
682
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700683config RCU_NOCB_CPU
Paul E. McKenney9a5739d2013-03-28 20:48:36 -0700684 bool "Offload RCU callback processing from boot-selected CPUs"
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700685 depends on TREE_RCU || TREE_PREEMPT_RCU
686 default n
687 help
688 Use this option to reduce OS jitter for aggressive HPC or
689 real-time workloads. It can also be used to offload RCU
690 callback invocation to energy-efficient CPUs in battery-powered
691 asymmetric multiprocessors.
692
693 This option offloads callback invocation from the set of
694 CPUs specified at boot time by the rcu_nocbs parameter.
Paul E. McKenneya4889852012-12-03 08:16:28 -0800695 For each such CPU, a kthread ("rcuox/N") will be created to
696 invoke callbacks, where the "N" is the CPU being offloaded,
697 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
698 "s" for RCU-sched. Nothing prevents this kthread from running
699 on the specified CPUs, but (1) the kthreads may be preempted
700 between each callback, and (2) affinity or cgroups can be used
701 to force the kthreads to run on whatever set of CPUs is desired.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700702
Paul E. McKenney34ed62462013-01-07 13:37:42 -0800703 Say Y here if you want to help to debug reduced OS jitter.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700704 Say N here if you are unsure.
705
Paul E. McKenney911af502013-02-11 10:23:27 -0800706choice
707 prompt "Build-forced no-CBs CPUs"
708 default RCU_NOCB_CPU_NONE
709 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700710 This option allows no-CBs CPUs (whose RCU callbacks are invoked
711 from kthreads rather than from softirq context) to be specified
712 at build time. Additional no-CBs CPUs may be specified by
713 the rcu_nocbs= boot parameter.
Paul E. McKenney911af502013-02-11 10:23:27 -0800714
715config RCU_NOCB_CPU_NONE
716 bool "No build_forced no-CBs CPUs"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200717 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800718 help
719 This option does not force any of the CPUs to be no-CBs CPUs.
720 Only CPUs designated by the rcu_nocbs= boot parameter will be
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700721 no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU
722 kthreads whose names begin with "rcuo". All other CPUs will
723 invoke their own RCU callbacks in softirq context.
724
725 Select this option if you want to choose no-CBs CPUs at
726 boot time, for example, to allow testing of different no-CBs
727 configurations without having to rebuild the kernel each time.
Paul E. McKenney911af502013-02-11 10:23:27 -0800728
729config RCU_NOCB_CPU_ZERO
730 bool "CPU 0 is a build_forced no-CBs CPU"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200731 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800732 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700733 This option forces CPU 0 to be a no-CBs CPU, so that its RCU
734 callbacks are invoked by a per-CPU kthread whose name begins
735 with "rcuo". Additional CPUs may be designated as no-CBs
736 CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs.
737 All other CPUs will invoke their own RCU callbacks in softirq
738 context.
Paul E. McKenney911af502013-02-11 10:23:27 -0800739
740 Select this if CPU 0 needs to be a no-CBs CPU for real-time
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700741 or energy-efficiency reasons, but the real reason it exists
742 is to ensure that randconfig testing covers mixed systems.
Paul E. McKenney911af502013-02-11 10:23:27 -0800743
744config RCU_NOCB_CPU_ALL
745 bool "All CPUs are build_forced no-CBs CPUs"
746 depends on RCU_NOCB_CPU
747 help
748 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700749 boot parameter will be ignored. All CPUs' RCU callbacks will
750 be executed in the context of per-CPU rcuo kthreads created for
751 this purpose. Assuming that the kthreads whose names start with
752 "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter
753 on the remaining CPUs, but might decrease memory locality during
754 RCU-callback invocation, thus potentially degrading throughput.
Paul E. McKenney911af502013-02-11 10:23:27 -0800755
756 Select this if all CPUs need to be no-CBs CPUs for real-time
757 or energy-efficiency reasons.
758
759endchoice
760
Mike Travisc903ff82009-01-15 12:28:29 -0800761endmenu # "RCU Subsystem"
762
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700764 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 ---help---
766 This option enables the complete Linux kernel ".config" file
767 contents to be saved in the kernel. It provides documentation
768 of which kernel options are used in a running kernel or in an
769 on-disk kernel. This information can be extracted from the kernel
770 image file with the script scripts/extract-ikconfig and used as
771 input to rebuild the current kernel or to build another kernel.
772 It can also be extracted from a running kernel by reading
773 /proc/config.gz if enabled (below).
774
775config IKCONFIG_PROC
776 bool "Enable access to .config through /proc/config.gz"
777 depends on IKCONFIG && PROC_FS
778 ---help---
779 This option enables access to the kernel configuration file
780 through /proc/config.gz.
781
Alistair John Strachan794543a2007-05-08 00:31:15 -0700782config LOG_BUF_SHIFT
783 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
784 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700785 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700786 help
787 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700788 Examples:
789 17 => 128 KB
790 16 => 64 KB
791 15 => 32 KB
792 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700793 13 => 8 KB
794 12 => 4 KB
795
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800796#
797# Architectures with an unreliable sched_clock() should select this:
798#
799config HAVE_UNSTABLE_SCHED_CLOCK
800 bool
801
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700802config GENERIC_SCHED_CLOCK
803 bool
804
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200805#
806# For architectures that want to enable the support for NUMA-affine scheduler
807# balancing logic:
808#
809config ARCH_SUPPORTS_NUMA_BALANCING
810 bool
811
812# For architectures that (ab)use NUMA to represent different memory regions
813# all cpu-local but of different latencies, such as SuperH.
814#
815config ARCH_WANT_NUMA_VARIABLE_LOCALITY
816 bool
817
818#
819# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
820config ARCH_WANTS_PROT_NUMA_PROT_NONE
821 bool
822
823config ARCH_USES_NUMA_PROT_NONE
824 bool
825 default y
826 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
827 depends on NUMA_BALANCING
828
Mel Gorman1a687c22012-11-22 11:16:36 +0000829config NUMA_BALANCING_DEFAULT_ENABLED
830 bool "Automatically enable NUMA aware memory/task placement"
831 default y
832 depends on NUMA_BALANCING
833 help
Paul Gortmaker6d56a412013-08-13 11:06:50 -0400834 If set, automatic NUMA balancing will be enabled if running on a NUMA
Mel Gorman1a687c22012-11-22 11:16:36 +0000835 machine.
836
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200837config NUMA_BALANCING
838 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200839 depends on ARCH_SUPPORTS_NUMA_BALANCING
840 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
841 depends on SMP && NUMA && MIGRATION
842 help
843 This option adds support for automatic NUMA aware memory/task placement.
844 The mechanism is quite primitive and is based on migrating memory when
Paul Gortmaker6d56a412013-08-13 11:06:50 -0400845 it has references to the node the task is running on.
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200846
847 This system will be inactive on UMA systems.
848
Li Zefan23964d22009-01-15 13:50:58 -0800849menuconfig CGROUPS
850 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800851 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700852 help
Li Zefan23964d22009-01-15 13:50:58 -0800853 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800854 use with process control subsystems such as Cpusets, CFS, memory
855 controls or device isolation.
856 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800857 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800858 - Documentation/cgroups/ (features for grouping, isolation
859 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700860
861 Say N if unsure.
862
Li Zefan23964d22009-01-15 13:50:58 -0800863if CGROUPS
864
Paul Menage006cb992007-10-18 23:39:43 -0700865config CGROUP_DEBUG
866 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700867 default n
Paul Menage006cb992007-10-18 23:39:43 -0700868 help
869 This option enables a simple cgroup subsystem that
870 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800871 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700872
Li Zefan23964d22009-01-15 13:50:58 -0800873 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700874
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700875config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800876 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800877 help
878 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700879 cgroup.
880
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700881config CGROUP_DEVICE
882 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700883 help
884 Provides a cgroup implementing whitelists for devices which
885 a process in the cgroup can mknod or open.
886
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887config CPUSETS
888 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700890 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 allow dynamically partitioning a system into sets of CPUs and
892 Memory Nodes and assigning tasks to run only within those sets.
893 This is primarily useful on large SMP or NUMA systems.
894
895 Say N if unsure.
896
Li Zefan23964d22009-01-15 13:50:58 -0800897config PROC_PID_CPUSET
898 bool "Include legacy /proc/<pid>/cpuset file"
899 depends on CPUSETS
900 default y
901
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100902config CGROUP_CPUACCT
903 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100904 help
905 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800906 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100907
Pavel Emelianove552b662008-02-07 00:13:49 -0800908config RESOURCE_COUNTERS
909 bool "Resource counters"
910 help
911 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800912 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800913
Andrew Mortonc255a452012-07-31 16:43:02 -0700914config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800915 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700916 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700917 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800918 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700919 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100920 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800921
922 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700923 associated with each page of memory in the system. By this,
Sergey Dyaslyf60e2a92013-07-03 15:03:30 -0700924 8(16)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700925 usage tracking struct at boot. Total amount of this is printed out
926 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800927
928 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700929 sure you need the memory resource controller. Even when you enable
930 this, you can set "cgroup_disable=memory" at your boot option to
931 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800932 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800933
Balbir Singhcf475ad2008-04-29 01:00:16 -0700934 This config option also selects MM_OWNER config option, which
935 could in turn add some fork/exit overhead.
936
Andrew Mortonc255a452012-07-31 16:43:02 -0700937config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700938 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700939 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800940 help
941 Add swap management feature to memory resource controller. When you
942 enable this, you can limit mem+swap usage per cgroup. In other words,
943 when you disable this, memory resource controller has no cares to
944 usage of swap...a process can exhaust all of the swap. This extension
945 is useful when you want to avoid exhaustion swap but this itself
946 adds more overheads and consumes memory for remembering information.
947 Especially if you use 32bit system or small memory system, please
948 be careful about enabling this. When memory resource controller
949 is disabled by boot option, this will be automatically disabled and
950 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700951 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700952 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
953 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700954config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800955 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700956 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800957 default y
958 help
959 Memory Resource Controller Swap Extension comes with its price in
960 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700961 which want to enable the feature but keep it disabled by default
Michal Hocko07555ac2013-08-22 16:35:46 -0700962 and let the user enable it by swapaccount=1 boot command line
Michal Hockoa42c3902010-11-24 12:57:08 -0800963 parameter should have this option unselected.
964 For those who want to have the feature enabled by default should
965 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700966 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700967config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700968 bool "Memory Resource Controller Kernel Memory accounting"
969 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800970 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000971 help
972 The Kernel Memory extension for Memory Resource Controller can limit
973 the amount of memory used by kernel objects in the system. Those are
974 fundamentally different from the entities handled by the standard
975 Memory Controller, which are page-based, and can be swapped. Users of
976 the kmem extension can use it to guarantee that no group of processes
977 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800978
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700979config CGROUP_HUGETLB
980 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700981 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700982 default n
983 help
984 Provides a cgroup Resource Controller for HugeTLB pages.
985 When you enable this, you can put a per cgroup limit on HugeTLB usage.
986 The limit is enforced during page fault. Since HugeTLB doesn't
987 support page reclaim, enforcing the limit at page fault time implies
988 that, the application will get SIGBUS signal if it tries to access
989 HugeTLB pages beyond its limit. This requires the application to know
990 beforehand how much HugeTLB pages it would require for its use. The
991 control group is tracked in the third page lru pointer. This means
992 that we cannot use the controller with huge page less than 3 pages.
993
Stephane Eraniane5d13672011-02-14 11:20:01 +0200994config CGROUP_PERF
995 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
996 depends on PERF_EVENTS && CGROUPS
997 help
998 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800999 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +02001000 designated cpu.
1001
1002 Say N if unsure.
1003
Dhaval Giani7c941432010-01-20 13:26:18 +01001004menuconfig CGROUP_SCHED
1005 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +01001006 default n
1007 help
1008 This feature lets CPU scheduler recognize task groups and control CPU
1009 bandwidth allocation to such task groups. It uses cgroups to group
1010 tasks.
1011
1012if CGROUP_SCHED
1013config FAIR_GROUP_SCHED
1014 bool "Group scheduling for SCHED_OTHER"
1015 depends on CGROUP_SCHED
1016 default CGROUP_SCHED
1017
Paul Turnerab84d312011-07-21 09:43:28 -07001018config CFS_BANDWIDTH
1019 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -07001020 depends on FAIR_GROUP_SCHED
1021 default n
1022 help
1023 This option allows users to define CPU bandwidth rates (limits) for
1024 tasks running within the fair group scheduler. Groups with no limit
1025 set are considered to be unconstrained and will run with no
1026 restriction.
1027 See tip/Documentation/scheduler/sched-bwc.txt for more information.
1028
Dhaval Giani7c941432010-01-20 13:26:18 +01001029config RT_GROUP_SCHED
1030 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +01001031 depends on CGROUP_SCHED
1032 default n
1033 help
1034 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +08001035 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +01001036 schedule realtime tasks for non-root users until you allocate
1037 realtime bandwidth for them.
1038 See Documentation/scheduler/sched-rt-group.txt for more information.
1039
1040endif #CGROUP_SCHED
1041
Vivek Goyalafc24d42010-04-26 19:27:56 +02001042config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -08001043 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -07001044 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +02001045 default n
1046 ---help---
1047 Generic block IO controller cgroup interface. This is the common
1048 cgroup interface which should be used by various IO controlling
1049 policies.
1050
1051 Currently, CFQ IO scheduler uses it to recognize task groups and
1052 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -04001053 to such task groups. It is also used by bio throttling logic in
1054 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001055
1056 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -04001057 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +00001058 enabling proportional weight division of disk bandwidth in CFQ, set
1059 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +00001060 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001061
1062 See Documentation/cgroups/blkio-controller.txt for more information.
1063
1064config DEBUG_BLK_CGROUP
1065 bool "Enable Block IO controller debugging"
1066 depends on BLK_CGROUP
1067 default n
1068 ---help---
1069 Enable some debugging help. Currently it exports additional stat
1070 files in a cgroup which can be useful for debugging.
1071
Li Zefan23964d22009-01-15 13:50:58 -08001072endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001073
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001074config CHECKPOINT_RESTORE
1075 bool "Checkpoint/restore support" if EXPERT
1076 default n
1077 help
1078 Enables additional kernel features in a sake of checkpoint/restore.
1079 In particular it adds auxiliary prctl codes to setup process text,
1080 data and heap segment sizes, and a few additional /proc filesystem
1081 entries.
1082
1083 If unsure, say N here.
1084
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001085menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001086 bool "Namespaces support" if EXPERT
1087 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001088 help
1089 Provides the way to make tasks work with different objects using
1090 the same id. For example same IPC id may refer to different objects
1091 or same user id or pid may refer to different tasks when used in
1092 different namespaces.
1093
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001094if NAMESPACES
1095
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001096config UTS_NS
1097 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001098 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001099 help
1100 In this namespace tasks see different info provided with the
1101 uname() system call
1102
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001103config IPC_NS
1104 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001105 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001106 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001107 help
1108 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001109 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001110
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001111config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001112 bool "User namespace"
Eric W. Biederman5673a942011-11-17 10:23:55 -08001113 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001114
Eric W. Biederman5673a942011-11-17 10:23:55 -08001115 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001116 help
1117 This allows containers, i.e. vservers, to use user namespaces
1118 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001119
1120 When user namespaces are enabled in the kernel it is
1121 recommended that the MEMCG and MEMCG_KMEM options also be
1122 enabled and that user-space use the memory control groups to
1123 limit the amount of memory a memory unprivileged users can
1124 use.
1125
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001126 If unsure, say N.
1127
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001128config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001129 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001130 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001131 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001132 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001133 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001134 pid namespaces. This is a building block of containers.
1135
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001136config NET_NS
1137 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001138 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001139 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001140 help
1141 Allow user space to create what appear to be multiple instances
1142 of the network stack.
1143
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001144endif # NAMESPACES
1145
Eric W. Biederman5673a942011-11-17 10:23:55 -08001146config UIDGID_STRICT_TYPE_CHECKS
1147 bool "Require conversions between uid/gids and their internal representation"
1148 default n
1149 help
1150 While the nececessary conversions are being added to all subsystems this option allows
1151 the code to continue to build for unconverted subsystems.
1152
1153 Say Y here if you want the strict type checking enabled
1154
Mike Galbraith5091faa2010-11-30 14:18:03 +01001155config SCHED_AUTOGROUP
1156 bool "Automatic process group scheduling"
1157 select EVENTFD
1158 select CGROUPS
1159 select CGROUP_SCHED
1160 select FAIR_GROUP_SCHED
1161 help
1162 This option optimizes the scheduler for common desktop workloads by
1163 automatically creating and populating task groups. This separation
1164 of workloads isolates aggressive CPU burners (like build jobs) from
1165 desktop applications. Task group autogeneration is currently based
1166 upon task session.
1167
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001168config MM_OWNER
1169 bool
1170
1171config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001172 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001173 depends on SYSFS
1174 default n
1175 help
1176 This option adds code that switches the layout of the "block" class
1177 devices, to not show up in /sys/class/block/, but only in
1178 /sys/block/.
1179
1180 This switch is only active when the sysfs.deprecated=1 boot option is
1181 passed or the SYSFS_DEPRECATED_V2 option is set.
1182
1183 This option allows new kernels to run on old distributions and tools,
1184 which might get confused by /sys/class/block/. Since 2007/2008 all
1185 major distributions and tools handle this just fine.
1186
1187 Recent distributions and userspace tools after 2009/2010 depend on
1188 the existence of /sys/class/block/, and will not work with this
1189 option enabled.
1190
1191 Only if you are using a new kernel on an old distribution, you might
1192 need to say Y here.
1193
1194config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001195 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001196 default n
1197 depends on SYSFS
1198 depends on SYSFS_DEPRECATED
1199 help
1200 Enable deprecated sysfs by default.
1201
1202 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1203 option.
1204
1205 Only if you are using a new kernel on an old distribution, you might
1206 need to say Y here. Even then, odds are you would not need it
1207 enabled, you can always pass the boot option if absolutely necessary.
1208
1209config RELAY
1210 bool "Kernel->user space relay support (formerly relayfs)"
1211 help
1212 This option enables support for relay interface support in
1213 certain file systems (such as debugfs).
1214 It is designed to provide an efficient mechanism for tools and
1215 facilities to relay large amounts of data from kernel space to
1216 user space.
1217
1218 If unsure, say N.
1219
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001220config BLK_DEV_INITRD
1221 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1222 depends on BROKEN || !FRV
1223 help
1224 The initial RAM filesystem is a ramfs which is loaded by the
1225 boot loader (loadlin or lilo) and that is mounted as root
1226 before the normal boot procedure. It is typically used to
1227 load modules needed to mount the "real" root file system,
1228 etc. See <file:Documentation/initrd.txt> for details.
1229
1230 If RAM disk support (BLK_DEV_RAM) is also included, this
1231 also enables initial RAM disk (initrd) support and adds
1232 15 Kbytes (more on some other architectures) to the kernel size.
1233
1234 If unsure say Y.
1235
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001236if BLK_DEV_INITRD
1237
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001238source "usr/Kconfig"
1239
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001240endif
1241
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001242config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001243 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001244 help
1245 Enabling this option will pass "-Os" instead of "-O2" to gcc
1246 resulting in a smaller kernel.
1247
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001248 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001249
Randy Dunlap08470622006-09-30 23:28:13 -07001250config SYSCTL
1251 bool
1252
Randy Dunlapb943c462009-03-10 12:55:46 -07001253config ANON_INODES
1254 bool
1255
Mike Frysinger657a5202013-04-30 15:28:45 -07001256config HAVE_UID16
1257 bool
1258
1259config SYSCTL_EXCEPTION_TRACE
1260 bool
1261 help
1262 Enable support for /proc/sys/debug/exception-trace.
1263
1264config SYSCTL_ARCH_UNALIGN_NO_WARN
1265 bool
1266 help
1267 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1268 Allows arch to define/use @no_unaligned_warning to possibly warn
1269 about unaligned access emulation going on under the hood.
1270
1271config SYSCTL_ARCH_UNALIGN_ALLOW
1272 bool
1273 help
1274 Enable support for /proc/sys/kernel/unaligned-trap
1275 Allows arches to define/use @unaligned_enabled to runtime toggle
1276 the unaligned access emulation.
1277 see arch/parisc/kernel/unaligned.c for reference
1278
Mike Frysinger657a5202013-04-30 15:28:45 -07001279config HAVE_PCSPKR_PLATFORM
1280 bool
1281
David Rientjes6a108a12011-01-20 14:44:16 -08001282menuconfig EXPERT
1283 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001284 # Unhide debug options, to make the on-by-default options visible
1285 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 help
1287 This option allows certain base kernel options and settings
1288 to be disabled or tweaked. This is for specialized
1289 environments which can tolerate a "non-standard" kernel.
1290 Only use this if you really know what you are doing.
1291
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001292config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001293 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001294 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001295 default y
1296 help
1297 This enables the legacy 16-bit UID syscall wrappers.
1298
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001299config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001300 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001301 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001302 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001303 select SYSCTL
1304 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001305 sys_sysctl uses binary paths that have been found challenging
1306 to properly maintain and use. The interface in /proc/sys
1307 using paths with ascii names is now the primary path to this
1308 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001309
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001310 Almost nothing using the binary sysctl interface so if you are
1311 trying to save some space it is probably safe to disable this,
1312 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001313
WANG Congc736de62011-11-02 13:39:25 -07001314 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001315
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001317 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318 default y
1319 help
1320 Say Y here to let the kernel print out symbolic crash information and
1321 symbolic stack backtraces. This increases the size of the kernel
1322 somewhat, as all symbols have to be loaded into the kernel image.
1323
1324config KALLSYMS_ALL
1325 bool "Include all symbols in kallsyms"
1326 depends on DEBUG_KERNEL && KALLSYMS
1327 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001328 Normally kallsyms only contains the symbols of functions for nicer
1329 OOPS messages and backtraces (i.e., symbols from the text and inittext
1330 sections). This is sufficient for most cases. And only in very rare
1331 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1332 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001334 This option makes sure that all symbols are loaded into the kernel
1335 image (i.e., symbols from all sections) in cost of increased kernel
1336 size (depending on the kernel configuration, it may be 300KiB or
1337 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001339 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001340
1341config PRINTK
1342 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001343 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001344 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001345 help
1346 This option enables normal printk support. Removing it
1347 eliminates most of the message strings from the kernel image
1348 and makes the kernel more or less silent. As this makes it
1349 very difficult to diagnose system problems, saying N here is
1350 strongly discouraged.
1351
Matt Mackallc8538a72005-05-01 08:59:01 -07001352config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001353 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001354 default y
1355 help
1356 Disabling this option eliminates support for BUG and WARN, reducing
1357 the size of your kernel image and potentially quietly ignoring
1358 numerous fatal conditions. You should only consider disabling this
1359 option for embedded systems with no facilities for reporting errors.
1360 Just say Y.
1361
Matt Mackall708e9a72006-01-08 01:05:25 -08001362config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001363 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001364 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001365 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001366 help
1367 Enable support for generating core dumps. Disabling saves about 4k.
1368
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001369
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001370config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001371 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001372 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001373 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001374 default y
1375 help
1376 This option allows to disable the internal PC-Speaker
1377 support, saving some memory.
1378
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379config BASE_FULL
1380 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001381 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 help
1383 Disabling this option reduces the size of miscellaneous core
1384 kernel data structures. This saves memory on small machines,
1385 but may reduce performance.
1386
1387config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001388 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001390 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001391 help
1392 Disabling this option will cause the kernel to be built without
1393 support for "fast userspace mutexes". The resulting kernel may not
1394 run glibc-based applications correctly.
1395
1396config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001397 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001399 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 help
1401 Disabling this option will cause the kernel to be built without
1402 support for epoll family of system calls.
1403
Davide Libenzifba2afa2007-05-10 22:23:13 -07001404config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001405 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001406 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001407 default y
1408 help
1409 Enable the signalfd() system call that allows to receive signals
1410 on a file descriptor.
1411
1412 If unsure, say Y.
1413
Davide Libenzib215e282007-05-10 22:23:16 -07001414config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001415 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001416 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001417 default y
1418 help
1419 Enable the timerfd() system call that allows to receive timer
1420 events on a file descriptor.
1421
1422 If unsure, say Y.
1423
Davide Libenzie1ad7462007-05-10 22:23:19 -07001424config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001425 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001426 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001427 default y
1428 help
1429 Enable the eventfd() system call that allows to receive both
1430 kernel notification (ie. KAIO) or userspace notifications.
1431
1432 If unsure, say Y.
1433
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001435 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436 default y
1437 depends on MMU
1438 help
1439 The shmem is an internal filesystem used to manage shared memory.
1440 It is backed by swap and manages resource limits. It is also exported
1441 to userspace as tmpfs if TMPFS is enabled. Disabling this
1442 option replaces shmem and tmpfs with the much simpler ramfs code,
1443 which may be appropriate on small systems without swap.
1444
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001445config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001446 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001447 default y
1448 help
1449 This option enables POSIX asynchronous I/O which may by used
Mike Frysinger657a5202013-04-30 15:28:45 -07001450 by some high performance threaded applications. Disabling
1451 this option saves about 7k.
1452
1453config PCI_QUIRKS
1454 default y
1455 bool "Enable PCI quirk workarounds" if EXPERT
1456 depends on PCI
1457 help
1458 This enables workarounds for various PCI chipset
1459 bugs/quirks. Disable this only if your target machine is
1460 unaffected by PCI quirks.
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001461
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001462config EMBEDDED
1463 bool "Embedded system"
1464 select EXPERT
1465 help
1466 This option should be enabled if compiling the kernel for
1467 an embedded system so certain expert options are available
1468 for configuration.
1469
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001470config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001471 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001472 help
1473 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001474
Peter Zijlstra906010b2009-09-21 16:08:49 +02001475config PERF_USE_VMALLOC
1476 bool
1477 help
1478 See tools/perf/design.txt for details
1479
Ingo Molnar57c0c152009-09-21 12:20:38 +02001480menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001481
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001482config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001483 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001484 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001485 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001486 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001487 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001488 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001489 Enable kernel support for various performance events provided
1490 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001491
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001492 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001493 use of generic tracepoints.
1494
1495 Most modern CPUs support performance events via performance
1496 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001497 types of hw events: such as instructions executed, cachemisses
1498 suffered, or branches mis-predicted - without slowing down the
1499 kernel or applications. These registers can also trigger interrupts
1500 when a threshold number of events have passed - and can thus be
1501 used to profile the code that runs on that CPU.
1502
Ingo Molnar57c0c152009-09-21 12:20:38 +02001503 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001504 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001505 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001506 provides per task and per CPU counters, and it provides event
1507 capabilities on top of those.
1508
1509 Say Y if unsure.
1510
Peter Zijlstra906010b2009-09-21 16:08:49 +02001511config DEBUG_PERF_USE_VMALLOC
1512 default n
1513 bool "Debug: use vmalloc to back perf mmap() buffers"
1514 depends on PERF_EVENTS && DEBUG_KERNEL
1515 select PERF_USE_VMALLOC
1516 help
1517 Use vmalloc memory to back perf mmap() buffers.
1518
1519 Mostly useful for debugging the vmalloc code on platforms
1520 that don't require it.
1521
1522 Say N if unsure.
1523
Thomas Gleixner0793a612008-12-04 20:12:29 +01001524endmenu
1525
Christoph Lameterf8891e52006-06-30 01:55:45 -07001526config VM_EVENT_COUNTERS
1527 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001528 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001529 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001530 VM event counters are needed for event counts to be shown.
1531 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001532 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001533 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001534
Christoph Lameter41ecc552007-05-09 02:32:44 -07001535config SLUB_DEBUG
1536 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001537 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001538 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001539 help
1540 SLUB has extensive debug support features. Disabling these can
1541 result in significant savings in code size. This also disables
1542 SLUB sysfs support. /sys/slab will not exist and there will be
1543 no support for cache validation etc.
1544
Randy Dunlapb943c462009-03-10 12:55:46 -07001545config COMPAT_BRK
1546 bool "Disable heap randomization"
1547 default y
1548 help
1549 Randomizing heap placement makes heap exploits harder, but it
1550 also breaks ancient binaries (including anything libc5 based).
1551 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001552 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001553 /proc/sys/kernel/randomize_va_space to 2.
1554
1555 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1556
Christoph Lameter81819f02007-05-06 14:49:36 -07001557choice
1558 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001559 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001560 help
1561 This option allows to select a slab allocator.
1562
1563config SLAB
1564 bool "SLAB"
1565 help
1566 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001567 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001568 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001569
1570config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001571 bool "SLUB (Unqueued Allocator)"
1572 help
1573 SLUB is a slab allocator that minimizes cache line usage
1574 instead of managing queues of cached objects (SLAB approach).
1575 Per cpu caching is realized using slabs of objects instead
1576 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001577 and has enhanced diagnostics. SLUB is the default choice for
1578 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001579
1580config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001581 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001582 bool "SLOB (Simple Allocator)"
1583 help
Matt Mackall37291452008-02-04 22:29:38 -08001584 SLOB replaces the stock allocator with a drastically simpler
1585 allocator. SLOB is generally more space efficient but
1586 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001587
1588endchoice
1589
Joonsoo Kim345c9052013-06-19 14:05:52 +09001590config SLUB_CPU_PARTIAL
1591 default y
Uwe Kleine-Königb39ffbf2013-07-17 16:54:59 +02001592 depends on SLUB && SMP
Joonsoo Kim345c9052013-06-19 14:05:52 +09001593 bool "SLUB per cpu partial cache"
1594 help
1595 Per cpu partial caches accellerate objects allocation and freeing
1596 that is local to a processor at the price of more indeterminism
1597 in the latency of the free. On overflow these caches will be cleared
1598 which requires the taking of locks that may cause latency spikes.
1599 Typically one would choose no for a realtime system.
1600
Jie Zhangea637632009-12-14 18:00:02 -08001601config MMAP_ALLOW_UNINITIALIZED
1602 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001603 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001604 default n
1605 help
1606 Normally, and according to the Linux spec, anonymous memory obtained
1607 from mmap() has it's contents cleared before it is passed to
1608 userspace. Enabling this config option allows you to request that
1609 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1610 providing a huge performance boost. If this option is not enabled,
1611 then the flag will be ignored.
1612
1613 This is taken advantage of by uClibc's malloc(), and also by
1614 ELF-FDPIC binfmt's brk and stack allocator.
1615
1616 Because of the obvious security issues, this option should only be
1617 enabled on embedded devices where you control what is run in
1618 userspace. Since that isn't generally a problem on no-MMU systems,
1619 it is normally safe to say Y here.
1620
1621 See Documentation/nommu-mmap.txt for more information.
1622
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001623config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001624 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001625 help
1626 Say Y here to enable the extended profiling support mechanisms used
1627 by profilers such as OProfile.
1628
Ingo Molnar5f87f112008-07-23 14:15:22 +02001629#
1630# Place an empty function call at each tracepoint site. Can be
1631# dynamically changed for a probe function.
1632#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001633config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001634 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001635
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001636source "arch/Kconfig"
1637
Linus Torvalds1da177e2005-04-16 15:20:36 -07001638endmenu # General setup
1639
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001640config HAVE_GENERIC_DMA_COHERENT
1641 bool
1642 default n
1643
Linus Torvalds158a9622008-01-02 13:04:48 -08001644config SLABINFO
1645 bool
1646 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001647 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001648 default y
1649
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001650config RT_MUTEXES
1651 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001652
Linus Torvalds1da177e2005-04-16 15:20:36 -07001653config BASE_SMALL
1654 int
1655 default 0 if BASE_FULL
1656 default 1 if !BASE_FULL
1657
David Howellsb56e5a12013-08-30 16:07:30 +01001658config SYSTEM_TRUSTED_KEYRING
1659 bool "Provide system-wide ring of trusted keys"
1660 depends on KEYS
1661 help
1662 Provide a system keyring to which trusted keys can be added. Keys in
1663 the keyring are considered to be trusted. Keys may be added at will
1664 by the kernel from compiled-in data and from hardware key stores, but
1665 userspace may only add extra keys if those keys can be verified by
1666 keys already in the keyring.
1667
1668 Keys in this keyring are used by module signature checking.
1669
Jan Engelhardt66da5732007-07-15 23:39:29 -07001670menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671 bool "Enable loadable module support"
Yann E. MORIN11097a02013-08-11 16:07:50 +02001672 option modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 help
1674 Kernel modules are small pieces of compiled code which can
1675 be inserted in the running kernel, rather than being
1676 permanently built into the kernel. You use the "modprobe"
1677 tool to add (and sometimes remove) them. If you say Y here,
1678 many parts of the kernel can be built as modules (by
1679 answering M instead of Y where indicated): this is most
1680 useful for infrequently used options which are not required
1681 for booting. For more information, see the man pages for
1682 modprobe, lsmod, modinfo, insmod and rmmod.
1683
1684 If you say Y here, you will need to run "make
1685 modules_install" to put the modules under /lib/modules/
1686 where modprobe can find them (you may need to be root to do
1687 this).
1688
1689 If unsure, say Y.
1690
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001691if MODULES
1692
Linus Torvalds826e4502008-05-04 17:04:16 -07001693config MODULE_FORCE_LOAD
1694 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001695 default n
1696 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001697 Allow loading of modules without version information (ie. modprobe
1698 --force). Forced module loading sets the 'F' (forced) taint flag and
1699 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001700
Linus Torvalds1da177e2005-04-16 15:20:36 -07001701config MODULE_UNLOAD
1702 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703 help
1704 Without this option you will not be able to unload any
1705 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001706 anyway), which makes your kernel smaller, faster
1707 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708
1709config MODULE_FORCE_UNLOAD
1710 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001711 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712 help
1713 This option allows you to force a module to unload, even if the
1714 kernel believes it is unsafe: the kernel will remove the module
1715 without waiting for anyone to stop using it (using the -f option to
1716 rmmod). This is mainly for kernel developers and desperate users.
1717 If unsure, say N.
1718
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001720 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721 help
1722 Usually, you have to use modules compiled with your kernel.
1723 Saying Y here makes it sometimes possible to use modules
1724 compiled for different kernels, by adding enough information
1725 to the modules to (hopefully) spot any changes which would
1726 make them incompatible with the kernel you are running. If
1727 unsure, say N.
1728
1729config MODULE_SRCVERSION_ALL
1730 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731 help
1732 Modules which contain a MODULE_VERSION get an extra "srcversion"
1733 field inserted into their modinfo section, which contains a
1734 sum of the source files which made it. This helps maintainers
1735 see exactly which source was used to build a module (since
1736 others sometimes change the module source without updating
1737 the version). With this option, such a "srcversion" field
1738 will be created for all modules. If unsure, say N.
1739
Rusty Russell106a4ee2012-09-26 10:09:40 +01001740config MODULE_SIG
1741 bool "Module signature verification"
1742 depends on MODULES
David Howellsb56e5a12013-08-30 16:07:30 +01001743 select SYSTEM_TRUSTED_KEYRING
David Howells48ba2462012-09-26 10:11:03 +01001744 select KEYS
1745 select CRYPTO
1746 select ASYMMETRIC_KEY_TYPE
1747 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1748 select PUBLIC_KEY_ALGO_RSA
1749 select ASN1
1750 select OID_REGISTRY
1751 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001752 help
1753 Check modules for valid signatures upon load: the signature
1754 is simply appended to the module. For more information see
1755 Documentation/module-signing.txt.
1756
David Howellsea0b6dc2012-09-26 10:09:50 +01001757 !!!WARNING!!! If you enable this option, you MUST make sure that the
1758 module DOES NOT get stripped after being signed. This includes the
1759 debuginfo strip done by some packagers (such as rpmbuild) and
1760 inclusion into an initramfs that wants the module size reduced.
1761
Rusty Russell106a4ee2012-09-26 10:09:40 +01001762config MODULE_SIG_FORCE
1763 bool "Require modules to be validly signed"
1764 depends on MODULE_SIG
1765 help
1766 Reject unsigned modules or signed modules for which we don't have a
1767 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001768
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301769config MODULE_SIG_ALL
1770 bool "Automatically sign all modules"
1771 default y
1772 depends on MODULE_SIG
1773 help
1774 Sign all modules during make modules_install. Without this option,
1775 modules must be signed manually, using the scripts/sign-file tool.
1776
1777comment "Do not forget to sign required modules with scripts/sign-file"
1778 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1779
David Howellsea0b6dc2012-09-26 10:09:50 +01001780choice
1781 prompt "Which hash algorithm should modules be signed with?"
1782 depends on MODULE_SIG
1783 help
1784 This determines which sort of hashing algorithm will be used during
1785 signature generation. This algorithm _must_ be built into the kernel
1786 directly so that signature verification can take place. It is not
1787 possible to load a signed module containing the algorithm to check
1788 the signature on that module.
1789
1790config MODULE_SIG_SHA1
1791 bool "Sign modules with SHA-1"
1792 select CRYPTO_SHA1
1793
1794config MODULE_SIG_SHA224
1795 bool "Sign modules with SHA-224"
1796 select CRYPTO_SHA256
1797
1798config MODULE_SIG_SHA256
1799 bool "Sign modules with SHA-256"
1800 select CRYPTO_SHA256
1801
1802config MODULE_SIG_SHA384
1803 bool "Sign modules with SHA-384"
1804 select CRYPTO_SHA512
1805
1806config MODULE_SIG_SHA512
1807 bool "Sign modules with SHA-512"
1808 select CRYPTO_SHA512
1809
1810endchoice
1811
Michal Marek22753672013-01-25 13:41:00 +10301812config MODULE_SIG_HASH
1813 string
1814 depends on MODULE_SIG
1815 default "sha1" if MODULE_SIG_SHA1
1816 default "sha224" if MODULE_SIG_SHA224
1817 default "sha256" if MODULE_SIG_SHA256
1818 default "sha384" if MODULE_SIG_SHA384
1819 default "sha512" if MODULE_SIG_SHA512
1820
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001821endif # MODULES
1822
Rusty Russell98a79d62008-12-13 21:19:41 +10301823config INIT_ALL_POSSIBLE
1824 bool
1825 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301826 Back when each arch used to define their own cpu_online_mask and
1827 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301828 with all 1s, and others with all 0s. When they were centralised,
1829 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001830 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301831
Linus Torvalds1da177e2005-04-16 15:20:36 -07001832config STOP_MACHINE
1833 bool
1834 default y
1835 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1836 help
1837 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001838
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001839source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001840
1841config PREEMPT_NOTIFIERS
1842 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001843
Steffen Klassert16295be2010-01-06 19:47:10 +11001844config PADATA
1845 depends on SMP
1846 bool
1847
Andi Kleen754b7b62012-10-04 17:11:27 -07001848# Can be selected by architectures with broken toolchains
1849# that get confused by correct const<->read_only section
1850# mappings
1851config BROKEN_RODATA
1852 bool
1853
David Howells4520c6a2012-09-21 23:31:13 +01001854config ASN1
1855 tristate
1856 help
1857 Build a simple ASN.1 grammar compiler that produces a bytecode output
1858 that can be interpreted by the ASN.1 stream decoder and used to
1859 inform it as to what tags are to be expected in a stream and what
1860 functions to call on what tags.
1861
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001862source "kernel/Kconfig.locks"