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Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
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
Peter Zijlstrabe5e6102013-11-18 18:27:06 +0100812#
813# For architectures that know their GCC __int128 support is sound
814#
815config ARCH_SUPPORTS_INT128
816 bool
817
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200818# For architectures that (ab)use NUMA to represent different memory regions
819# all cpu-local but of different latencies, such as SuperH.
820#
821config ARCH_WANT_NUMA_VARIABLE_LOCALITY
822 bool
823
824#
825# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
826config ARCH_WANTS_PROT_NUMA_PROT_NONE
827 bool
828
829config ARCH_USES_NUMA_PROT_NONE
830 bool
831 default y
832 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
833 depends on NUMA_BALANCING
834
Mel Gorman1a687c22012-11-22 11:16:36 +0000835config NUMA_BALANCING_DEFAULT_ENABLED
836 bool "Automatically enable NUMA aware memory/task placement"
837 default y
838 depends on NUMA_BALANCING
839 help
Paul Gortmaker6d56a412013-08-13 11:06:50 -0400840 If set, automatic NUMA balancing will be enabled if running on a NUMA
Mel Gorman1a687c22012-11-22 11:16:36 +0000841 machine.
842
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200843config NUMA_BALANCING
844 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200845 depends on ARCH_SUPPORTS_NUMA_BALANCING
846 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
847 depends on SMP && NUMA && MIGRATION
848 help
849 This option adds support for automatic NUMA aware memory/task placement.
850 The mechanism is quite primitive and is based on migrating memory when
Paul Gortmaker6d56a412013-08-13 11:06:50 -0400851 it has references to the node the task is running on.
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200852
853 This system will be inactive on UMA systems.
854
Li Zefan23964d22009-01-15 13:50:58 -0800855menuconfig CGROUPS
856 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800857 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700858 help
Li Zefan23964d22009-01-15 13:50:58 -0800859 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800860 use with process control subsystems such as Cpusets, CFS, memory
861 controls or device isolation.
862 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800863 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800864 - Documentation/cgroups/ (features for grouping, isolation
865 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700866
867 Say N if unsure.
868
Li Zefan23964d22009-01-15 13:50:58 -0800869if CGROUPS
870
Paul Menage006cb992007-10-18 23:39:43 -0700871config CGROUP_DEBUG
872 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700873 default n
Paul Menage006cb992007-10-18 23:39:43 -0700874 help
875 This option enables a simple cgroup subsystem that
876 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800877 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700878
Li Zefan23964d22009-01-15 13:50:58 -0800879 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700880
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700881config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800882 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800883 help
884 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700885 cgroup.
886
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700887config CGROUP_DEVICE
888 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700889 help
890 Provides a cgroup implementing whitelists for devices which
891 a process in the cgroup can mknod or open.
892
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893config CPUSETS
894 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700896 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 allow dynamically partitioning a system into sets of CPUs and
898 Memory Nodes and assigning tasks to run only within those sets.
899 This is primarily useful on large SMP or NUMA systems.
900
901 Say N if unsure.
902
Li Zefan23964d22009-01-15 13:50:58 -0800903config PROC_PID_CPUSET
904 bool "Include legacy /proc/<pid>/cpuset file"
905 depends on CPUSETS
906 default y
907
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100908config CGROUP_CPUACCT
909 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100910 help
911 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800912 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100913
Pavel Emelianove552b662008-02-07 00:13:49 -0800914config RESOURCE_COUNTERS
915 bool "Resource counters"
916 help
917 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800918 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800919
Andrew Mortonc255a452012-07-31 16:43:02 -0700920config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800921 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700922 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700923 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800924 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700925 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100926 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800927
928 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700929 associated with each page of memory in the system. By this,
Sergey Dyaslyf60e2a92013-07-03 15:03:30 -0700930 8(16)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700931 usage tracking struct at boot. Total amount of this is printed out
932 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800933
934 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700935 sure you need the memory resource controller. Even when you enable
936 this, you can set "cgroup_disable=memory" at your boot option to
937 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800938 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800939
Balbir Singhcf475ad2008-04-29 01:00:16 -0700940 This config option also selects MM_OWNER config option, which
941 could in turn add some fork/exit overhead.
942
Andrew Mortonc255a452012-07-31 16:43:02 -0700943config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700944 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700945 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800946 help
947 Add swap management feature to memory resource controller. When you
948 enable this, you can limit mem+swap usage per cgroup. In other words,
949 when you disable this, memory resource controller has no cares to
950 usage of swap...a process can exhaust all of the swap. This extension
951 is useful when you want to avoid exhaustion swap but this itself
952 adds more overheads and consumes memory for remembering information.
953 Especially if you use 32bit system or small memory system, please
954 be careful about enabling this. When memory resource controller
955 is disabled by boot option, this will be automatically disabled and
956 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700957 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700958 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
959 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700960config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800961 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700962 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800963 default y
964 help
965 Memory Resource Controller Swap Extension comes with its price in
966 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700967 which want to enable the feature but keep it disabled by default
Michal Hocko07555ac2013-08-22 16:35:46 -0700968 and let the user enable it by swapaccount=1 boot command line
Michal Hockoa42c3902010-11-24 12:57:08 -0800969 parameter should have this option unselected.
970 For those who want to have the feature enabled by default should
971 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700972 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700973config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700974 bool "Memory Resource Controller Kernel Memory accounting"
975 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800976 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000977 help
978 The Kernel Memory extension for Memory Resource Controller can limit
979 the amount of memory used by kernel objects in the system. Those are
980 fundamentally different from the entities handled by the standard
981 Memory Controller, which are page-based, and can be swapped. Users of
982 the kmem extension can use it to guarantee that no group of processes
983 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800984
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700985config CGROUP_HUGETLB
986 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700987 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700988 default n
989 help
990 Provides a cgroup Resource Controller for HugeTLB pages.
991 When you enable this, you can put a per cgroup limit on HugeTLB usage.
992 The limit is enforced during page fault. Since HugeTLB doesn't
993 support page reclaim, enforcing the limit at page fault time implies
994 that, the application will get SIGBUS signal if it tries to access
995 HugeTLB pages beyond its limit. This requires the application to know
996 beforehand how much HugeTLB pages it would require for its use. The
997 control group is tracked in the third page lru pointer. This means
998 that we cannot use the controller with huge page less than 3 pages.
999
Stephane Eraniane5d13672011-02-14 11:20:01 +02001000config CGROUP_PERF
1001 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
1002 depends on PERF_EVENTS && CGROUPS
1003 help
1004 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +08001005 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +02001006 designated cpu.
1007
1008 Say N if unsure.
1009
Dhaval Giani7c941432010-01-20 13:26:18 +01001010menuconfig CGROUP_SCHED
1011 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +01001012 default n
1013 help
1014 This feature lets CPU scheduler recognize task groups and control CPU
1015 bandwidth allocation to such task groups. It uses cgroups to group
1016 tasks.
1017
1018if CGROUP_SCHED
1019config FAIR_GROUP_SCHED
1020 bool "Group scheduling for SCHED_OTHER"
1021 depends on CGROUP_SCHED
1022 default CGROUP_SCHED
1023
Paul Turnerab84d312011-07-21 09:43:28 -07001024config CFS_BANDWIDTH
1025 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -07001026 depends on FAIR_GROUP_SCHED
1027 default n
1028 help
1029 This option allows users to define CPU bandwidth rates (limits) for
1030 tasks running within the fair group scheduler. Groups with no limit
1031 set are considered to be unconstrained and will run with no
1032 restriction.
1033 See tip/Documentation/scheduler/sched-bwc.txt for more information.
1034
Dhaval Giani7c941432010-01-20 13:26:18 +01001035config RT_GROUP_SCHED
1036 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +01001037 depends on CGROUP_SCHED
1038 default n
1039 help
1040 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +08001041 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +01001042 schedule realtime tasks for non-root users until you allocate
1043 realtime bandwidth for them.
1044 See Documentation/scheduler/sched-rt-group.txt for more information.
1045
1046endif #CGROUP_SCHED
1047
Vivek Goyalafc24d42010-04-26 19:27:56 +02001048config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -08001049 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -07001050 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +02001051 default n
1052 ---help---
1053 Generic block IO controller cgroup interface. This is the common
1054 cgroup interface which should be used by various IO controlling
1055 policies.
1056
1057 Currently, CFQ IO scheduler uses it to recognize task groups and
1058 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -04001059 to such task groups. It is also used by bio throttling logic in
1060 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001061
1062 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -04001063 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +00001064 enabling proportional weight division of disk bandwidth in CFQ, set
1065 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +00001066 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001067
1068 See Documentation/cgroups/blkio-controller.txt for more information.
1069
1070config DEBUG_BLK_CGROUP
1071 bool "Enable Block IO controller debugging"
1072 depends on BLK_CGROUP
1073 default n
1074 ---help---
1075 Enable some debugging help. Currently it exports additional stat
1076 files in a cgroup which can be useful for debugging.
1077
Li Zefan23964d22009-01-15 13:50:58 -08001078endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001079
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001080config CHECKPOINT_RESTORE
1081 bool "Checkpoint/restore support" if EXPERT
1082 default n
1083 help
1084 Enables additional kernel features in a sake of checkpoint/restore.
1085 In particular it adds auxiliary prctl codes to setup process text,
1086 data and heap segment sizes, and a few additional /proc filesystem
1087 entries.
1088
1089 If unsure, say N here.
1090
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001091menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001092 bool "Namespaces support" if EXPERT
1093 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001094 help
1095 Provides the way to make tasks work with different objects using
1096 the same id. For example same IPC id may refer to different objects
1097 or same user id or pid may refer to different tasks when used in
1098 different namespaces.
1099
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001100if NAMESPACES
1101
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001102config UTS_NS
1103 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001104 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001105 help
1106 In this namespace tasks see different info provided with the
1107 uname() system call
1108
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001109config IPC_NS
1110 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001111 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001112 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001113 help
1114 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001115 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001116
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001117config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001118 bool "User namespace"
Eric W. Biederman5673a942011-11-17 10:23:55 -08001119 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001120
Eric W. Biederman5673a942011-11-17 10:23:55 -08001121 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001122 help
1123 This allows containers, i.e. vservers, to use user namespaces
1124 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001125
1126 When user namespaces are enabled in the kernel it is
1127 recommended that the MEMCG and MEMCG_KMEM options also be
1128 enabled and that user-space use the memory control groups to
1129 limit the amount of memory a memory unprivileged users can
1130 use.
1131
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001132 If unsure, say N.
1133
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001134config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001135 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001136 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001137 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001138 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001139 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001140 pid namespaces. This is a building block of containers.
1141
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001142config NET_NS
1143 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001144 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001145 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001146 help
1147 Allow user space to create what appear to be multiple instances
1148 of the network stack.
1149
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001150endif # NAMESPACES
1151
Eric W. Biederman5673a942011-11-17 10:23:55 -08001152config UIDGID_STRICT_TYPE_CHECKS
1153 bool "Require conversions between uid/gids and their internal representation"
1154 default n
1155 help
1156 While the nececessary conversions are being added to all subsystems this option allows
1157 the code to continue to build for unconverted subsystems.
1158
1159 Say Y here if you want the strict type checking enabled
1160
Mike Galbraith5091faa2010-11-30 14:18:03 +01001161config SCHED_AUTOGROUP
1162 bool "Automatic process group scheduling"
1163 select EVENTFD
1164 select CGROUPS
1165 select CGROUP_SCHED
1166 select FAIR_GROUP_SCHED
1167 help
1168 This option optimizes the scheduler for common desktop workloads by
1169 automatically creating and populating task groups. This separation
1170 of workloads isolates aggressive CPU burners (like build jobs) from
1171 desktop applications. Task group autogeneration is currently based
1172 upon task session.
1173
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001174config MM_OWNER
1175 bool
1176
1177config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001178 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001179 depends on SYSFS
1180 default n
1181 help
1182 This option adds code that switches the layout of the "block" class
1183 devices, to not show up in /sys/class/block/, but only in
1184 /sys/block/.
1185
1186 This switch is only active when the sysfs.deprecated=1 boot option is
1187 passed or the SYSFS_DEPRECATED_V2 option is set.
1188
1189 This option allows new kernels to run on old distributions and tools,
1190 which might get confused by /sys/class/block/. Since 2007/2008 all
1191 major distributions and tools handle this just fine.
1192
1193 Recent distributions and userspace tools after 2009/2010 depend on
1194 the existence of /sys/class/block/, and will not work with this
1195 option enabled.
1196
1197 Only if you are using a new kernel on an old distribution, you might
1198 need to say Y here.
1199
1200config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001201 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001202 default n
1203 depends on SYSFS
1204 depends on SYSFS_DEPRECATED
1205 help
1206 Enable deprecated sysfs by default.
1207
1208 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1209 option.
1210
1211 Only if you are using a new kernel on an old distribution, you might
1212 need to say Y here. Even then, odds are you would not need it
1213 enabled, you can always pass the boot option if absolutely necessary.
1214
1215config RELAY
1216 bool "Kernel->user space relay support (formerly relayfs)"
1217 help
1218 This option enables support for relay interface support in
1219 certain file systems (such as debugfs).
1220 It is designed to provide an efficient mechanism for tools and
1221 facilities to relay large amounts of data from kernel space to
1222 user space.
1223
1224 If unsure, say N.
1225
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001226config BLK_DEV_INITRD
1227 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1228 depends on BROKEN || !FRV
1229 help
1230 The initial RAM filesystem is a ramfs which is loaded by the
1231 boot loader (loadlin or lilo) and that is mounted as root
1232 before the normal boot procedure. It is typically used to
1233 load modules needed to mount the "real" root file system,
1234 etc. See <file:Documentation/initrd.txt> for details.
1235
1236 If RAM disk support (BLK_DEV_RAM) is also included, this
1237 also enables initial RAM disk (initrd) support and adds
1238 15 Kbytes (more on some other architectures) to the kernel size.
1239
1240 If unsure say Y.
1241
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001242if BLK_DEV_INITRD
1243
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001244source "usr/Kconfig"
1245
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001246endif
1247
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001248config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001249 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001250 help
1251 Enabling this option will pass "-Os" instead of "-O2" to gcc
1252 resulting in a smaller kernel.
1253
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001254 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001255
Randy Dunlap08470622006-09-30 23:28:13 -07001256config SYSCTL
1257 bool
1258
Randy Dunlapb943c462009-03-10 12:55:46 -07001259config ANON_INODES
1260 bool
1261
Mike Frysinger657a5202013-04-30 15:28:45 -07001262config HAVE_UID16
1263 bool
1264
1265config SYSCTL_EXCEPTION_TRACE
1266 bool
1267 help
1268 Enable support for /proc/sys/debug/exception-trace.
1269
1270config SYSCTL_ARCH_UNALIGN_NO_WARN
1271 bool
1272 help
1273 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1274 Allows arch to define/use @no_unaligned_warning to possibly warn
1275 about unaligned access emulation going on under the hood.
1276
1277config SYSCTL_ARCH_UNALIGN_ALLOW
1278 bool
1279 help
1280 Enable support for /proc/sys/kernel/unaligned-trap
1281 Allows arches to define/use @unaligned_enabled to runtime toggle
1282 the unaligned access emulation.
1283 see arch/parisc/kernel/unaligned.c for reference
1284
Mike Frysinger657a5202013-04-30 15:28:45 -07001285config HAVE_PCSPKR_PLATFORM
1286 bool
1287
David Rientjes6a108a12011-01-20 14:44:16 -08001288menuconfig EXPERT
1289 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001290 # Unhide debug options, to make the on-by-default options visible
1291 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 help
1293 This option allows certain base kernel options and settings
1294 to be disabled or tweaked. This is for specialized
1295 environments which can tolerate a "non-standard" kernel.
1296 Only use this if you really know what you are doing.
1297
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001298config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001299 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001300 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001301 default y
1302 help
1303 This enables the legacy 16-bit UID syscall wrappers.
1304
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001305config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001306 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001307 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001308 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001309 select SYSCTL
1310 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001311 sys_sysctl uses binary paths that have been found challenging
1312 to properly maintain and use. The interface in /proc/sys
1313 using paths with ascii names is now the primary path to this
1314 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001315
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001316 Almost nothing using the binary sysctl interface so if you are
1317 trying to save some space it is probably safe to disable this,
1318 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001319
WANG Congc736de62011-11-02 13:39:25 -07001320 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001321
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001323 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324 default y
1325 help
1326 Say Y here to let the kernel print out symbolic crash information and
1327 symbolic stack backtraces. This increases the size of the kernel
1328 somewhat, as all symbols have to be loaded into the kernel image.
1329
1330config KALLSYMS_ALL
1331 bool "Include all symbols in kallsyms"
1332 depends on DEBUG_KERNEL && KALLSYMS
1333 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001334 Normally kallsyms only contains the symbols of functions for nicer
1335 OOPS messages and backtraces (i.e., symbols from the text and inittext
1336 sections). This is sufficient for most cases. And only in very rare
1337 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1338 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001340 This option makes sure that all symbols are loaded into the kernel
1341 image (i.e., symbols from all sections) in cost of increased kernel
1342 size (depending on the kernel configuration, it may be 300KiB or
1343 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001344
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001345 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001346
1347config PRINTK
1348 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001349 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001350 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001351 help
1352 This option enables normal printk support. Removing it
1353 eliminates most of the message strings from the kernel image
1354 and makes the kernel more or less silent. As this makes it
1355 very difficult to diagnose system problems, saying N here is
1356 strongly discouraged.
1357
Matt Mackallc8538a72005-05-01 08:59:01 -07001358config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001359 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001360 default y
1361 help
1362 Disabling this option eliminates support for BUG and WARN, reducing
1363 the size of your kernel image and potentially quietly ignoring
1364 numerous fatal conditions. You should only consider disabling this
1365 option for embedded systems with no facilities for reporting errors.
1366 Just say Y.
1367
Matt Mackall708e9a72006-01-08 01:05:25 -08001368config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001369 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001370 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001371 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001372 help
1373 Enable support for generating core dumps. Disabling saves about 4k.
1374
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001375
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001376config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001377 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001378 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001379 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001380 default y
1381 help
1382 This option allows to disable the internal PC-Speaker
1383 support, saving some memory.
1384
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385config BASE_FULL
1386 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001387 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388 help
1389 Disabling this option reduces the size of miscellaneous core
1390 kernel data structures. This saves memory on small machines,
1391 but may reduce performance.
1392
1393config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001394 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001396 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397 help
1398 Disabling this option will cause the kernel to be built without
1399 support for "fast userspace mutexes". The resulting kernel may not
1400 run glibc-based applications correctly.
1401
1402config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001403 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001405 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406 help
1407 Disabling this option will cause the kernel to be built without
1408 support for epoll family of system calls.
1409
Davide Libenzifba2afa2007-05-10 22:23:13 -07001410config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001411 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001412 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001413 default y
1414 help
1415 Enable the signalfd() system call that allows to receive signals
1416 on a file descriptor.
1417
1418 If unsure, say Y.
1419
Davide Libenzib215e282007-05-10 22:23:16 -07001420config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001421 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001422 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001423 default y
1424 help
1425 Enable the timerfd() system call that allows to receive timer
1426 events on a file descriptor.
1427
1428 If unsure, say Y.
1429
Davide Libenzie1ad7462007-05-10 22:23:19 -07001430config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001431 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001432 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001433 default y
1434 help
1435 Enable the eventfd() system call that allows to receive both
1436 kernel notification (ie. KAIO) or userspace notifications.
1437
1438 If unsure, say Y.
1439
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001441 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442 default y
1443 depends on MMU
1444 help
1445 The shmem is an internal filesystem used to manage shared memory.
1446 It is backed by swap and manages resource limits. It is also exported
1447 to userspace as tmpfs if TMPFS is enabled. Disabling this
1448 option replaces shmem and tmpfs with the much simpler ramfs code,
1449 which may be appropriate on small systems without swap.
1450
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001451config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001452 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001453 default y
1454 help
1455 This option enables POSIX asynchronous I/O which may by used
Mike Frysinger657a5202013-04-30 15:28:45 -07001456 by some high performance threaded applications. Disabling
1457 this option saves about 7k.
1458
1459config PCI_QUIRKS
1460 default y
1461 bool "Enable PCI quirk workarounds" if EXPERT
1462 depends on PCI
1463 help
1464 This enables workarounds for various PCI chipset
1465 bugs/quirks. Disable this only if your target machine is
1466 unaffected by PCI quirks.
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001467
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001468config EMBEDDED
1469 bool "Embedded system"
1470 select EXPERT
1471 help
1472 This option should be enabled if compiling the kernel for
1473 an embedded system so certain expert options are available
1474 for configuration.
1475
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001476config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001477 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001478 help
1479 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001480
Peter Zijlstra906010b2009-09-21 16:08:49 +02001481config PERF_USE_VMALLOC
1482 bool
1483 help
1484 See tools/perf/design.txt for details
1485
Ingo Molnar57c0c152009-09-21 12:20:38 +02001486menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001487
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001488config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001489 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001490 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001491 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001492 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001493 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001494 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001495 Enable kernel support for various performance events provided
1496 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001497
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001498 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001499 use of generic tracepoints.
1500
1501 Most modern CPUs support performance events via performance
1502 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001503 types of hw events: such as instructions executed, cachemisses
1504 suffered, or branches mis-predicted - without slowing down the
1505 kernel or applications. These registers can also trigger interrupts
1506 when a threshold number of events have passed - and can thus be
1507 used to profile the code that runs on that CPU.
1508
Ingo Molnar57c0c152009-09-21 12:20:38 +02001509 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001510 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001511 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001512 provides per task and per CPU counters, and it provides event
1513 capabilities on top of those.
1514
1515 Say Y if unsure.
1516
Peter Zijlstra906010b2009-09-21 16:08:49 +02001517config DEBUG_PERF_USE_VMALLOC
1518 default n
1519 bool "Debug: use vmalloc to back perf mmap() buffers"
1520 depends on PERF_EVENTS && DEBUG_KERNEL
1521 select PERF_USE_VMALLOC
1522 help
1523 Use vmalloc memory to back perf mmap() buffers.
1524
1525 Mostly useful for debugging the vmalloc code on platforms
1526 that don't require it.
1527
1528 Say N if unsure.
1529
Thomas Gleixner0793a612008-12-04 20:12:29 +01001530endmenu
1531
Christoph Lameterf8891e52006-06-30 01:55:45 -07001532config VM_EVENT_COUNTERS
1533 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001534 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001535 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001536 VM event counters are needed for event counts to be shown.
1537 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001538 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001539 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001540
Christoph Lameter41ecc552007-05-09 02:32:44 -07001541config SLUB_DEBUG
1542 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001543 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001544 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001545 help
1546 SLUB has extensive debug support features. Disabling these can
1547 result in significant savings in code size. This also disables
1548 SLUB sysfs support. /sys/slab will not exist and there will be
1549 no support for cache validation etc.
1550
Randy Dunlapb943c462009-03-10 12:55:46 -07001551config COMPAT_BRK
1552 bool "Disable heap randomization"
1553 default y
1554 help
1555 Randomizing heap placement makes heap exploits harder, but it
1556 also breaks ancient binaries (including anything libc5 based).
1557 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001558 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001559 /proc/sys/kernel/randomize_va_space to 2.
1560
1561 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1562
Christoph Lameter81819f02007-05-06 14:49:36 -07001563choice
1564 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001565 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001566 help
1567 This option allows to select a slab allocator.
1568
1569config SLAB
1570 bool "SLAB"
1571 help
1572 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001573 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001574 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001575
1576config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001577 bool "SLUB (Unqueued Allocator)"
1578 help
1579 SLUB is a slab allocator that minimizes cache line usage
1580 instead of managing queues of cached objects (SLAB approach).
1581 Per cpu caching is realized using slabs of objects instead
1582 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001583 and has enhanced diagnostics. SLUB is the default choice for
1584 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001585
1586config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001587 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001588 bool "SLOB (Simple Allocator)"
1589 help
Matt Mackall37291452008-02-04 22:29:38 -08001590 SLOB replaces the stock allocator with a drastically simpler
1591 allocator. SLOB is generally more space efficient but
1592 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001593
1594endchoice
1595
Joonsoo Kim345c9052013-06-19 14:05:52 +09001596config SLUB_CPU_PARTIAL
1597 default y
Uwe Kleine-Königb39ffbf2013-07-17 16:54:59 +02001598 depends on SLUB && SMP
Joonsoo Kim345c9052013-06-19 14:05:52 +09001599 bool "SLUB per cpu partial cache"
1600 help
1601 Per cpu partial caches accellerate objects allocation and freeing
1602 that is local to a processor at the price of more indeterminism
1603 in the latency of the free. On overflow these caches will be cleared
1604 which requires the taking of locks that may cause latency spikes.
1605 Typically one would choose no for a realtime system.
1606
Jie Zhangea637632009-12-14 18:00:02 -08001607config MMAP_ALLOW_UNINITIALIZED
1608 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001609 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001610 default n
1611 help
1612 Normally, and according to the Linux spec, anonymous memory obtained
1613 from mmap() has it's contents cleared before it is passed to
1614 userspace. Enabling this config option allows you to request that
1615 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1616 providing a huge performance boost. If this option is not enabled,
1617 then the flag will be ignored.
1618
1619 This is taken advantage of by uClibc's malloc(), and also by
1620 ELF-FDPIC binfmt's brk and stack allocator.
1621
1622 Because of the obvious security issues, this option should only be
1623 enabled on embedded devices where you control what is run in
1624 userspace. Since that isn't generally a problem on no-MMU systems,
1625 it is normally safe to say Y here.
1626
1627 See Documentation/nommu-mmap.txt for more information.
1628
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001629config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001630 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001631 help
1632 Say Y here to enable the extended profiling support mechanisms used
1633 by profilers such as OProfile.
1634
Ingo Molnar5f87f112008-07-23 14:15:22 +02001635#
1636# Place an empty function call at each tracepoint site. Can be
1637# dynamically changed for a probe function.
1638#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001639config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001640 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001641
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001642source "arch/Kconfig"
1643
Linus Torvalds1da177e2005-04-16 15:20:36 -07001644endmenu # General setup
1645
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001646config HAVE_GENERIC_DMA_COHERENT
1647 bool
1648 default n
1649
Linus Torvalds158a9622008-01-02 13:04:48 -08001650config SLABINFO
1651 bool
1652 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001653 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001654 default y
1655
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001656config RT_MUTEXES
1657 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001658
Linus Torvalds1da177e2005-04-16 15:20:36 -07001659config BASE_SMALL
1660 int
1661 default 0 if BASE_FULL
1662 default 1 if !BASE_FULL
1663
David Howellsb56e5a12013-08-30 16:07:30 +01001664config SYSTEM_TRUSTED_KEYRING
1665 bool "Provide system-wide ring of trusted keys"
1666 depends on KEYS
1667 help
1668 Provide a system keyring to which trusted keys can be added. Keys in
1669 the keyring are considered to be trusted. Keys may be added at will
1670 by the kernel from compiled-in data and from hardware key stores, but
1671 userspace may only add extra keys if those keys can be verified by
1672 keys already in the keyring.
1673
1674 Keys in this keyring are used by module signature checking.
1675
Jan Engelhardt66da5732007-07-15 23:39:29 -07001676menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677 bool "Enable loadable module support"
Yann E. MORIN11097a02013-08-11 16:07:50 +02001678 option modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001679 help
1680 Kernel modules are small pieces of compiled code which can
1681 be inserted in the running kernel, rather than being
1682 permanently built into the kernel. You use the "modprobe"
1683 tool to add (and sometimes remove) them. If you say Y here,
1684 many parts of the kernel can be built as modules (by
1685 answering M instead of Y where indicated): this is most
1686 useful for infrequently used options which are not required
1687 for booting. For more information, see the man pages for
1688 modprobe, lsmod, modinfo, insmod and rmmod.
1689
1690 If you say Y here, you will need to run "make
1691 modules_install" to put the modules under /lib/modules/
1692 where modprobe can find them (you may need to be root to do
1693 this).
1694
1695 If unsure, say Y.
1696
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001697if MODULES
1698
Linus Torvalds826e4502008-05-04 17:04:16 -07001699config MODULE_FORCE_LOAD
1700 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001701 default n
1702 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001703 Allow loading of modules without version information (ie. modprobe
1704 --force). Forced module loading sets the 'F' (forced) taint flag and
1705 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001706
Linus Torvalds1da177e2005-04-16 15:20:36 -07001707config MODULE_UNLOAD
1708 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001709 help
1710 Without this option you will not be able to unload any
1711 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001712 anyway), which makes your kernel smaller, faster
1713 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714
1715config MODULE_FORCE_UNLOAD
1716 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001717 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718 help
1719 This option allows you to force a module to unload, even if the
1720 kernel believes it is unsafe: the kernel will remove the module
1721 without waiting for anyone to stop using it (using the -f option to
1722 rmmod). This is mainly for kernel developers and desperate users.
1723 If unsure, say N.
1724
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001726 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001727 help
1728 Usually, you have to use modules compiled with your kernel.
1729 Saying Y here makes it sometimes possible to use modules
1730 compiled for different kernels, by adding enough information
1731 to the modules to (hopefully) spot any changes which would
1732 make them incompatible with the kernel you are running. If
1733 unsure, say N.
1734
1735config MODULE_SRCVERSION_ALL
1736 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001737 help
1738 Modules which contain a MODULE_VERSION get an extra "srcversion"
1739 field inserted into their modinfo section, which contains a
1740 sum of the source files which made it. This helps maintainers
1741 see exactly which source was used to build a module (since
1742 others sometimes change the module source without updating
1743 the version). With this option, such a "srcversion" field
1744 will be created for all modules. If unsure, say N.
1745
Rusty Russell106a4ee2012-09-26 10:09:40 +01001746config MODULE_SIG
1747 bool "Module signature verification"
1748 depends on MODULES
David Howellsb56e5a12013-08-30 16:07:30 +01001749 select SYSTEM_TRUSTED_KEYRING
David Howells48ba2462012-09-26 10:11:03 +01001750 select KEYS
1751 select CRYPTO
1752 select ASYMMETRIC_KEY_TYPE
1753 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1754 select PUBLIC_KEY_ALGO_RSA
1755 select ASN1
1756 select OID_REGISTRY
1757 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001758 help
1759 Check modules for valid signatures upon load: the signature
1760 is simply appended to the module. For more information see
1761 Documentation/module-signing.txt.
1762
David Howellsea0b6dc2012-09-26 10:09:50 +01001763 !!!WARNING!!! If you enable this option, you MUST make sure that the
1764 module DOES NOT get stripped after being signed. This includes the
1765 debuginfo strip done by some packagers (such as rpmbuild) and
1766 inclusion into an initramfs that wants the module size reduced.
1767
Rusty Russell106a4ee2012-09-26 10:09:40 +01001768config MODULE_SIG_FORCE
1769 bool "Require modules to be validly signed"
1770 depends on MODULE_SIG
1771 help
1772 Reject unsigned modules or signed modules for which we don't have a
1773 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001774
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301775config MODULE_SIG_ALL
1776 bool "Automatically sign all modules"
1777 default y
1778 depends on MODULE_SIG
1779 help
1780 Sign all modules during make modules_install. Without this option,
1781 modules must be signed manually, using the scripts/sign-file tool.
1782
1783comment "Do not forget to sign required modules with scripts/sign-file"
1784 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1785
David Howellsea0b6dc2012-09-26 10:09:50 +01001786choice
1787 prompt "Which hash algorithm should modules be signed with?"
1788 depends on MODULE_SIG
1789 help
1790 This determines which sort of hashing algorithm will be used during
1791 signature generation. This algorithm _must_ be built into the kernel
1792 directly so that signature verification can take place. It is not
1793 possible to load a signed module containing the algorithm to check
1794 the signature on that module.
1795
1796config MODULE_SIG_SHA1
1797 bool "Sign modules with SHA-1"
1798 select CRYPTO_SHA1
1799
1800config MODULE_SIG_SHA224
1801 bool "Sign modules with SHA-224"
1802 select CRYPTO_SHA256
1803
1804config MODULE_SIG_SHA256
1805 bool "Sign modules with SHA-256"
1806 select CRYPTO_SHA256
1807
1808config MODULE_SIG_SHA384
1809 bool "Sign modules with SHA-384"
1810 select CRYPTO_SHA512
1811
1812config MODULE_SIG_SHA512
1813 bool "Sign modules with SHA-512"
1814 select CRYPTO_SHA512
1815
1816endchoice
1817
Michal Marek22753672013-01-25 13:41:00 +10301818config MODULE_SIG_HASH
1819 string
1820 depends on MODULE_SIG
1821 default "sha1" if MODULE_SIG_SHA1
1822 default "sha224" if MODULE_SIG_SHA224
1823 default "sha256" if MODULE_SIG_SHA256
1824 default "sha384" if MODULE_SIG_SHA384
1825 default "sha512" if MODULE_SIG_SHA512
1826
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001827endif # MODULES
1828
Rusty Russell98a79d62008-12-13 21:19:41 +10301829config INIT_ALL_POSSIBLE
1830 bool
1831 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301832 Back when each arch used to define their own cpu_online_mask and
1833 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301834 with all 1s, and others with all 0s. When they were centralised,
1835 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001836 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301837
Linus Torvalds1da177e2005-04-16 15:20:36 -07001838config STOP_MACHINE
1839 bool
1840 default y
1841 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1842 help
1843 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001844
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001845source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001846
1847config PREEMPT_NOTIFIERS
1848 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001849
Steffen Klassert16295be2010-01-06 19:47:10 +11001850config PADATA
1851 depends on SMP
1852 bool
1853
Andi Kleen754b7b62012-10-04 17:11:27 -07001854# Can be selected by architectures with broken toolchains
1855# that get confused by correct const<->read_only section
1856# mappings
1857config BROKEN_RODATA
1858 bool
1859
David Howells4520c6a2012-09-21 23:31:13 +01001860config ASN1
1861 tristate
1862 help
1863 Build a simple ASN.1 grammar compiler that produces a bytecode output
1864 that can be interpreted by the ASN.1 stream decoder and used to
1865 inform it as to what tags are to be expected in a stream and what
1866 functions to call on what tags.
1867
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001868source "kernel/Kconfig.locks"