blob: 80a6907f91c5d0fd6578cc3a2b82a5f090602773 [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 Dunlap34ad92c22005-10-30 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
Konstantin Khlebnikov226b4cc2014-06-04 16:10:50 -0700264config CROSS_MEMORY_ATTACH
265 bool "Enable process_vm_readv/writev syscalls"
266 depends on MMU
267 default y
268 help
269 Enabling this option adds the system calls process_vm_readv and
270 process_vm_writev which allow a process with the correct privileges
Geert Uytterhoevena2a368d2014-08-12 13:46:11 -0700271 to directly read from or write to another process' address space.
Konstantin Khlebnikov226b4cc2014-06-04 16:10:50 -0700272 See the man page for more details.
273
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530274config FHANDLE
275 bool "open by fhandle syscalls"
276 select EXPORTFS
277 help
278 If you say Y here, a user level program will be able to map
279 file names to handle and then later use the handle for
280 different file system operations. This is useful in implementing
281 userspace file servers, which now track files using handles instead
282 of names. The handle would remain the same even if file names
283 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
284 syscalls.
285
Josh Triplett69369a72014-04-03 14:48:27 -0700286config USELIB
287 bool "uselib syscall"
288 default y
289 help
290 This option enables the uselib syscall, a system call used in the
291 dynamic linker from libc5 and earlier. glibc does not use this
292 system call. If you intend to run programs built on libc5 or
293 earlier, you may need to enable this syscall. Current systems
294 running glibc can safely disable this.
295
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296config AUDIT
297 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100298 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 help
300 Enable auditing infrastructure that can be used with another
301 kernel subsystem, such as SELinux (which requires this for
302 logging of avc messages output). Does not do system-call
303 auditing without CONFIG_AUDITSYSCALL.
304
AKASHI Takahiro7a017722014-02-25 18:16:24 +0900305config HAVE_ARCH_AUDITSYSCALL
306 bool
307
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308config AUDITSYSCALL
309 bool "Enable system-call auditing support"
AKASHI Takahiro7a017722014-02-25 18:16:24 +0900310 depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 default y if SECURITY_SELINUX
312 help
313 Enable low-overhead system-call auditing infrastructure that
314 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500315 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
Eric Paris939a67f2009-12-17 20:12:06 -0500317config AUDIT_WATCH
318 def_bool y
319 depends on AUDITSYSCALL
320 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321
Al Viro74c3cbe2007-07-22 08:04:18 -0400322config AUDIT_TREE
323 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400324 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500325 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400326
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000327source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200328source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000329
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200330menu "CPU/Task time and stats accounting"
331
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200332config VIRT_CPU_ACCOUNTING
333 bool
334
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200335choice
336 prompt "Cputime accounting"
337 default TICK_CPU_ACCOUNTING if !PPC64
Stephen Rothwell02fc8d32013-02-08 14:19:38 +1100338 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200339
340# Kind of a stub config for the pure tick based cputime accounting
341config TICK_CPU_ACCOUNTING
342 bool "Simple tick based cputime accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200343 depends on !S390 && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200344 help
345 This is the basic tick based cputime accounting that maintains
346 statistics about user, system and idle time spent on per jiffies
347 granularity.
348
349 If unsure, say Y.
350
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200351config VIRT_CPU_ACCOUNTING_NATIVE
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200352 bool "Deterministic task and CPU time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200353 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200354 select VIRT_CPU_ACCOUNTING
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200355 help
356 Select this option to enable more accurate task and CPU time
357 accounting. This is done by reading a CPU counter on each
358 kernel entry and exit and on transitions within the kernel
359 between system, softirq and hardirq state, so there is a
360 small performance impact. In the case of s390 or IBM POWER > 5,
361 this also enables accounting of stolen time on logically-partitioned
362 systems.
363
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200364config VIRT_CPU_ACCOUNTING_GEN
365 bool "Full dynticks CPU time accounting"
Kevin Hilmanff3fb252013-09-16 15:28:19 -0700366 depends on HAVE_CONTEXT_TRACKING
Kevin Hilman554b0002013-09-16 15:28:21 -0700367 depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200368 select VIRT_CPU_ACCOUNTING
369 select CONTEXT_TRACKING
370 help
371 Select this option to enable task and CPU time accounting on full
372 dynticks systems. This accounting is implemented by watching every
373 kernel-user boundaries using the context tracking subsystem.
374 The accounting is thus performed at the expense of some significant
375 overhead.
376
377 For now this is only useful if you are working on the full
378 dynticks subsystem development.
379
380 If unsure, say N.
381
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200382config IRQ_TIME_ACCOUNTING
383 bool "Fine granularity task level IRQ time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200384 depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200385 help
386 Select this option to enable fine granularity task irq time
387 accounting. This is done by reading a timestamp on each
388 transitions between softirq and hardirq state, so there can be a
389 small performance impact.
390
391 If in doubt, say N here.
392
393endchoice
394
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200395config BSD_PROCESS_ACCT
396 bool "BSD Process Accounting"
397 help
398 If you say Y here, a user level program will be able to instruct the
399 kernel (via a special system call) to write process accounting
400 information to a file: whenever a process exits, information about
401 that process will be appended to the file by the kernel. The
402 information includes things such as creation time, owning user,
403 command name, memory usage, controlling terminal etc. (the complete
404 list is in the struct acct in <file:include/linux/acct.h>). It is
405 up to the user level program to do useful things with this
406 information. This is generally a good idea, so say Y.
407
408config BSD_PROCESS_ACCT_V3
409 bool "BSD Process Accounting version 3 file format"
410 depends on BSD_PROCESS_ACCT
411 default n
412 help
413 If you say Y here, the process accounting information is written
414 in a new file format that also logs the process IDs of each
415 process and it's parent. Note that this file format is incompatible
416 with previous v0/v1/v2 file formats, so you will need updated tools
417 for processing it. A preliminary version of these tools is available
418 at <http://www.gnu.org/software/acct/>.
419
420config TASKSTATS
Kees Cook19c92392012-10-02 11:19:29 -0700421 bool "Export task/process statistics through netlink"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200422 depends on NET
423 default n
424 help
425 Export selected statistics for tasks/processes through the
426 generic netlink interface. Unlike BSD process accounting, the
427 statistics are available during the lifetime of tasks/processes as
428 responses to commands. Like BSD accounting, they are sent to user
429 space on task exit.
430
431 Say N if unsure.
432
433config TASK_DELAY_ACCT
Kees Cook19c92392012-10-02 11:19:29 -0700434 bool "Enable per-task delay accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200435 depends on TASKSTATS
436 help
437 Collect information on time spent by a task waiting for system
438 resources like cpu, synchronous block I/O completion and swapping
439 in pages. Such statistics can help in setting a task's priorities
440 relative to other tasks for cpu, io, rss limits etc.
441
442 Say N if unsure.
443
444config TASK_XACCT
Kees Cook19c92392012-10-02 11:19:29 -0700445 bool "Enable extended accounting over taskstats"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200446 depends on TASKSTATS
447 help
448 Collect extended task accounting data and send the data
449 to userland for processing over the taskstats interface.
450
451 Say N if unsure.
452
453config TASK_IO_ACCOUNTING
Kees Cook19c92392012-10-02 11:19:29 -0700454 bool "Enable per-task storage I/O accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200455 depends on TASK_XACCT
456 help
457 Collect information on the number of bytes of storage I/O which this
458 task has caused.
459
460 Say N if unsure.
461
462endmenu # "CPU/Task time and stats accounting"
463
Mike Travisc903ff82009-01-15 12:28:29 -0800464menu "RCU Subsystem"
465
466choice
467 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700468 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800469
Mike Travisc903ff82009-01-15 12:28:29 -0800470config TREE_RCU
471 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700472 depends on !PREEMPT && SMP
Steven Rostedt016a8d52013-05-28 17:32:53 -0400473 select IRQ_WORK
Mike Travisc903ff82009-01-15 12:28:29 -0800474 help
475 This option selects the RCU implementation that is
476 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700477 thousands of CPUs. It also scales down nicely to
478 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800479
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700480config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700481 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800482 depends on PREEMPT
James Hogan53614712013-07-25 15:34:25 +0100483 select IRQ_WORK
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700484 help
485 This option selects the RCU implementation that is
486 designed for very large SMP systems with hundreds or
487 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700488 is also required. It also scales down nicely to
489 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700490
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800491 Select this option if you are unsure.
492
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700493config TINY_RCU
494 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700495 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700496 help
497 This option selects the RCU implementation that is
498 designed for UP systems from which real-time response
499 is not required. This option greatly reduces the
500 memory footprint of RCU.
501
Mike Travisc903ff82009-01-15 12:28:29 -0800502endchoice
503
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700504config PREEMPT_RCU
Paul E. McKenney127781d2013-03-27 08:44:00 -0700505 def_bool TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700506 help
507 This option enables preemptible-RCU code that is common between
Paul E. McKenneyab74fdf2014-05-04 15:41:21 -0700508 TREE_PREEMPT_RCU and, in the old days, TINY_PREEMPT_RCU.
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700509
Paul E. McKenney6bfc09e2012-10-19 12:49:17 -0700510config RCU_STALL_COMMON
511 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
512 help
513 This option enables RCU CPU stall code that is common between
514 the TINY and TREE variants of RCU. The purpose is to allow
515 the tiny variants to disable RCU CPU stall warnings, while
516 making these warnings mandatory for the tree variants.
517
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100518config CONTEXT_TRACKING
519 bool
520
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200521config RCU_USER_QS
522 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100523 depends on HAVE_CONTEXT_TRACKING && SMP
524 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200525 help
526 This option sets hooks on kernel / userspace boundaries and
527 puts RCU in extended quiescent state when the CPU runs in
528 userspace. It means that when a CPU runs in userspace, it is
529 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700530 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200531
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200532 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100533 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700534 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200535
536 If unsure say N
537
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100538config CONTEXT_TRACKING_FORCE
539 bool "Force context tracking"
540 depends on CONTEXT_TRACKING
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200541 default y if !NO_HZ_FULL
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200542 help
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200543 The major pre-requirement for full dynticks to work is to
544 support the context tracking subsystem. But there are also
545 other dependencies to provide in order to make the full
546 dynticks working.
547
548 This option stands for testing when an arch implements the
549 context tracking backend but doesn't yet fullfill all the
550 requirements to make the full dynticks feature working.
551 Without the full dynticks, there is no way to test the support
552 for context tracking and the subsystems that rely on it: RCU
553 userspace extended quiescent state and tickless cputime
554 accounting. This option copes with the absence of the full
555 dynticks subsystem by forcing the context tracking on all
556 CPUs in the system.
557
Paul Gortmaker99c8b1e2013-10-24 10:07:47 -0400558 Say Y only if you're working on the development of an
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200559 architecture backend for the context tracking.
560
561 Say N otherwise, this option brings an overhead that you
562 don't want in production.
563
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200564
Mike Travisc903ff82009-01-15 12:28:29 -0800565config RCU_FANOUT
566 int "Tree-based hierarchical RCU fanout value"
567 range 2 64 if 64BIT
568 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700569 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800570 default 64 if 64BIT
571 default 32 if !64BIT
572 help
573 This option controls the fanout of hierarchical implementations
574 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700575 large numbers of CPUs. This value must be at least the fourth
576 root of NR_CPUS, which allows NR_CPUS to be insanely large.
577 The default value of RCU_FANOUT should be used for production
578 systems, but if you are stress-testing the RCU implementation
579 itself, small RCU_FANOUT values allow you to test large-system
580 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800581
582 Select a specific number if testing RCU itself.
583 Take the default if unsure.
584
Paul E. McKenney8932a632012-04-19 12:20:14 -0700585config RCU_FANOUT_LEAF
586 int "Tree-based hierarchical RCU leaf-level fanout value"
587 range 2 RCU_FANOUT if 64BIT
588 range 2 RCU_FANOUT if !64BIT
589 depends on TREE_RCU || TREE_PREEMPT_RCU
590 default 16
591 help
592 This option controls the leaf-level fanout of hierarchical
593 implementations of RCU, and allows trading off cache misses
594 against lock contention. Systems that synchronize their
595 scheduling-clock interrupts for energy-efficiency reasons will
596 want the default because the smaller leaf-level fanout keeps
597 lock contention levels acceptably low. Very large systems
598 (hundreds or thousands of CPUs) will instead want to set this
599 value to the maximum value possible in order to reduce the
600 number of cache misses incurred during RCU's grace-period
601 initialization. These systems tend to run CPU-bound, and thus
602 are not helped by synchronized interrupts, and thus tend to
603 skew them, which reduces lock contention enough that large
604 leaf-level fanouts work well.
605
606 Select a specific number if testing RCU itself.
607
608 Select the maximum permissible value for large systems.
609
610 Take the default if unsure.
611
Mike Travisc903ff82009-01-15 12:28:29 -0800612config RCU_FANOUT_EXACT
613 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700614 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800615 default n
616 help
617 This option forces use of the exact RCU_FANOUT value specified,
618 regardless of imbalances in the hierarchy. This is useful for
619 testing RCU itself, and might one day be useful on systems with
620 strong NUMA behavior.
621
622 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
623
624 Say N if unsure.
625
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800626config RCU_FAST_NO_HZ
627 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Frederic Weisbecker3451d022011-08-10 23:21:01 +0200628 depends on NO_HZ_COMMON && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800629 default n
630 help
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800631 This option permits CPUs to enter dynticks-idle state even if
632 they have RCU callbacks queued, and prevents RCU from waking
633 these CPUs up more than roughly once every four jiffies (by
634 default, you can adjust this using the rcutree.rcu_idle_gp_delay
635 parameter), thus improving energy efficiency. On the other
636 hand, this option increases the duration of RCU grace periods,
637 for example, slowing down synchronize_rcu().
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800638
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800639 Say Y if energy efficiency is critically important, and you
640 don't care about increased grace-period durations.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800641
642 Say N if you are unsure.
643
Mike Travisc903ff82009-01-15 12:28:29 -0800644config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700645 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800646 select DEBUG_FS
647 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700648 This option provides tracing for the TREE_RCU and
649 TREE_PREEMPT_RCU implementations, permitting Makefile to
650 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800651
Paul E. McKenney24278d12010-09-27 17:25:23 -0700652config RCU_BOOST
653 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800654 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700655 default n
656 help
657 This option boosts the priority of preempted RCU readers that
658 block the current preemptible RCU grace period for too long.
659 This option also prevents heavy loads from blocking RCU
660 callback invocation for all flavors of RCU.
661
662 Say Y here if you are working with real-time apps or heavy loads
663 Say N here if you are unsure.
664
665config RCU_BOOST_PRIO
666 int "Real-time priority to boost RCU readers to"
667 range 1 99
668 depends on RCU_BOOST
669 default 1
670 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700671 This option specifies the real-time priority to which long-term
672 preempted RCU readers are to be boosted. If you are working
673 with a real-time application that has one or more CPU-bound
674 threads running at a real-time priority level, you should set
675 RCU_BOOST_PRIO to a priority higher then the highest-priority
676 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
677 of 1 is appropriate in the common case, which is real-time
678 applications that do not have any CPU-bound threads.
679
680 Some real-time applications might not have a single real-time
681 thread that saturates a given CPU, but instead might have
682 multiple real-time threads that, taken together, fully utilize
683 that CPU. In this case, you should set RCU_BOOST_PRIO to
684 a priority higher than the lowest-priority thread that is
685 conspiring to prevent the CPU from running any non-real-time
686 tasks. For example, if one thread at priority 10 and another
687 thread at priority 5 are between themselves fully consuming
688 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
689 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700690
691 Specify the real-time priority, or take the default if unsure.
692
693config RCU_BOOST_DELAY
694 int "Milliseconds to delay boosting after RCU grace-period start"
695 range 0 3000
696 depends on RCU_BOOST
697 default 500
698 help
699 This option specifies the time to wait after the beginning of
700 a given grace period before priority-boosting preempted RCU
701 readers blocking that grace period. Note that any RCU reader
702 blocking an expedited RCU grace period is boosted immediately.
703
704 Accept the default if unsure.
705
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700706config RCU_NOCB_CPU
Paul E. McKenney9a5739d2013-03-28 20:48:36 -0700707 bool "Offload RCU callback processing from boot-selected CPUs"
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700708 depends on TREE_RCU || TREE_PREEMPT_RCU
709 default n
710 help
711 Use this option to reduce OS jitter for aggressive HPC or
712 real-time workloads. It can also be used to offload RCU
713 callback invocation to energy-efficient CPUs in battery-powered
714 asymmetric multiprocessors.
715
716 This option offloads callback invocation from the set of
717 CPUs specified at boot time by the rcu_nocbs parameter.
Paul E. McKenneya4889852012-12-03 08:16:28 -0800718 For each such CPU, a kthread ("rcuox/N") will be created to
719 invoke callbacks, where the "N" is the CPU being offloaded,
720 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
721 "s" for RCU-sched. Nothing prevents this kthread from running
722 on the specified CPUs, but (1) the kthreads may be preempted
723 between each callback, and (2) affinity or cgroups can be used
724 to force the kthreads to run on whatever set of CPUs is desired.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700725
Paul E. McKenney34ed62462013-01-07 13:37:42 -0800726 Say Y here if you want to help to debug reduced OS jitter.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700727 Say N here if you are unsure.
728
Paul E. McKenney911af502013-02-11 10:23:27 -0800729choice
730 prompt "Build-forced no-CBs CPUs"
731 default RCU_NOCB_CPU_NONE
732 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700733 This option allows no-CBs CPUs (whose RCU callbacks are invoked
734 from kthreads rather than from softirq context) to be specified
735 at build time. Additional no-CBs CPUs may be specified by
736 the rcu_nocbs= boot parameter.
Paul E. McKenney911af502013-02-11 10:23:27 -0800737
738config RCU_NOCB_CPU_NONE
739 bool "No build_forced no-CBs CPUs"
Paul E. McKenneyb58cc462014-07-02 10:13:24 -0700740 depends on RCU_NOCB_CPU && !NO_HZ_FULL_ALL
Paul E. McKenney911af502013-02-11 10:23:27 -0800741 help
742 This option does not force any of the CPUs to be no-CBs CPUs.
743 Only CPUs designated by the rcu_nocbs= boot parameter will be
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700744 no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU
745 kthreads whose names begin with "rcuo". All other CPUs will
746 invoke their own RCU callbacks in softirq context.
747
748 Select this option if you want to choose no-CBs CPUs at
749 boot time, for example, to allow testing of different no-CBs
750 configurations without having to rebuild the kernel each time.
Paul E. McKenney911af502013-02-11 10:23:27 -0800751
752config RCU_NOCB_CPU_ZERO
753 bool "CPU 0 is a build_forced no-CBs CPU"
Paul E. McKenneyb58cc462014-07-02 10:13:24 -0700754 depends on RCU_NOCB_CPU && !NO_HZ_FULL_ALL
Paul E. McKenney911af502013-02-11 10:23:27 -0800755 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700756 This option forces CPU 0 to be a no-CBs CPU, so that its RCU
757 callbacks are invoked by a per-CPU kthread whose name begins
758 with "rcuo". Additional CPUs may be designated as no-CBs
759 CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs.
760 All other CPUs will invoke their own RCU callbacks in softirq
761 context.
Paul E. McKenney911af502013-02-11 10:23:27 -0800762
763 Select this if CPU 0 needs to be a no-CBs CPU for real-time
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700764 or energy-efficiency reasons, but the real reason it exists
765 is to ensure that randconfig testing covers mixed systems.
Paul E. McKenney911af502013-02-11 10:23:27 -0800766
767config RCU_NOCB_CPU_ALL
768 bool "All CPUs are build_forced no-CBs CPUs"
769 depends on RCU_NOCB_CPU
770 help
771 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700772 boot parameter will be ignored. All CPUs' RCU callbacks will
773 be executed in the context of per-CPU rcuo kthreads created for
774 this purpose. Assuming that the kthreads whose names start with
775 "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter
776 on the remaining CPUs, but might decrease memory locality during
777 RCU-callback invocation, thus potentially degrading throughput.
Paul E. McKenney911af502013-02-11 10:23:27 -0800778
779 Select this if all CPUs need to be no-CBs CPUs for real-time
780 or energy-efficiency reasons.
781
782endchoice
783
Mike Travisc903ff82009-01-15 12:28:29 -0800784endmenu # "RCU Subsystem"
785
Vivek Goyalde5b56b2014-08-08 14:25:41 -0700786config BUILD_BIN2C
787 bool
788 default n
789
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700791 tristate "Kernel .config support"
Vivek Goyalde5b56b2014-08-08 14:25:41 -0700792 select BUILD_BIN2C
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 ---help---
794 This option enables the complete Linux kernel ".config" file
795 contents to be saved in the kernel. It provides documentation
796 of which kernel options are used in a running kernel or in an
797 on-disk kernel. This information can be extracted from the kernel
798 image file with the script scripts/extract-ikconfig and used as
799 input to rebuild the current kernel or to build another kernel.
800 It can also be extracted from a running kernel by reading
801 /proc/config.gz if enabled (below).
802
803config IKCONFIG_PROC
804 bool "Enable access to .config through /proc/config.gz"
805 depends on IKCONFIG && PROC_FS
806 ---help---
807 This option enables access to the kernel configuration file
808 through /proc/config.gz.
809
Alistair John Strachan794543a2007-05-08 00:31:15 -0700810config LOG_BUF_SHIFT
811 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
812 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700813 default 17
Josh Triplett361e9df2014-10-03 16:00:54 -0700814 depends on PRINTK
Alistair John Strachan794543a2007-05-08 00:31:15 -0700815 help
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700816 Select the minimal kernel log buffer size as a power of 2.
817 The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
818 parameter, see below. Any higher size also might be forced
819 by "log_buf_len" boot parameter.
820
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700821 Examples:
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700822 17 => 128 KB
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700823 16 => 64 KB
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700824 15 => 32 KB
825 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700826 13 => 8 KB
827 12 => 4 KB
828
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700829config LOG_CPU_MAX_BUF_SHIFT
830 int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
831 range 0 21
832 default 12 if !BASE_SMALL
833 default 0 if BASE_SMALL
Josh Triplett361e9df2014-10-03 16:00:54 -0700834 depends on PRINTK
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700835 help
836 This option allows to increase the default ring buffer size
837 according to the number of CPUs. The value defines the contribution
838 of each CPU as a power of 2. The used space is typically only few
839 lines however it might be much more when problems are reported,
840 e.g. backtraces.
841
842 The increased size means that a new buffer has to be allocated and
843 the original static one is unused. It makes sense only on systems
844 with more CPUs. Therefore this value is used only when the sum of
845 contributions is greater than the half of the default kernel ring
846 buffer as defined by LOG_BUF_SHIFT. The default values are set
847 so that more than 64 CPUs are needed to trigger the allocation.
848
849 Also this option is ignored when "log_buf_len" kernel parameter is
850 used as it forces an exact (power of two) size of the ring buffer.
851
852 The number of possible CPUs is used for this computation ignoring
853 hotplugging making the compuation optimal for the the worst case
854 scenerio while allowing a simple algorithm to be used from bootup.
855
856 Examples shift values and their meaning:
857 17 => 128 KB for each CPU
858 16 => 64 KB for each CPU
859 15 => 32 KB for each CPU
860 14 => 16 KB for each CPU
861 13 => 8 KB for each CPU
862 12 => 4 KB for each CPU
863
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800864#
865# Architectures with an unreliable sched_clock() should select this:
866#
867config HAVE_UNSTABLE_SCHED_CLOCK
868 bool
869
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700870config GENERIC_SCHED_CLOCK
871 bool
872
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200873#
874# For architectures that want to enable the support for NUMA-affine scheduler
875# balancing logic:
876#
877config ARCH_SUPPORTS_NUMA_BALANCING
878 bool
879
Peter Zijlstrabe5e6102013-11-18 18:27:06 +0100880#
881# For architectures that know their GCC __int128 support is sound
882#
883config ARCH_SUPPORTS_INT128
884 bool
885
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200886# For architectures that (ab)use NUMA to represent different memory regions
887# all cpu-local but of different latencies, such as SuperH.
888#
889config ARCH_WANT_NUMA_VARIABLE_LOCALITY
890 bool
891
892#
893# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
894config ARCH_WANTS_PROT_NUMA_PROT_NONE
895 bool
896
897config ARCH_USES_NUMA_PROT_NONE
898 bool
899 default y
900 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
901 depends on NUMA_BALANCING
902
Mel Gorman1a687c22012-11-22 11:16:36 +0000903config NUMA_BALANCING_DEFAULT_ENABLED
904 bool "Automatically enable NUMA aware memory/task placement"
905 default y
906 depends on NUMA_BALANCING
907 help
Paul Gortmaker6d56a412013-08-13 11:06:50 -0400908 If set, automatic NUMA balancing will be enabled if running on a NUMA
Mel Gorman1a687c22012-11-22 11:16:36 +0000909 machine.
910
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200911config NUMA_BALANCING
912 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200913 depends on ARCH_SUPPORTS_NUMA_BALANCING
914 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
915 depends on SMP && NUMA && MIGRATION
916 help
917 This option adds support for automatic NUMA aware memory/task placement.
918 The mechanism is quite primitive and is based on migrating memory when
Paul Gortmaker6d56a412013-08-13 11:06:50 -0400919 it has references to the node the task is running on.
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200920
921 This system will be inactive on UMA systems.
922
Li Zefan23964d22009-01-15 13:50:58 -0800923menuconfig CGROUPS
924 boolean "Control Group support"
Tejun Heo2bd59d42014-02-11 11:52:49 -0500925 select KERNFS
Paul Menageddbcc7e2007-10-18 23:39:30 -0700926 help
Li Zefan23964d22009-01-15 13:50:58 -0800927 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800928 use with process control subsystems such as Cpusets, CFS, memory
929 controls or device isolation.
930 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800931 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800932 - Documentation/cgroups/ (features for grouping, isolation
933 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700934
935 Say N if unsure.
936
Li Zefan23964d22009-01-15 13:50:58 -0800937if CGROUPS
938
Paul Menage006cb992007-10-18 23:39:43 -0700939config CGROUP_DEBUG
940 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700941 default n
Paul Menage006cb992007-10-18 23:39:43 -0700942 help
943 This option enables a simple cgroup subsystem that
944 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800945 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700946
Li Zefan23964d22009-01-15 13:50:58 -0800947 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700948
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700949config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800950 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800951 help
952 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700953 cgroup.
954
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700955config CGROUP_DEVICE
956 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700957 help
958 Provides a cgroup implementing whitelists for devices which
959 a process in the cgroup can mknod or open.
960
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961config CPUSETS
962 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700964 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 allow dynamically partitioning a system into sets of CPUs and
966 Memory Nodes and assigning tasks to run only within those sets.
967 This is primarily useful on large SMP or NUMA systems.
968
969 Say N if unsure.
970
Li Zefan23964d22009-01-15 13:50:58 -0800971config PROC_PID_CPUSET
972 bool "Include legacy /proc/<pid>/cpuset file"
973 depends on CPUSETS
974 default y
975
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100976config CGROUP_CPUACCT
977 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100978 help
979 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800980 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100981
Pavel Emelianove552b662008-02-07 00:13:49 -0800982config RESOURCE_COUNTERS
983 bool "Resource counters"
984 help
985 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800986 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800987
Andrew Mortonc255a452012-07-31 16:43:02 -0700988config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800989 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700990 depends on RESOURCE_COUNTERS
Tejun Heo79bd9812013-11-22 18:20:42 -0500991 select EVENTFD
Balbir Singh00f0b822008-03-04 14:28:39 -0800992 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700993 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100994 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800995
996 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700997 associated with each page of memory in the system. By this,
Sergey Dyaslyf60e2a92013-07-03 15:03:30 -0700998 8(16)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700999 usage tracking struct at boot. Total amount of this is printed out
1000 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -08001001
1002 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -07001003 sure you need the memory resource controller. Even when you enable
1004 this, you can set "cgroup_disable=memory" at your boot option to
1005 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -08001006 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -08001007
Andrew Mortonc255a452012-07-31 16:43:02 -07001008config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -07001009 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -07001010 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001011 help
1012 Add swap management feature to memory resource controller. When you
1013 enable this, you can limit mem+swap usage per cgroup. In other words,
1014 when you disable this, memory resource controller has no cares to
1015 usage of swap...a process can exhaust all of the swap. This extension
1016 is useful when you want to avoid exhaustion swap but this itself
1017 adds more overheads and consumes memory for remembering information.
1018 Especially if you use 32bit system or small memory system, please
1019 be careful about enabling this. When memory resource controller
1020 is disabled by boot option, this will be automatically disabled and
1021 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -07001022 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -07001023 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
1024 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -07001025config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -08001026 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -07001027 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -08001028 default y
1029 help
1030 Memory Resource Controller Swap Extension comes with its price in
1031 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -07001032 which want to enable the feature but keep it disabled by default
Michal Hocko07555ac2013-08-22 16:35:46 -07001033 and let the user enable it by swapaccount=1 boot command line
Michal Hockoa42c3902010-11-24 12:57:08 -08001034 parameter should have this option unselected.
1035 For those who want to have the feature enabled by default should
1036 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -07001037 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -07001038config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -07001039 bool "Memory Resource Controller Kernel Memory accounting"
1040 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -08001041 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +00001042 help
1043 The Kernel Memory extension for Memory Resource Controller can limit
1044 the amount of memory used by kernel objects in the system. Those are
1045 fundamentally different from the entities handled by the standard
1046 Memory Controller, which are page-based, and can be swapped. Users of
1047 the kmem extension can use it to guarantee that no group of processes
1048 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001049
Vladimir Davydov2ee06462014-06-04 16:07:28 -07001050 WARNING: Current implementation lacks reclaim support. That means
1051 allocation attempts will fail when close to the limit even if there
1052 are plenty of kmem available for reclaim. That makes this option
1053 unusable in real life so DO NOT SELECT IT unless for development
1054 purposes.
1055
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -07001056config CGROUP_HUGETLB
1057 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -07001058 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -07001059 default n
1060 help
1061 Provides a cgroup Resource Controller for HugeTLB pages.
1062 When you enable this, you can put a per cgroup limit on HugeTLB usage.
1063 The limit is enforced during page fault. Since HugeTLB doesn't
1064 support page reclaim, enforcing the limit at page fault time implies
1065 that, the application will get SIGBUS signal if it tries to access
1066 HugeTLB pages beyond its limit. This requires the application to know
1067 beforehand how much HugeTLB pages it would require for its use. The
1068 control group is tracked in the third page lru pointer. This means
1069 that we cannot use the controller with huge page less than 3 pages.
1070
Stephane Eraniane5d13672011-02-14 11:20:01 +02001071config CGROUP_PERF
1072 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
1073 depends on PERF_EVENTS && CGROUPS
1074 help
1075 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +08001076 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +02001077 designated cpu.
1078
1079 Say N if unsure.
1080
Dhaval Giani7c941432010-01-20 13:26:18 +01001081menuconfig CGROUP_SCHED
1082 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +01001083 default n
1084 help
1085 This feature lets CPU scheduler recognize task groups and control CPU
1086 bandwidth allocation to such task groups. It uses cgroups to group
1087 tasks.
1088
1089if CGROUP_SCHED
1090config FAIR_GROUP_SCHED
1091 bool "Group scheduling for SCHED_OTHER"
1092 depends on CGROUP_SCHED
1093 default CGROUP_SCHED
1094
Paul Turnerab84d312011-07-21 09:43:28 -07001095config CFS_BANDWIDTH
1096 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -07001097 depends on FAIR_GROUP_SCHED
1098 default n
1099 help
1100 This option allows users to define CPU bandwidth rates (limits) for
1101 tasks running within the fair group scheduler. Groups with no limit
1102 set are considered to be unconstrained and will run with no
1103 restriction.
1104 See tip/Documentation/scheduler/sched-bwc.txt for more information.
1105
Dhaval Giani7c941432010-01-20 13:26:18 +01001106config RT_GROUP_SCHED
1107 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +01001108 depends on CGROUP_SCHED
1109 default n
1110 help
1111 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +08001112 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +01001113 schedule realtime tasks for non-root users until you allocate
1114 realtime bandwidth for them.
1115 See Documentation/scheduler/sched-rt-group.txt for more information.
1116
1117endif #CGROUP_SCHED
1118
Vivek Goyalafc24d42010-04-26 19:27:56 +02001119config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -08001120 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -07001121 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +02001122 default n
1123 ---help---
1124 Generic block IO controller cgroup interface. This is the common
1125 cgroup interface which should be used by various IO controlling
1126 policies.
1127
1128 Currently, CFQ IO scheduler uses it to recognize task groups and
1129 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -04001130 to such task groups. It is also used by bio throttling logic in
1131 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001132
1133 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -04001134 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +00001135 enabling proportional weight division of disk bandwidth in CFQ, set
1136 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +00001137 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001138
1139 See Documentation/cgroups/blkio-controller.txt for more information.
1140
1141config DEBUG_BLK_CGROUP
1142 bool "Enable Block IO controller debugging"
1143 depends on BLK_CGROUP
1144 default n
1145 ---help---
1146 Enable some debugging help. Currently it exports additional stat
1147 files in a cgroup which can be useful for debugging.
1148
Li Zefan23964d22009-01-15 13:50:58 -08001149endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001150
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001151config CHECKPOINT_RESTORE
1152 bool "Checkpoint/restore support" if EXPERT
1153 default n
1154 help
1155 Enables additional kernel features in a sake of checkpoint/restore.
1156 In particular it adds auxiliary prctl codes to setup process text,
1157 data and heap segment sizes, and a few additional /proc filesystem
1158 entries.
1159
1160 If unsure, say N here.
1161
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001162menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001163 bool "Namespaces support" if EXPERT
1164 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001165 help
1166 Provides the way to make tasks work with different objects using
1167 the same id. For example same IPC id may refer to different objects
1168 or same user id or pid may refer to different tasks when used in
1169 different namespaces.
1170
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001171if NAMESPACES
1172
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001173config UTS_NS
1174 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001175 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001176 help
1177 In this namespace tasks see different info provided with the
1178 uname() system call
1179
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001180config IPC_NS
1181 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001182 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001183 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001184 help
1185 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001186 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001187
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001188config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001189 bool "User namespace"
Eric W. Biederman5673a942011-11-17 10:23:55 -08001190 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001191 help
1192 This allows containers, i.e. vservers, to use user namespaces
1193 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001194
1195 When user namespaces are enabled in the kernel it is
1196 recommended that the MEMCG and MEMCG_KMEM options also be
1197 enabled and that user-space use the memory control groups to
1198 limit the amount of memory a memory unprivileged users can
1199 use.
1200
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001201 If unsure, say N.
1202
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001203config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001204 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001205 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001206 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001207 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001208 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001209 pid namespaces. This is a building block of containers.
1210
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001211config NET_NS
1212 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001213 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001214 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001215 help
1216 Allow user space to create what appear to be multiple instances
1217 of the network stack.
1218
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001219endif # NAMESPACES
1220
Mike Galbraith5091faa2010-11-30 14:18:03 +01001221config SCHED_AUTOGROUP
1222 bool "Automatic process group scheduling"
Mike Galbraith5091faa2010-11-30 14:18:03 +01001223 select CGROUPS
1224 select CGROUP_SCHED
1225 select FAIR_GROUP_SCHED
1226 help
1227 This option optimizes the scheduler for common desktop workloads by
1228 automatically creating and populating task groups. This separation
1229 of workloads isolates aggressive CPU burners (like build jobs) from
1230 desktop applications. Task group autogeneration is currently based
1231 upon task session.
1232
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001233config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001234 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001235 depends on SYSFS
1236 default n
1237 help
1238 This option adds code that switches the layout of the "block" class
1239 devices, to not show up in /sys/class/block/, but only in
1240 /sys/block/.
1241
1242 This switch is only active when the sysfs.deprecated=1 boot option is
1243 passed or the SYSFS_DEPRECATED_V2 option is set.
1244
1245 This option allows new kernels to run on old distributions and tools,
1246 which might get confused by /sys/class/block/. Since 2007/2008 all
1247 major distributions and tools handle this just fine.
1248
1249 Recent distributions and userspace tools after 2009/2010 depend on
1250 the existence of /sys/class/block/, and will not work with this
1251 option enabled.
1252
1253 Only if you are using a new kernel on an old distribution, you might
1254 need to say Y here.
1255
1256config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001257 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001258 default n
1259 depends on SYSFS
1260 depends on SYSFS_DEPRECATED
1261 help
1262 Enable deprecated sysfs by default.
1263
1264 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1265 option.
1266
1267 Only if you are using a new kernel on an old distribution, you might
1268 need to say Y here. Even then, odds are you would not need it
1269 enabled, you can always pass the boot option if absolutely necessary.
1270
1271config RELAY
1272 bool "Kernel->user space relay support (formerly relayfs)"
1273 help
1274 This option enables support for relay interface support in
1275 certain file systems (such as debugfs).
1276 It is designed to provide an efficient mechanism for tools and
1277 facilities to relay large amounts of data from kernel space to
1278 user space.
1279
1280 If unsure, say N.
1281
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001282config BLK_DEV_INITRD
1283 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1284 depends on BROKEN || !FRV
1285 help
1286 The initial RAM filesystem is a ramfs which is loaded by the
1287 boot loader (loadlin or lilo) and that is mounted as root
1288 before the normal boot procedure. It is typically used to
1289 load modules needed to mount the "real" root file system,
1290 etc. See <file:Documentation/initrd.txt> for details.
1291
1292 If RAM disk support (BLK_DEV_RAM) is also included, this
1293 also enables initial RAM disk (initrd) support and adds
1294 15 Kbytes (more on some other architectures) to the kernel size.
1295
1296 If unsure say Y.
1297
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001298if BLK_DEV_INITRD
1299
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001300source "usr/Kconfig"
1301
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001302endif
1303
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001304config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001305 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001306 help
1307 Enabling this option will pass "-Os" instead of "-O2" to gcc
1308 resulting in a smaller kernel.
1309
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001310 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001311
Randy Dunlap08470622006-09-30 23:28:13 -07001312config SYSCTL
1313 bool
1314
Randy Dunlapb943c462009-03-10 12:55:46 -07001315config ANON_INODES
1316 bool
1317
Mike Frysinger657a5202013-04-30 15:28:45 -07001318config HAVE_UID16
1319 bool
1320
1321config SYSCTL_EXCEPTION_TRACE
1322 bool
1323 help
1324 Enable support for /proc/sys/debug/exception-trace.
1325
1326config SYSCTL_ARCH_UNALIGN_NO_WARN
1327 bool
1328 help
1329 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1330 Allows arch to define/use @no_unaligned_warning to possibly warn
1331 about unaligned access emulation going on under the hood.
1332
1333config SYSCTL_ARCH_UNALIGN_ALLOW
1334 bool
1335 help
1336 Enable support for /proc/sys/kernel/unaligned-trap
1337 Allows arches to define/use @unaligned_enabled to runtime toggle
1338 the unaligned access emulation.
1339 see arch/parisc/kernel/unaligned.c for reference
1340
Mike Frysinger657a5202013-04-30 15:28:45 -07001341config HAVE_PCSPKR_PLATFORM
1342 bool
1343
David Rientjes6a108a12011-01-20 14:44:16 -08001344menuconfig EXPERT
1345 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001346 # Unhide debug options, to make the on-by-default options visible
1347 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348 help
1349 This option allows certain base kernel options and settings
1350 to be disabled or tweaked. This is for specialized
1351 environments which can tolerate a "non-standard" kernel.
1352 Only use this if you really know what you are doing.
1353
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001354config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001355 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001356 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001357 default y
1358 help
1359 This enables the legacy 16-bit UID syscall wrappers.
1360
Fabian Frederickf6187762014-06-04 16:11:12 -07001361config SGETMASK_SYSCALL
1362 bool "sgetmask/ssetmask syscalls support" if EXPERT
1363 def_bool PARISC || MN10300 || BLACKFIN || M68K || PPC || MIPS || X86 || SPARC || CRIS || MICROBLAZE || SUPERH
1364 ---help---
1365 sys_sgetmask and sys_ssetmask are obsolete system calls
1366 no longer supported in libc but still enabled by default in some
1367 architectures.
1368
1369 If unsure, leave the default option here.
1370
Fabian Frederick6af9f7b2014-04-03 14:48:25 -07001371config SYSFS_SYSCALL
1372 bool "Sysfs syscall support" if EXPERT
1373 default y
1374 ---help---
1375 sys_sysfs is an obsolete system call no longer supported in libc.
1376 Note that disabling this option is more secure but might break
1377 compatibility with some systems.
1378
1379 If unsure say Y here.
1380
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001381config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001382 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001383 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001384 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001385 select SYSCTL
1386 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001387 sys_sysctl uses binary paths that have been found challenging
1388 to properly maintain and use. The interface in /proc/sys
1389 using paths with ascii names is now the primary path to this
1390 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001391
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001392 Almost nothing using the binary sysctl interface so if you are
1393 trying to save some space it is probably safe to disable this,
1394 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001395
WANG Congc736de62011-11-02 13:39:25 -07001396 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001397
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001399 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 default y
1401 help
1402 Say Y here to let the kernel print out symbolic crash information and
1403 symbolic stack backtraces. This increases the size of the kernel
1404 somewhat, as all symbols have to be loaded into the kernel image.
1405
1406config KALLSYMS_ALL
1407 bool "Include all symbols in kallsyms"
1408 depends on DEBUG_KERNEL && KALLSYMS
1409 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001410 Normally kallsyms only contains the symbols of functions for nicer
1411 OOPS messages and backtraces (i.e., symbols from the text and inittext
1412 sections). This is sufficient for most cases. And only in very rare
1413 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1414 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001416 This option makes sure that all symbols are loaded into the kernel
1417 image (i.e., symbols from all sections) in cost of increased kernel
1418 size (depending on the kernel configuration, it may be 300KiB or
1419 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001420
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001421 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001422
1423config PRINTK
1424 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001425 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001426 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001427 help
1428 This option enables normal printk support. Removing it
1429 eliminates most of the message strings from the kernel image
1430 and makes the kernel more or less silent. As this makes it
1431 very difficult to diagnose system problems, saying N here is
1432 strongly discouraged.
1433
Matt Mackallc8538a72005-05-01 08:59:01 -07001434config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001435 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001436 default y
1437 help
1438 Disabling this option eliminates support for BUG and WARN, reducing
1439 the size of your kernel image and potentially quietly ignoring
1440 numerous fatal conditions. You should only consider disabling this
1441 option for embedded systems with no facilities for reporting errors.
1442 Just say Y.
1443
Matt Mackall708e9a72006-01-08 01:05:25 -08001444config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001445 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001446 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001447 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001448 help
1449 Enable support for generating core dumps. Disabling saves about 4k.
1450
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001451
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001452config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001453 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001454 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001455 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001456 default y
1457 help
1458 This option allows to disable the internal PC-Speaker
1459 support, saving some memory.
1460
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461config BASE_FULL
1462 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001463 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001464 help
1465 Disabling this option reduces the size of miscellaneous core
1466 kernel data structures. This saves memory on small machines,
1467 but may reduce performance.
1468
1469config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001470 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001471 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001472 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001473 help
1474 Disabling this option will cause the kernel to be built without
1475 support for "fast userspace mutexes". The resulting kernel may not
1476 run glibc-based applications correctly.
1477
Heiko Carstens03b8c7b2014-03-02 13:09:47 +01001478config HAVE_FUTEX_CMPXCHG
1479 bool
Josh Triplett62b4d202014-10-03 16:19:24 -07001480 depends on FUTEX
Heiko Carstens03b8c7b2014-03-02 13:09:47 +01001481 help
1482 Architectures should select this if futex_atomic_cmpxchg_inatomic()
1483 is implemented and always working. This removes a couple of runtime
1484 checks.
1485
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001487 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001489 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 help
1491 Disabling this option will cause the kernel to be built without
1492 support for epoll family of system calls.
1493
Davide Libenzifba2afa2007-05-10 22:23:13 -07001494config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001495 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001496 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001497 default y
1498 help
1499 Enable the signalfd() system call that allows to receive signals
1500 on a file descriptor.
1501
1502 If unsure, say Y.
1503
Davide Libenzib215e282007-05-10 22:23:16 -07001504config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001505 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001506 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001507 default y
1508 help
1509 Enable the timerfd() system call that allows to receive timer
1510 events on a file descriptor.
1511
1512 If unsure, say Y.
1513
Davide Libenzie1ad7462007-05-10 22:23:19 -07001514config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001515 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001516 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001517 default y
1518 help
1519 Enable the eventfd() system call that allows to receive both
1520 kernel notification (ie. KAIO) or userspace notifications.
1521
1522 If unsure, say Y.
1523
Linus Torvalds1da177e2005-04-16 15:20:36 -07001524config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001525 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526 default y
1527 depends on MMU
1528 help
1529 The shmem is an internal filesystem used to manage shared memory.
1530 It is backed by swap and manages resource limits. It is also exported
1531 to userspace as tmpfs if TMPFS is enabled. Disabling this
1532 option replaces shmem and tmpfs with the much simpler ramfs code,
1533 which may be appropriate on small systems without swap.
1534
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001535config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001536 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001537 default y
1538 help
1539 This option enables POSIX asynchronous I/O which may by used
Mike Frysinger657a5202013-04-30 15:28:45 -07001540 by some high performance threaded applications. Disabling
1541 this option saves about 7k.
1542
1543config PCI_QUIRKS
1544 default y
1545 bool "Enable PCI quirk workarounds" if EXPERT
1546 depends on PCI
1547 help
1548 This enables workarounds for various PCI chipset
1549 bugs/quirks. Disable this only if your target machine is
1550 unaffected by PCI quirks.
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001551
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001552config EMBEDDED
1553 bool "Embedded system"
Josh Triplett5d2acfc2014-04-07 15:39:09 -07001554 option allnoconfig_y
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001555 select EXPERT
1556 help
1557 This option should be enabled if compiling the kernel for
1558 an embedded system so certain expert options are available
1559 for configuration.
1560
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001561config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001562 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001563 help
1564 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001565
Peter Zijlstra906010b2009-09-21 16:08:49 +02001566config PERF_USE_VMALLOC
1567 bool
1568 help
1569 See tools/perf/design.txt for details
1570
Ingo Molnar57c0c152009-09-21 12:20:38 +02001571menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001572
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001573config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001574 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001575 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001576 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001577 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001578 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001579 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001580 Enable kernel support for various performance events provided
1581 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001582
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001583 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001584 use of generic tracepoints.
1585
1586 Most modern CPUs support performance events via performance
1587 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001588 types of hw events: such as instructions executed, cachemisses
1589 suffered, or branches mis-predicted - without slowing down the
1590 kernel or applications. These registers can also trigger interrupts
1591 when a threshold number of events have passed - and can thus be
1592 used to profile the code that runs on that CPU.
1593
Ingo Molnar57c0c152009-09-21 12:20:38 +02001594 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001595 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001596 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001597 provides per task and per CPU counters, and it provides event
1598 capabilities on top of those.
1599
1600 Say Y if unsure.
1601
Peter Zijlstra906010b2009-09-21 16:08:49 +02001602config DEBUG_PERF_USE_VMALLOC
1603 default n
1604 bool "Debug: use vmalloc to back perf mmap() buffers"
1605 depends on PERF_EVENTS && DEBUG_KERNEL
1606 select PERF_USE_VMALLOC
1607 help
1608 Use vmalloc memory to back perf mmap() buffers.
1609
1610 Mostly useful for debugging the vmalloc code on platforms
1611 that don't require it.
1612
1613 Say N if unsure.
1614
Thomas Gleixner0793a612008-12-04 20:12:29 +01001615endmenu
1616
Christoph Lameterf8891e52006-06-30 01:55:45 -07001617config VM_EVENT_COUNTERS
1618 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001619 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001620 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001621 VM event counters are needed for event counts to be shown.
1622 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001623 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001624 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001625
Christoph Lameter41ecc552007-05-09 02:32:44 -07001626config SLUB_DEBUG
1627 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001628 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001629 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001630 help
1631 SLUB has extensive debug support features. Disabling these can
1632 result in significant savings in code size. This also disables
1633 SLUB sysfs support. /sys/slab will not exist and there will be
1634 no support for cache validation etc.
1635
Randy Dunlapb943c462009-03-10 12:55:46 -07001636config COMPAT_BRK
1637 bool "Disable heap randomization"
1638 default y
1639 help
1640 Randomizing heap placement makes heap exploits harder, but it
1641 also breaks ancient binaries (including anything libc5 based).
1642 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001643 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001644 /proc/sys/kernel/randomize_va_space to 2.
1645
1646 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1647
Christoph Lameter81819f02007-05-06 14:49:36 -07001648choice
1649 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001650 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001651 help
1652 This option allows to select a slab allocator.
1653
1654config SLAB
1655 bool "SLAB"
1656 help
1657 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001658 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001659 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001660
1661config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001662 bool "SLUB (Unqueued Allocator)"
1663 help
1664 SLUB is a slab allocator that minimizes cache line usage
1665 instead of managing queues of cached objects (SLAB approach).
1666 Per cpu caching is realized using slabs of objects instead
1667 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001668 and has enhanced diagnostics. SLUB is the default choice for
1669 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001670
1671config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001672 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001673 bool "SLOB (Simple Allocator)"
1674 help
Matt Mackall37291452008-02-04 22:29:38 -08001675 SLOB replaces the stock allocator with a drastically simpler
1676 allocator. SLOB is generally more space efficient but
1677 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001678
1679endchoice
1680
Joonsoo Kim345c9052013-06-19 14:05:52 +09001681config SLUB_CPU_PARTIAL
1682 default y
Uwe Kleine-Königb39ffbf2013-07-17 16:54:59 +02001683 depends on SLUB && SMP
Joonsoo Kim345c9052013-06-19 14:05:52 +09001684 bool "SLUB per cpu partial cache"
1685 help
1686 Per cpu partial caches accellerate objects allocation and freeing
1687 that is local to a processor at the price of more indeterminism
1688 in the latency of the free. On overflow these caches will be cleared
1689 which requires the taking of locks that may cause latency spikes.
1690 Typically one would choose no for a realtime system.
1691
Jie Zhangea637632009-12-14 18:00:02 -08001692config MMAP_ALLOW_UNINITIALIZED
1693 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001694 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001695 default n
1696 help
1697 Normally, and according to the Linux spec, anonymous memory obtained
1698 from mmap() has it's contents cleared before it is passed to
1699 userspace. Enabling this config option allows you to request that
1700 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1701 providing a huge performance boost. If this option is not enabled,
1702 then the flag will be ignored.
1703
1704 This is taken advantage of by uClibc's malloc(), and also by
1705 ELF-FDPIC binfmt's brk and stack allocator.
1706
1707 Because of the obvious security issues, this option should only be
1708 enabled on embedded devices where you control what is run in
1709 userspace. Since that isn't generally a problem on no-MMU systems,
1710 it is normally safe to say Y here.
1711
1712 See Documentation/nommu-mmap.txt for more information.
1713
Peter Foley82c04ff2014-04-18 15:07:11 -07001714config SYSTEM_TRUSTED_KEYRING
1715 bool "Provide system-wide ring of trusted keys"
1716 depends on KEYS
1717 help
1718 Provide a system keyring to which trusted keys can be added. Keys in
1719 the keyring are considered to be trusted. Keys may be added at will
1720 by the kernel from compiled-in data and from hardware key stores, but
1721 userspace may only add extra keys if those keys can be verified by
1722 keys already in the keyring.
1723
1724 Keys in this keyring are used by module signature checking.
1725
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001726config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001727 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001728 help
1729 Say Y here to enable the extended profiling support mechanisms used
1730 by profilers such as OProfile.
1731
Ingo Molnar5f87f112008-07-23 14:15:22 +02001732#
1733# Place an empty function call at each tracepoint site. Can be
1734# dynamically changed for a probe function.
1735#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001736config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001737 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001738
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001739source "arch/Kconfig"
1740
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741endmenu # General setup
1742
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001743config HAVE_GENERIC_DMA_COHERENT
1744 bool
1745 default n
1746
Linus Torvalds158a9622008-01-02 13:04:48 -08001747config SLABINFO
1748 bool
1749 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001750 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001751 default y
1752
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001753config RT_MUTEXES
1754 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001755
Linus Torvalds1da177e2005-04-16 15:20:36 -07001756config BASE_SMALL
1757 int
1758 default 0 if BASE_FULL
1759 default 1 if !BASE_FULL
1760
Jan Engelhardt66da5732007-07-15 23:39:29 -07001761menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001762 bool "Enable loadable module support"
Yann E. MORIN11097a02013-08-11 16:07:50 +02001763 option modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001764 help
1765 Kernel modules are small pieces of compiled code which can
1766 be inserted in the running kernel, rather than being
1767 permanently built into the kernel. You use the "modprobe"
1768 tool to add (and sometimes remove) them. If you say Y here,
1769 many parts of the kernel can be built as modules (by
1770 answering M instead of Y where indicated): this is most
1771 useful for infrequently used options which are not required
1772 for booting. For more information, see the man pages for
1773 modprobe, lsmod, modinfo, insmod and rmmod.
1774
1775 If you say Y here, you will need to run "make
1776 modules_install" to put the modules under /lib/modules/
1777 where modprobe can find them (you may need to be root to do
1778 this).
1779
1780 If unsure, say Y.
1781
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001782if MODULES
1783
Linus Torvalds826e4502008-05-04 17:04:16 -07001784config MODULE_FORCE_LOAD
1785 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001786 default n
1787 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001788 Allow loading of modules without version information (ie. modprobe
1789 --force). Forced module loading sets the 'F' (forced) taint flag and
1790 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001791
Linus Torvalds1da177e2005-04-16 15:20:36 -07001792config MODULE_UNLOAD
1793 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001794 help
1795 Without this option you will not be able to unload any
1796 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001797 anyway), which makes your kernel smaller, faster
1798 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001799
1800config MODULE_FORCE_UNLOAD
1801 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001802 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001803 help
1804 This option allows you to force a module to unload, even if the
1805 kernel believes it is unsafe: the kernel will remove the module
1806 without waiting for anyone to stop using it (using the -f option to
1807 rmmod). This is mainly for kernel developers and desperate users.
1808 If unsure, say N.
1809
Linus Torvalds1da177e2005-04-16 15:20:36 -07001810config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001811 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812 help
1813 Usually, you have to use modules compiled with your kernel.
1814 Saying Y here makes it sometimes possible to use modules
1815 compiled for different kernels, by adding enough information
1816 to the modules to (hopefully) spot any changes which would
1817 make them incompatible with the kernel you are running. If
1818 unsure, say N.
1819
1820config MODULE_SRCVERSION_ALL
1821 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001822 help
1823 Modules which contain a MODULE_VERSION get an extra "srcversion"
1824 field inserted into their modinfo section, which contains a
1825 sum of the source files which made it. This helps maintainers
1826 see exactly which source was used to build a module (since
1827 others sometimes change the module source without updating
1828 the version). With this option, such a "srcversion" field
1829 will be created for all modules. If unsure, say N.
1830
Rusty Russell106a4ee2012-09-26 10:09:40 +01001831config MODULE_SIG
1832 bool "Module signature verification"
1833 depends on MODULES
David Howellsb56e5a12013-08-30 16:07:30 +01001834 select SYSTEM_TRUSTED_KEYRING
David Howells48ba2462012-09-26 10:11:03 +01001835 select KEYS
1836 select CRYPTO
1837 select ASYMMETRIC_KEY_TYPE
1838 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1839 select PUBLIC_KEY_ALGO_RSA
1840 select ASN1
1841 select OID_REGISTRY
1842 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001843 help
1844 Check modules for valid signatures upon load: the signature
1845 is simply appended to the module. For more information see
1846 Documentation/module-signing.txt.
1847
David Howellsea0b6dc2012-09-26 10:09:50 +01001848 !!!WARNING!!! If you enable this option, you MUST make sure that the
1849 module DOES NOT get stripped after being signed. This includes the
1850 debuginfo strip done by some packagers (such as rpmbuild) and
1851 inclusion into an initramfs that wants the module size reduced.
1852
Rusty Russell106a4ee2012-09-26 10:09:40 +01001853config MODULE_SIG_FORCE
1854 bool "Require modules to be validly signed"
1855 depends on MODULE_SIG
1856 help
1857 Reject unsigned modules or signed modules for which we don't have a
1858 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001859
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301860config MODULE_SIG_ALL
1861 bool "Automatically sign all modules"
1862 default y
1863 depends on MODULE_SIG
1864 help
1865 Sign all modules during make modules_install. Without this option,
1866 modules must be signed manually, using the scripts/sign-file tool.
1867
1868comment "Do not forget to sign required modules with scripts/sign-file"
1869 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1870
David Howellsea0b6dc2012-09-26 10:09:50 +01001871choice
1872 prompt "Which hash algorithm should modules be signed with?"
1873 depends on MODULE_SIG
1874 help
1875 This determines which sort of hashing algorithm will be used during
1876 signature generation. This algorithm _must_ be built into the kernel
1877 directly so that signature verification can take place. It is not
1878 possible to load a signed module containing the algorithm to check
1879 the signature on that module.
1880
1881config MODULE_SIG_SHA1
1882 bool "Sign modules with SHA-1"
1883 select CRYPTO_SHA1
1884
1885config MODULE_SIG_SHA224
1886 bool "Sign modules with SHA-224"
1887 select CRYPTO_SHA256
1888
1889config MODULE_SIG_SHA256
1890 bool "Sign modules with SHA-256"
1891 select CRYPTO_SHA256
1892
1893config MODULE_SIG_SHA384
1894 bool "Sign modules with SHA-384"
1895 select CRYPTO_SHA512
1896
1897config MODULE_SIG_SHA512
1898 bool "Sign modules with SHA-512"
1899 select CRYPTO_SHA512
1900
1901endchoice
1902
Michal Marek22753672013-01-25 13:41:00 +10301903config MODULE_SIG_HASH
1904 string
1905 depends on MODULE_SIG
1906 default "sha1" if MODULE_SIG_SHA1
1907 default "sha224" if MODULE_SIG_SHA224
1908 default "sha256" if MODULE_SIG_SHA256
1909 default "sha384" if MODULE_SIG_SHA384
1910 default "sha512" if MODULE_SIG_SHA512
1911
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001912endif # MODULES
1913
Rusty Russell98a79d62008-12-13 21:19:41 +10301914config INIT_ALL_POSSIBLE
1915 bool
1916 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301917 Back when each arch used to define their own cpu_online_mask and
1918 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301919 with all 1s, and others with all 0s. When they were centralised,
1920 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001921 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301922
Linus Torvalds1da177e2005-04-16 15:20:36 -07001923config STOP_MACHINE
1924 bool
1925 default y
1926 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1927 help
1928 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001929
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001930source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001931
1932config PREEMPT_NOTIFIERS
1933 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001934
Steffen Klassert16295be2010-01-06 19:47:10 +11001935config PADATA
1936 depends on SMP
1937 bool
1938
Andi Kleen754b7b62012-10-04 17:11:27 -07001939# Can be selected by architectures with broken toolchains
1940# that get confused by correct const<->read_only section
1941# mappings
1942config BROKEN_RODATA
1943 bool
1944
David Howells4520c6a2012-09-21 23:31:13 +01001945config ASN1
1946 tristate
1947 help
1948 Build a simple ASN.1 grammar compiler that produces a bytecode output
1949 that can be interpreted by the ASN.1 stream decoder and used to
1950 inform it as to what tags are to be expected in a stream and what
1951 functions to call on what tags.
1952
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001953source "kernel/Kconfig.locks"