blob: 2081a4d3d9171f5323a077a1f3a9805223e715be [file] [log] [blame]
Roman Zippel80daa5602008-01-14 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 Oberparleiterb99b87f72009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
Peter Oberparleiterb99b87f72009-06-17 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. Dayb0e376502007-05-09 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. McKenney8315f422014-06-27 13:42:20 -0700510config TASKS_RCU
511 bool "Task_based RCU implementation using voluntary context switch"
512 default n
513 help
514 This option enables a task-based RCU implementation that uses
515 only voluntary context switch (not preemption!), idle, and
516 user-mode execution as quiescent states.
517
518 If unsure, say N.
519
Paul E. McKenney6bfc09e2012-10-19 12:49:17 -0700520config RCU_STALL_COMMON
521 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
522 help
523 This option enables RCU CPU stall code that is common between
524 the TINY and TREE variants of RCU. The purpose is to allow
525 the tiny variants to disable RCU CPU stall warnings, while
526 making these warnings mandatory for the tree variants.
527
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100528config CONTEXT_TRACKING
529 bool
530
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200531config RCU_USER_QS
532 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100533 depends on HAVE_CONTEXT_TRACKING && SMP
534 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200535 help
536 This option sets hooks on kernel / userspace boundaries and
537 puts RCU in extended quiescent state when the CPU runs in
538 userspace. It means that when a CPU runs in userspace, it is
539 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700540 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200541
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200542 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100543 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700544 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200545
546 If unsure say N
547
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100548config CONTEXT_TRACKING_FORCE
549 bool "Force context tracking"
550 depends on CONTEXT_TRACKING
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200551 default y if !NO_HZ_FULL
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200552 help
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200553 The major pre-requirement for full dynticks to work is to
554 support the context tracking subsystem. But there are also
555 other dependencies to provide in order to make the full
556 dynticks working.
557
558 This option stands for testing when an arch implements the
559 context tracking backend but doesn't yet fullfill all the
560 requirements to make the full dynticks feature working.
561 Without the full dynticks, there is no way to test the support
562 for context tracking and the subsystems that rely on it: RCU
563 userspace extended quiescent state and tickless cputime
564 accounting. This option copes with the absence of the full
565 dynticks subsystem by forcing the context tracking on all
566 CPUs in the system.
567
Paul Gortmaker99c8b1e2013-10-24 10:07:47 -0400568 Say Y only if you're working on the development of an
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200569 architecture backend for the context tracking.
570
571 Say N otherwise, this option brings an overhead that you
572 don't want in production.
573
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200574
Mike Travisc903ff82009-01-15 12:28:29 -0800575config RCU_FANOUT
576 int "Tree-based hierarchical RCU fanout value"
577 range 2 64 if 64BIT
578 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700579 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800580 default 64 if 64BIT
581 default 32 if !64BIT
582 help
583 This option controls the fanout of hierarchical implementations
584 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700585 large numbers of CPUs. This value must be at least the fourth
586 root of NR_CPUS, which allows NR_CPUS to be insanely large.
587 The default value of RCU_FANOUT should be used for production
588 systems, but if you are stress-testing the RCU implementation
589 itself, small RCU_FANOUT values allow you to test large-system
590 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800591
592 Select a specific number if testing RCU itself.
593 Take the default if unsure.
594
Paul E. McKenney8932a632012-04-19 12:20:14 -0700595config RCU_FANOUT_LEAF
596 int "Tree-based hierarchical RCU leaf-level fanout value"
597 range 2 RCU_FANOUT if 64BIT
598 range 2 RCU_FANOUT if !64BIT
599 depends on TREE_RCU || TREE_PREEMPT_RCU
600 default 16
601 help
602 This option controls the leaf-level fanout of hierarchical
603 implementations of RCU, and allows trading off cache misses
604 against lock contention. Systems that synchronize their
605 scheduling-clock interrupts for energy-efficiency reasons will
606 want the default because the smaller leaf-level fanout keeps
607 lock contention levels acceptably low. Very large systems
608 (hundreds or thousands of CPUs) will instead want to set this
609 value to the maximum value possible in order to reduce the
610 number of cache misses incurred during RCU's grace-period
611 initialization. These systems tend to run CPU-bound, and thus
612 are not helped by synchronized interrupts, and thus tend to
613 skew them, which reduces lock contention enough that large
614 leaf-level fanouts work well.
615
616 Select a specific number if testing RCU itself.
617
618 Select the maximum permissible value for large systems.
619
620 Take the default if unsure.
621
Mike Travisc903ff82009-01-15 12:28:29 -0800622config RCU_FANOUT_EXACT
623 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700624 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800625 default n
626 help
627 This option forces use of the exact RCU_FANOUT value specified,
628 regardless of imbalances in the hierarchy. This is useful for
629 testing RCU itself, and might one day be useful on systems with
630 strong NUMA behavior.
631
632 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
633
634 Say N if unsure.
635
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800636config RCU_FAST_NO_HZ
637 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Frederic Weisbecker3451d022011-08-10 23:21:01 +0200638 depends on NO_HZ_COMMON && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800639 default n
640 help
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800641 This option permits CPUs to enter dynticks-idle state even if
642 they have RCU callbacks queued, and prevents RCU from waking
643 these CPUs up more than roughly once every four jiffies (by
644 default, you can adjust this using the rcutree.rcu_idle_gp_delay
645 parameter), thus improving energy efficiency. On the other
646 hand, this option increases the duration of RCU grace periods,
647 for example, slowing down synchronize_rcu().
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800648
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800649 Say Y if energy efficiency is critically important, and you
650 don't care about increased grace-period durations.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800651
652 Say N if you are unsure.
653
Mike Travisc903ff82009-01-15 12:28:29 -0800654config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700655 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800656 select DEBUG_FS
657 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700658 This option provides tracing for the TREE_RCU and
659 TREE_PREEMPT_RCU implementations, permitting Makefile to
660 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800661
Paul E. McKenney24278d12010-09-27 17:25:23 -0700662config RCU_BOOST
663 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800664 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700665 default n
666 help
667 This option boosts the priority of preempted RCU readers that
668 block the current preemptible RCU grace period for too long.
669 This option also prevents heavy loads from blocking RCU
670 callback invocation for all flavors of RCU.
671
672 Say Y here if you are working with real-time apps or heavy loads
673 Say N here if you are unsure.
674
675config RCU_BOOST_PRIO
676 int "Real-time priority to boost RCU readers to"
677 range 1 99
678 depends on RCU_BOOST
679 default 1
680 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700681 This option specifies the real-time priority to which long-term
682 preempted RCU readers are to be boosted. If you are working
683 with a real-time application that has one or more CPU-bound
684 threads running at a real-time priority level, you should set
685 RCU_BOOST_PRIO to a priority higher then the highest-priority
686 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
687 of 1 is appropriate in the common case, which is real-time
688 applications that do not have any CPU-bound threads.
689
690 Some real-time applications might not have a single real-time
691 thread that saturates a given CPU, but instead might have
692 multiple real-time threads that, taken together, fully utilize
693 that CPU. In this case, you should set RCU_BOOST_PRIO to
694 a priority higher than the lowest-priority thread that is
695 conspiring to prevent the CPU from running any non-real-time
696 tasks. For example, if one thread at priority 10 and another
697 thread at priority 5 are between themselves fully consuming
698 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
699 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700700
701 Specify the real-time priority, or take the default if unsure.
702
703config RCU_BOOST_DELAY
704 int "Milliseconds to delay boosting after RCU grace-period start"
705 range 0 3000
706 depends on RCU_BOOST
707 default 500
708 help
709 This option specifies the time to wait after the beginning of
710 a given grace period before priority-boosting preempted RCU
711 readers blocking that grace period. Note that any RCU reader
712 blocking an expedited RCU grace period is boosted immediately.
713
714 Accept the default if unsure.
715
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700716config RCU_NOCB_CPU
Paul E. McKenney9a5739d72013-03-28 20:48:36 -0700717 bool "Offload RCU callback processing from boot-selected CPUs"
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700718 depends on TREE_RCU || TREE_PREEMPT_RCU
719 default n
720 help
721 Use this option to reduce OS jitter for aggressive HPC or
722 real-time workloads. It can also be used to offload RCU
723 callback invocation to energy-efficient CPUs in battery-powered
724 asymmetric multiprocessors.
725
726 This option offloads callback invocation from the set of
727 CPUs specified at boot time by the rcu_nocbs parameter.
Paul E. McKenneya4889852012-12-03 08:16:28 -0800728 For each such CPU, a kthread ("rcuox/N") will be created to
729 invoke callbacks, where the "N" is the CPU being offloaded,
730 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
731 "s" for RCU-sched. Nothing prevents this kthread from running
732 on the specified CPUs, but (1) the kthreads may be preempted
733 between each callback, and (2) affinity or cgroups can be used
734 to force the kthreads to run on whatever set of CPUs is desired.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700735
Paul E. McKenney34ed62462013-01-07 13:37:42 -0800736 Say Y here if you want to help to debug reduced OS jitter.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700737 Say N here if you are unsure.
738
Paul E. McKenney911af502013-02-11 10:23:27 -0800739choice
740 prompt "Build-forced no-CBs CPUs"
741 default RCU_NOCB_CPU_NONE
742 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700743 This option allows no-CBs CPUs (whose RCU callbacks are invoked
744 from kthreads rather than from softirq context) to be specified
745 at build time. Additional no-CBs CPUs may be specified by
746 the rcu_nocbs= boot parameter.
Paul E. McKenney911af502013-02-11 10:23:27 -0800747
748config RCU_NOCB_CPU_NONE
749 bool "No build_forced no-CBs CPUs"
Paul E. McKenneyf4579fc2014-07-25 11:21:47 -0700750 depends on RCU_NOCB_CPU
Paul E. McKenney911af502013-02-11 10:23:27 -0800751 help
752 This option does not force any of the CPUs to be no-CBs CPUs.
753 Only CPUs designated by the rcu_nocbs= boot parameter will be
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700754 no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU
755 kthreads whose names begin with "rcuo". All other CPUs will
756 invoke their own RCU callbacks in softirq context.
757
758 Select this option if you want to choose no-CBs CPUs at
759 boot time, for example, to allow testing of different no-CBs
760 configurations without having to rebuild the kernel each time.
Paul E. McKenney911af502013-02-11 10:23:27 -0800761
762config RCU_NOCB_CPU_ZERO
763 bool "CPU 0 is a build_forced no-CBs CPU"
Paul E. McKenneyf4579fc2014-07-25 11:21:47 -0700764 depends on RCU_NOCB_CPU
Paul E. McKenney911af502013-02-11 10:23:27 -0800765 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700766 This option forces CPU 0 to be a no-CBs CPU, so that its RCU
767 callbacks are invoked by a per-CPU kthread whose name begins
768 with "rcuo". Additional CPUs may be designated as no-CBs
769 CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs.
770 All other CPUs will invoke their own RCU callbacks in softirq
771 context.
Paul E. McKenney911af502013-02-11 10:23:27 -0800772
773 Select this if CPU 0 needs to be a no-CBs CPU for real-time
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700774 or energy-efficiency reasons, but the real reason it exists
775 is to ensure that randconfig testing covers mixed systems.
Paul E. McKenney911af502013-02-11 10:23:27 -0800776
777config RCU_NOCB_CPU_ALL
778 bool "All CPUs are build_forced no-CBs CPUs"
779 depends on RCU_NOCB_CPU
780 help
781 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700782 boot parameter will be ignored. All CPUs' RCU callbacks will
783 be executed in the context of per-CPU rcuo kthreads created for
784 this purpose. Assuming that the kthreads whose names start with
785 "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter
786 on the remaining CPUs, but might decrease memory locality during
787 RCU-callback invocation, thus potentially degrading throughput.
Paul E. McKenney911af502013-02-11 10:23:27 -0800788
789 Select this if all CPUs need to be no-CBs CPUs for real-time
790 or energy-efficiency reasons.
791
792endchoice
793
Mike Travisc903ff82009-01-15 12:28:29 -0800794endmenu # "RCU Subsystem"
795
Vivek Goyalde5b56b2014-08-08 14:25:41 -0700796config BUILD_BIN2C
797 bool
798 default n
799
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700801 tristate "Kernel .config support"
Vivek Goyalde5b56b2014-08-08 14:25:41 -0700802 select BUILD_BIN2C
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 ---help---
804 This option enables the complete Linux kernel ".config" file
805 contents to be saved in the kernel. It provides documentation
806 of which kernel options are used in a running kernel or in an
807 on-disk kernel. This information can be extracted from the kernel
808 image file with the script scripts/extract-ikconfig and used as
809 input to rebuild the current kernel or to build another kernel.
810 It can also be extracted from a running kernel by reading
811 /proc/config.gz if enabled (below).
812
813config IKCONFIG_PROC
814 bool "Enable access to .config through /proc/config.gz"
815 depends on IKCONFIG && PROC_FS
816 ---help---
817 This option enables access to the kernel configuration file
818 through /proc/config.gz.
819
Alistair John Strachan794543a2007-05-08 00:31:15 -0700820config LOG_BUF_SHIFT
821 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
822 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700823 default 17
Josh Triplett361e9df2014-10-03 16:00:54 -0700824 depends on PRINTK
Alistair John Strachan794543a2007-05-08 00:31:15 -0700825 help
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700826 Select the minimal kernel log buffer size as a power of 2.
827 The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
828 parameter, see below. Any higher size also might be forced
829 by "log_buf_len" boot parameter.
830
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700831 Examples:
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700832 17 => 128 KB
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700833 16 => 64 KB
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700834 15 => 32 KB
835 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700836 13 => 8 KB
837 12 => 4 KB
838
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700839config LOG_CPU_MAX_BUF_SHIFT
840 int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
Geert Uytterhoeven2240a312014-10-13 15:51:11 -0700841 depends on SMP
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700842 range 0 21
843 default 12 if !BASE_SMALL
844 default 0 if BASE_SMALL
Josh Triplett361e9df2014-10-03 16:00:54 -0700845 depends on PRINTK
Luis R. Rodriguez23b28992014-08-06 16:08:56 -0700846 help
847 This option allows to increase the default ring buffer size
848 according to the number of CPUs. The value defines the contribution
849 of each CPU as a power of 2. The used space is typically only few
850 lines however it might be much more when problems are reported,
851 e.g. backtraces.
852
853 The increased size means that a new buffer has to be allocated and
854 the original static one is unused. It makes sense only on systems
855 with more CPUs. Therefore this value is used only when the sum of
856 contributions is greater than the half of the default kernel ring
857 buffer as defined by LOG_BUF_SHIFT. The default values are set
858 so that more than 64 CPUs are needed to trigger the allocation.
859
860 Also this option is ignored when "log_buf_len" kernel parameter is
861 used as it forces an exact (power of two) size of the ring buffer.
862
863 The number of possible CPUs is used for this computation ignoring
864 hotplugging making the compuation optimal for the the worst case
865 scenerio while allowing a simple algorithm to be used from bootup.
866
867 Examples shift values and their meaning:
868 17 => 128 KB for each CPU
869 16 => 64 KB for each CPU
870 15 => 32 KB for each CPU
871 14 => 16 KB for each CPU
872 13 => 8 KB for each CPU
873 12 => 4 KB for each CPU
874
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800875#
876# Architectures with an unreliable sched_clock() should select this:
877#
878config HAVE_UNSTABLE_SCHED_CLOCK
879 bool
880
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700881config GENERIC_SCHED_CLOCK
882 bool
883
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200884#
885# For architectures that want to enable the support for NUMA-affine scheduler
886# balancing logic:
887#
888config ARCH_SUPPORTS_NUMA_BALANCING
889 bool
890
Peter Zijlstrabe5e6102013-11-18 18:27:06 +0100891#
892# For architectures that know their GCC __int128 support is sound
893#
894config ARCH_SUPPORTS_INT128
895 bool
896
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200897# For architectures that (ab)use NUMA to represent different memory regions
898# all cpu-local but of different latencies, such as SuperH.
899#
900config ARCH_WANT_NUMA_VARIABLE_LOCALITY
901 bool
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
Alexei Starovoitovf89b7752014-10-23 18:41:08 -07001344# interpreter that classic socket filters depend on
1345config BPF
1346 bool
1347
David Rientjes6a108a12011-01-20 14:44:16 -08001348menuconfig EXPERT
1349 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001350 # Unhide debug options, to make the on-by-default options visible
1351 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 help
1353 This option allows certain base kernel options and settings
1354 to be disabled or tweaked. This is for specialized
1355 environments which can tolerate a "non-standard" kernel.
1356 Only use this if you really know what you are doing.
1357
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001358config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001359 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001360 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001361 default y
1362 help
1363 This enables the legacy 16-bit UID syscall wrappers.
1364
Fabian Frederickf6187762014-06-04 16:11:12 -07001365config SGETMASK_SYSCALL
1366 bool "sgetmask/ssetmask syscalls support" if EXPERT
1367 def_bool PARISC || MN10300 || BLACKFIN || M68K || PPC || MIPS || X86 || SPARC || CRIS || MICROBLAZE || SUPERH
1368 ---help---
1369 sys_sgetmask and sys_ssetmask are obsolete system calls
1370 no longer supported in libc but still enabled by default in some
1371 architectures.
1372
1373 If unsure, leave the default option here.
1374
Fabian Frederick6af9f7b2014-04-03 14:48:25 -07001375config SYSFS_SYSCALL
1376 bool "Sysfs syscall support" if EXPERT
1377 default y
1378 ---help---
1379 sys_sysfs is an obsolete system call no longer supported in libc.
1380 Note that disabling this option is more secure but might break
1381 compatibility with some systems.
1382
1383 If unsure say Y here.
1384
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001385config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001386 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001387 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001388 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001389 select SYSCTL
1390 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001391 sys_sysctl uses binary paths that have been found challenging
1392 to properly maintain and use. The interface in /proc/sys
1393 using paths with ascii names is now the primary path to this
1394 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001395
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001396 Almost nothing using the binary sysctl interface so if you are
1397 trying to save some space it is probably safe to disable this,
1398 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001399
WANG Congc736de62011-11-02 13:39:25 -07001400 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001401
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001403 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404 default y
1405 help
1406 Say Y here to let the kernel print out symbolic crash information and
1407 symbolic stack backtraces. This increases the size of the kernel
1408 somewhat, as all symbols have to be loaded into the kernel image.
1409
1410config KALLSYMS_ALL
1411 bool "Include all symbols in kallsyms"
1412 depends on DEBUG_KERNEL && KALLSYMS
1413 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001414 Normally kallsyms only contains the symbols of functions for nicer
1415 OOPS messages and backtraces (i.e., symbols from the text and inittext
1416 sections). This is sufficient for most cases. And only in very rare
1417 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1418 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001420 This option makes sure that all symbols are loaded into the kernel
1421 image (i.e., symbols from all sections) in cost of increased kernel
1422 size (depending on the kernel configuration, it may be 300KiB or
1423 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001425 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001426
1427config PRINTK
1428 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001429 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001430 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001431 help
1432 This option enables normal printk support. Removing it
1433 eliminates most of the message strings from the kernel image
1434 and makes the kernel more or less silent. As this makes it
1435 very difficult to diagnose system problems, saying N here is
1436 strongly discouraged.
1437
Matt Mackallc8538a72005-05-01 08:59:01 -07001438config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001439 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001440 default y
1441 help
1442 Disabling this option eliminates support for BUG and WARN, reducing
1443 the size of your kernel image and potentially quietly ignoring
1444 numerous fatal conditions. You should only consider disabling this
1445 option for embedded systems with no facilities for reporting errors.
1446 Just say Y.
1447
Matt Mackall708e9a72006-01-08 01:05:25 -08001448config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001449 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001450 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001451 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001452 help
1453 Enable support for generating core dumps. Disabling saves about 4k.
1454
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001455
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001456config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001457 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001458 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001459 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001460 default y
1461 help
1462 This option allows to disable the internal PC-Speaker
1463 support, saving some memory.
1464
Linus Torvalds1da177e2005-04-16 15:20:36 -07001465config BASE_FULL
1466 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001467 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001468 help
1469 Disabling this option reduces the size of miscellaneous core
1470 kernel data structures. This saves memory on small machines,
1471 but may reduce performance.
1472
1473config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001474 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001475 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001476 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001477 help
1478 Disabling this option will cause the kernel to be built without
1479 support for "fast userspace mutexes". The resulting kernel may not
1480 run glibc-based applications correctly.
1481
Heiko Carstens03b8c7b2014-03-02 13:09:47 +01001482config HAVE_FUTEX_CMPXCHG
1483 bool
Josh Triplett62b4d202014-10-03 16:19:24 -07001484 depends on FUTEX
Heiko Carstens03b8c7b2014-03-02 13:09:47 +01001485 help
1486 Architectures should select this if futex_atomic_cmpxchg_inatomic()
1487 is implemented and always working. This removes a couple of runtime
1488 checks.
1489
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001491 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001493 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001494 help
1495 Disabling this option will cause the kernel to be built without
1496 support for epoll family of system calls.
1497
Davide Libenzifba2afa2007-05-10 22:23:13 -07001498config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001499 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001500 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001501 default y
1502 help
1503 Enable the signalfd() system call that allows to receive signals
1504 on a file descriptor.
1505
1506 If unsure, say Y.
1507
Davide Libenzib215e282007-05-10 22:23:16 -07001508config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001509 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001510 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001511 default y
1512 help
1513 Enable the timerfd() system call that allows to receive timer
1514 events on a file descriptor.
1515
1516 If unsure, say Y.
1517
Davide Libenzie1ad7462007-05-10 22:23:19 -07001518config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001519 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001520 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001521 default y
1522 help
1523 Enable the eventfd() system call that allows to receive both
1524 kernel notification (ie. KAIO) or userspace notifications.
1525
1526 If unsure, say Y.
1527
Alexei Starovoitovf89b7752014-10-23 18:41:08 -07001528# syscall, maps, verifier
1529config BPF_SYSCALL
1530 bool "Enable bpf() system call" if EXPERT
1531 select ANON_INODES
1532 select BPF
1533 default n
1534 help
1535 Enable the bpf() system call that allows to manipulate eBPF
1536 programs and maps via file descriptors.
1537
Linus Torvalds1da177e2005-04-16 15:20:36 -07001538config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001539 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540 default y
1541 depends on MMU
1542 help
1543 The shmem is an internal filesystem used to manage shared memory.
1544 It is backed by swap and manages resource limits. It is also exported
1545 to userspace as tmpfs if TMPFS is enabled. Disabling this
1546 option replaces shmem and tmpfs with the much simpler ramfs code,
1547 which may be appropriate on small systems without swap.
1548
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001549config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001550 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001551 default y
1552 help
1553 This option enables POSIX asynchronous I/O which may by used
Mike Frysinger657a5202013-04-30 15:28:45 -07001554 by some high performance threaded applications. Disabling
1555 this option saves about 7k.
1556
Josh Triplettd3ac21c2014-08-17 19:41:09 -05001557config ADVISE_SYSCALLS
1558 bool "Enable madvise/fadvise syscalls" if EXPERT
1559 default y
1560 help
1561 This option enables the madvise and fadvise syscalls, used by
1562 applications to advise the kernel about their future memory or file
1563 usage, improving performance. If building an embedded system where no
1564 applications use these syscalls, you can disable this option to save
1565 space.
1566
Mike Frysinger657a5202013-04-30 15:28:45 -07001567config PCI_QUIRKS
1568 default y
1569 bool "Enable PCI quirk workarounds" if EXPERT
1570 depends on PCI
1571 help
1572 This enables workarounds for various PCI chipset
1573 bugs/quirks. Disable this only if your target machine is
1574 unaffected by PCI quirks.
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001575
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001576config EMBEDDED
1577 bool "Embedded system"
Josh Triplett5d2acfc2014-04-07 15:39:09 -07001578 option allnoconfig_y
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001579 select EXPERT
1580 help
1581 This option should be enabled if compiling the kernel for
1582 an embedded system so certain expert options are available
1583 for configuration.
1584
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001585config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001586 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001587 help
1588 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001589
Peter Zijlstra906010b2009-09-21 16:08:49 +02001590config PERF_USE_VMALLOC
1591 bool
1592 help
1593 See tools/perf/design.txt for details
1594
Ingo Molnar57c0c152009-09-21 12:20:38 +02001595menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001596
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001597config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001598 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001599 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001600 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001601 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001602 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001603 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001604 Enable kernel support for various performance events provided
1605 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001606
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001607 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001608 use of generic tracepoints.
1609
1610 Most modern CPUs support performance events via performance
1611 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001612 types of hw events: such as instructions executed, cachemisses
1613 suffered, or branches mis-predicted - without slowing down the
1614 kernel or applications. These registers can also trigger interrupts
1615 when a threshold number of events have passed - and can thus be
1616 used to profile the code that runs on that CPU.
1617
Ingo Molnar57c0c152009-09-21 12:20:38 +02001618 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001619 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001620 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001621 provides per task and per CPU counters, and it provides event
1622 capabilities on top of those.
1623
1624 Say Y if unsure.
1625
Peter Zijlstra906010b2009-09-21 16:08:49 +02001626config DEBUG_PERF_USE_VMALLOC
1627 default n
1628 bool "Debug: use vmalloc to back perf mmap() buffers"
1629 depends on PERF_EVENTS && DEBUG_KERNEL
1630 select PERF_USE_VMALLOC
1631 help
1632 Use vmalloc memory to back perf mmap() buffers.
1633
1634 Mostly useful for debugging the vmalloc code on platforms
1635 that don't require it.
1636
1637 Say N if unsure.
1638
Thomas Gleixner0793a612008-12-04 20:12:29 +01001639endmenu
1640
Christoph Lameterf8891e52006-06-30 01:55:45 -07001641config VM_EVENT_COUNTERS
1642 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001643 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001644 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001645 VM event counters are needed for event counts to be shown.
1646 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001647 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001648 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001649
Christoph Lameter41ecc552007-05-09 02:32:44 -07001650config SLUB_DEBUG
1651 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001652 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001653 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001654 help
1655 SLUB has extensive debug support features. Disabling these can
1656 result in significant savings in code size. This also disables
1657 SLUB sysfs support. /sys/slab will not exist and there will be
1658 no support for cache validation etc.
1659
Randy Dunlapb943c462009-03-10 12:55:46 -07001660config COMPAT_BRK
1661 bool "Disable heap randomization"
1662 default y
1663 help
1664 Randomizing heap placement makes heap exploits harder, but it
1665 also breaks ancient binaries (including anything libc5 based).
1666 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001667 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001668 /proc/sys/kernel/randomize_va_space to 2.
1669
1670 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1671
Christoph Lameter81819f02007-05-06 14:49:36 -07001672choice
1673 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001674 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001675 help
1676 This option allows to select a slab allocator.
1677
1678config SLAB
1679 bool "SLAB"
1680 help
1681 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001682 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001683 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001684
1685config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001686 bool "SLUB (Unqueued Allocator)"
1687 help
1688 SLUB is a slab allocator that minimizes cache line usage
1689 instead of managing queues of cached objects (SLAB approach).
1690 Per cpu caching is realized using slabs of objects instead
1691 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001692 and has enhanced diagnostics. SLUB is the default choice for
1693 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001694
1695config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001696 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001697 bool "SLOB (Simple Allocator)"
1698 help
Matt Mackall37291452008-02-04 22:29:38 -08001699 SLOB replaces the stock allocator with a drastically simpler
1700 allocator. SLOB is generally more space efficient but
1701 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001702
1703endchoice
1704
Joonsoo Kim345c9052013-06-19 14:05:52 +09001705config SLUB_CPU_PARTIAL
1706 default y
Uwe Kleine-Königb39ffbf2013-07-17 16:54:59 +02001707 depends on SLUB && SMP
Joonsoo Kim345c9052013-06-19 14:05:52 +09001708 bool "SLUB per cpu partial cache"
1709 help
1710 Per cpu partial caches accellerate objects allocation and freeing
1711 that is local to a processor at the price of more indeterminism
1712 in the latency of the free. On overflow these caches will be cleared
1713 which requires the taking of locks that may cause latency spikes.
1714 Typically one would choose no for a realtime system.
1715
Jie Zhangea637632009-12-14 18:00:02 -08001716config MMAP_ALLOW_UNINITIALIZED
1717 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001718 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001719 default n
1720 help
1721 Normally, and according to the Linux spec, anonymous memory obtained
1722 from mmap() has it's contents cleared before it is passed to
1723 userspace. Enabling this config option allows you to request that
1724 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1725 providing a huge performance boost. If this option is not enabled,
1726 then the flag will be ignored.
1727
1728 This is taken advantage of by uClibc's malloc(), and also by
1729 ELF-FDPIC binfmt's brk and stack allocator.
1730
1731 Because of the obvious security issues, this option should only be
1732 enabled on embedded devices where you control what is run in
1733 userspace. Since that isn't generally a problem on no-MMU systems,
1734 it is normally safe to say Y here.
1735
1736 See Documentation/nommu-mmap.txt for more information.
1737
Peter Foley82c04ff2014-04-18 15:07:11 -07001738config SYSTEM_TRUSTED_KEYRING
1739 bool "Provide system-wide ring of trusted keys"
1740 depends on KEYS
1741 help
1742 Provide a system keyring to which trusted keys can be added. Keys in
1743 the keyring are considered to be trusted. Keys may be added at will
1744 by the kernel from compiled-in data and from hardware key stores, but
1745 userspace may only add extra keys if those keys can be verified by
1746 keys already in the keyring.
1747
1748 Keys in this keyring are used by module signature checking.
1749
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001750config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001751 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001752 help
1753 Say Y here to enable the extended profiling support mechanisms used
1754 by profilers such as OProfile.
1755
Ingo Molnar5f87f112008-07-23 14:15:22 +02001756#
1757# Place an empty function call at each tracepoint site. Can be
1758# dynamically changed for a probe function.
1759#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001760config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001761 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001762
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001763source "arch/Kconfig"
1764
Linus Torvalds1da177e2005-04-16 15:20:36 -07001765endmenu # General setup
1766
Dmitry Baryshkovee7e55162008-06-29 14:18:46 +04001767config HAVE_GENERIC_DMA_COHERENT
1768 bool
1769 default n
1770
Linus Torvalds158a9622008-01-02 13:04:48 -08001771config SLABINFO
1772 bool
1773 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001774 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001775 default y
1776
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001777config RT_MUTEXES
1778 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001779
Linus Torvalds1da177e2005-04-16 15:20:36 -07001780config BASE_SMALL
1781 int
1782 default 0 if BASE_FULL
1783 default 1 if !BASE_FULL
1784
Jan Engelhardt66da5732007-07-15 23:39:29 -07001785menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786 bool "Enable loadable module support"
Yann E. MORIN11097a02013-08-11 16:07:50 +02001787 option modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001788 help
1789 Kernel modules are small pieces of compiled code which can
1790 be inserted in the running kernel, rather than being
1791 permanently built into the kernel. You use the "modprobe"
1792 tool to add (and sometimes remove) them. If you say Y here,
1793 many parts of the kernel can be built as modules (by
1794 answering M instead of Y where indicated): this is most
1795 useful for infrequently used options which are not required
1796 for booting. For more information, see the man pages for
1797 modprobe, lsmod, modinfo, insmod and rmmod.
1798
1799 If you say Y here, you will need to run "make
1800 modules_install" to put the modules under /lib/modules/
1801 where modprobe can find them (you may need to be root to do
1802 this).
1803
1804 If unsure, say Y.
1805
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001806if MODULES
1807
Linus Torvalds826e4502008-05-04 17:04:16 -07001808config MODULE_FORCE_LOAD
1809 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001810 default n
1811 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001812 Allow loading of modules without version information (ie. modprobe
1813 --force). Forced module loading sets the 'F' (forced) taint flag and
1814 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001815
Linus Torvalds1da177e2005-04-16 15:20:36 -07001816config MODULE_UNLOAD
1817 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001818 help
1819 Without this option you will not be able to unload any
1820 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001821 anyway), which makes your kernel smaller, faster
1822 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001823
1824config MODULE_FORCE_UNLOAD
1825 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001826 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001827 help
1828 This option allows you to force a module to unload, even if the
1829 kernel believes it is unsafe: the kernel will remove the module
1830 without waiting for anyone to stop using it (using the -f option to
1831 rmmod). This is mainly for kernel developers and desperate users.
1832 If unsure, say N.
1833
Linus Torvalds1da177e2005-04-16 15:20:36 -07001834config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001835 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001836 help
1837 Usually, you have to use modules compiled with your kernel.
1838 Saying Y here makes it sometimes possible to use modules
1839 compiled for different kernels, by adding enough information
1840 to the modules to (hopefully) spot any changes which would
1841 make them incompatible with the kernel you are running. If
1842 unsure, say N.
1843
1844config MODULE_SRCVERSION_ALL
1845 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001846 help
1847 Modules which contain a MODULE_VERSION get an extra "srcversion"
1848 field inserted into their modinfo section, which contains a
1849 sum of the source files which made it. This helps maintainers
1850 see exactly which source was used to build a module (since
1851 others sometimes change the module source without updating
1852 the version). With this option, such a "srcversion" field
1853 will be created for all modules. If unsure, say N.
1854
Rusty Russell106a4ee2012-09-26 10:09:40 +01001855config MODULE_SIG
1856 bool "Module signature verification"
1857 depends on MODULES
David Howellsb56e5a12013-08-30 16:07:30 +01001858 select SYSTEM_TRUSTED_KEYRING
David Howells48ba2462012-09-26 10:11:03 +01001859 select KEYS
1860 select CRYPTO
1861 select ASYMMETRIC_KEY_TYPE
1862 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1863 select PUBLIC_KEY_ALGO_RSA
1864 select ASN1
1865 select OID_REGISTRY
1866 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001867 help
1868 Check modules for valid signatures upon load: the signature
1869 is simply appended to the module. For more information see
1870 Documentation/module-signing.txt.
1871
David Howellsea0b6dc2012-09-26 10:09:50 +01001872 !!!WARNING!!! If you enable this option, you MUST make sure that the
1873 module DOES NOT get stripped after being signed. This includes the
1874 debuginfo strip done by some packagers (such as rpmbuild) and
1875 inclusion into an initramfs that wants the module size reduced.
1876
Rusty Russell106a4ee2012-09-26 10:09:40 +01001877config MODULE_SIG_FORCE
1878 bool "Require modules to be validly signed"
1879 depends on MODULE_SIG
1880 help
1881 Reject unsigned modules or signed modules for which we don't have a
1882 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001883
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301884config MODULE_SIG_ALL
1885 bool "Automatically sign all modules"
1886 default y
1887 depends on MODULE_SIG
1888 help
1889 Sign all modules during make modules_install. Without this option,
1890 modules must be signed manually, using the scripts/sign-file tool.
1891
1892comment "Do not forget to sign required modules with scripts/sign-file"
1893 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1894
David Howellsea0b6dc2012-09-26 10:09:50 +01001895choice
1896 prompt "Which hash algorithm should modules be signed with?"
1897 depends on MODULE_SIG
1898 help
1899 This determines which sort of hashing algorithm will be used during
1900 signature generation. This algorithm _must_ be built into the kernel
1901 directly so that signature verification can take place. It is not
1902 possible to load a signed module containing the algorithm to check
1903 the signature on that module.
1904
1905config MODULE_SIG_SHA1
1906 bool "Sign modules with SHA-1"
1907 select CRYPTO_SHA1
1908
1909config MODULE_SIG_SHA224
1910 bool "Sign modules with SHA-224"
1911 select CRYPTO_SHA256
1912
1913config MODULE_SIG_SHA256
1914 bool "Sign modules with SHA-256"
1915 select CRYPTO_SHA256
1916
1917config MODULE_SIG_SHA384
1918 bool "Sign modules with SHA-384"
1919 select CRYPTO_SHA512
1920
1921config MODULE_SIG_SHA512
1922 bool "Sign modules with SHA-512"
1923 select CRYPTO_SHA512
1924
1925endchoice
1926
Michal Marek22753672013-01-25 13:41:00 +10301927config MODULE_SIG_HASH
1928 string
1929 depends on MODULE_SIG
1930 default "sha1" if MODULE_SIG_SHA1
1931 default "sha224" if MODULE_SIG_SHA224
1932 default "sha256" if MODULE_SIG_SHA256
1933 default "sha384" if MODULE_SIG_SHA384
1934 default "sha512" if MODULE_SIG_SHA512
1935
Bertrand Jacquinbeb50df2014-08-27 20:31:56 +09301936config MODULE_COMPRESS
1937 bool "Compress modules on installation"
1938 depends on MODULES
1939 help
1940 This option compresses the kernel modules when 'make
1941 modules_install' is run.
1942
1943 The modules will be compressed either using gzip or xz depend on the
1944 choice made in "Compression algorithm".
1945
1946 module-init-tools has support for gzip format while kmod handle gzip
1947 and xz compressed modules.
1948
1949 When a kernel module is installed from outside of the main kernel
1950 source and uses the Kbuild system for installing modules then that
1951 kernel module will also be compressed when it is installed.
1952
1953 This option provides little benefit when the modules are to be used inside
1954 an initrd or initramfs, it generally is more efficient to compress the whole
1955 initrd or initramfs instead.
1956
1957 This is fully compatible with signed modules while the signed module is
1958 compressed. module-init-tools or kmod handles decompression and provide to
1959 other layer the uncompressed but signed payload.
1960
1961choice
1962 prompt "Compression algorithm"
1963 depends on MODULE_COMPRESS
1964 default MODULE_COMPRESS_GZIP
1965 help
1966 This determines which sort of compression will be used during
1967 'make modules_install'.
1968
1969 GZIP (default) and XZ are supported.
1970
1971config MODULE_COMPRESS_GZIP
1972 bool "GZIP"
1973
1974config MODULE_COMPRESS_XZ
1975 bool "XZ"
1976
1977endchoice
1978
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001979endif # MODULES
1980
Rusty Russell98a79d62008-12-13 21:19:41 +10301981config INIT_ALL_POSSIBLE
1982 bool
1983 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301984 Back when each arch used to define their own cpu_online_mask and
1985 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301986 with all 1s, and others with all 0s. When they were centralised,
1987 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001988 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301989
Linus Torvalds1da177e2005-04-16 15:20:36 -07001990config STOP_MACHINE
1991 bool
1992 default y
1993 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1994 help
1995 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001996
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001997source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001998
1999config PREEMPT_NOTIFIERS
2000 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01002001
Steffen Klassert16295be2010-01-06 19:47:10 +11002002config PADATA
2003 depends on SMP
2004 bool
2005
Andi Kleen754b7b62012-10-04 17:11:27 -07002006# Can be selected by architectures with broken toolchains
2007# that get confused by correct const<->read_only section
2008# mappings
2009config BROKEN_RODATA
2010 bool
2011
David Howells4520c6a2012-09-21 23:31:13 +01002012config ASN1
2013 tristate
2014 help
2015 Build a simple ASN.1 grammar compiler that produces a bytecode output
2016 that can be interpreted by the ASN.1 stream decoder and used to
2017 inform it as to what tags are to be expected in a stream and what
2018 functions to call on what tags.
2019
Thomas Gleixner6beb0002009-11-09 15:21:34 +00002020source "kernel/Kconfig.locks"