blob: 1e825c299ea5f1e30086824a7d198aa758a58645 [file] [log] [blame]
Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter 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
Alain Knaff30d65db2009-01-04 22:46:17 +0100115choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800116 prompt "Kernel compression mode"
117 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800118 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800119 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100120 The linux kernel is a kind of self-extracting executable.
121 Several compression algorithms are available, which differ
122 in efficiency, compression and decompression speed.
123 Compression speed is only relevant when building a kernel.
124 Decompression speed is relevant at each boot.
125
126 If you have any problems with bzip2 or lzma compressed
127 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
128 version of this functionality (bzip2 only), for 2.4, was
129 supplied by Christian Ludwig)
130
131 High compression options are mostly useful for users, who
132 are low on disk space (embedded systems), but for whom ram
133 size matters less.
134
135 If in doubt, select 'gzip'
136
137config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800138 bool "Gzip"
139 depends on HAVE_KERNEL_GZIP
140 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800141 The old and tried gzip compression. It provides a good balance
142 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100143
144config KERNEL_BZIP2
145 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800146 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100147 help
148 Its compression ratio and speed is intermediate.
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700149 Decompression speed is slowest among the choices. The kernel
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800150 size is about 10% smaller with bzip2, in comparison to gzip.
151 Bzip2 uses a large amount of memory. For modern kernels you
152 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100153
154config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800155 bool "LZMA"
156 depends on HAVE_KERNEL_LZMA
157 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700158 This compression algorithm's ratio is best. Decompression speed
159 is between gzip and bzip2. Compression is slowest.
160 The kernel size is about 33% smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100161
Lasse Collin3ebe1242011-01-12 17:01:23 -0800162config KERNEL_XZ
163 bool "XZ"
164 depends on HAVE_KERNEL_XZ
165 help
166 XZ uses the LZMA2 algorithm and instruction set specific
167 BCJ filters which can improve compression ratio of executable
168 code. The size of the kernel is about 30% smaller with XZ in
169 comparison to gzip. On architectures for which there is a BCJ
170 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
171 will create a few percent smaller kernel than plain LZMA.
172
173 The speed is about the same as with LZMA: The decompression
174 speed of XZ is better than that of bzip2 but worse than gzip
175 and LZO. Compression is slow.
176
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800177config KERNEL_LZO
178 bool "LZO"
179 depends on HAVE_KERNEL_LZO
180 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700181 Its compression ratio is the poorest among the choices. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200182 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800183 (both compression and decompression) is the fastest.
184
Alain Knaff30d65db2009-01-04 22:46:17 +0100185endchoice
186
Josh Triplettbd5dc172011-06-15 15:08:28 -0700187config DEFAULT_HOSTNAME
188 string "Default hostname"
189 default "(none)"
190 help
191 This option determines the default system hostname before userspace
192 calls sethostname(2). The kernel traditionally uses "(none)" here,
193 but you may wish to use a different default here to make a minimal
194 system more usable with less configuration.
195
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196config SWAP
197 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200198 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 default y
200 help
201 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100202 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 used to provide more virtual memory than the actual RAM present
204 in your computer. If unsure say Y.
205
206config SYSVIPC
207 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 ---help---
209 Inter Process Communication is a suite of library functions and
210 system calls which let processes (running programs) synchronize and
211 exchange information. It is generally considered to be a good thing,
212 and some programs won't run unless you say Y here. In particular, if
213 you want to run the DOS emulator dosemu under Linux (read the
214 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
215 you'll need to say Y here.
216
217 You can find documentation about IPC with "info ipc" and also in
218 section 6.4 of the Linux Programmer's Guide, available from
219 <http://www.tldp.org/guides.html>.
220
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800221config SYSVIPC_SYSCTL
222 bool
223 depends on SYSVIPC
224 depends on SYSCTL
225 default y
226
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227config POSIX_MQUEUE
228 bool "POSIX Message Queues"
Kees Cook19c92392012-10-02 11:19:29 -0700229 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 ---help---
231 POSIX variant of message queues is a part of IPC. In POSIX message
232 queues every message has a priority which decides about succession
233 of receiving it by a process. If you want to compile and run
234 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200235 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
237 POSIX message queues are visible as a filesystem called 'mqueue'
238 and can be mounted somewhere if you want to do filesystem
239 operations on message queues.
240
241 If unsure, say Y.
242
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700243config POSIX_MQUEUE_SYSCTL
244 bool
245 depends on POSIX_MQUEUE
246 depends on SYSCTL
247 default y
248
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530249config FHANDLE
250 bool "open by fhandle syscalls"
251 select EXPORTFS
252 help
253 If you say Y here, a user level program will be able to map
254 file names to handle and then later use the handle for
255 different file system operations. This is useful in implementing
256 userspace file servers, which now track files using handles instead
257 of names. The handle would remain the same even if file names
258 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
259 syscalls.
260
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261config AUDIT
262 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100263 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 help
265 Enable auditing infrastructure that can be used with another
266 kernel subsystem, such as SELinux (which requires this for
267 logging of avc messages output). Does not do system-call
268 auditing without CONFIG_AUDITSYSCALL.
269
270config AUDITSYSCALL
271 bool "Enable system-call auditing support"
Will Deacon8f827a12012-07-06 15:48:16 +0100272 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 default y if SECURITY_SELINUX
274 help
275 Enable low-overhead system-call auditing infrastructure that
276 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500277 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278
Eric Paris939a67f2009-12-17 20:12:06 -0500279config AUDIT_WATCH
280 def_bool y
281 depends on AUDITSYSCALL
282 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
Al Viro74c3cbe2007-07-22 08:04:18 -0400284config AUDIT_TREE
285 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400286 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500287 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400288
Eric Paris633b4542012-01-03 14:23:08 -0500289config AUDIT_LOGINUID_IMMUTABLE
290 bool "Make audit loginuid immutable"
291 depends on AUDIT
292 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800293 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500294 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
295 but should instead only allow setting its loginuid if it was never
296 previously set. On systems which use systemd or a similar central
297 process to restart login services this should be set to true. On older
298 systems in which an admin would typically have to directly stop and
299 start processes this should be set to false. Setting this to true allows
300 one to drop potentially dangerous capabilites from the login tasks,
301 but may not be backwards compatible with older init systems.
302
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000303source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200304source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000305
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200306menu "CPU/Task time and stats accounting"
307
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200308config VIRT_CPU_ACCOUNTING
309 bool
310
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200311choice
312 prompt "Cputime accounting"
313 default TICK_CPU_ACCOUNTING if !PPC64
Stephen Rothwell02fc8d32013-02-08 14:19:38 +1100314 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200315
316# Kind of a stub config for the pure tick based cputime accounting
317config TICK_CPU_ACCOUNTING
318 bool "Simple tick based cputime accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200319 depends on !S390 && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200320 help
321 This is the basic tick based cputime accounting that maintains
322 statistics about user, system and idle time spent on per jiffies
323 granularity.
324
325 If unsure, say Y.
326
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200327config VIRT_CPU_ACCOUNTING_NATIVE
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200328 bool "Deterministic task and CPU time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200329 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200330 select VIRT_CPU_ACCOUNTING
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200331 help
332 Select this option to enable more accurate task and CPU time
333 accounting. This is done by reading a CPU counter on each
334 kernel entry and exit and on transitions within the kernel
335 between system, softirq and hardirq state, so there is a
336 small performance impact. In the case of s390 or IBM POWER > 5,
337 this also enables accounting of stolen time on logically-partitioned
338 systems.
339
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200340config VIRT_CPU_ACCOUNTING_GEN
341 bool "Full dynticks CPU time accounting"
342 depends on HAVE_CONTEXT_TRACKING && 64BIT
343 select VIRT_CPU_ACCOUNTING
344 select CONTEXT_TRACKING
345 help
346 Select this option to enable task and CPU time accounting on full
347 dynticks systems. This accounting is implemented by watching every
348 kernel-user boundaries using the context tracking subsystem.
349 The accounting is thus performed at the expense of some significant
350 overhead.
351
352 For now this is only useful if you are working on the full
353 dynticks subsystem development.
354
355 If unsure, say N.
356
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200357config IRQ_TIME_ACCOUNTING
358 bool "Fine granularity task level IRQ time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200359 depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200360 help
361 Select this option to enable fine granularity task irq time
362 accounting. This is done by reading a timestamp on each
363 transitions between softirq and hardirq state, so there can be a
364 small performance impact.
365
366 If in doubt, say N here.
367
368endchoice
369
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200370config BSD_PROCESS_ACCT
371 bool "BSD Process Accounting"
372 help
373 If you say Y here, a user level program will be able to instruct the
374 kernel (via a special system call) to write process accounting
375 information to a file: whenever a process exits, information about
376 that process will be appended to the file by the kernel. The
377 information includes things such as creation time, owning user,
378 command name, memory usage, controlling terminal etc. (the complete
379 list is in the struct acct in <file:include/linux/acct.h>). It is
380 up to the user level program to do useful things with this
381 information. This is generally a good idea, so say Y.
382
383config BSD_PROCESS_ACCT_V3
384 bool "BSD Process Accounting version 3 file format"
385 depends on BSD_PROCESS_ACCT
386 default n
387 help
388 If you say Y here, the process accounting information is written
389 in a new file format that also logs the process IDs of each
390 process and it's parent. Note that this file format is incompatible
391 with previous v0/v1/v2 file formats, so you will need updated tools
392 for processing it. A preliminary version of these tools is available
393 at <http://www.gnu.org/software/acct/>.
394
395config TASKSTATS
Kees Cook19c92392012-10-02 11:19:29 -0700396 bool "Export task/process statistics through netlink"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200397 depends on NET
398 default n
399 help
400 Export selected statistics for tasks/processes through the
401 generic netlink interface. Unlike BSD process accounting, the
402 statistics are available during the lifetime of tasks/processes as
403 responses to commands. Like BSD accounting, they are sent to user
404 space on task exit.
405
406 Say N if unsure.
407
408config TASK_DELAY_ACCT
Kees Cook19c92392012-10-02 11:19:29 -0700409 bool "Enable per-task delay accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200410 depends on TASKSTATS
411 help
412 Collect information on time spent by a task waiting for system
413 resources like cpu, synchronous block I/O completion and swapping
414 in pages. Such statistics can help in setting a task's priorities
415 relative to other tasks for cpu, io, rss limits etc.
416
417 Say N if unsure.
418
419config TASK_XACCT
Kees Cook19c92392012-10-02 11:19:29 -0700420 bool "Enable extended accounting over taskstats"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200421 depends on TASKSTATS
422 help
423 Collect extended task accounting data and send the data
424 to userland for processing over the taskstats interface.
425
426 Say N if unsure.
427
428config TASK_IO_ACCOUNTING
Kees Cook19c92392012-10-02 11:19:29 -0700429 bool "Enable per-task storage I/O accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200430 depends on TASK_XACCT
431 help
432 Collect information on the number of bytes of storage I/O which this
433 task has caused.
434
435 Say N if unsure.
436
437endmenu # "CPU/Task time and stats accounting"
438
Mike Travisc903ff82009-01-15 12:28:29 -0800439menu "RCU Subsystem"
440
441choice
442 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700443 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800444
Mike Travisc903ff82009-01-15 12:28:29 -0800445config TREE_RCU
446 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700447 depends on !PREEMPT && SMP
Steven Rostedt016a8d52013-05-28 17:32:53 -0400448 select IRQ_WORK
Mike Travisc903ff82009-01-15 12:28:29 -0800449 help
450 This option selects the RCU implementation that is
451 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700452 thousands of CPUs. It also scales down nicely to
453 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800454
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700455config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700456 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800457 depends on PREEMPT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700458 help
459 This option selects the RCU implementation that is
460 designed for very large SMP systems with hundreds or
461 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700462 is also required. It also scales down nicely to
463 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700464
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800465 Select this option if you are unsure.
466
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700467config TINY_RCU
468 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700469 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700470 help
471 This option selects the RCU implementation that is
472 designed for UP systems from which real-time response
473 is not required. This option greatly reduces the
474 memory footprint of RCU.
475
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700476config TINY_PREEMPT_RCU
477 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700478 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700479 help
480 This option selects the RCU implementation that is designed
481 for real-time UP systems. This option greatly reduces the
482 memory footprint of RCU.
483
Mike Travisc903ff82009-01-15 12:28:29 -0800484endchoice
485
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700486config PREEMPT_RCU
487 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
488 help
489 This option enables preemptible-RCU code that is common between
490 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
491
Paul E. McKenney6bfc09e2012-10-19 12:49:17 -0700492config RCU_STALL_COMMON
493 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
494 help
495 This option enables RCU CPU stall code that is common between
496 the TINY and TREE variants of RCU. The purpose is to allow
497 the tiny variants to disable RCU CPU stall warnings, while
498 making these warnings mandatory for the tree variants.
499
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100500config CONTEXT_TRACKING
501 bool
502
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200503config RCU_USER_QS
504 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100505 depends on HAVE_CONTEXT_TRACKING && SMP
506 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200507 help
508 This option sets hooks on kernel / userspace boundaries and
509 puts RCU in extended quiescent state when the CPU runs in
510 userspace. It means that when a CPU runs in userspace, it is
511 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700512 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200513
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200514 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100515 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700516 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200517
518 If unsure say N
519
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100520config CONTEXT_TRACKING_FORCE
521 bool "Force context tracking"
522 depends on CONTEXT_TRACKING
Frederic Weisbecker8b438762013-02-26 15:37:59 +0100523 default CONTEXT_TRACKING
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200524 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100525 Probe on user/kernel boundaries by default in order to
526 test the features that rely on it such as userspace RCU extended
527 quiescent states.
528 This test is there for debugging until we have a real user like the
529 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200530
Mike Travisc903ff82009-01-15 12:28:29 -0800531config RCU_FANOUT
532 int "Tree-based hierarchical RCU fanout value"
533 range 2 64 if 64BIT
534 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700535 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800536 default 64 if 64BIT
537 default 32 if !64BIT
538 help
539 This option controls the fanout of hierarchical implementations
540 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700541 large numbers of CPUs. This value must be at least the fourth
542 root of NR_CPUS, which allows NR_CPUS to be insanely large.
543 The default value of RCU_FANOUT should be used for production
544 systems, but if you are stress-testing the RCU implementation
545 itself, small RCU_FANOUT values allow you to test large-system
546 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800547
548 Select a specific number if testing RCU itself.
549 Take the default if unsure.
550
Paul E. McKenney8932a632012-04-19 12:20:14 -0700551config RCU_FANOUT_LEAF
552 int "Tree-based hierarchical RCU leaf-level fanout value"
553 range 2 RCU_FANOUT if 64BIT
554 range 2 RCU_FANOUT if !64BIT
555 depends on TREE_RCU || TREE_PREEMPT_RCU
556 default 16
557 help
558 This option controls the leaf-level fanout of hierarchical
559 implementations of RCU, and allows trading off cache misses
560 against lock contention. Systems that synchronize their
561 scheduling-clock interrupts for energy-efficiency reasons will
562 want the default because the smaller leaf-level fanout keeps
563 lock contention levels acceptably low. Very large systems
564 (hundreds or thousands of CPUs) will instead want to set this
565 value to the maximum value possible in order to reduce the
566 number of cache misses incurred during RCU's grace-period
567 initialization. These systems tend to run CPU-bound, and thus
568 are not helped by synchronized interrupts, and thus tend to
569 skew them, which reduces lock contention enough that large
570 leaf-level fanouts work well.
571
572 Select a specific number if testing RCU itself.
573
574 Select the maximum permissible value for large systems.
575
576 Take the default if unsure.
577
Mike Travisc903ff82009-01-15 12:28:29 -0800578config RCU_FANOUT_EXACT
579 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700580 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800581 default n
582 help
583 This option forces use of the exact RCU_FANOUT value specified,
584 regardless of imbalances in the hierarchy. This is useful for
585 testing RCU itself, and might one day be useful on systems with
586 strong NUMA behavior.
587
588 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
589
590 Say N if unsure.
591
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800592config RCU_FAST_NO_HZ
593 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Frederic Weisbecker3451d022011-08-10 23:21:01 +0200594 depends on NO_HZ_COMMON && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800595 default n
596 help
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800597 This option permits CPUs to enter dynticks-idle state even if
598 they have RCU callbacks queued, and prevents RCU from waking
599 these CPUs up more than roughly once every four jiffies (by
600 default, you can adjust this using the rcutree.rcu_idle_gp_delay
601 parameter), thus improving energy efficiency. On the other
602 hand, this option increases the duration of RCU grace periods,
603 for example, slowing down synchronize_rcu().
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800604
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800605 Say Y if energy efficiency is critically important, and you
606 don't care about increased grace-period durations.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800607
608 Say N if you are unsure.
609
Mike Travisc903ff82009-01-15 12:28:29 -0800610config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700611 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800612 select DEBUG_FS
613 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700614 This option provides tracing for the TREE_RCU and
615 TREE_PREEMPT_RCU implementations, permitting Makefile to
616 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800617
Paul E. McKenney24278d12010-09-27 17:25:23 -0700618config RCU_BOOST
619 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800620 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700621 default n
622 help
623 This option boosts the priority of preempted RCU readers that
624 block the current preemptible RCU grace period for too long.
625 This option also prevents heavy loads from blocking RCU
626 callback invocation for all flavors of RCU.
627
628 Say Y here if you are working with real-time apps or heavy loads
629 Say N here if you are unsure.
630
631config RCU_BOOST_PRIO
632 int "Real-time priority to boost RCU readers to"
633 range 1 99
634 depends on RCU_BOOST
635 default 1
636 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700637 This option specifies the real-time priority to which long-term
638 preempted RCU readers are to be boosted. If you are working
639 with a real-time application that has one or more CPU-bound
640 threads running at a real-time priority level, you should set
641 RCU_BOOST_PRIO to a priority higher then the highest-priority
642 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
643 of 1 is appropriate in the common case, which is real-time
644 applications that do not have any CPU-bound threads.
645
646 Some real-time applications might not have a single real-time
647 thread that saturates a given CPU, but instead might have
648 multiple real-time threads that, taken together, fully utilize
649 that CPU. In this case, you should set RCU_BOOST_PRIO to
650 a priority higher than the lowest-priority thread that is
651 conspiring to prevent the CPU from running any non-real-time
652 tasks. For example, if one thread at priority 10 and another
653 thread at priority 5 are between themselves fully consuming
654 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
655 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700656
657 Specify the real-time priority, or take the default if unsure.
658
659config RCU_BOOST_DELAY
660 int "Milliseconds to delay boosting after RCU grace-period start"
661 range 0 3000
662 depends on RCU_BOOST
663 default 500
664 help
665 This option specifies the time to wait after the beginning of
666 a given grace period before priority-boosting preempted RCU
667 readers blocking that grace period. Note that any RCU reader
668 blocking an expedited RCU grace period is boosted immediately.
669
670 Accept the default if unsure.
671
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700672config RCU_NOCB_CPU
Paul E. McKenney34ed62462013-01-07 13:37:42 -0800673 bool "Offload RCU callback processing from boot-selected CPUs (EXPERIMENTAL"
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700674 depends on TREE_RCU || TREE_PREEMPT_RCU
675 default n
676 help
677 Use this option to reduce OS jitter for aggressive HPC or
678 real-time workloads. It can also be used to offload RCU
679 callback invocation to energy-efficient CPUs in battery-powered
680 asymmetric multiprocessors.
681
682 This option offloads callback invocation from the set of
683 CPUs specified at boot time by the rcu_nocbs parameter.
Paul E. McKenneya4889852012-12-03 08:16:28 -0800684 For each such CPU, a kthread ("rcuox/N") will be created to
685 invoke callbacks, where the "N" is the CPU being offloaded,
686 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
687 "s" for RCU-sched. Nothing prevents this kthread from running
688 on the specified CPUs, but (1) the kthreads may be preempted
689 between each callback, and (2) affinity or cgroups can be used
690 to force the kthreads to run on whatever set of CPUs is desired.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700691
Paul E. McKenney34ed62462013-01-07 13:37:42 -0800692 Say Y here if you want to help to debug reduced OS jitter.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700693 Say N here if you are unsure.
694
Paul E. McKenney911af502013-02-11 10:23:27 -0800695choice
696 prompt "Build-forced no-CBs CPUs"
697 default RCU_NOCB_CPU_NONE
698 help
699 This option allows no-CBs CPUs to be specified at build time.
700 Additional no-CBs CPUs may be specified by the rcu_nocbs=
701 boot parameter.
702
703config RCU_NOCB_CPU_NONE
704 bool "No build_forced no-CBs CPUs"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200705 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800706 help
707 This option does not force any of the CPUs to be no-CBs CPUs.
708 Only CPUs designated by the rcu_nocbs= boot parameter will be
709 no-CBs CPUs.
710
711config RCU_NOCB_CPU_ZERO
712 bool "CPU 0 is a build_forced no-CBs CPU"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200713 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800714 help
715 This option forces CPU 0 to be a no-CBs CPU. Additional CPUs
716 may be designated as no-CBs CPUs using the rcu_nocbs= boot
717 parameter will be no-CBs CPUs.
718
719 Select this if CPU 0 needs to be a no-CBs CPU for real-time
720 or energy-efficiency reasons.
721
722config RCU_NOCB_CPU_ALL
723 bool "All CPUs are build_forced no-CBs CPUs"
724 depends on RCU_NOCB_CPU
725 help
726 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
727 boot parameter will be ignored.
728
729 Select this if all CPUs need to be no-CBs CPUs for real-time
730 or energy-efficiency reasons.
731
732endchoice
733
Mike Travisc903ff82009-01-15 12:28:29 -0800734endmenu # "RCU Subsystem"
735
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700737 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 ---help---
739 This option enables the complete Linux kernel ".config" file
740 contents to be saved in the kernel. It provides documentation
741 of which kernel options are used in a running kernel or in an
742 on-disk kernel. This information can be extracted from the kernel
743 image file with the script scripts/extract-ikconfig and used as
744 input to rebuild the current kernel or to build another kernel.
745 It can also be extracted from a running kernel by reading
746 /proc/config.gz if enabled (below).
747
748config IKCONFIG_PROC
749 bool "Enable access to .config through /proc/config.gz"
750 depends on IKCONFIG && PROC_FS
751 ---help---
752 This option enables access to the kernel configuration file
753 through /proc/config.gz.
754
Alistair John Strachan794543a2007-05-08 00:31:15 -0700755config LOG_BUF_SHIFT
756 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
757 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700758 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700759 help
760 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700761 Examples:
762 17 => 128 KB
763 16 => 64 KB
764 15 => 32 KB
765 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700766 13 => 8 KB
767 12 => 4 KB
768
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800769#
770# Architectures with an unreliable sched_clock() should select this:
771#
772config HAVE_UNSTABLE_SCHED_CLOCK
773 bool
774
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200775#
776# For architectures that want to enable the support for NUMA-affine scheduler
777# balancing logic:
778#
779config ARCH_SUPPORTS_NUMA_BALANCING
780 bool
781
782# For architectures that (ab)use NUMA to represent different memory regions
783# all cpu-local but of different latencies, such as SuperH.
784#
785config ARCH_WANT_NUMA_VARIABLE_LOCALITY
786 bool
787
788#
789# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
790config ARCH_WANTS_PROT_NUMA_PROT_NONE
791 bool
792
793config ARCH_USES_NUMA_PROT_NONE
794 bool
795 default y
796 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
797 depends on NUMA_BALANCING
798
Mel Gorman1a687c22012-11-22 11:16:36 +0000799config NUMA_BALANCING_DEFAULT_ENABLED
800 bool "Automatically enable NUMA aware memory/task placement"
801 default y
802 depends on NUMA_BALANCING
803 help
804 If set, autonumic NUMA balancing will be enabled if running on a NUMA
805 machine.
806
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200807config NUMA_BALANCING
808 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200809 depends on ARCH_SUPPORTS_NUMA_BALANCING
810 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
811 depends on SMP && NUMA && MIGRATION
812 help
813 This option adds support for automatic NUMA aware memory/task placement.
814 The mechanism is quite primitive and is based on migrating memory when
815 it is references to the node the task is running on.
816
817 This system will be inactive on UMA systems.
818
Li Zefan23964d22009-01-15 13:50:58 -0800819menuconfig CGROUPS
820 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800821 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700822 help
Li Zefan23964d22009-01-15 13:50:58 -0800823 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800824 use with process control subsystems such as Cpusets, CFS, memory
825 controls or device isolation.
826 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800827 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800828 - Documentation/cgroups/ (features for grouping, isolation
829 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700830
831 Say N if unsure.
832
Li Zefan23964d22009-01-15 13:50:58 -0800833if CGROUPS
834
Paul Menage006cb992007-10-18 23:39:43 -0700835config CGROUP_DEBUG
836 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700837 default n
Paul Menage006cb992007-10-18 23:39:43 -0700838 help
839 This option enables a simple cgroup subsystem that
840 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800841 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700842
Li Zefan23964d22009-01-15 13:50:58 -0800843 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700844
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700845config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800846 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800847 help
848 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700849 cgroup.
850
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700851config CGROUP_DEVICE
852 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700853 help
854 Provides a cgroup implementing whitelists for devices which
855 a process in the cgroup can mknod or open.
856
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857config CPUSETS
858 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700860 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 allow dynamically partitioning a system into sets of CPUs and
862 Memory Nodes and assigning tasks to run only within those sets.
863 This is primarily useful on large SMP or NUMA systems.
864
865 Say N if unsure.
866
Li Zefan23964d22009-01-15 13:50:58 -0800867config PROC_PID_CPUSET
868 bool "Include legacy /proc/<pid>/cpuset file"
869 depends on CPUSETS
870 default y
871
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100872config CGROUP_CPUACCT
873 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100874 help
875 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800876 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100877
Pavel Emelianove552b662008-02-07 00:13:49 -0800878config RESOURCE_COUNTERS
879 bool "Resource counters"
880 help
881 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800882 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800883
Andrew Mortonc255a452012-07-31 16:43:02 -0700884config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800885 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700886 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700887 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800888 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700889 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100890 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800891
892 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700893 associated with each page of memory in the system. By this,
894 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
895 usage tracking struct at boot. Total amount of this is printed out
896 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800897
898 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700899 sure you need the memory resource controller. Even when you enable
900 this, you can set "cgroup_disable=memory" at your boot option to
901 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800902 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800903
Balbir Singhcf475ad2008-04-29 01:00:16 -0700904 This config option also selects MM_OWNER config option, which
905 could in turn add some fork/exit overhead.
906
Andrew Mortonc255a452012-07-31 16:43:02 -0700907config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700908 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700909 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800910 help
911 Add swap management feature to memory resource controller. When you
912 enable this, you can limit mem+swap usage per cgroup. In other words,
913 when you disable this, memory resource controller has no cares to
914 usage of swap...a process can exhaust all of the swap. This extension
915 is useful when you want to avoid exhaustion swap but this itself
916 adds more overheads and consumes memory for remembering information.
917 Especially if you use 32bit system or small memory system, please
918 be careful about enabling this. When memory resource controller
919 is disabled by boot option, this will be automatically disabled and
920 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700921 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700922 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
923 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700924config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800925 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700926 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800927 default y
928 help
929 Memory Resource Controller Swap Extension comes with its price in
930 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700931 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800932 and let the user enable it by swapaccount boot command line
933 parameter should have this option unselected.
934 For those who want to have the feature enabled by default should
935 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700936 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700937config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700938 bool "Memory Resource Controller Kernel Memory accounting"
939 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800940 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000941 help
942 The Kernel Memory extension for Memory Resource Controller can limit
943 the amount of memory used by kernel objects in the system. Those are
944 fundamentally different from the entities handled by the standard
945 Memory Controller, which are page-based, and can be swapped. Users of
946 the kmem extension can use it to guarantee that no group of processes
947 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800948
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700949config CGROUP_HUGETLB
950 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700951 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700952 default n
953 help
954 Provides a cgroup Resource Controller for HugeTLB pages.
955 When you enable this, you can put a per cgroup limit on HugeTLB usage.
956 The limit is enforced during page fault. Since HugeTLB doesn't
957 support page reclaim, enforcing the limit at page fault time implies
958 that, the application will get SIGBUS signal if it tries to access
959 HugeTLB pages beyond its limit. This requires the application to know
960 beforehand how much HugeTLB pages it would require for its use. The
961 control group is tracked in the third page lru pointer. This means
962 that we cannot use the controller with huge page less than 3 pages.
963
Stephane Eraniane5d13672011-02-14 11:20:01 +0200964config CGROUP_PERF
965 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
966 depends on PERF_EVENTS && CGROUPS
967 help
968 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800969 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200970 designated cpu.
971
972 Say N if unsure.
973
Dhaval Giani7c941432010-01-20 13:26:18 +0100974menuconfig CGROUP_SCHED
975 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100976 default n
977 help
978 This feature lets CPU scheduler recognize task groups and control CPU
979 bandwidth allocation to such task groups. It uses cgroups to group
980 tasks.
981
982if CGROUP_SCHED
983config FAIR_GROUP_SCHED
984 bool "Group scheduling for SCHED_OTHER"
985 depends on CGROUP_SCHED
986 default CGROUP_SCHED
987
Paul Turnerab84d312011-07-21 09:43:28 -0700988config CFS_BANDWIDTH
989 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -0700990 depends on FAIR_GROUP_SCHED
991 default n
992 help
993 This option allows users to define CPU bandwidth rates (limits) for
994 tasks running within the fair group scheduler. Groups with no limit
995 set are considered to be unconstrained and will run with no
996 restriction.
997 See tip/Documentation/scheduler/sched-bwc.txt for more information.
998
Dhaval Giani7c941432010-01-20 13:26:18 +0100999config RT_GROUP_SCHED
1000 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +01001001 depends on CGROUP_SCHED
1002 default n
1003 help
1004 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +08001005 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +01001006 schedule realtime tasks for non-root users until you allocate
1007 realtime bandwidth for them.
1008 See Documentation/scheduler/sched-rt-group.txt for more information.
1009
1010endif #CGROUP_SCHED
1011
Vivek Goyalafc24d42010-04-26 19:27:56 +02001012config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -08001013 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -07001014 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +02001015 default n
1016 ---help---
1017 Generic block IO controller cgroup interface. This is the common
1018 cgroup interface which should be used by various IO controlling
1019 policies.
1020
1021 Currently, CFQ IO scheduler uses it to recognize task groups and
1022 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -04001023 to such task groups. It is also used by bio throttling logic in
1024 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001025
1026 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -04001027 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +00001028 enabling proportional weight division of disk bandwidth in CFQ, set
1029 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +00001030 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001031
1032 See Documentation/cgroups/blkio-controller.txt for more information.
1033
1034config DEBUG_BLK_CGROUP
1035 bool "Enable Block IO controller debugging"
1036 depends on BLK_CGROUP
1037 default n
1038 ---help---
1039 Enable some debugging help. Currently it exports additional stat
1040 files in a cgroup which can be useful for debugging.
1041
Li Zefan23964d22009-01-15 13:50:58 -08001042endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001043
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001044config CHECKPOINT_RESTORE
1045 bool "Checkpoint/restore support" if EXPERT
1046 default n
1047 help
1048 Enables additional kernel features in a sake of checkpoint/restore.
1049 In particular it adds auxiliary prctl codes to setup process text,
1050 data and heap segment sizes, and a few additional /proc filesystem
1051 entries.
1052
1053 If unsure, say N here.
1054
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001055menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001056 bool "Namespaces support" if EXPERT
1057 default !EXPERT
Pavel Emelyanovc5289a692008-02-08 04:18:19 -08001058 help
1059 Provides the way to make tasks work with different objects using
1060 the same id. For example same IPC id may refer to different objects
1061 or same user id or pid may refer to different tasks when used in
1062 different namespaces.
1063
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001064if NAMESPACES
1065
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001066config UTS_NS
1067 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001068 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001069 help
1070 In this namespace tasks see different info provided with the
1071 uname() system call
1072
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001073config IPC_NS
1074 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001075 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001076 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001077 help
1078 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001079 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001080
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001081config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001082 bool "User namespace"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001083 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001084 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001085
Eric W. Biederman5673a942011-11-17 10:23:55 -08001086 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001087 help
1088 This allows containers, i.e. vservers, to use user namespaces
1089 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001090
1091 When user namespaces are enabled in the kernel it is
1092 recommended that the MEMCG and MEMCG_KMEM options also be
1093 enabled and that user-space use the memory control groups to
1094 limit the amount of memory a memory unprivileged users can
1095 use.
1096
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001097 If unsure, say N.
1098
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001099config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001100 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001101 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001102 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001103 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001104 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001105 pid namespaces. This is a building block of containers.
1106
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001107config NET_NS
1108 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001109 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001110 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001111 help
1112 Allow user space to create what appear to be multiple instances
1113 of the network stack.
1114
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001115endif # NAMESPACES
1116
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001117config UIDGID_CONVERTED
1118 # True if all of the selected software conmponents are known
1119 # to have uid_t and gid_t converted to kuid_t and kgid_t
1120 # where appropriate and are otherwise safe to use with
1121 # the user namespace.
1122 bool
1123 default y
1124
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001125 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001126 depends on XFS_FS = n
1127
Eric W. Biederman5673a942011-11-17 10:23:55 -08001128config UIDGID_STRICT_TYPE_CHECKS
1129 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001130 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001131 default n
1132 help
1133 While the nececessary conversions are being added to all subsystems this option allows
1134 the code to continue to build for unconverted subsystems.
1135
1136 Say Y here if you want the strict type checking enabled
1137
Mike Galbraith5091faa2010-11-30 14:18:03 +01001138config SCHED_AUTOGROUP
1139 bool "Automatic process group scheduling"
1140 select EVENTFD
1141 select CGROUPS
1142 select CGROUP_SCHED
1143 select FAIR_GROUP_SCHED
1144 help
1145 This option optimizes the scheduler for common desktop workloads by
1146 automatically creating and populating task groups. This separation
1147 of workloads isolates aggressive CPU burners (like build jobs) from
1148 desktop applications. Task group autogeneration is currently based
1149 upon task session.
1150
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001151config MM_OWNER
1152 bool
1153
1154config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001155 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001156 depends on SYSFS
1157 default n
1158 help
1159 This option adds code that switches the layout of the "block" class
1160 devices, to not show up in /sys/class/block/, but only in
1161 /sys/block/.
1162
1163 This switch is only active when the sysfs.deprecated=1 boot option is
1164 passed or the SYSFS_DEPRECATED_V2 option is set.
1165
1166 This option allows new kernels to run on old distributions and tools,
1167 which might get confused by /sys/class/block/. Since 2007/2008 all
1168 major distributions and tools handle this just fine.
1169
1170 Recent distributions and userspace tools after 2009/2010 depend on
1171 the existence of /sys/class/block/, and will not work with this
1172 option enabled.
1173
1174 Only if you are using a new kernel on an old distribution, you might
1175 need to say Y here.
1176
1177config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001178 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001179 default n
1180 depends on SYSFS
1181 depends on SYSFS_DEPRECATED
1182 help
1183 Enable deprecated sysfs by default.
1184
1185 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1186 option.
1187
1188 Only if you are using a new kernel on an old distribution, you might
1189 need to say Y here. Even then, odds are you would not need it
1190 enabled, you can always pass the boot option if absolutely necessary.
1191
1192config RELAY
1193 bool "Kernel->user space relay support (formerly relayfs)"
1194 help
1195 This option enables support for relay interface support in
1196 certain file systems (such as debugfs).
1197 It is designed to provide an efficient mechanism for tools and
1198 facilities to relay large amounts of data from kernel space to
1199 user space.
1200
1201 If unsure, say N.
1202
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001203config BLK_DEV_INITRD
1204 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1205 depends on BROKEN || !FRV
1206 help
1207 The initial RAM filesystem is a ramfs which is loaded by the
1208 boot loader (loadlin or lilo) and that is mounted as root
1209 before the normal boot procedure. It is typically used to
1210 load modules needed to mount the "real" root file system,
1211 etc. See <file:Documentation/initrd.txt> for details.
1212
1213 If RAM disk support (BLK_DEV_RAM) is also included, this
1214 also enables initial RAM disk (initrd) support and adds
1215 15 Kbytes (more on some other architectures) to the kernel size.
1216
1217 If unsure say Y.
1218
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001219if BLK_DEV_INITRD
1220
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001221source "usr/Kconfig"
1222
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001223endif
1224
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001225config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001226 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001227 help
1228 Enabling this option will pass "-Os" instead of "-O2" to gcc
1229 resulting in a smaller kernel.
1230
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001231 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001232
Randy Dunlap08470622006-09-30 23:28:13 -07001233config SYSCTL
1234 bool
1235
Randy Dunlapb943c462009-03-10 12:55:46 -07001236config ANON_INODES
1237 bool
1238
Mike Frysinger657a5202013-04-30 15:28:45 -07001239config HAVE_UID16
1240 bool
1241
1242config SYSCTL_EXCEPTION_TRACE
1243 bool
1244 help
1245 Enable support for /proc/sys/debug/exception-trace.
1246
1247config SYSCTL_ARCH_UNALIGN_NO_WARN
1248 bool
1249 help
1250 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1251 Allows arch to define/use @no_unaligned_warning to possibly warn
1252 about unaligned access emulation going on under the hood.
1253
1254config SYSCTL_ARCH_UNALIGN_ALLOW
1255 bool
1256 help
1257 Enable support for /proc/sys/kernel/unaligned-trap
1258 Allows arches to define/use @unaligned_enabled to runtime toggle
1259 the unaligned access emulation.
1260 see arch/parisc/kernel/unaligned.c for reference
1261
Mike Frysinger657a5202013-04-30 15:28:45 -07001262config HAVE_PCSPKR_PLATFORM
1263 bool
1264
David Rientjes6a108a12011-01-20 14:44:16 -08001265menuconfig EXPERT
1266 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001267 # Unhide debug options, to make the on-by-default options visible
1268 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 help
1270 This option allows certain base kernel options and settings
1271 to be disabled or tweaked. This is for specialized
1272 environments which can tolerate a "non-standard" kernel.
1273 Only use this if you really know what you are doing.
1274
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001275config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001276 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001277 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001278 default y
1279 help
1280 This enables the legacy 16-bit UID syscall wrappers.
1281
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001282config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001283 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001284 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001285 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001286 select SYSCTL
1287 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001288 sys_sysctl uses binary paths that have been found challenging
1289 to properly maintain and use. The interface in /proc/sys
1290 using paths with ascii names is now the primary path to this
1291 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001292
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001293 Almost nothing using the binary sysctl interface so if you are
1294 trying to save some space it is probably safe to disable this,
1295 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001296
WANG Congc736de62011-11-02 13:39:25 -07001297 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001298
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001300 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 default y
1302 help
1303 Say Y here to let the kernel print out symbolic crash information and
1304 symbolic stack backtraces. This increases the size of the kernel
1305 somewhat, as all symbols have to be loaded into the kernel image.
1306
1307config KALLSYMS_ALL
1308 bool "Include all symbols in kallsyms"
1309 depends on DEBUG_KERNEL && KALLSYMS
1310 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001311 Normally kallsyms only contains the symbols of functions for nicer
1312 OOPS messages and backtraces (i.e., symbols from the text and inittext
1313 sections). This is sufficient for most cases. And only in very rare
1314 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1315 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001317 This option makes sure that all symbols are loaded into the kernel
1318 image (i.e., symbols from all sections) in cost of increased kernel
1319 size (depending on the kernel configuration, it may be 300KiB or
1320 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001322 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001323
1324config PRINTK
1325 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001326 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001327 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001328 help
1329 This option enables normal printk support. Removing it
1330 eliminates most of the message strings from the kernel image
1331 and makes the kernel more or less silent. As this makes it
1332 very difficult to diagnose system problems, saying N here is
1333 strongly discouraged.
1334
Matt Mackallc8538a72005-05-01 08:59:01 -07001335config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001336 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001337 default y
1338 help
1339 Disabling this option eliminates support for BUG and WARN, reducing
1340 the size of your kernel image and potentially quietly ignoring
1341 numerous fatal conditions. You should only consider disabling this
1342 option for embedded systems with no facilities for reporting errors.
1343 Just say Y.
1344
Matt Mackall708e9a72006-01-08 01:05:25 -08001345config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001346 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001347 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001348 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001349 help
1350 Enable support for generating core dumps. Disabling saves about 4k.
1351
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001352
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001353config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001354 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001355 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001356 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001357 default y
1358 help
1359 This option allows to disable the internal PC-Speaker
1360 support, saving some memory.
1361
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362config BASE_FULL
1363 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001364 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365 help
1366 Disabling this option reduces the size of miscellaneous core
1367 kernel data structures. This saves memory on small machines,
1368 but may reduce performance.
1369
1370config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001371 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001372 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001373 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374 help
1375 Disabling this option will cause the kernel to be built without
1376 support for "fast userspace mutexes". The resulting kernel may not
1377 run glibc-based applications correctly.
1378
1379config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001380 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001381 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001382 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383 help
1384 Disabling this option will cause the kernel to be built without
1385 support for epoll family of system calls.
1386
Davide Libenzifba2afa2007-05-10 22:23:13 -07001387config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001388 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001389 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001390 default y
1391 help
1392 Enable the signalfd() system call that allows to receive signals
1393 on a file descriptor.
1394
1395 If unsure, say Y.
1396
Davide Libenzib215e282007-05-10 22:23:16 -07001397config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001398 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001399 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001400 default y
1401 help
1402 Enable the timerfd() system call that allows to receive timer
1403 events on a file descriptor.
1404
1405 If unsure, say Y.
1406
Davide Libenzie1ad7462007-05-10 22:23:19 -07001407config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001408 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001409 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001410 default y
1411 help
1412 Enable the eventfd() system call that allows to receive both
1413 kernel notification (ie. KAIO) or userspace notifications.
1414
1415 If unsure, say Y.
1416
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001418 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419 default y
1420 depends on MMU
1421 help
1422 The shmem is an internal filesystem used to manage shared memory.
1423 It is backed by swap and manages resource limits. It is also exported
1424 to userspace as tmpfs if TMPFS is enabled. Disabling this
1425 option replaces shmem and tmpfs with the much simpler ramfs code,
1426 which may be appropriate on small systems without swap.
1427
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001428config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001429 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001430 default y
1431 help
1432 This option enables POSIX asynchronous I/O which may by used
Mike Frysinger657a5202013-04-30 15:28:45 -07001433 by some high performance threaded applications. Disabling
1434 this option saves about 7k.
1435
1436config PCI_QUIRKS
1437 default y
1438 bool "Enable PCI quirk workarounds" if EXPERT
1439 depends on PCI
1440 help
1441 This enables workarounds for various PCI chipset
1442 bugs/quirks. Disable this only if your target machine is
1443 unaffected by PCI quirks.
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001444
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001445config EMBEDDED
1446 bool "Embedded system"
1447 select EXPERT
1448 help
1449 This option should be enabled if compiling the kernel for
1450 an embedded system so certain expert options are available
1451 for configuration.
1452
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001453config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001454 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001455 help
1456 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001457
Peter Zijlstra906010b2009-09-21 16:08:49 +02001458config PERF_USE_VMALLOC
1459 bool
1460 help
1461 See tools/perf/design.txt for details
1462
Ingo Molnar57c0c152009-09-21 12:20:38 +02001463menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001464
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001465config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001466 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001467 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001468 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001469 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001470 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001471 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001472 Enable kernel support for various performance events provided
1473 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001474
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001475 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001476 use of generic tracepoints.
1477
1478 Most modern CPUs support performance events via performance
1479 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001480 types of hw events: such as instructions executed, cachemisses
1481 suffered, or branches mis-predicted - without slowing down the
1482 kernel or applications. These registers can also trigger interrupts
1483 when a threshold number of events have passed - and can thus be
1484 used to profile the code that runs on that CPU.
1485
Ingo Molnar57c0c152009-09-21 12:20:38 +02001486 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001487 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001488 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001489 provides per task and per CPU counters, and it provides event
1490 capabilities on top of those.
1491
1492 Say Y if unsure.
1493
Peter Zijlstra906010b2009-09-21 16:08:49 +02001494config DEBUG_PERF_USE_VMALLOC
1495 default n
1496 bool "Debug: use vmalloc to back perf mmap() buffers"
1497 depends on PERF_EVENTS && DEBUG_KERNEL
1498 select PERF_USE_VMALLOC
1499 help
1500 Use vmalloc memory to back perf mmap() buffers.
1501
1502 Mostly useful for debugging the vmalloc code on platforms
1503 that don't require it.
1504
1505 Say N if unsure.
1506
Thomas Gleixner0793a612008-12-04 20:12:29 +01001507endmenu
1508
Christoph Lameterf8891e52006-06-30 01:55:45 -07001509config VM_EVENT_COUNTERS
1510 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001511 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001512 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001513 VM event counters are needed for event counts to be shown.
1514 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001515 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001516 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001517
Christoph Lameter41ecc552007-05-09 02:32:44 -07001518config SLUB_DEBUG
1519 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001520 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001521 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001522 help
1523 SLUB has extensive debug support features. Disabling these can
1524 result in significant savings in code size. This also disables
1525 SLUB sysfs support. /sys/slab will not exist and there will be
1526 no support for cache validation etc.
1527
Randy Dunlapb943c462009-03-10 12:55:46 -07001528config COMPAT_BRK
1529 bool "Disable heap randomization"
1530 default y
1531 help
1532 Randomizing heap placement makes heap exploits harder, but it
1533 also breaks ancient binaries (including anything libc5 based).
1534 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001535 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001536 /proc/sys/kernel/randomize_va_space to 2.
1537
1538 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1539
Christoph Lameter81819f02007-05-06 14:49:36 -07001540choice
1541 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001542 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001543 help
1544 This option allows to select a slab allocator.
1545
1546config SLAB
1547 bool "SLAB"
1548 help
1549 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001550 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001551 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001552
1553config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001554 bool "SLUB (Unqueued Allocator)"
1555 help
1556 SLUB is a slab allocator that minimizes cache line usage
1557 instead of managing queues of cached objects (SLAB approach).
1558 Per cpu caching is realized using slabs of objects instead
1559 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001560 and has enhanced diagnostics. SLUB is the default choice for
1561 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001562
1563config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001564 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001565 bool "SLOB (Simple Allocator)"
1566 help
Matt Mackall37291452008-02-04 22:29:38 -08001567 SLOB replaces the stock allocator with a drastically simpler
1568 allocator. SLOB is generally more space efficient but
1569 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001570
1571endchoice
1572
Jie Zhangea637632009-12-14 18:00:02 -08001573config MMAP_ALLOW_UNINITIALIZED
1574 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001575 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001576 default n
1577 help
1578 Normally, and according to the Linux spec, anonymous memory obtained
1579 from mmap() has it's contents cleared before it is passed to
1580 userspace. Enabling this config option allows you to request that
1581 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1582 providing a huge performance boost. If this option is not enabled,
1583 then the flag will be ignored.
1584
1585 This is taken advantage of by uClibc's malloc(), and also by
1586 ELF-FDPIC binfmt's brk and stack allocator.
1587
1588 Because of the obvious security issues, this option should only be
1589 enabled on embedded devices where you control what is run in
1590 userspace. Since that isn't generally a problem on no-MMU systems,
1591 it is normally safe to say Y here.
1592
1593 See Documentation/nommu-mmap.txt for more information.
1594
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001595config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001596 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001597 help
1598 Say Y here to enable the extended profiling support mechanisms used
1599 by profilers such as OProfile.
1600
Ingo Molnar5f87f112008-07-23 14:15:22 +02001601#
1602# Place an empty function call at each tracepoint site. Can be
1603# dynamically changed for a probe function.
1604#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001605config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001606 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001607
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001608source "arch/Kconfig"
1609
Linus Torvalds1da177e2005-04-16 15:20:36 -07001610endmenu # General setup
1611
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001612config HAVE_GENERIC_DMA_COHERENT
1613 bool
1614 default n
1615
Linus Torvalds158a9622008-01-02 13:04:48 -08001616config SLABINFO
1617 bool
1618 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001619 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001620 default y
1621
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001622config RT_MUTEXES
1623 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001624
Linus Torvalds1da177e2005-04-16 15:20:36 -07001625config BASE_SMALL
1626 int
1627 default 0 if BASE_FULL
1628 default 1 if !BASE_FULL
1629
Jan Engelhardt66da5732007-07-15 23:39:29 -07001630menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 bool "Enable loadable module support"
1632 help
1633 Kernel modules are small pieces of compiled code which can
1634 be inserted in the running kernel, rather than being
1635 permanently built into the kernel. You use the "modprobe"
1636 tool to add (and sometimes remove) them. If you say Y here,
1637 many parts of the kernel can be built as modules (by
1638 answering M instead of Y where indicated): this is most
1639 useful for infrequently used options which are not required
1640 for booting. For more information, see the man pages for
1641 modprobe, lsmod, modinfo, insmod and rmmod.
1642
1643 If you say Y here, you will need to run "make
1644 modules_install" to put the modules under /lib/modules/
1645 where modprobe can find them (you may need to be root to do
1646 this).
1647
1648 If unsure, say Y.
1649
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001650if MODULES
1651
Linus Torvalds826e4502008-05-04 17:04:16 -07001652config MODULE_FORCE_LOAD
1653 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001654 default n
1655 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001656 Allow loading of modules without version information (ie. modprobe
1657 --force). Forced module loading sets the 'F' (forced) taint flag and
1658 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001659
Linus Torvalds1da177e2005-04-16 15:20:36 -07001660config MODULE_UNLOAD
1661 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001662 help
1663 Without this option you will not be able to unload any
1664 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001665 anyway), which makes your kernel smaller, faster
1666 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001667
1668config MODULE_FORCE_UNLOAD
1669 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001670 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671 help
1672 This option allows you to force a module to unload, even if the
1673 kernel believes it is unsafe: the kernel will remove the module
1674 without waiting for anyone to stop using it (using the -f option to
1675 rmmod). This is mainly for kernel developers and desperate users.
1676 If unsure, say N.
1677
Linus Torvalds1da177e2005-04-16 15:20:36 -07001678config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001679 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001680 help
1681 Usually, you have to use modules compiled with your kernel.
1682 Saying Y here makes it sometimes possible to use modules
1683 compiled for different kernels, by adding enough information
1684 to the modules to (hopefully) spot any changes which would
1685 make them incompatible with the kernel you are running. If
1686 unsure, say N.
1687
1688config MODULE_SRCVERSION_ALL
1689 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690 help
1691 Modules which contain a MODULE_VERSION get an extra "srcversion"
1692 field inserted into their modinfo section, which contains a
1693 sum of the source files which made it. This helps maintainers
1694 see exactly which source was used to build a module (since
1695 others sometimes change the module source without updating
1696 the version). With this option, such a "srcversion" field
1697 will be created for all modules. If unsure, say N.
1698
Rusty Russell106a4ee2012-09-26 10:09:40 +01001699config MODULE_SIG
1700 bool "Module signature verification"
1701 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001702 select KEYS
1703 select CRYPTO
1704 select ASYMMETRIC_KEY_TYPE
1705 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1706 select PUBLIC_KEY_ALGO_RSA
1707 select ASN1
1708 select OID_REGISTRY
1709 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001710 help
1711 Check modules for valid signatures upon load: the signature
1712 is simply appended to the module. For more information see
1713 Documentation/module-signing.txt.
1714
David Howellsea0b6dc2012-09-26 10:09:50 +01001715 !!!WARNING!!! If you enable this option, you MUST make sure that the
1716 module DOES NOT get stripped after being signed. This includes the
1717 debuginfo strip done by some packagers (such as rpmbuild) and
1718 inclusion into an initramfs that wants the module size reduced.
1719
Rusty Russell106a4ee2012-09-26 10:09:40 +01001720config MODULE_SIG_FORCE
1721 bool "Require modules to be validly signed"
1722 depends on MODULE_SIG
1723 help
1724 Reject unsigned modules or signed modules for which we don't have a
1725 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001726
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301727config MODULE_SIG_ALL
1728 bool "Automatically sign all modules"
1729 default y
1730 depends on MODULE_SIG
1731 help
1732 Sign all modules during make modules_install. Without this option,
1733 modules must be signed manually, using the scripts/sign-file tool.
1734
1735comment "Do not forget to sign required modules with scripts/sign-file"
1736 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1737
David Howellsea0b6dc2012-09-26 10:09:50 +01001738choice
1739 prompt "Which hash algorithm should modules be signed with?"
1740 depends on MODULE_SIG
1741 help
1742 This determines which sort of hashing algorithm will be used during
1743 signature generation. This algorithm _must_ be built into the kernel
1744 directly so that signature verification can take place. It is not
1745 possible to load a signed module containing the algorithm to check
1746 the signature on that module.
1747
1748config MODULE_SIG_SHA1
1749 bool "Sign modules with SHA-1"
1750 select CRYPTO_SHA1
1751
1752config MODULE_SIG_SHA224
1753 bool "Sign modules with SHA-224"
1754 select CRYPTO_SHA256
1755
1756config MODULE_SIG_SHA256
1757 bool "Sign modules with SHA-256"
1758 select CRYPTO_SHA256
1759
1760config MODULE_SIG_SHA384
1761 bool "Sign modules with SHA-384"
1762 select CRYPTO_SHA512
1763
1764config MODULE_SIG_SHA512
1765 bool "Sign modules with SHA-512"
1766 select CRYPTO_SHA512
1767
1768endchoice
1769
Michal Marek22753672013-01-25 13:41:00 +10301770config MODULE_SIG_HASH
1771 string
1772 depends on MODULE_SIG
1773 default "sha1" if MODULE_SIG_SHA1
1774 default "sha224" if MODULE_SIG_SHA224
1775 default "sha256" if MODULE_SIG_SHA256
1776 default "sha384" if MODULE_SIG_SHA384
1777 default "sha512" if MODULE_SIG_SHA512
1778
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001779endif # MODULES
1780
Rusty Russell98a79d62008-12-13 21:19:41 +10301781config INIT_ALL_POSSIBLE
1782 bool
1783 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301784 Back when each arch used to define their own cpu_online_mask and
1785 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301786 with all 1s, and others with all 0s. When they were centralised,
1787 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001788 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301789
Linus Torvalds1da177e2005-04-16 15:20:36 -07001790config STOP_MACHINE
1791 bool
1792 default y
1793 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1794 help
1795 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001796
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001797source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001798
1799config PREEMPT_NOTIFIERS
1800 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001801
Steffen Klassert16295be2010-01-06 19:47:10 +11001802config PADATA
1803 depends on SMP
1804 bool
1805
Andi Kleen754b7b62012-10-04 17:11:27 -07001806# Can be selected by architectures with broken toolchains
1807# that get confused by correct const<->read_only section
1808# mappings
1809config BROKEN_RODATA
1810 bool
1811
David Howells4520c6a2012-09-21 23:31:13 +01001812config ASN1
1813 tristate
1814 help
1815 Build a simple ASN.1 grammar compiler that produces a bytecode output
1816 that can be interpreted by the ASN.1 stream decoder and used to
1817 inform it as to what tags are to be expected in a stream and what
1818 functions to call on what tags.
1819
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001820source "kernel/Kconfig.locks"