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Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070022
Peter Zijlstrae360adb2010-10-14 14:01:34 +080023config IRQ_WORK
24 bool
Peter Zijlstrae360adb2010-10-14 14:01:34 +080025
David Daney1dbdc6f2012-04-19 14:59:57 -070026config BUILDTIME_EXTABLE_SORT
27 bool
28
Al Boldiff0cfc62007-07-31 00:39:23 -070029menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Linus Torvalds1da177e2005-04-16 15:20:36 -070031config BROKEN
32 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34config BROKEN_ON_SMP
35 bool
36 depends on BROKEN || !SMP
37 default y
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039config INIT_ENV_ARG_LIMIT
40 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070041 default 32 if !UML
42 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080044 Maximum of each of the number of arguments and environment
45 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Roland McGrath84336462009-12-21 16:24:06 -080048config CROSS_COMPILE
49 string "Cross-compiler tool prefix"
50 help
51 Same as running 'make CROSS_COMPILE=prefix-' but stored for
52 default make runs in this kernel build directory. You don't
53 need to set this unless you want the configured kernel build
54 directory to select the cross-compiler automatically.
55
Linus Torvalds1da177e2005-04-16 15:20:36 -070056config LOCALVERSION
57 string "Local version - append to kernel release"
58 help
59 Append an extra string to the end of your kernel version.
60 This will show up when you type uname, for example.
61 The string you set here will be appended after the contents of
62 any files with a filename matching localversion* in your
63 object and source tree, in that order. Your total string can
64 be a maximum of 64 characters.
65
Ryan Andersonaaebf432005-07-31 04:57:49 -040066config LOCALVERSION_AUTO
67 bool "Automatically append version information to the version string"
68 default y
69 help
70 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020071 release tree by looking for git tags that belong to the current
72 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040073
74 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020075 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040076 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020077 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -040078
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020079 (The actual string used here is the first eight characters produced
80 by running the command:
81
82 $ git rev-parse --verify HEAD
83
84 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -040085
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -080086config HAVE_KERNEL_GZIP
87 bool
88
89config HAVE_KERNEL_BZIP2
90 bool
91
92config HAVE_KERNEL_LZMA
93 bool
94
Lasse Collin3ebe1242011-01-12 17:01:23 -080095config HAVE_KERNEL_XZ
96 bool
97
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -080098config HAVE_KERNEL_LZO
99 bool
100
Alain Knaff30d65db2009-01-04 22:46:17 +0100101choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800102 prompt "Kernel compression mode"
103 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800104 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 -0800105 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100106 The linux kernel is a kind of self-extracting executable.
107 Several compression algorithms are available, which differ
108 in efficiency, compression and decompression speed.
109 Compression speed is only relevant when building a kernel.
110 Decompression speed is relevant at each boot.
111
112 If you have any problems with bzip2 or lzma compressed
113 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
114 version of this functionality (bzip2 only), for 2.4, was
115 supplied by Christian Ludwig)
116
117 High compression options are mostly useful for users, who
118 are low on disk space (embedded systems), but for whom ram
119 size matters less.
120
121 If in doubt, select 'gzip'
122
123config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800124 bool "Gzip"
125 depends on HAVE_KERNEL_GZIP
126 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800127 The old and tried gzip compression. It provides a good balance
128 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100129
130config KERNEL_BZIP2
131 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800132 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100133 help
134 Its compression ratio and speed is intermediate.
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700135 Decompression speed is slowest among the choices. The kernel
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800136 size is about 10% smaller with bzip2, in comparison to gzip.
137 Bzip2 uses a large amount of memory. For modern kernels you
138 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100139
140config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800141 bool "LZMA"
142 depends on HAVE_KERNEL_LZMA
143 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700144 This compression algorithm's ratio is best. Decompression speed
145 is between gzip and bzip2. Compression is slowest.
146 The kernel size is about 33% smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100147
Lasse Collin3ebe1242011-01-12 17:01:23 -0800148config KERNEL_XZ
149 bool "XZ"
150 depends on HAVE_KERNEL_XZ
151 help
152 XZ uses the LZMA2 algorithm and instruction set specific
153 BCJ filters which can improve compression ratio of executable
154 code. The size of the kernel is about 30% smaller with XZ in
155 comparison to gzip. On architectures for which there is a BCJ
156 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
157 will create a few percent smaller kernel than plain LZMA.
158
159 The speed is about the same as with LZMA: The decompression
160 speed of XZ is better than that of bzip2 but worse than gzip
161 and LZO. Compression is slow.
162
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800163config KERNEL_LZO
164 bool "LZO"
165 depends on HAVE_KERNEL_LZO
166 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700167 Its compression ratio is the poorest among the choices. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200168 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800169 (both compression and decompression) is the fastest.
170
Alain Knaff30d65db2009-01-04 22:46:17 +0100171endchoice
172
Josh Triplettbd5dc172011-06-15 15:08:28 -0700173config DEFAULT_HOSTNAME
174 string "Default hostname"
175 default "(none)"
176 help
177 This option determines the default system hostname before userspace
178 calls sethostname(2). The kernel traditionally uses "(none)" here,
179 but you may wish to use a different default here to make a minimal
180 system more usable with less configuration.
181
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182config SWAP
183 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200184 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 default y
186 help
187 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100188 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 used to provide more virtual memory than the actual RAM present
190 in your computer. If unsure say Y.
191
192config SYSVIPC
193 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 ---help---
195 Inter Process Communication is a suite of library functions and
196 system calls which let processes (running programs) synchronize and
197 exchange information. It is generally considered to be a good thing,
198 and some programs won't run unless you say Y here. In particular, if
199 you want to run the DOS emulator dosemu under Linux (read the
200 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
201 you'll need to say Y here.
202
203 You can find documentation about IPC with "info ipc" and also in
204 section 6.4 of the Linux Programmer's Guide, available from
205 <http://www.tldp.org/guides.html>.
206
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800207config SYSVIPC_SYSCTL
208 bool
209 depends on SYSVIPC
210 depends on SYSCTL
211 default y
212
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213config POSIX_MQUEUE
214 bool "POSIX Message Queues"
Kees Cook19c92392012-10-02 11:19:29 -0700215 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 ---help---
217 POSIX variant of message queues is a part of IPC. In POSIX message
218 queues every message has a priority which decides about succession
219 of receiving it by a process. If you want to compile and run
220 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200221 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222
223 POSIX message queues are visible as a filesystem called 'mqueue'
224 and can be mounted somewhere if you want to do filesystem
225 operations on message queues.
226
227 If unsure, say Y.
228
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700229config POSIX_MQUEUE_SYSCTL
230 bool
231 depends on POSIX_MQUEUE
232 depends on SYSCTL
233 default y
234
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530235config FHANDLE
236 bool "open by fhandle syscalls"
237 select EXPORTFS
238 help
239 If you say Y here, a user level program will be able to map
240 file names to handle and then later use the handle for
241 different file system operations. This is useful in implementing
242 userspace file servers, which now track files using handles instead
243 of names. The handle would remain the same even if file names
244 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
245 syscalls.
246
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247config AUDIT
248 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100249 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 help
251 Enable auditing infrastructure that can be used with another
252 kernel subsystem, such as SELinux (which requires this for
253 logging of avc messages output). Does not do system-call
254 auditing without CONFIG_AUDITSYSCALL.
255
256config AUDITSYSCALL
257 bool "Enable system-call auditing support"
Will Deacon8f827a12012-07-06 15:48:16 +0100258 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 default y if SECURITY_SELINUX
260 help
261 Enable low-overhead system-call auditing infrastructure that
262 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500263 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
Eric Paris939a67f2009-12-17 20:12:06 -0500265config AUDIT_WATCH
266 def_bool y
267 depends on AUDITSYSCALL
268 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
Al Viro74c3cbe2007-07-22 08:04:18 -0400270config AUDIT_TREE
271 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400272 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500273 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400274
Eric Paris633b4542012-01-03 14:23:08 -0500275config AUDIT_LOGINUID_IMMUTABLE
276 bool "Make audit loginuid immutable"
277 depends on AUDIT
278 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800279 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500280 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
281 but should instead only allow setting its loginuid if it was never
282 previously set. On systems which use systemd or a similar central
283 process to restart login services this should be set to true. On older
284 systems in which an admin would typically have to directly stop and
285 start processes this should be set to false. Setting this to true allows
286 one to drop potentially dangerous capabilites from the login tasks,
287 but may not be backwards compatible with older init systems.
288
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000289source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200290source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000291
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200292menu "CPU/Task time and stats accounting"
293
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200294config VIRT_CPU_ACCOUNTING
295 bool
296
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200297choice
298 prompt "Cputime accounting"
299 default TICK_CPU_ACCOUNTING if !PPC64
Stephen Rothwell02fc8d32013-02-08 14:19:38 +1100300 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200301
302# Kind of a stub config for the pure tick based cputime accounting
303config TICK_CPU_ACCOUNTING
304 bool "Simple tick based cputime accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200305 depends on !S390 && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200306 help
307 This is the basic tick based cputime accounting that maintains
308 statistics about user, system and idle time spent on per jiffies
309 granularity.
310
311 If unsure, say Y.
312
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200313config VIRT_CPU_ACCOUNTING_NATIVE
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200314 bool "Deterministic task and CPU time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200315 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200316 select VIRT_CPU_ACCOUNTING
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200317 help
318 Select this option to enable more accurate task and CPU time
319 accounting. This is done by reading a CPU counter on each
320 kernel entry and exit and on transitions within the kernel
321 between system, softirq and hardirq state, so there is a
322 small performance impact. In the case of s390 or IBM POWER > 5,
323 this also enables accounting of stolen time on logically-partitioned
324 systems.
325
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200326config VIRT_CPU_ACCOUNTING_GEN
327 bool "Full dynticks CPU time accounting"
328 depends on HAVE_CONTEXT_TRACKING && 64BIT
329 select VIRT_CPU_ACCOUNTING
330 select CONTEXT_TRACKING
331 help
332 Select this option to enable task and CPU time accounting on full
333 dynticks systems. This accounting is implemented by watching every
334 kernel-user boundaries using the context tracking subsystem.
335 The accounting is thus performed at the expense of some significant
336 overhead.
337
338 For now this is only useful if you are working on the full
339 dynticks subsystem development.
340
341 If unsure, say N.
342
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200343config IRQ_TIME_ACCOUNTING
344 bool "Fine granularity task level IRQ time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200345 depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200346 help
347 Select this option to enable fine granularity task irq time
348 accounting. This is done by reading a timestamp on each
349 transitions between softirq and hardirq state, so there can be a
350 small performance impact.
351
352 If in doubt, say N here.
353
354endchoice
355
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200356config BSD_PROCESS_ACCT
357 bool "BSD Process Accounting"
358 help
359 If you say Y here, a user level program will be able to instruct the
360 kernel (via a special system call) to write process accounting
361 information to a file: whenever a process exits, information about
362 that process will be appended to the file by the kernel. The
363 information includes things such as creation time, owning user,
364 command name, memory usage, controlling terminal etc. (the complete
365 list is in the struct acct in <file:include/linux/acct.h>). It is
366 up to the user level program to do useful things with this
367 information. This is generally a good idea, so say Y.
368
369config BSD_PROCESS_ACCT_V3
370 bool "BSD Process Accounting version 3 file format"
371 depends on BSD_PROCESS_ACCT
372 default n
373 help
374 If you say Y here, the process accounting information is written
375 in a new file format that also logs the process IDs of each
376 process and it's parent. Note that this file format is incompatible
377 with previous v0/v1/v2 file formats, so you will need updated tools
378 for processing it. A preliminary version of these tools is available
379 at <http://www.gnu.org/software/acct/>.
380
381config TASKSTATS
Kees Cook19c92392012-10-02 11:19:29 -0700382 bool "Export task/process statistics through netlink"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200383 depends on NET
384 default n
385 help
386 Export selected statistics for tasks/processes through the
387 generic netlink interface. Unlike BSD process accounting, the
388 statistics are available during the lifetime of tasks/processes as
389 responses to commands. Like BSD accounting, they are sent to user
390 space on task exit.
391
392 Say N if unsure.
393
394config TASK_DELAY_ACCT
Kees Cook19c92392012-10-02 11:19:29 -0700395 bool "Enable per-task delay accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200396 depends on TASKSTATS
397 help
398 Collect information on time spent by a task waiting for system
399 resources like cpu, synchronous block I/O completion and swapping
400 in pages. Such statistics can help in setting a task's priorities
401 relative to other tasks for cpu, io, rss limits etc.
402
403 Say N if unsure.
404
405config TASK_XACCT
Kees Cook19c92392012-10-02 11:19:29 -0700406 bool "Enable extended accounting over taskstats"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200407 depends on TASKSTATS
408 help
409 Collect extended task accounting data and send the data
410 to userland for processing over the taskstats interface.
411
412 Say N if unsure.
413
414config TASK_IO_ACCOUNTING
Kees Cook19c92392012-10-02 11:19:29 -0700415 bool "Enable per-task storage I/O accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200416 depends on TASK_XACCT
417 help
418 Collect information on the number of bytes of storage I/O which this
419 task has caused.
420
421 Say N if unsure.
422
423endmenu # "CPU/Task time and stats accounting"
424
Mike Travisc903ff82009-01-15 12:28:29 -0800425menu "RCU Subsystem"
426
427choice
428 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700429 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800430
Mike Travisc903ff82009-01-15 12:28:29 -0800431config TREE_RCU
432 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700433 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800434 help
435 This option selects the RCU implementation that is
436 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700437 thousands of CPUs. It also scales down nicely to
438 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800439
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700440config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700441 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800442 depends on PREEMPT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700443 help
444 This option selects the RCU implementation that is
445 designed for very large SMP systems with hundreds or
446 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700447 is also required. It also scales down nicely to
448 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700449
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800450 Select this option if you are unsure.
451
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700452config TINY_RCU
453 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700454 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700455 help
456 This option selects the RCU implementation that is
457 designed for UP systems from which real-time response
458 is not required. This option greatly reduces the
459 memory footprint of RCU.
460
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700461config TINY_PREEMPT_RCU
462 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700463 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700464 help
465 This option selects the RCU implementation that is designed
466 for real-time UP systems. This option greatly reduces the
467 memory footprint of RCU.
468
Mike Travisc903ff82009-01-15 12:28:29 -0800469endchoice
470
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700471config PREEMPT_RCU
472 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
473 help
474 This option enables preemptible-RCU code that is common between
475 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
476
Paul E. McKenney6bfc09e2012-10-19 12:49:17 -0700477config RCU_STALL_COMMON
478 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
479 help
480 This option enables RCU CPU stall code that is common between
481 the TINY and TREE variants of RCU. The purpose is to allow
482 the tiny variants to disable RCU CPU stall warnings, while
483 making these warnings mandatory for the tree variants.
484
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100485config CONTEXT_TRACKING
486 bool
487
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200488config RCU_USER_QS
489 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100490 depends on HAVE_CONTEXT_TRACKING && SMP
491 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200492 help
493 This option sets hooks on kernel / userspace boundaries and
494 puts RCU in extended quiescent state when the CPU runs in
495 userspace. It means that when a CPU runs in userspace, it is
496 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700497 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200498
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200499 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100500 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700501 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200502
503 If unsure say N
504
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100505config CONTEXT_TRACKING_FORCE
506 bool "Force context tracking"
507 depends on CONTEXT_TRACKING
Frederic Weisbecker8b438762013-02-26 15:37:59 +0100508 default CONTEXT_TRACKING
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200509 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100510 Probe on user/kernel boundaries by default in order to
511 test the features that rely on it such as userspace RCU extended
512 quiescent states.
513 This test is there for debugging until we have a real user like the
514 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200515
Mike Travisc903ff82009-01-15 12:28:29 -0800516config RCU_FANOUT
517 int "Tree-based hierarchical RCU fanout value"
518 range 2 64 if 64BIT
519 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700520 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800521 default 64 if 64BIT
522 default 32 if !64BIT
523 help
524 This option controls the fanout of hierarchical implementations
525 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700526 large numbers of CPUs. This value must be at least the fourth
527 root of NR_CPUS, which allows NR_CPUS to be insanely large.
528 The default value of RCU_FANOUT should be used for production
529 systems, but if you are stress-testing the RCU implementation
530 itself, small RCU_FANOUT values allow you to test large-system
531 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800532
533 Select a specific number if testing RCU itself.
534 Take the default if unsure.
535
Paul E. McKenney8932a632012-04-19 12:20:14 -0700536config RCU_FANOUT_LEAF
537 int "Tree-based hierarchical RCU leaf-level fanout value"
538 range 2 RCU_FANOUT if 64BIT
539 range 2 RCU_FANOUT if !64BIT
540 depends on TREE_RCU || TREE_PREEMPT_RCU
541 default 16
542 help
543 This option controls the leaf-level fanout of hierarchical
544 implementations of RCU, and allows trading off cache misses
545 against lock contention. Systems that synchronize their
546 scheduling-clock interrupts for energy-efficiency reasons will
547 want the default because the smaller leaf-level fanout keeps
548 lock contention levels acceptably low. Very large systems
549 (hundreds or thousands of CPUs) will instead want to set this
550 value to the maximum value possible in order to reduce the
551 number of cache misses incurred during RCU's grace-period
552 initialization. These systems tend to run CPU-bound, and thus
553 are not helped by synchronized interrupts, and thus tend to
554 skew them, which reduces lock contention enough that large
555 leaf-level fanouts work well.
556
557 Select a specific number if testing RCU itself.
558
559 Select the maximum permissible value for large systems.
560
561 Take the default if unsure.
562
Mike Travisc903ff82009-01-15 12:28:29 -0800563config RCU_FANOUT_EXACT
564 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700565 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800566 default n
567 help
568 This option forces use of the exact RCU_FANOUT value specified,
569 regardless of imbalances in the hierarchy. This is useful for
570 testing RCU itself, and might one day be useful on systems with
571 strong NUMA behavior.
572
573 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
574
575 Say N if unsure.
576
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800577config RCU_FAST_NO_HZ
578 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Frederic Weisbecker3451d022011-08-10 23:21:01 +0200579 depends on NO_HZ_COMMON && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800580 default n
581 help
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800582 This option permits CPUs to enter dynticks-idle state even if
583 they have RCU callbacks queued, and prevents RCU from waking
584 these CPUs up more than roughly once every four jiffies (by
585 default, you can adjust this using the rcutree.rcu_idle_gp_delay
586 parameter), thus improving energy efficiency. On the other
587 hand, this option increases the duration of RCU grace periods,
588 for example, slowing down synchronize_rcu().
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800589
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800590 Say Y if energy efficiency is critically important, and you
591 don't care about increased grace-period durations.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800592
593 Say N if you are unsure.
594
Mike Travisc903ff82009-01-15 12:28:29 -0800595config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700596 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800597 select DEBUG_FS
598 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700599 This option provides tracing for the TREE_RCU and
600 TREE_PREEMPT_RCU implementations, permitting Makefile to
601 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800602
Paul E. McKenney24278d12010-09-27 17:25:23 -0700603config RCU_BOOST
604 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800605 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700606 default n
607 help
608 This option boosts the priority of preempted RCU readers that
609 block the current preemptible RCU grace period for too long.
610 This option also prevents heavy loads from blocking RCU
611 callback invocation for all flavors of RCU.
612
613 Say Y here if you are working with real-time apps or heavy loads
614 Say N here if you are unsure.
615
616config RCU_BOOST_PRIO
617 int "Real-time priority to boost RCU readers to"
618 range 1 99
619 depends on RCU_BOOST
620 default 1
621 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700622 This option specifies the real-time priority to which long-term
623 preempted RCU readers are to be boosted. If you are working
624 with a real-time application that has one or more CPU-bound
625 threads running at a real-time priority level, you should set
626 RCU_BOOST_PRIO to a priority higher then the highest-priority
627 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
628 of 1 is appropriate in the common case, which is real-time
629 applications that do not have any CPU-bound threads.
630
631 Some real-time applications might not have a single real-time
632 thread that saturates a given CPU, but instead might have
633 multiple real-time threads that, taken together, fully utilize
634 that CPU. In this case, you should set RCU_BOOST_PRIO to
635 a priority higher than the lowest-priority thread that is
636 conspiring to prevent the CPU from running any non-real-time
637 tasks. For example, if one thread at priority 10 and another
638 thread at priority 5 are between themselves fully consuming
639 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
640 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700641
642 Specify the real-time priority, or take the default if unsure.
643
644config RCU_BOOST_DELAY
645 int "Milliseconds to delay boosting after RCU grace-period start"
646 range 0 3000
647 depends on RCU_BOOST
648 default 500
649 help
650 This option specifies the time to wait after the beginning of
651 a given grace period before priority-boosting preempted RCU
652 readers blocking that grace period. Note that any RCU reader
653 blocking an expedited RCU grace period is boosted immediately.
654
655 Accept the default if unsure.
656
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700657config RCU_NOCB_CPU
Paul E. McKenney34ed62462013-01-07 13:37:42 -0800658 bool "Offload RCU callback processing from boot-selected CPUs (EXPERIMENTAL"
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700659 depends on TREE_RCU || TREE_PREEMPT_RCU
660 default n
661 help
662 Use this option to reduce OS jitter for aggressive HPC or
663 real-time workloads. It can also be used to offload RCU
664 callback invocation to energy-efficient CPUs in battery-powered
665 asymmetric multiprocessors.
666
667 This option offloads callback invocation from the set of
668 CPUs specified at boot time by the rcu_nocbs parameter.
Paul E. McKenneya4889852012-12-03 08:16:28 -0800669 For each such CPU, a kthread ("rcuox/N") will be created to
670 invoke callbacks, where the "N" is the CPU being offloaded,
671 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
672 "s" for RCU-sched. Nothing prevents this kthread from running
673 on the specified CPUs, but (1) the kthreads may be preempted
674 between each callback, and (2) affinity or cgroups can be used
675 to force the kthreads to run on whatever set of CPUs is desired.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700676
Paul E. McKenney34ed62462013-01-07 13:37:42 -0800677 Say Y here if you want to help to debug reduced OS jitter.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700678 Say N here if you are unsure.
679
Paul E. McKenney911af502013-02-11 10:23:27 -0800680choice
681 prompt "Build-forced no-CBs CPUs"
682 default RCU_NOCB_CPU_NONE
683 help
684 This option allows no-CBs CPUs to be specified at build time.
685 Additional no-CBs CPUs may be specified by the rcu_nocbs=
686 boot parameter.
687
688config RCU_NOCB_CPU_NONE
689 bool "No build_forced no-CBs CPUs"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200690 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800691 help
692 This option does not force any of the CPUs to be no-CBs CPUs.
693 Only CPUs designated by the rcu_nocbs= boot parameter will be
694 no-CBs CPUs.
695
696config RCU_NOCB_CPU_ZERO
697 bool "CPU 0 is a build_forced no-CBs CPU"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200698 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800699 help
700 This option forces CPU 0 to be a no-CBs CPU. Additional CPUs
701 may be designated as no-CBs CPUs using the rcu_nocbs= boot
702 parameter will be no-CBs CPUs.
703
704 Select this if CPU 0 needs to be a no-CBs CPU for real-time
705 or energy-efficiency reasons.
706
707config RCU_NOCB_CPU_ALL
708 bool "All CPUs are build_forced no-CBs CPUs"
709 depends on RCU_NOCB_CPU
710 help
711 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
712 boot parameter will be ignored.
713
714 Select this if all CPUs need to be no-CBs CPUs for real-time
715 or energy-efficiency reasons.
716
717endchoice
718
Mike Travisc903ff82009-01-15 12:28:29 -0800719endmenu # "RCU Subsystem"
720
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700722 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 ---help---
724 This option enables the complete Linux kernel ".config" file
725 contents to be saved in the kernel. It provides documentation
726 of which kernel options are used in a running kernel or in an
727 on-disk kernel. This information can be extracted from the kernel
728 image file with the script scripts/extract-ikconfig and used as
729 input to rebuild the current kernel or to build another kernel.
730 It can also be extracted from a running kernel by reading
731 /proc/config.gz if enabled (below).
732
733config IKCONFIG_PROC
734 bool "Enable access to .config through /proc/config.gz"
735 depends on IKCONFIG && PROC_FS
736 ---help---
737 This option enables access to the kernel configuration file
738 through /proc/config.gz.
739
Alistair John Strachan794543a2007-05-08 00:31:15 -0700740config LOG_BUF_SHIFT
741 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
742 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700743 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700744 help
745 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700746 Examples:
747 17 => 128 KB
748 16 => 64 KB
749 15 => 32 KB
750 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700751 13 => 8 KB
752 12 => 4 KB
753
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800754#
755# Architectures with an unreliable sched_clock() should select this:
756#
757config HAVE_UNSTABLE_SCHED_CLOCK
758 bool
759
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200760#
761# For architectures that want to enable the support for NUMA-affine scheduler
762# balancing logic:
763#
764config ARCH_SUPPORTS_NUMA_BALANCING
765 bool
766
767# For architectures that (ab)use NUMA to represent different memory regions
768# all cpu-local but of different latencies, such as SuperH.
769#
770config ARCH_WANT_NUMA_VARIABLE_LOCALITY
771 bool
772
773#
774# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
775config ARCH_WANTS_PROT_NUMA_PROT_NONE
776 bool
777
778config ARCH_USES_NUMA_PROT_NONE
779 bool
780 default y
781 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
782 depends on NUMA_BALANCING
783
Mel Gorman1a687c22012-11-22 11:16:36 +0000784config NUMA_BALANCING_DEFAULT_ENABLED
785 bool "Automatically enable NUMA aware memory/task placement"
786 default y
787 depends on NUMA_BALANCING
788 help
789 If set, autonumic NUMA balancing will be enabled if running on a NUMA
790 machine.
791
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200792config NUMA_BALANCING
793 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200794 depends on ARCH_SUPPORTS_NUMA_BALANCING
795 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
796 depends on SMP && NUMA && MIGRATION
797 help
798 This option adds support for automatic NUMA aware memory/task placement.
799 The mechanism is quite primitive and is based on migrating memory when
800 it is references to the node the task is running on.
801
802 This system will be inactive on UMA systems.
803
Li Zefan23964d22009-01-15 13:50:58 -0800804menuconfig CGROUPS
805 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800806 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700807 help
Li Zefan23964d22009-01-15 13:50:58 -0800808 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800809 use with process control subsystems such as Cpusets, CFS, memory
810 controls or device isolation.
811 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800812 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800813 - Documentation/cgroups/ (features for grouping, isolation
814 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700815
816 Say N if unsure.
817
Li Zefan23964d22009-01-15 13:50:58 -0800818if CGROUPS
819
Paul Menage006cb992007-10-18 23:39:43 -0700820config CGROUP_DEBUG
821 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700822 default n
Paul Menage006cb992007-10-18 23:39:43 -0700823 help
824 This option enables a simple cgroup subsystem that
825 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800826 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700827
Li Zefan23964d22009-01-15 13:50:58 -0800828 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700829
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700830config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800831 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800832 help
833 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700834 cgroup.
835
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700836config CGROUP_DEVICE
837 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700838 help
839 Provides a cgroup implementing whitelists for devices which
840 a process in the cgroup can mknod or open.
841
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842config CPUSETS
843 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700845 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 allow dynamically partitioning a system into sets of CPUs and
847 Memory Nodes and assigning tasks to run only within those sets.
848 This is primarily useful on large SMP or NUMA systems.
849
850 Say N if unsure.
851
Li Zefan23964d22009-01-15 13:50:58 -0800852config PROC_PID_CPUSET
853 bool "Include legacy /proc/<pid>/cpuset file"
854 depends on CPUSETS
855 default y
856
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100857config CGROUP_CPUACCT
858 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100859 help
860 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800861 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100862
Pavel Emelianove552b662008-02-07 00:13:49 -0800863config RESOURCE_COUNTERS
864 bool "Resource counters"
865 help
866 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800867 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800868
Andrew Mortonc255a452012-07-31 16:43:02 -0700869config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800870 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700871 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700872 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800873 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700874 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100875 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800876
877 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700878 associated with each page of memory in the system. By this,
879 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
880 usage tracking struct at boot. Total amount of this is printed out
881 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800882
883 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700884 sure you need the memory resource controller. Even when you enable
885 this, you can set "cgroup_disable=memory" at your boot option to
886 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800887 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800888
Balbir Singhcf475ad2008-04-29 01:00:16 -0700889 This config option also selects MM_OWNER config option, which
890 could in turn add some fork/exit overhead.
891
Andrew Mortonc255a452012-07-31 16:43:02 -0700892config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700893 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700894 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800895 help
896 Add swap management feature to memory resource controller. When you
897 enable this, you can limit mem+swap usage per cgroup. In other words,
898 when you disable this, memory resource controller has no cares to
899 usage of swap...a process can exhaust all of the swap. This extension
900 is useful when you want to avoid exhaustion swap but this itself
901 adds more overheads and consumes memory for remembering information.
902 Especially if you use 32bit system or small memory system, please
903 be careful about enabling this. When memory resource controller
904 is disabled by boot option, this will be automatically disabled and
905 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700906 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700907 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
908 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700909config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800910 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700911 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800912 default y
913 help
914 Memory Resource Controller Swap Extension comes with its price in
915 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700916 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800917 and let the user enable it by swapaccount boot command line
918 parameter should have this option unselected.
919 For those who want to have the feature enabled by default should
920 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700921 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700922config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700923 bool "Memory Resource Controller Kernel Memory accounting"
924 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800925 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000926 help
927 The Kernel Memory extension for Memory Resource Controller can limit
928 the amount of memory used by kernel objects in the system. Those are
929 fundamentally different from the entities handled by the standard
930 Memory Controller, which are page-based, and can be swapped. Users of
931 the kmem extension can use it to guarantee that no group of processes
932 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800933
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700934config CGROUP_HUGETLB
935 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700936 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700937 default n
938 help
939 Provides a cgroup Resource Controller for HugeTLB pages.
940 When you enable this, you can put a per cgroup limit on HugeTLB usage.
941 The limit is enforced during page fault. Since HugeTLB doesn't
942 support page reclaim, enforcing the limit at page fault time implies
943 that, the application will get SIGBUS signal if it tries to access
944 HugeTLB pages beyond its limit. This requires the application to know
945 beforehand how much HugeTLB pages it would require for its use. The
946 control group is tracked in the third page lru pointer. This means
947 that we cannot use the controller with huge page less than 3 pages.
948
Stephane Eraniane5d13672011-02-14 11:20:01 +0200949config CGROUP_PERF
950 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
951 depends on PERF_EVENTS && CGROUPS
952 help
953 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800954 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200955 designated cpu.
956
957 Say N if unsure.
958
Dhaval Giani7c941432010-01-20 13:26:18 +0100959menuconfig CGROUP_SCHED
960 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100961 default n
962 help
963 This feature lets CPU scheduler recognize task groups and control CPU
964 bandwidth allocation to such task groups. It uses cgroups to group
965 tasks.
966
967if CGROUP_SCHED
968config FAIR_GROUP_SCHED
969 bool "Group scheduling for SCHED_OTHER"
970 depends on CGROUP_SCHED
971 default CGROUP_SCHED
972
Paul Turnerab84d312011-07-21 09:43:28 -0700973config CFS_BANDWIDTH
974 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -0700975 depends on FAIR_GROUP_SCHED
976 default n
977 help
978 This option allows users to define CPU bandwidth rates (limits) for
979 tasks running within the fair group scheduler. Groups with no limit
980 set are considered to be unconstrained and will run with no
981 restriction.
982 See tip/Documentation/scheduler/sched-bwc.txt for more information.
983
Dhaval Giani7c941432010-01-20 13:26:18 +0100984config RT_GROUP_SCHED
985 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +0100986 depends on CGROUP_SCHED
987 default n
988 help
989 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800990 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100991 schedule realtime tasks for non-root users until you allocate
992 realtime bandwidth for them.
993 See Documentation/scheduler/sched-rt-group.txt for more information.
994
995endif #CGROUP_SCHED
996
Vivek Goyalafc24d42010-04-26 19:27:56 +0200997config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800998 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700999 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +02001000 default n
1001 ---help---
1002 Generic block IO controller cgroup interface. This is the common
1003 cgroup interface which should be used by various IO controlling
1004 policies.
1005
1006 Currently, CFQ IO scheduler uses it to recognize task groups and
1007 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -04001008 to such task groups. It is also used by bio throttling logic in
1009 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001010
1011 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -04001012 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +00001013 enabling proportional weight division of disk bandwidth in CFQ, set
1014 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +00001015 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001016
1017 See Documentation/cgroups/blkio-controller.txt for more information.
1018
1019config DEBUG_BLK_CGROUP
1020 bool "Enable Block IO controller debugging"
1021 depends on BLK_CGROUP
1022 default n
1023 ---help---
1024 Enable some debugging help. Currently it exports additional stat
1025 files in a cgroup which can be useful for debugging.
1026
Li Zefan23964d22009-01-15 13:50:58 -08001027endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001028
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001029config CHECKPOINT_RESTORE
1030 bool "Checkpoint/restore support" if EXPERT
1031 default n
1032 help
1033 Enables additional kernel features in a sake of checkpoint/restore.
1034 In particular it adds auxiliary prctl codes to setup process text,
1035 data and heap segment sizes, and a few additional /proc filesystem
1036 entries.
1037
1038 If unsure, say N here.
1039
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001040menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001041 bool "Namespaces support" if EXPERT
1042 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001043 help
1044 Provides the way to make tasks work with different objects using
1045 the same id. For example same IPC id may refer to different objects
1046 or same user id or pid may refer to different tasks when used in
1047 different namespaces.
1048
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001049if NAMESPACES
1050
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001051config UTS_NS
1052 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001053 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001054 help
1055 In this namespace tasks see different info provided with the
1056 uname() system call
1057
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001058config IPC_NS
1059 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001060 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001061 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001062 help
1063 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001064 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001065
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001066config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001067 bool "User namespace"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001068 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001069 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001070
Eric W. Biederman5673a942011-11-17 10:23:55 -08001071 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001072 help
1073 This allows containers, i.e. vservers, to use user namespaces
1074 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001075
1076 When user namespaces are enabled in the kernel it is
1077 recommended that the MEMCG and MEMCG_KMEM options also be
1078 enabled and that user-space use the memory control groups to
1079 limit the amount of memory a memory unprivileged users can
1080 use.
1081
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001082 If unsure, say N.
1083
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001084config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001085 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001086 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001087 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001088 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001089 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001090 pid namespaces. This is a building block of containers.
1091
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001092config NET_NS
1093 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001094 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001095 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001096 help
1097 Allow user space to create what appear to be multiple instances
1098 of the network stack.
1099
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001100endif # NAMESPACES
1101
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001102config UIDGID_CONVERTED
1103 # True if all of the selected software conmponents are known
1104 # to have uid_t and gid_t converted to kuid_t and kgid_t
1105 # where appropriate and are otherwise safe to use with
1106 # the user namespace.
1107 bool
1108 default y
1109
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001110 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001111 depends on XFS_FS = n
1112
Eric W. Biederman5673a942011-11-17 10:23:55 -08001113config UIDGID_STRICT_TYPE_CHECKS
1114 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001115 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001116 default n
1117 help
1118 While the nececessary conversions are being added to all subsystems this option allows
1119 the code to continue to build for unconverted subsystems.
1120
1121 Say Y here if you want the strict type checking enabled
1122
Mike Galbraith5091faa2010-11-30 14:18:03 +01001123config SCHED_AUTOGROUP
1124 bool "Automatic process group scheduling"
1125 select EVENTFD
1126 select CGROUPS
1127 select CGROUP_SCHED
1128 select FAIR_GROUP_SCHED
1129 help
1130 This option optimizes the scheduler for common desktop workloads by
1131 automatically creating and populating task groups. This separation
1132 of workloads isolates aggressive CPU burners (like build jobs) from
1133 desktop applications. Task group autogeneration is currently based
1134 upon task session.
1135
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001136config MM_OWNER
1137 bool
1138
1139config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001140 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001141 depends on SYSFS
1142 default n
1143 help
1144 This option adds code that switches the layout of the "block" class
1145 devices, to not show up in /sys/class/block/, but only in
1146 /sys/block/.
1147
1148 This switch is only active when the sysfs.deprecated=1 boot option is
1149 passed or the SYSFS_DEPRECATED_V2 option is set.
1150
1151 This option allows new kernels to run on old distributions and tools,
1152 which might get confused by /sys/class/block/. Since 2007/2008 all
1153 major distributions and tools handle this just fine.
1154
1155 Recent distributions and userspace tools after 2009/2010 depend on
1156 the existence of /sys/class/block/, and will not work with this
1157 option enabled.
1158
1159 Only if you are using a new kernel on an old distribution, you might
1160 need to say Y here.
1161
1162config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001163 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001164 default n
1165 depends on SYSFS
1166 depends on SYSFS_DEPRECATED
1167 help
1168 Enable deprecated sysfs by default.
1169
1170 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1171 option.
1172
1173 Only if you are using a new kernel on an old distribution, you might
1174 need to say Y here. Even then, odds are you would not need it
1175 enabled, you can always pass the boot option if absolutely necessary.
1176
1177config RELAY
1178 bool "Kernel->user space relay support (formerly relayfs)"
1179 help
1180 This option enables support for relay interface support in
1181 certain file systems (such as debugfs).
1182 It is designed to provide an efficient mechanism for tools and
1183 facilities to relay large amounts of data from kernel space to
1184 user space.
1185
1186 If unsure, say N.
1187
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001188config BLK_DEV_INITRD
1189 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1190 depends on BROKEN || !FRV
1191 help
1192 The initial RAM filesystem is a ramfs which is loaded by the
1193 boot loader (loadlin or lilo) and that is mounted as root
1194 before the normal boot procedure. It is typically used to
1195 load modules needed to mount the "real" root file system,
1196 etc. See <file:Documentation/initrd.txt> for details.
1197
1198 If RAM disk support (BLK_DEV_RAM) is also included, this
1199 also enables initial RAM disk (initrd) support and adds
1200 15 Kbytes (more on some other architectures) to the kernel size.
1201
1202 If unsure say Y.
1203
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001204if BLK_DEV_INITRD
1205
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001206source "usr/Kconfig"
1207
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001208endif
1209
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001210config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001211 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001212 help
1213 Enabling this option will pass "-Os" instead of "-O2" to gcc
1214 resulting in a smaller kernel.
1215
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001216 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001217
Randy Dunlap08470622006-09-30 23:28:13 -07001218config SYSCTL
1219 bool
1220
Randy Dunlapb943c462009-03-10 12:55:46 -07001221config ANON_INODES
1222 bool
1223
David Rientjes6a108a12011-01-20 14:44:16 -08001224menuconfig EXPERT
1225 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001226 # Unhide debug options, to make the on-by-default options visible
1227 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228 help
1229 This option allows certain base kernel options and settings
1230 to be disabled or tweaked. This is for specialized
1231 environments which can tolerate a "non-standard" kernel.
1232 Only use this if you really know what you are doing.
1233
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001234config HAVE_UID16
1235 bool
1236
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001237config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001238 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001239 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001240 default y
1241 help
1242 This enables the legacy 16-bit UID syscall wrappers.
1243
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001244config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001245 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001246 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001247 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001248 select SYSCTL
1249 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001250 sys_sysctl uses binary paths that have been found challenging
1251 to properly maintain and use. The interface in /proc/sys
1252 using paths with ascii names is now the primary path to this
1253 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001254
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001255 Almost nothing using the binary sysctl interface so if you are
1256 trying to save some space it is probably safe to disable this,
1257 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001258
WANG Congc736de62011-11-02 13:39:25 -07001259 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001260
Catalin Marinas7ac57a82012-10-08 16:28:16 -07001261config SYSCTL_EXCEPTION_TRACE
1262 bool
1263 help
1264 Enable support for /proc/sys/debug/exception-trace.
1265
Vineet Guptab6fca722013-01-09 20:06:28 +05301266config SYSCTL_ARCH_UNALIGN_NO_WARN
1267 bool
1268 help
1269 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1270 Allows arch to define/use @no_unaligned_warning to possibly warn
1271 about unaligned access emulation going on under the hood.
1272
Vineet Guptabf14e3b2013-01-18 15:12:24 +05301273config SYSCTL_ARCH_UNALIGN_ALLOW
1274 bool
1275 help
1276 Enable support for /proc/sys/kernel/unaligned-trap
1277 Allows arches to define/use @unaligned_enabled to runtime toggle
1278 the unaligned access emulation.
1279 see arch/parisc/kernel/unaligned.c for reference
1280
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001282 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 default y
1284 help
1285 Say Y here to let the kernel print out symbolic crash information and
1286 symbolic stack backtraces. This increases the size of the kernel
1287 somewhat, as all symbols have to be loaded into the kernel image.
1288
1289config KALLSYMS_ALL
1290 bool "Include all symbols in kallsyms"
1291 depends on DEBUG_KERNEL && KALLSYMS
1292 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001293 Normally kallsyms only contains the symbols of functions for nicer
1294 OOPS messages and backtraces (i.e., symbols from the text and inittext
1295 sections). This is sufficient for most cases. And only in very rare
1296 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1297 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001299 This option makes sure that all symbols are loaded into the kernel
1300 image (i.e., symbols from all sections) in cost of increased kernel
1301 size (depending on the kernel configuration, it may be 300KiB or
1302 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001304 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001305
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001306config HOTPLUG
Greg Kroah-Hartman45f035a2012-09-04 17:01:08 -07001307 def_bool y
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001308
Matt Mackalld59745c2005-05-01 08:59:02 -07001309config PRINTK
1310 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001311 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001312 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001313 help
1314 This option enables normal printk support. Removing it
1315 eliminates most of the message strings from the kernel image
1316 and makes the kernel more or less silent. As this makes it
1317 very difficult to diagnose system problems, saying N here is
1318 strongly discouraged.
1319
Matt Mackallc8538a72005-05-01 08:59:01 -07001320config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001321 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001322 default y
1323 help
1324 Disabling this option eliminates support for BUG and WARN, reducing
1325 the size of your kernel image and potentially quietly ignoring
1326 numerous fatal conditions. You should only consider disabling this
1327 option for embedded systems with no facilities for reporting errors.
1328 Just say Y.
1329
Matt Mackall708e9a72006-01-08 01:05:25 -08001330config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001331 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001332 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001333 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001334 help
1335 Enable support for generating core dumps. Disabling saves about 4k.
1336
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001337
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001338config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001339 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001340 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001341 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001342 default y
1343 help
1344 This option allows to disable the internal PC-Speaker
1345 support, saving some memory.
1346
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001347config HAVE_PCSPKR_PLATFORM
1348 bool
1349
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350config BASE_FULL
1351 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001352 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353 help
1354 Disabling this option reduces the size of miscellaneous core
1355 kernel data structures. This saves memory on small machines,
1356 but may reduce performance.
1357
1358config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001359 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001361 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 help
1363 Disabling this option will cause the kernel to be built without
1364 support for "fast userspace mutexes". The resulting kernel may not
1365 run glibc-based applications correctly.
1366
1367config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001368 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001370 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371 help
1372 Disabling this option will cause the kernel to be built without
1373 support for epoll family of system calls.
1374
Davide Libenzifba2afa2007-05-10 22:23:13 -07001375config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001376 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001377 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001378 default y
1379 help
1380 Enable the signalfd() system call that allows to receive signals
1381 on a file descriptor.
1382
1383 If unsure, say Y.
1384
Davide Libenzib215e282007-05-10 22:23:16 -07001385config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001386 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001387 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001388 default y
1389 help
1390 Enable the timerfd() system call that allows to receive timer
1391 events on a file descriptor.
1392
1393 If unsure, say Y.
1394
Davide Libenzie1ad7462007-05-10 22:23:19 -07001395config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001396 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001397 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001398 default y
1399 help
1400 Enable the eventfd() system call that allows to receive both
1401 kernel notification (ie. KAIO) or userspace notifications.
1402
1403 If unsure, say Y.
1404
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001406 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 default y
1408 depends on MMU
1409 help
1410 The shmem is an internal filesystem used to manage shared memory.
1411 It is backed by swap and manages resource limits. It is also exported
1412 to userspace as tmpfs if TMPFS is enabled. Disabling this
1413 option replaces shmem and tmpfs with the much simpler ramfs code,
1414 which may be appropriate on small systems without swap.
1415
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001416config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001417 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001418 default y
1419 help
1420 This option enables POSIX asynchronous I/O which may by used
1421 by some high performance threaded applications. Disabling
1422 this option saves about 7k.
1423
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001424config EMBEDDED
1425 bool "Embedded system"
1426 select EXPERT
1427 help
1428 This option should be enabled if compiling the kernel for
1429 an embedded system so certain expert options are available
1430 for configuration.
1431
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001432config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001433 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001434 help
1435 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001436
Peter Zijlstra906010b2009-09-21 16:08:49 +02001437config PERF_USE_VMALLOC
1438 bool
1439 help
1440 See tools/perf/design.txt for details
1441
Ingo Molnar57c0c152009-09-21 12:20:38 +02001442menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001443
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001444config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001445 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001446 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001447 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001448 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001449 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001450 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001451 Enable kernel support for various performance events provided
1452 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001453
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001454 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001455 use of generic tracepoints.
1456
1457 Most modern CPUs support performance events via performance
1458 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001459 types of hw events: such as instructions executed, cachemisses
1460 suffered, or branches mis-predicted - without slowing down the
1461 kernel or applications. These registers can also trigger interrupts
1462 when a threshold number of events have passed - and can thus be
1463 used to profile the code that runs on that CPU.
1464
Ingo Molnar57c0c152009-09-21 12:20:38 +02001465 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001466 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001467 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001468 provides per task and per CPU counters, and it provides event
1469 capabilities on top of those.
1470
1471 Say Y if unsure.
1472
Peter Zijlstra906010b2009-09-21 16:08:49 +02001473config DEBUG_PERF_USE_VMALLOC
1474 default n
1475 bool "Debug: use vmalloc to back perf mmap() buffers"
1476 depends on PERF_EVENTS && DEBUG_KERNEL
1477 select PERF_USE_VMALLOC
1478 help
1479 Use vmalloc memory to back perf mmap() buffers.
1480
1481 Mostly useful for debugging the vmalloc code on platforms
1482 that don't require it.
1483
1484 Say N if unsure.
1485
Thomas Gleixner0793a612008-12-04 20:12:29 +01001486endmenu
1487
Christoph Lameterf8891e52006-06-30 01:55:45 -07001488config VM_EVENT_COUNTERS
1489 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001490 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001491 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001492 VM event counters are needed for event counts to be shown.
1493 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001494 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001495 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001496
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001497config PCI_QUIRKS
1498 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001499 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001500 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001501 help
1502 This enables workarounds for various PCI chipset
1503 bugs/quirks. Disable this only if your target machine is
1504 unaffected by PCI quirks.
1505
Christoph Lameter41ecc552007-05-09 02:32:44 -07001506config SLUB_DEBUG
1507 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001508 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001509 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001510 help
1511 SLUB has extensive debug support features. Disabling these can
1512 result in significant savings in code size. This also disables
1513 SLUB sysfs support. /sys/slab will not exist and there will be
1514 no support for cache validation etc.
1515
Randy Dunlapb943c462009-03-10 12:55:46 -07001516config COMPAT_BRK
1517 bool "Disable heap randomization"
1518 default y
1519 help
1520 Randomizing heap placement makes heap exploits harder, but it
1521 also breaks ancient binaries (including anything libc5 based).
1522 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001523 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001524 /proc/sys/kernel/randomize_va_space to 2.
1525
1526 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1527
Christoph Lameter81819f02007-05-06 14:49:36 -07001528choice
1529 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001530 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001531 help
1532 This option allows to select a slab allocator.
1533
1534config SLAB
1535 bool "SLAB"
1536 help
1537 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001538 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001539 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001540
1541config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001542 bool "SLUB (Unqueued Allocator)"
1543 help
1544 SLUB is a slab allocator that minimizes cache line usage
1545 instead of managing queues of cached objects (SLAB approach).
1546 Per cpu caching is realized using slabs of objects instead
1547 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001548 and has enhanced diagnostics. SLUB is the default choice for
1549 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001550
1551config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001552 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001553 bool "SLOB (Simple Allocator)"
1554 help
Matt Mackall37291452008-02-04 22:29:38 -08001555 SLOB replaces the stock allocator with a drastically simpler
1556 allocator. SLOB is generally more space efficient but
1557 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001558
1559endchoice
1560
Jie Zhangea637632009-12-14 18:00:02 -08001561config MMAP_ALLOW_UNINITIALIZED
1562 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001563 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001564 default n
1565 help
1566 Normally, and according to the Linux spec, anonymous memory obtained
1567 from mmap() has it's contents cleared before it is passed to
1568 userspace. Enabling this config option allows you to request that
1569 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1570 providing a huge performance boost. If this option is not enabled,
1571 then the flag will be ignored.
1572
1573 This is taken advantage of by uClibc's malloc(), and also by
1574 ELF-FDPIC binfmt's brk and stack allocator.
1575
1576 Because of the obvious security issues, this option should only be
1577 enabled on embedded devices where you control what is run in
1578 userspace. Since that isn't generally a problem on no-MMU systems,
1579 it is normally safe to say Y here.
1580
1581 See Documentation/nommu-mmap.txt for more information.
1582
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001583config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001584 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001585 help
1586 Say Y here to enable the extended profiling support mechanisms used
1587 by profilers such as OProfile.
1588
Ingo Molnar5f87f112008-07-23 14:15:22 +02001589#
1590# Place an empty function call at each tracepoint site. Can be
1591# dynamically changed for a probe function.
1592#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001593config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001594 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001595
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001596source "arch/Kconfig"
1597
Linus Torvalds1da177e2005-04-16 15:20:36 -07001598endmenu # General setup
1599
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001600config HAVE_GENERIC_DMA_COHERENT
1601 bool
1602 default n
1603
Linus Torvalds158a9622008-01-02 13:04:48 -08001604config SLABINFO
1605 bool
1606 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001607 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001608 default y
1609
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001610config RT_MUTEXES
1611 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001612
Linus Torvalds1da177e2005-04-16 15:20:36 -07001613config BASE_SMALL
1614 int
1615 default 0 if BASE_FULL
1616 default 1 if !BASE_FULL
1617
Jan Engelhardt66da5732007-07-15 23:39:29 -07001618menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001619 bool "Enable loadable module support"
1620 help
1621 Kernel modules are small pieces of compiled code which can
1622 be inserted in the running kernel, rather than being
1623 permanently built into the kernel. You use the "modprobe"
1624 tool to add (and sometimes remove) them. If you say Y here,
1625 many parts of the kernel can be built as modules (by
1626 answering M instead of Y where indicated): this is most
1627 useful for infrequently used options which are not required
1628 for booting. For more information, see the man pages for
1629 modprobe, lsmod, modinfo, insmod and rmmod.
1630
1631 If you say Y here, you will need to run "make
1632 modules_install" to put the modules under /lib/modules/
1633 where modprobe can find them (you may need to be root to do
1634 this).
1635
1636 If unsure, say Y.
1637
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001638if MODULES
1639
Linus Torvalds826e4502008-05-04 17:04:16 -07001640config MODULE_FORCE_LOAD
1641 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001642 default n
1643 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001644 Allow loading of modules without version information (ie. modprobe
1645 --force). Forced module loading sets the 'F' (forced) taint flag and
1646 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001647
Linus Torvalds1da177e2005-04-16 15:20:36 -07001648config MODULE_UNLOAD
1649 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001650 help
1651 Without this option you will not be able to unload any
1652 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001653 anyway), which makes your kernel smaller, faster
1654 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001655
1656config MODULE_FORCE_UNLOAD
1657 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001658 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001659 help
1660 This option allows you to force a module to unload, even if the
1661 kernel believes it is unsafe: the kernel will remove the module
1662 without waiting for anyone to stop using it (using the -f option to
1663 rmmod). This is mainly for kernel developers and desperate users.
1664 If unsure, say N.
1665
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001667 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001668 help
1669 Usually, you have to use modules compiled with your kernel.
1670 Saying Y here makes it sometimes possible to use modules
1671 compiled for different kernels, by adding enough information
1672 to the modules to (hopefully) spot any changes which would
1673 make them incompatible with the kernel you are running. If
1674 unsure, say N.
1675
1676config MODULE_SRCVERSION_ALL
1677 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001678 help
1679 Modules which contain a MODULE_VERSION get an extra "srcversion"
1680 field inserted into their modinfo section, which contains a
1681 sum of the source files which made it. This helps maintainers
1682 see exactly which source was used to build a module (since
1683 others sometimes change the module source without updating
1684 the version). With this option, such a "srcversion" field
1685 will be created for all modules. If unsure, say N.
1686
Rusty Russell106a4ee2012-09-26 10:09:40 +01001687config MODULE_SIG
1688 bool "Module signature verification"
1689 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001690 select KEYS
1691 select CRYPTO
1692 select ASYMMETRIC_KEY_TYPE
1693 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1694 select PUBLIC_KEY_ALGO_RSA
1695 select ASN1
1696 select OID_REGISTRY
1697 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001698 help
1699 Check modules for valid signatures upon load: the signature
1700 is simply appended to the module. For more information see
1701 Documentation/module-signing.txt.
1702
David Howellsea0b6dc2012-09-26 10:09:50 +01001703 !!!WARNING!!! If you enable this option, you MUST make sure that the
1704 module DOES NOT get stripped after being signed. This includes the
1705 debuginfo strip done by some packagers (such as rpmbuild) and
1706 inclusion into an initramfs that wants the module size reduced.
1707
Rusty Russell106a4ee2012-09-26 10:09:40 +01001708config MODULE_SIG_FORCE
1709 bool "Require modules to be validly signed"
1710 depends on MODULE_SIG
1711 help
1712 Reject unsigned modules or signed modules for which we don't have a
1713 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001714
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301715config MODULE_SIG_ALL
1716 bool "Automatically sign all modules"
1717 default y
1718 depends on MODULE_SIG
1719 help
1720 Sign all modules during make modules_install. Without this option,
1721 modules must be signed manually, using the scripts/sign-file tool.
1722
1723comment "Do not forget to sign required modules with scripts/sign-file"
1724 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1725
David Howellsea0b6dc2012-09-26 10:09:50 +01001726choice
1727 prompt "Which hash algorithm should modules be signed with?"
1728 depends on MODULE_SIG
1729 help
1730 This determines which sort of hashing algorithm will be used during
1731 signature generation. This algorithm _must_ be built into the kernel
1732 directly so that signature verification can take place. It is not
1733 possible to load a signed module containing the algorithm to check
1734 the signature on that module.
1735
1736config MODULE_SIG_SHA1
1737 bool "Sign modules with SHA-1"
1738 select CRYPTO_SHA1
1739
1740config MODULE_SIG_SHA224
1741 bool "Sign modules with SHA-224"
1742 select CRYPTO_SHA256
1743
1744config MODULE_SIG_SHA256
1745 bool "Sign modules with SHA-256"
1746 select CRYPTO_SHA256
1747
1748config MODULE_SIG_SHA384
1749 bool "Sign modules with SHA-384"
1750 select CRYPTO_SHA512
1751
1752config MODULE_SIG_SHA512
1753 bool "Sign modules with SHA-512"
1754 select CRYPTO_SHA512
1755
1756endchoice
1757
Michal Marek22753672013-01-25 13:41:00 +10301758config MODULE_SIG_HASH
1759 string
1760 depends on MODULE_SIG
1761 default "sha1" if MODULE_SIG_SHA1
1762 default "sha224" if MODULE_SIG_SHA224
1763 default "sha256" if MODULE_SIG_SHA256
1764 default "sha384" if MODULE_SIG_SHA384
1765 default "sha512" if MODULE_SIG_SHA512
1766
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001767endif # MODULES
1768
Rusty Russell98a79d62008-12-13 21:19:41 +10301769config INIT_ALL_POSSIBLE
1770 bool
1771 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301772 Back when each arch used to define their own cpu_online_mask and
1773 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301774 with all 1s, and others with all 0s. When they were centralised,
1775 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001776 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301777
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778config STOP_MACHINE
1779 bool
1780 default y
1781 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1782 help
1783 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001784
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001785source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001786
1787config PREEMPT_NOTIFIERS
1788 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001789
Steffen Klassert16295be2010-01-06 19:47:10 +11001790config PADATA
1791 depends on SMP
1792 bool
1793
Andi Kleen754b7b62012-10-04 17:11:27 -07001794# Can be selected by architectures with broken toolchains
1795# that get confused by correct const<->read_only section
1796# mappings
1797config BROKEN_RODATA
1798 bool
1799
David Howells4520c6a2012-09-21 23:31:13 +01001800config ASN1
1801 tristate
1802 help
1803 Build a simple ASN.1 grammar compiler that produces a bytecode output
1804 that can be interpreted by the ASN.1 stream decoder and used to
1805 inform it as to what tags are to be expected in a stream and what
1806 functions to call on what tags.
1807
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001808source "kernel/Kconfig.locks"