blob: ea1be003275aba5b49f5a234875d8dc16f56f5c3 [file] [log] [blame]
Roman Zippel80daa5602008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f72009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
Peter Oberparleiterb99b87f72009-06-17 16:28:03 -070022
Peter Zijlstrae360adb2010-10-14 14:01:34 +080023config IRQ_WORK
24 bool
Peter Zijlstrae360adb2010-10-14 14:01:34 +080025
David Daney1dbdc6f2012-04-19 14:59:57 -070026config BUILDTIME_EXTABLE_SORT
27 bool
28
Al Boldiff0cfc62007-07-31 00:39:23 -070029menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Linus Torvalds1da177e2005-04-16 15:20:36 -070031config BROKEN
32 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34config BROKEN_ON_SMP
35 bool
36 depends on BROKEN || !SMP
37 default y
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039config INIT_ENV_ARG_LIMIT
40 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070041 default 32 if !UML
42 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 help
Randy Dunlap34ad92c22005-10-30 15:01:46 -080044 Maximum of each of the number of arguments and environment
45 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Roland McGrath84336462009-12-21 16:24:06 -080048config CROSS_COMPILE
49 string "Cross-compiler tool prefix"
50 help
51 Same as running 'make CROSS_COMPILE=prefix-' but stored for
52 default make runs in this kernel build directory. You don't
53 need to set this unless you want the configured kernel build
54 directory to select the cross-compiler automatically.
55
Jiri Slaby4bb16672013-05-22 10:56:24 +020056config COMPILE_TEST
57 bool "Compile also drivers which will not load"
58 default n
59 help
60 Some drivers can be compiled on a different platform than they are
61 intended to be run on. Despite they cannot be loaded there (or even
62 when they load they cannot be used due to missing HW support),
63 developers still, opposing to distributors, might want to build such
64 drivers to compile-test them.
65
66 If you are a developer and want to build everything available, say Y
67 here. If you are a user/distributor, say N here to exclude useless
68 drivers to be distributed.
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070config LOCALVERSION
71 string "Local version - append to kernel release"
72 help
73 Append an extra string to the end of your kernel version.
74 This will show up when you type uname, for example.
75 The string you set here will be appended after the contents of
76 any files with a filename matching localversion* in your
77 object and source tree, in that order. Your total string can
78 be a maximum of 64 characters.
79
Ryan Andersonaaebf432005-07-31 04:57:49 -040080config LOCALVERSION_AUTO
81 bool "Automatically append version information to the version string"
82 default y
83 help
84 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020085 release tree by looking for git tags that belong to the current
86 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040087
88 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020089 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040090 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020091 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -040092
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020093 (The actual string used here is the first eight characters produced
94 by running the command:
95
96 $ git rev-parse --verify HEAD
97
98 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -040099
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800100config HAVE_KERNEL_GZIP
101 bool
102
103config HAVE_KERNEL_BZIP2
104 bool
105
106config HAVE_KERNEL_LZMA
107 bool
108
Lasse Collin3ebe1242011-01-12 17:01:23 -0800109config HAVE_KERNEL_XZ
110 bool
111
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800112config HAVE_KERNEL_LZO
113 bool
114
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. Dayb0e376502007-05-09 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 Deacon8f827a142012-07-06 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
Mike Travisc903ff82009-01-15 12:28:29 -0800476endchoice
477
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700478config PREEMPT_RCU
Paul E. McKenney127781d2013-03-27 08:44:00 -0700479 def_bool TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700480 help
481 This option enables preemptible-RCU code that is common between
482 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
483
Paul E. McKenney6bfc09e2012-10-19 12:49:17 -0700484config RCU_STALL_COMMON
485 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
486 help
487 This option enables RCU CPU stall code that is common between
488 the TINY and TREE variants of RCU. The purpose is to allow
489 the tiny variants to disable RCU CPU stall warnings, while
490 making these warnings mandatory for the tree variants.
491
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100492config CONTEXT_TRACKING
493 bool
494
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200495config RCU_USER_QS
496 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100497 depends on HAVE_CONTEXT_TRACKING && SMP
498 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200499 help
500 This option sets hooks on kernel / userspace boundaries and
501 puts RCU in extended quiescent state when the CPU runs in
502 userspace. It means that when a CPU runs in userspace, it is
503 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700504 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200505
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200506 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100507 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700508 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200509
510 If unsure say N
511
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100512config CONTEXT_TRACKING_FORCE
513 bool "Force context tracking"
514 depends on CONTEXT_TRACKING
Frederic Weisbecker8b438762013-02-26 15:37:59 +0100515 default CONTEXT_TRACKING
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200516 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100517 Probe on user/kernel boundaries by default in order to
518 test the features that rely on it such as userspace RCU extended
519 quiescent states.
520 This test is there for debugging until we have a real user like the
521 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200522
Mike Travisc903ff82009-01-15 12:28:29 -0800523config RCU_FANOUT
524 int "Tree-based hierarchical RCU fanout value"
525 range 2 64 if 64BIT
526 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700527 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800528 default 64 if 64BIT
529 default 32 if !64BIT
530 help
531 This option controls the fanout of hierarchical implementations
532 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700533 large numbers of CPUs. This value must be at least the fourth
534 root of NR_CPUS, which allows NR_CPUS to be insanely large.
535 The default value of RCU_FANOUT should be used for production
536 systems, but if you are stress-testing the RCU implementation
537 itself, small RCU_FANOUT values allow you to test large-system
538 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800539
540 Select a specific number if testing RCU itself.
541 Take the default if unsure.
542
Paul E. McKenney8932a632012-04-19 12:20:14 -0700543config RCU_FANOUT_LEAF
544 int "Tree-based hierarchical RCU leaf-level fanout value"
545 range 2 RCU_FANOUT if 64BIT
546 range 2 RCU_FANOUT if !64BIT
547 depends on TREE_RCU || TREE_PREEMPT_RCU
548 default 16
549 help
550 This option controls the leaf-level fanout of hierarchical
551 implementations of RCU, and allows trading off cache misses
552 against lock contention. Systems that synchronize their
553 scheduling-clock interrupts for energy-efficiency reasons will
554 want the default because the smaller leaf-level fanout keeps
555 lock contention levels acceptably low. Very large systems
556 (hundreds or thousands of CPUs) will instead want to set this
557 value to the maximum value possible in order to reduce the
558 number of cache misses incurred during RCU's grace-period
559 initialization. These systems tend to run CPU-bound, and thus
560 are not helped by synchronized interrupts, and thus tend to
561 skew them, which reduces lock contention enough that large
562 leaf-level fanouts work well.
563
564 Select a specific number if testing RCU itself.
565
566 Select the maximum permissible value for large systems.
567
568 Take the default if unsure.
569
Mike Travisc903ff82009-01-15 12:28:29 -0800570config RCU_FANOUT_EXACT
571 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700572 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800573 default n
574 help
575 This option forces use of the exact RCU_FANOUT value specified,
576 regardless of imbalances in the hierarchy. This is useful for
577 testing RCU itself, and might one day be useful on systems with
578 strong NUMA behavior.
579
580 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
581
582 Say N if unsure.
583
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800584config RCU_FAST_NO_HZ
585 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Frederic Weisbecker3451d022011-08-10 23:21:01 +0200586 depends on NO_HZ_COMMON && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800587 default n
588 help
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800589 This option permits CPUs to enter dynticks-idle state even if
590 they have RCU callbacks queued, and prevents RCU from waking
591 these CPUs up more than roughly once every four jiffies (by
592 default, you can adjust this using the rcutree.rcu_idle_gp_delay
593 parameter), thus improving energy efficiency. On the other
594 hand, this option increases the duration of RCU grace periods,
595 for example, slowing down synchronize_rcu().
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800596
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800597 Say Y if energy efficiency is critically important, and you
598 don't care about increased grace-period durations.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800599
600 Say N if you are unsure.
601
Mike Travisc903ff82009-01-15 12:28:29 -0800602config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700603 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800604 select DEBUG_FS
605 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700606 This option provides tracing for the TREE_RCU and
607 TREE_PREEMPT_RCU implementations, permitting Makefile to
608 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800609
Paul E. McKenney24278d12010-09-27 17:25:23 -0700610config RCU_BOOST
611 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800612 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700613 default n
614 help
615 This option boosts the priority of preempted RCU readers that
616 block the current preemptible RCU grace period for too long.
617 This option also prevents heavy loads from blocking RCU
618 callback invocation for all flavors of RCU.
619
620 Say Y here if you are working with real-time apps or heavy loads
621 Say N here if you are unsure.
622
623config RCU_BOOST_PRIO
624 int "Real-time priority to boost RCU readers to"
625 range 1 99
626 depends on RCU_BOOST
627 default 1
628 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700629 This option specifies the real-time priority to which long-term
630 preempted RCU readers are to be boosted. If you are working
631 with a real-time application that has one or more CPU-bound
632 threads running at a real-time priority level, you should set
633 RCU_BOOST_PRIO to a priority higher then the highest-priority
634 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
635 of 1 is appropriate in the common case, which is real-time
636 applications that do not have any CPU-bound threads.
637
638 Some real-time applications might not have a single real-time
639 thread that saturates a given CPU, but instead might have
640 multiple real-time threads that, taken together, fully utilize
641 that CPU. In this case, you should set RCU_BOOST_PRIO to
642 a priority higher than the lowest-priority thread that is
643 conspiring to prevent the CPU from running any non-real-time
644 tasks. For example, if one thread at priority 10 and another
645 thread at priority 5 are between themselves fully consuming
646 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
647 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700648
649 Specify the real-time priority, or take the default if unsure.
650
651config RCU_BOOST_DELAY
652 int "Milliseconds to delay boosting after RCU grace-period start"
653 range 0 3000
654 depends on RCU_BOOST
655 default 500
656 help
657 This option specifies the time to wait after the beginning of
658 a given grace period before priority-boosting preempted RCU
659 readers blocking that grace period. Note that any RCU reader
660 blocking an expedited RCU grace period is boosted immediately.
661
662 Accept the default if unsure.
663
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700664config RCU_NOCB_CPU
Paul E. McKenney9a5739d72013-03-28 20:48:36 -0700665 bool "Offload RCU callback processing from boot-selected CPUs"
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700666 depends on TREE_RCU || TREE_PREEMPT_RCU
667 default n
668 help
669 Use this option to reduce OS jitter for aggressive HPC or
670 real-time workloads. It can also be used to offload RCU
671 callback invocation to energy-efficient CPUs in battery-powered
672 asymmetric multiprocessors.
673
674 This option offloads callback invocation from the set of
675 CPUs specified at boot time by the rcu_nocbs parameter.
Paul E. McKenneya4889852012-12-03 08:16:28 -0800676 For each such CPU, a kthread ("rcuox/N") will be created to
677 invoke callbacks, where the "N" is the CPU being offloaded,
678 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
679 "s" for RCU-sched. Nothing prevents this kthread from running
680 on the specified CPUs, but (1) the kthreads may be preempted
681 between each callback, and (2) affinity or cgroups can be used
682 to force the kthreads to run on whatever set of CPUs is desired.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700683
Paul E. McKenney34ed62462013-01-07 13:37:42 -0800684 Say Y here if you want to help to debug reduced OS jitter.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700685 Say N here if you are unsure.
686
Paul E. McKenney911af502013-02-11 10:23:27 -0800687choice
688 prompt "Build-forced no-CBs CPUs"
689 default RCU_NOCB_CPU_NONE
690 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700691 This option allows no-CBs CPUs (whose RCU callbacks are invoked
692 from kthreads rather than from softirq context) to be specified
693 at build time. Additional no-CBs CPUs may be specified by
694 the rcu_nocbs= boot parameter.
Paul E. McKenney911af502013-02-11 10:23:27 -0800695
696config RCU_NOCB_CPU_NONE
697 bool "No build_forced no-CBs CPUs"
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 does not force any of the CPUs to be no-CBs CPUs.
701 Only CPUs designated by the rcu_nocbs= boot parameter will be
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700702 no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU
703 kthreads whose names begin with "rcuo". All other CPUs will
704 invoke their own RCU callbacks in softirq context.
705
706 Select this option if you want to choose no-CBs CPUs at
707 boot time, for example, to allow testing of different no-CBs
708 configurations without having to rebuild the kernel each time.
Paul E. McKenney911af502013-02-11 10:23:27 -0800709
710config RCU_NOCB_CPU_ZERO
711 bool "CPU 0 is a build_forced no-CBs CPU"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200712 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800713 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700714 This option forces CPU 0 to be a no-CBs CPU, so that its RCU
715 callbacks are invoked by a per-CPU kthread whose name begins
716 with "rcuo". Additional CPUs may be designated as no-CBs
717 CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs.
718 All other CPUs will invoke their own RCU callbacks in softirq
719 context.
Paul E. McKenney911af502013-02-11 10:23:27 -0800720
721 Select this if CPU 0 needs to be a no-CBs CPU for real-time
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700722 or energy-efficiency reasons, but the real reason it exists
723 is to ensure that randconfig testing covers mixed systems.
Paul E. McKenney911af502013-02-11 10:23:27 -0800724
725config RCU_NOCB_CPU_ALL
726 bool "All CPUs are build_forced no-CBs CPUs"
727 depends on RCU_NOCB_CPU
728 help
729 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700730 boot parameter will be ignored. All CPUs' RCU callbacks will
731 be executed in the context of per-CPU rcuo kthreads created for
732 this purpose. Assuming that the kthreads whose names start with
733 "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter
734 on the remaining CPUs, but might decrease memory locality during
735 RCU-callback invocation, thus potentially degrading throughput.
Paul E. McKenney911af502013-02-11 10:23:27 -0800736
737 Select this if all CPUs need to be no-CBs CPUs for real-time
738 or energy-efficiency reasons.
739
740endchoice
741
Mike Travisc903ff82009-01-15 12:28:29 -0800742endmenu # "RCU Subsystem"
743
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700745 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 ---help---
747 This option enables the complete Linux kernel ".config" file
748 contents to be saved in the kernel. It provides documentation
749 of which kernel options are used in a running kernel or in an
750 on-disk kernel. This information can be extracted from the kernel
751 image file with the script scripts/extract-ikconfig and used as
752 input to rebuild the current kernel or to build another kernel.
753 It can also be extracted from a running kernel by reading
754 /proc/config.gz if enabled (below).
755
756config IKCONFIG_PROC
757 bool "Enable access to .config through /proc/config.gz"
758 depends on IKCONFIG && PROC_FS
759 ---help---
760 This option enables access to the kernel configuration file
761 through /proc/config.gz.
762
Alistair John Strachan794543a2007-05-08 00:31:15 -0700763config LOG_BUF_SHIFT
764 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
765 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700766 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700767 help
768 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700769 Examples:
770 17 => 128 KB
771 16 => 64 KB
772 15 => 32 KB
773 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700774 13 => 8 KB
775 12 => 4 KB
776
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800777#
778# Architectures with an unreliable sched_clock() should select this:
779#
780config HAVE_UNSTABLE_SCHED_CLOCK
781 bool
782
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700783config GENERIC_SCHED_CLOCK
784 bool
785
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200786#
787# For architectures that want to enable the support for NUMA-affine scheduler
788# balancing logic:
789#
790config ARCH_SUPPORTS_NUMA_BALANCING
791 bool
792
793# For architectures that (ab)use NUMA to represent different memory regions
794# all cpu-local but of different latencies, such as SuperH.
795#
796config ARCH_WANT_NUMA_VARIABLE_LOCALITY
797 bool
798
799#
800# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
801config ARCH_WANTS_PROT_NUMA_PROT_NONE
802 bool
803
804config ARCH_USES_NUMA_PROT_NONE
805 bool
806 default y
807 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
808 depends on NUMA_BALANCING
809
Mel Gorman1a687c22012-11-22 11:16:36 +0000810config NUMA_BALANCING_DEFAULT_ENABLED
811 bool "Automatically enable NUMA aware memory/task placement"
812 default y
813 depends on NUMA_BALANCING
814 help
815 If set, autonumic NUMA balancing will be enabled if running on a NUMA
816 machine.
817
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200818config NUMA_BALANCING
819 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200820 depends on ARCH_SUPPORTS_NUMA_BALANCING
821 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
822 depends on SMP && NUMA && MIGRATION
823 help
824 This option adds support for automatic NUMA aware memory/task placement.
825 The mechanism is quite primitive and is based on migrating memory when
826 it is references to the node the task is running on.
827
828 This system will be inactive on UMA systems.
829
Li Zefan23964d22009-01-15 13:50:58 -0800830menuconfig CGROUPS
831 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800832 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700833 help
Li Zefan23964d22009-01-15 13:50:58 -0800834 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800835 use with process control subsystems such as Cpusets, CFS, memory
836 controls or device isolation.
837 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800838 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800839 - Documentation/cgroups/ (features for grouping, isolation
840 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700841
842 Say N if unsure.
843
Li Zefan23964d22009-01-15 13:50:58 -0800844if CGROUPS
845
Paul Menage006cb992007-10-18 23:39:43 -0700846config CGROUP_DEBUG
847 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700848 default n
Paul Menage006cb992007-10-18 23:39:43 -0700849 help
850 This option enables a simple cgroup subsystem that
851 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800852 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700853
Li Zefan23964d22009-01-15 13:50:58 -0800854 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700855
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700856config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800857 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800858 help
859 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700860 cgroup.
861
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700862config CGROUP_DEVICE
863 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700864 help
865 Provides a cgroup implementing whitelists for devices which
866 a process in the cgroup can mknod or open.
867
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868config CPUSETS
869 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700871 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 allow dynamically partitioning a system into sets of CPUs and
873 Memory Nodes and assigning tasks to run only within those sets.
874 This is primarily useful on large SMP or NUMA systems.
875
876 Say N if unsure.
877
Li Zefan23964d22009-01-15 13:50:58 -0800878config PROC_PID_CPUSET
879 bool "Include legacy /proc/<pid>/cpuset file"
880 depends on CPUSETS
881 default y
882
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100883config CGROUP_CPUACCT
884 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100885 help
886 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800887 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100888
Pavel Emelianove552b662008-02-07 00:13:49 -0800889config RESOURCE_COUNTERS
890 bool "Resource counters"
891 help
892 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800893 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800894
Andrew Mortonc255a452012-07-31 16:43:02 -0700895config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800896 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700897 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700898 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800899 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700900 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100901 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800902
903 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700904 associated with each page of memory in the system. By this,
Sergey Dyaslyf60e2a92013-07-03 15:03:30 -0700905 8(16)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700906 usage tracking struct at boot. Total amount of this is printed out
907 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800908
909 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700910 sure you need the memory resource controller. Even when you enable
911 this, you can set "cgroup_disable=memory" at your boot option to
912 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800913 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800914
Balbir Singhcf475ad2008-04-29 01:00:16 -0700915 This config option also selects MM_OWNER config option, which
916 could in turn add some fork/exit overhead.
917
Andrew Mortonc255a452012-07-31 16:43:02 -0700918config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700919 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700920 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800921 help
922 Add swap management feature to memory resource controller. When you
923 enable this, you can limit mem+swap usage per cgroup. In other words,
924 when you disable this, memory resource controller has no cares to
925 usage of swap...a process can exhaust all of the swap. This extension
926 is useful when you want to avoid exhaustion swap but this itself
927 adds more overheads and consumes memory for remembering information.
928 Especially if you use 32bit system or small memory system, please
929 be careful about enabling this. When memory resource controller
930 is disabled by boot option, this will be automatically disabled and
931 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700932 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700933 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
934 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700935config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800936 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700937 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800938 default y
939 help
940 Memory Resource Controller Swap Extension comes with its price in
941 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700942 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800943 and let the user enable it by swapaccount boot command line
944 parameter should have this option unselected.
945 For those who want to have the feature enabled by default should
946 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700947 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700948config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700949 bool "Memory Resource Controller Kernel Memory accounting"
950 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800951 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000952 help
953 The Kernel Memory extension for Memory Resource Controller can limit
954 the amount of memory used by kernel objects in the system. Those are
955 fundamentally different from the entities handled by the standard
956 Memory Controller, which are page-based, and can be swapped. Users of
957 the kmem extension can use it to guarantee that no group of processes
958 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800959
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700960config CGROUP_HUGETLB
961 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700962 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700963 default n
964 help
965 Provides a cgroup Resource Controller for HugeTLB pages.
966 When you enable this, you can put a per cgroup limit on HugeTLB usage.
967 The limit is enforced during page fault. Since HugeTLB doesn't
968 support page reclaim, enforcing the limit at page fault time implies
969 that, the application will get SIGBUS signal if it tries to access
970 HugeTLB pages beyond its limit. This requires the application to know
971 beforehand how much HugeTLB pages it would require for its use. The
972 control group is tracked in the third page lru pointer. This means
973 that we cannot use the controller with huge page less than 3 pages.
974
Stephane Eraniane5d13672011-02-14 11:20:01 +0200975config CGROUP_PERF
976 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
977 depends on PERF_EVENTS && CGROUPS
978 help
979 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800980 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200981 designated cpu.
982
983 Say N if unsure.
984
Dhaval Giani7c941432010-01-20 13:26:18 +0100985menuconfig CGROUP_SCHED
986 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100987 default n
988 help
989 This feature lets CPU scheduler recognize task groups and control CPU
990 bandwidth allocation to such task groups. It uses cgroups to group
991 tasks.
992
993if CGROUP_SCHED
994config FAIR_GROUP_SCHED
995 bool "Group scheduling for SCHED_OTHER"
996 depends on CGROUP_SCHED
997 default CGROUP_SCHED
998
Paul Turnerab84d312011-07-21 09:43:28 -0700999config CFS_BANDWIDTH
1000 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -07001001 depends on FAIR_GROUP_SCHED
1002 default n
1003 help
1004 This option allows users to define CPU bandwidth rates (limits) for
1005 tasks running within the fair group scheduler. Groups with no limit
1006 set are considered to be unconstrained and will run with no
1007 restriction.
1008 See tip/Documentation/scheduler/sched-bwc.txt for more information.
1009
Dhaval Giani7c941432010-01-20 13:26:18 +01001010config RT_GROUP_SCHED
1011 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +01001012 depends on CGROUP_SCHED
1013 default n
1014 help
1015 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +08001016 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +01001017 schedule realtime tasks for non-root users until you allocate
1018 realtime bandwidth for them.
1019 See Documentation/scheduler/sched-rt-group.txt for more information.
1020
1021endif #CGROUP_SCHED
1022
Vivek Goyalafc24d42010-04-26 19:27:56 +02001023config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -08001024 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -07001025 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +02001026 default n
1027 ---help---
1028 Generic block IO controller cgroup interface. This is the common
1029 cgroup interface which should be used by various IO controlling
1030 policies.
1031
1032 Currently, CFQ IO scheduler uses it to recognize task groups and
1033 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -04001034 to such task groups. It is also used by bio throttling logic in
1035 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001036
1037 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -04001038 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +00001039 enabling proportional weight division of disk bandwidth in CFQ, set
1040 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +00001041 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001042
1043 See Documentation/cgroups/blkio-controller.txt for more information.
1044
1045config DEBUG_BLK_CGROUP
1046 bool "Enable Block IO controller debugging"
1047 depends on BLK_CGROUP
1048 default n
1049 ---help---
1050 Enable some debugging help. Currently it exports additional stat
1051 files in a cgroup which can be useful for debugging.
1052
Li Zefan23964d22009-01-15 13:50:58 -08001053endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001054
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001055config CHECKPOINT_RESTORE
1056 bool "Checkpoint/restore support" if EXPERT
1057 default n
1058 help
1059 Enables additional kernel features in a sake of checkpoint/restore.
1060 In particular it adds auxiliary prctl codes to setup process text,
1061 data and heap segment sizes, and a few additional /proc filesystem
1062 entries.
1063
1064 If unsure, say N here.
1065
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001066menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001067 bool "Namespaces support" if EXPERT
1068 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001069 help
1070 Provides the way to make tasks work with different objects using
1071 the same id. For example same IPC id may refer to different objects
1072 or same user id or pid may refer to different tasks when used in
1073 different namespaces.
1074
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001075if NAMESPACES
1076
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001077config UTS_NS
1078 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001079 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001080 help
1081 In this namespace tasks see different info provided with the
1082 uname() system call
1083
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001084config IPC_NS
1085 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001086 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001087 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001088 help
1089 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001090 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001091
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001092config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001093 bool "User namespace"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001094 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001095 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001096
Eric W. Biederman5673a942011-11-17 10:23:55 -08001097 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001098 help
1099 This allows containers, i.e. vservers, to use user namespaces
1100 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001101
1102 When user namespaces are enabled in the kernel it is
1103 recommended that the MEMCG and MEMCG_KMEM options also be
1104 enabled and that user-space use the memory control groups to
1105 limit the amount of memory a memory unprivileged users can
1106 use.
1107
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001108 If unsure, say N.
1109
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001110config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001111 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001112 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001113 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001114 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001115 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001116 pid namespaces. This is a building block of containers.
1117
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001118config NET_NS
1119 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001120 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001121 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001122 help
1123 Allow user space to create what appear to be multiple instances
1124 of the network stack.
1125
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001126endif # NAMESPACES
1127
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001128config UIDGID_CONVERTED
1129 # True if all of the selected software conmponents are known
1130 # to have uid_t and gid_t converted to kuid_t and kgid_t
1131 # where appropriate and are otherwise safe to use with
1132 # the user namespace.
1133 bool
1134 default y
1135
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001136 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001137 depends on XFS_FS = n
1138
Eric W. Biederman5673a942011-11-17 10:23:55 -08001139config UIDGID_STRICT_TYPE_CHECKS
1140 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001141 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001142 default n
1143 help
1144 While the nececessary conversions are being added to all subsystems this option allows
1145 the code to continue to build for unconverted subsystems.
1146
1147 Say Y here if you want the strict type checking enabled
1148
Mike Galbraith5091faa2010-11-30 14:18:03 +01001149config SCHED_AUTOGROUP
1150 bool "Automatic process group scheduling"
1151 select EVENTFD
1152 select CGROUPS
1153 select CGROUP_SCHED
1154 select FAIR_GROUP_SCHED
1155 help
1156 This option optimizes the scheduler for common desktop workloads by
1157 automatically creating and populating task groups. This separation
1158 of workloads isolates aggressive CPU burners (like build jobs) from
1159 desktop applications. Task group autogeneration is currently based
1160 upon task session.
1161
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001162config MM_OWNER
1163 bool
1164
1165config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001166 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001167 depends on SYSFS
1168 default n
1169 help
1170 This option adds code that switches the layout of the "block" class
1171 devices, to not show up in /sys/class/block/, but only in
1172 /sys/block/.
1173
1174 This switch is only active when the sysfs.deprecated=1 boot option is
1175 passed or the SYSFS_DEPRECATED_V2 option is set.
1176
1177 This option allows new kernels to run on old distributions and tools,
1178 which might get confused by /sys/class/block/. Since 2007/2008 all
1179 major distributions and tools handle this just fine.
1180
1181 Recent distributions and userspace tools after 2009/2010 depend on
1182 the existence of /sys/class/block/, and will not work with this
1183 option enabled.
1184
1185 Only if you are using a new kernel on an old distribution, you might
1186 need to say Y here.
1187
1188config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001189 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001190 default n
1191 depends on SYSFS
1192 depends on SYSFS_DEPRECATED
1193 help
1194 Enable deprecated sysfs by default.
1195
1196 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1197 option.
1198
1199 Only if you are using a new kernel on an old distribution, you might
1200 need to say Y here. Even then, odds are you would not need it
1201 enabled, you can always pass the boot option if absolutely necessary.
1202
1203config RELAY
1204 bool "Kernel->user space relay support (formerly relayfs)"
1205 help
1206 This option enables support for relay interface support in
1207 certain file systems (such as debugfs).
1208 It is designed to provide an efficient mechanism for tools and
1209 facilities to relay large amounts of data from kernel space to
1210 user space.
1211
1212 If unsure, say N.
1213
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001214config BLK_DEV_INITRD
1215 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1216 depends on BROKEN || !FRV
1217 help
1218 The initial RAM filesystem is a ramfs which is loaded by the
1219 boot loader (loadlin or lilo) and that is mounted as root
1220 before the normal boot procedure. It is typically used to
1221 load modules needed to mount the "real" root file system,
1222 etc. See <file:Documentation/initrd.txt> for details.
1223
1224 If RAM disk support (BLK_DEV_RAM) is also included, this
1225 also enables initial RAM disk (initrd) support and adds
1226 15 Kbytes (more on some other architectures) to the kernel size.
1227
1228 If unsure say Y.
1229
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001230if BLK_DEV_INITRD
1231
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001232source "usr/Kconfig"
1233
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001234endif
1235
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001236config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001237 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001238 help
1239 Enabling this option will pass "-Os" instead of "-O2" to gcc
1240 resulting in a smaller kernel.
1241
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001242 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001243
Randy Dunlap08470622006-09-30 23:28:13 -07001244config SYSCTL
1245 bool
1246
Randy Dunlapb943c462009-03-10 12:55:46 -07001247config ANON_INODES
1248 bool
1249
Mike Frysinger657a5202013-04-30 15:28:45 -07001250config HAVE_UID16
1251 bool
1252
1253config SYSCTL_EXCEPTION_TRACE
1254 bool
1255 help
1256 Enable support for /proc/sys/debug/exception-trace.
1257
1258config SYSCTL_ARCH_UNALIGN_NO_WARN
1259 bool
1260 help
1261 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1262 Allows arch to define/use @no_unaligned_warning to possibly warn
1263 about unaligned access emulation going on under the hood.
1264
1265config SYSCTL_ARCH_UNALIGN_ALLOW
1266 bool
1267 help
1268 Enable support for /proc/sys/kernel/unaligned-trap
1269 Allows arches to define/use @unaligned_enabled to runtime toggle
1270 the unaligned access emulation.
1271 see arch/parisc/kernel/unaligned.c for reference
1272
Mike Frysinger657a5202013-04-30 15:28:45 -07001273config HAVE_PCSPKR_PLATFORM
1274 bool
1275
David Rientjes6a108a12011-01-20 14:44:16 -08001276menuconfig EXPERT
1277 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001278 # Unhide debug options, to make the on-by-default options visible
1279 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280 help
1281 This option allows certain base kernel options and settings
1282 to be disabled or tweaked. This is for specialized
1283 environments which can tolerate a "non-standard" kernel.
1284 Only use this if you really know what you are doing.
1285
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001286config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001287 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001288 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001289 default y
1290 help
1291 This enables the legacy 16-bit UID syscall wrappers.
1292
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001293config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001294 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001295 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001296 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001297 select SYSCTL
1298 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001299 sys_sysctl uses binary paths that have been found challenging
1300 to properly maintain and use. The interface in /proc/sys
1301 using paths with ascii names is now the primary path to this
1302 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001303
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001304 Almost nothing using the binary sysctl interface so if you are
1305 trying to save some space it is probably safe to disable this,
1306 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001307
WANG Congc736de62011-11-02 13:39:25 -07001308 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001309
Linus Torvalds1da177e2005-04-16 15:20:36 -07001310config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001311 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 default y
1313 help
1314 Say Y here to let the kernel print out symbolic crash information and
1315 symbolic stack backtraces. This increases the size of the kernel
1316 somewhat, as all symbols have to be loaded into the kernel image.
1317
1318config KALLSYMS_ALL
1319 bool "Include all symbols in kallsyms"
1320 depends on DEBUG_KERNEL && KALLSYMS
1321 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001322 Normally kallsyms only contains the symbols of functions for nicer
1323 OOPS messages and backtraces (i.e., symbols from the text and inittext
1324 sections). This is sufficient for most cases. And only in very rare
1325 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1326 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001328 This option makes sure that all symbols are loaded into the kernel
1329 image (i.e., symbols from all sections) in cost of increased kernel
1330 size (depending on the kernel configuration, it may be 300KiB or
1331 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001333 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001334
1335config PRINTK
1336 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001337 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001338 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001339 help
1340 This option enables normal printk support. Removing it
1341 eliminates most of the message strings from the kernel image
1342 and makes the kernel more or less silent. As this makes it
1343 very difficult to diagnose system problems, saying N here is
1344 strongly discouraged.
1345
Matt Mackallc8538a72005-05-01 08:59:01 -07001346config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001347 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001348 default y
1349 help
1350 Disabling this option eliminates support for BUG and WARN, reducing
1351 the size of your kernel image and potentially quietly ignoring
1352 numerous fatal conditions. You should only consider disabling this
1353 option for embedded systems with no facilities for reporting errors.
1354 Just say Y.
1355
Matt Mackall708e9a72006-01-08 01:05:25 -08001356config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001357 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001358 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001359 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001360 help
1361 Enable support for generating core dumps. Disabling saves about 4k.
1362
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001363
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001364config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001365 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001366 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001367 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001368 default y
1369 help
1370 This option allows to disable the internal PC-Speaker
1371 support, saving some memory.
1372
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373config BASE_FULL
1374 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001375 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001376 help
1377 Disabling this option reduces the size of miscellaneous core
1378 kernel data structures. This saves memory on small machines,
1379 but may reduce performance.
1380
1381config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001382 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001384 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385 help
1386 Disabling this option will cause the kernel to be built without
1387 support for "fast userspace mutexes". The resulting kernel may not
1388 run glibc-based applications correctly.
1389
1390config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001391 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001393 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394 help
1395 Disabling this option will cause the kernel to be built without
1396 support for epoll family of system calls.
1397
Davide Libenzifba2afa2007-05-10 22:23:13 -07001398config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001399 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001400 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001401 default y
1402 help
1403 Enable the signalfd() system call that allows to receive signals
1404 on a file descriptor.
1405
1406 If unsure, say Y.
1407
Davide Libenzib215e282007-05-10 22:23:16 -07001408config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001409 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001410 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001411 default y
1412 help
1413 Enable the timerfd() system call that allows to receive timer
1414 events on a file descriptor.
1415
1416 If unsure, say Y.
1417
Davide Libenzie1ad7462007-05-10 22:23:19 -07001418config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001419 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001420 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001421 default y
1422 help
1423 Enable the eventfd() system call that allows to receive both
1424 kernel notification (ie. KAIO) or userspace notifications.
1425
1426 If unsure, say Y.
1427
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001429 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430 default y
1431 depends on MMU
1432 help
1433 The shmem is an internal filesystem used to manage shared memory.
1434 It is backed by swap and manages resource limits. It is also exported
1435 to userspace as tmpfs if TMPFS is enabled. Disabling this
1436 option replaces shmem and tmpfs with the much simpler ramfs code,
1437 which may be appropriate on small systems without swap.
1438
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001439config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001440 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001441 default y
1442 help
1443 This option enables POSIX asynchronous I/O which may by used
Mike Frysinger657a5202013-04-30 15:28:45 -07001444 by some high performance threaded applications. Disabling
1445 this option saves about 7k.
1446
1447config PCI_QUIRKS
1448 default y
1449 bool "Enable PCI quirk workarounds" if EXPERT
1450 depends on PCI
1451 help
1452 This enables workarounds for various PCI chipset
1453 bugs/quirks. Disable this only if your target machine is
1454 unaffected by PCI quirks.
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001455
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001456config EMBEDDED
1457 bool "Embedded system"
1458 select EXPERT
1459 help
1460 This option should be enabled if compiling the kernel for
1461 an embedded system so certain expert options are available
1462 for configuration.
1463
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001464config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001465 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001466 help
1467 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001468
Peter Zijlstra906010b2009-09-21 16:08:49 +02001469config PERF_USE_VMALLOC
1470 bool
1471 help
1472 See tools/perf/design.txt for details
1473
Ingo Molnar57c0c152009-09-21 12:20:38 +02001474menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001475
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001476config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001477 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001478 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001479 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001480 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001481 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001482 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001483 Enable kernel support for various performance events provided
1484 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001485
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001486 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001487 use of generic tracepoints.
1488
1489 Most modern CPUs support performance events via performance
1490 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001491 types of hw events: such as instructions executed, cachemisses
1492 suffered, or branches mis-predicted - without slowing down the
1493 kernel or applications. These registers can also trigger interrupts
1494 when a threshold number of events have passed - and can thus be
1495 used to profile the code that runs on that CPU.
1496
Ingo Molnar57c0c152009-09-21 12:20:38 +02001497 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001498 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001499 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001500 provides per task and per CPU counters, and it provides event
1501 capabilities on top of those.
1502
1503 Say Y if unsure.
1504
Peter Zijlstra906010b2009-09-21 16:08:49 +02001505config DEBUG_PERF_USE_VMALLOC
1506 default n
1507 bool "Debug: use vmalloc to back perf mmap() buffers"
1508 depends on PERF_EVENTS && DEBUG_KERNEL
1509 select PERF_USE_VMALLOC
1510 help
1511 Use vmalloc memory to back perf mmap() buffers.
1512
1513 Mostly useful for debugging the vmalloc code on platforms
1514 that don't require it.
1515
1516 Say N if unsure.
1517
Thomas Gleixner0793a612008-12-04 20:12:29 +01001518endmenu
1519
Christoph Lameterf8891e52006-06-30 01:55:45 -07001520config VM_EVENT_COUNTERS
1521 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001522 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001523 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001524 VM event counters are needed for event counts to be shown.
1525 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001526 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001527 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001528
Christoph Lameter41ecc552007-05-09 02:32:44 -07001529config SLUB_DEBUG
1530 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001531 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001532 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001533 help
1534 SLUB has extensive debug support features. Disabling these can
1535 result in significant savings in code size. This also disables
1536 SLUB sysfs support. /sys/slab will not exist and there will be
1537 no support for cache validation etc.
1538
Randy Dunlapb943c462009-03-10 12:55:46 -07001539config COMPAT_BRK
1540 bool "Disable heap randomization"
1541 default y
1542 help
1543 Randomizing heap placement makes heap exploits harder, but it
1544 also breaks ancient binaries (including anything libc5 based).
1545 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001546 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001547 /proc/sys/kernel/randomize_va_space to 2.
1548
1549 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1550
Christoph Lameter81819f02007-05-06 14:49:36 -07001551choice
1552 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001553 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001554 help
1555 This option allows to select a slab allocator.
1556
1557config SLAB
1558 bool "SLAB"
1559 help
1560 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001561 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001562 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001563
1564config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001565 bool "SLUB (Unqueued Allocator)"
1566 help
1567 SLUB is a slab allocator that minimizes cache line usage
1568 instead of managing queues of cached objects (SLAB approach).
1569 Per cpu caching is realized using slabs of objects instead
1570 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001571 and has enhanced diagnostics. SLUB is the default choice for
1572 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001573
1574config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001575 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001576 bool "SLOB (Simple Allocator)"
1577 help
Matt Mackall37291452008-02-04 22:29:38 -08001578 SLOB replaces the stock allocator with a drastically simpler
1579 allocator. SLOB is generally more space efficient but
1580 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001581
1582endchoice
1583
Jie Zhangea637632009-12-14 18:00:02 -08001584config MMAP_ALLOW_UNINITIALIZED
1585 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001586 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001587 default n
1588 help
1589 Normally, and according to the Linux spec, anonymous memory obtained
1590 from mmap() has it's contents cleared before it is passed to
1591 userspace. Enabling this config option allows you to request that
1592 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1593 providing a huge performance boost. If this option is not enabled,
1594 then the flag will be ignored.
1595
1596 This is taken advantage of by uClibc's malloc(), and also by
1597 ELF-FDPIC binfmt's brk and stack allocator.
1598
1599 Because of the obvious security issues, this option should only be
1600 enabled on embedded devices where you control what is run in
1601 userspace. Since that isn't generally a problem on no-MMU systems,
1602 it is normally safe to say Y here.
1603
1604 See Documentation/nommu-mmap.txt for more information.
1605
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001606config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001607 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001608 help
1609 Say Y here to enable the extended profiling support mechanisms used
1610 by profilers such as OProfile.
1611
Ingo Molnar5f87f112008-07-23 14:15:22 +02001612#
1613# Place an empty function call at each tracepoint site. Can be
1614# dynamically changed for a probe function.
1615#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001616config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001617 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001618
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001619source "arch/Kconfig"
1620
Linus Torvalds1da177e2005-04-16 15:20:36 -07001621endmenu # General setup
1622
Dmitry Baryshkovee7e55162008-06-29 14:18:46 +04001623config HAVE_GENERIC_DMA_COHERENT
1624 bool
1625 default n
1626
Linus Torvalds158a9622008-01-02 13:04:48 -08001627config SLABINFO
1628 bool
1629 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001630 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001631 default y
1632
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001633config RT_MUTEXES
1634 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001635
Linus Torvalds1da177e2005-04-16 15:20:36 -07001636config BASE_SMALL
1637 int
1638 default 0 if BASE_FULL
1639 default 1 if !BASE_FULL
1640
Jan Engelhardt66da5732007-07-15 23:39:29 -07001641menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001642 bool "Enable loadable module support"
1643 help
1644 Kernel modules are small pieces of compiled code which can
1645 be inserted in the running kernel, rather than being
1646 permanently built into the kernel. You use the "modprobe"
1647 tool to add (and sometimes remove) them. If you say Y here,
1648 many parts of the kernel can be built as modules (by
1649 answering M instead of Y where indicated): this is most
1650 useful for infrequently used options which are not required
1651 for booting. For more information, see the man pages for
1652 modprobe, lsmod, modinfo, insmod and rmmod.
1653
1654 If you say Y here, you will need to run "make
1655 modules_install" to put the modules under /lib/modules/
1656 where modprobe can find them (you may need to be root to do
1657 this).
1658
1659 If unsure, say Y.
1660
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001661if MODULES
1662
Linus Torvalds826e4502008-05-04 17:04:16 -07001663config MODULE_FORCE_LOAD
1664 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001665 default n
1666 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001667 Allow loading of modules without version information (ie. modprobe
1668 --force). Forced module loading sets the 'F' (forced) taint flag and
1669 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001670
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671config MODULE_UNLOAD
1672 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 help
1674 Without this option you will not be able to unload any
1675 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001676 anyway), which makes your kernel smaller, faster
1677 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001678
1679config MODULE_FORCE_UNLOAD
1680 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001681 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001682 help
1683 This option allows you to force a module to unload, even if the
1684 kernel believes it is unsafe: the kernel will remove the module
1685 without waiting for anyone to stop using it (using the -f option to
1686 rmmod). This is mainly for kernel developers and desperate users.
1687 If unsure, say N.
1688
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001690 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001691 help
1692 Usually, you have to use modules compiled with your kernel.
1693 Saying Y here makes it sometimes possible to use modules
1694 compiled for different kernels, by adding enough information
1695 to the modules to (hopefully) spot any changes which would
1696 make them incompatible with the kernel you are running. If
1697 unsure, say N.
1698
1699config MODULE_SRCVERSION_ALL
1700 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001701 help
1702 Modules which contain a MODULE_VERSION get an extra "srcversion"
1703 field inserted into their modinfo section, which contains a
1704 sum of the source files which made it. This helps maintainers
1705 see exactly which source was used to build a module (since
1706 others sometimes change the module source without updating
1707 the version). With this option, such a "srcversion" field
1708 will be created for all modules. If unsure, say N.
1709
Rusty Russell106a4ee2012-09-26 10:09:40 +01001710config MODULE_SIG
1711 bool "Module signature verification"
1712 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001713 select KEYS
1714 select CRYPTO
1715 select ASYMMETRIC_KEY_TYPE
1716 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1717 select PUBLIC_KEY_ALGO_RSA
1718 select ASN1
1719 select OID_REGISTRY
1720 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001721 help
1722 Check modules for valid signatures upon load: the signature
1723 is simply appended to the module. For more information see
1724 Documentation/module-signing.txt.
1725
David Howellsea0b6dc2012-09-26 10:09:50 +01001726 !!!WARNING!!! If you enable this option, you MUST make sure that the
1727 module DOES NOT get stripped after being signed. This includes the
1728 debuginfo strip done by some packagers (such as rpmbuild) and
1729 inclusion into an initramfs that wants the module size reduced.
1730
Rusty Russell106a4ee2012-09-26 10:09:40 +01001731config MODULE_SIG_FORCE
1732 bool "Require modules to be validly signed"
1733 depends on MODULE_SIG
1734 help
1735 Reject unsigned modules or signed modules for which we don't have a
1736 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001737
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301738config MODULE_SIG_ALL
1739 bool "Automatically sign all modules"
1740 default y
1741 depends on MODULE_SIG
1742 help
1743 Sign all modules during make modules_install. Without this option,
1744 modules must be signed manually, using the scripts/sign-file tool.
1745
1746comment "Do not forget to sign required modules with scripts/sign-file"
1747 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1748
David Howellsea0b6dc2012-09-26 10:09:50 +01001749choice
1750 prompt "Which hash algorithm should modules be signed with?"
1751 depends on MODULE_SIG
1752 help
1753 This determines which sort of hashing algorithm will be used during
1754 signature generation. This algorithm _must_ be built into the kernel
1755 directly so that signature verification can take place. It is not
1756 possible to load a signed module containing the algorithm to check
1757 the signature on that module.
1758
1759config MODULE_SIG_SHA1
1760 bool "Sign modules with SHA-1"
1761 select CRYPTO_SHA1
1762
1763config MODULE_SIG_SHA224
1764 bool "Sign modules with SHA-224"
1765 select CRYPTO_SHA256
1766
1767config MODULE_SIG_SHA256
1768 bool "Sign modules with SHA-256"
1769 select CRYPTO_SHA256
1770
1771config MODULE_SIG_SHA384
1772 bool "Sign modules with SHA-384"
1773 select CRYPTO_SHA512
1774
1775config MODULE_SIG_SHA512
1776 bool "Sign modules with SHA-512"
1777 select CRYPTO_SHA512
1778
1779endchoice
1780
Michal Marek22753672013-01-25 13:41:00 +10301781config MODULE_SIG_HASH
1782 string
1783 depends on MODULE_SIG
1784 default "sha1" if MODULE_SIG_SHA1
1785 default "sha224" if MODULE_SIG_SHA224
1786 default "sha256" if MODULE_SIG_SHA256
1787 default "sha384" if MODULE_SIG_SHA384
1788 default "sha512" if MODULE_SIG_SHA512
1789
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001790endif # MODULES
1791
Rusty Russell98a79d62008-12-13 21:19:41 +10301792config INIT_ALL_POSSIBLE
1793 bool
1794 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301795 Back when each arch used to define their own cpu_online_mask and
1796 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301797 with all 1s, and others with all 0s. When they were centralised,
1798 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001799 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301800
Linus Torvalds1da177e2005-04-16 15:20:36 -07001801config STOP_MACHINE
1802 bool
1803 default y
1804 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1805 help
1806 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001807
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001808source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001809
1810config PREEMPT_NOTIFIERS
1811 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001812
Steffen Klassert16295be2010-01-06 19:47:10 +11001813config PADATA
1814 depends on SMP
1815 bool
1816
Andi Kleen754b7b62012-10-04 17:11:27 -07001817# Can be selected by architectures with broken toolchains
1818# that get confused by correct const<->read_only section
1819# mappings
1820config BROKEN_RODATA
1821 bool
1822
David Howells4520c6a2012-09-21 23:31:13 +01001823config ASN1
1824 tristate
1825 help
1826 Build a simple ASN.1 grammar compiler that produces a bytecode output
1827 that can be interpreted by the ASN.1 stream decoder and used to
1828 inform it as to what tags are to be expected in a stream and what
1829 functions to call on what tags.
1830
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001831source "kernel/Kconfig.locks"