blob: 5341d7232c3ac083c2f87c8a3e1098a9c5e8d601 [file] [log] [blame]
Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070022
Peter Zijlstrae360adb2010-10-14 14:01:34 +080023config IRQ_WORK
24 bool
Peter Zijlstrae360adb2010-10-14 14:01:34 +080025
David Daney1dbdc6f2012-04-19 14:59:57 -070026config BUILDTIME_EXTABLE_SORT
27 bool
28
Al Boldiff0cfc62007-07-31 00:39:23 -070029menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Linus Torvalds1da177e2005-04-16 15:20:36 -070031config BROKEN
32 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34config BROKEN_ON_SMP
35 bool
36 depends on BROKEN || !SMP
37 default y
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039config INIT_ENV_ARG_LIMIT
40 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070041 default 32 if !UML
42 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 help
Randy 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"
305 depends on !S390
306 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"
315 depends on HAVE_VIRT_CPU_ACCOUNTING
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"
345 depends on HAVE_IRQ_TIME_ACCOUNTING
346 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 Weisbecker1fd2b442012-07-11 20:26:40 +0200508 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100509 Probe on user/kernel boundaries by default in order to
510 test the features that rely on it such as userspace RCU extended
511 quiescent states.
512 This test is there for debugging until we have a real user like the
513 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200514
Mike Travisc903ff82009-01-15 12:28:29 -0800515config RCU_FANOUT
516 int "Tree-based hierarchical RCU fanout value"
517 range 2 64 if 64BIT
518 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700519 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800520 default 64 if 64BIT
521 default 32 if !64BIT
522 help
523 This option controls the fanout of hierarchical implementations
524 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700525 large numbers of CPUs. This value must be at least the fourth
526 root of NR_CPUS, which allows NR_CPUS to be insanely large.
527 The default value of RCU_FANOUT should be used for production
528 systems, but if you are stress-testing the RCU implementation
529 itself, small RCU_FANOUT values allow you to test large-system
530 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800531
532 Select a specific number if testing RCU itself.
533 Take the default if unsure.
534
Paul E. McKenney8932a632012-04-19 12:20:14 -0700535config RCU_FANOUT_LEAF
536 int "Tree-based hierarchical RCU leaf-level fanout value"
537 range 2 RCU_FANOUT if 64BIT
538 range 2 RCU_FANOUT if !64BIT
539 depends on TREE_RCU || TREE_PREEMPT_RCU
540 default 16
541 help
542 This option controls the leaf-level fanout of hierarchical
543 implementations of RCU, and allows trading off cache misses
544 against lock contention. Systems that synchronize their
545 scheduling-clock interrupts for energy-efficiency reasons will
546 want the default because the smaller leaf-level fanout keeps
547 lock contention levels acceptably low. Very large systems
548 (hundreds or thousands of CPUs) will instead want to set this
549 value to the maximum value possible in order to reduce the
550 number of cache misses incurred during RCU's grace-period
551 initialization. These systems tend to run CPU-bound, and thus
552 are not helped by synchronized interrupts, and thus tend to
553 skew them, which reduces lock contention enough that large
554 leaf-level fanouts work well.
555
556 Select a specific number if testing RCU itself.
557
558 Select the maximum permissible value for large systems.
559
560 Take the default if unsure.
561
Mike Travisc903ff82009-01-15 12:28:29 -0800562config RCU_FANOUT_EXACT
563 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700564 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800565 default n
566 help
567 This option forces use of the exact RCU_FANOUT value specified,
568 regardless of imbalances in the hierarchy. This is useful for
569 testing RCU itself, and might one day be useful on systems with
570 strong NUMA behavior.
571
572 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
573
574 Say N if unsure.
575
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800576config RCU_FAST_NO_HZ
577 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700578 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800579 default n
580 help
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700581 This option causes RCU to attempt to accelerate grace periods in
582 order to allow CPUs to enter dynticks-idle state more quickly.
583 On the other hand, this option increases the overhead of the
584 dynticks-idle checking, thus degrading scheduling latency.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800585
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700586 Say Y if energy efficiency is critically important, and you don't
587 care about real-time response.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800588
589 Say N if you are unsure.
590
Mike Travisc903ff82009-01-15 12:28:29 -0800591config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700592 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800593 select DEBUG_FS
594 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700595 This option provides tracing for the TREE_RCU and
596 TREE_PREEMPT_RCU implementations, permitting Makefile to
597 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800598
Paul E. McKenney24278d12010-09-27 17:25:23 -0700599config RCU_BOOST
600 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800601 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700602 default n
603 help
604 This option boosts the priority of preempted RCU readers that
605 block the current preemptible RCU grace period for too long.
606 This option also prevents heavy loads from blocking RCU
607 callback invocation for all flavors of RCU.
608
609 Say Y here if you are working with real-time apps or heavy loads
610 Say N here if you are unsure.
611
612config RCU_BOOST_PRIO
613 int "Real-time priority to boost RCU readers to"
614 range 1 99
615 depends on RCU_BOOST
616 default 1
617 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700618 This option specifies the real-time priority to which long-term
619 preempted RCU readers are to be boosted. If you are working
620 with a real-time application that has one or more CPU-bound
621 threads running at a real-time priority level, you should set
622 RCU_BOOST_PRIO to a priority higher then the highest-priority
623 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
624 of 1 is appropriate in the common case, which is real-time
625 applications that do not have any CPU-bound threads.
626
627 Some real-time applications might not have a single real-time
628 thread that saturates a given CPU, but instead might have
629 multiple real-time threads that, taken together, fully utilize
630 that CPU. In this case, you should set RCU_BOOST_PRIO to
631 a priority higher than the lowest-priority thread that is
632 conspiring to prevent the CPU from running any non-real-time
633 tasks. For example, if one thread at priority 10 and another
634 thread at priority 5 are between themselves fully consuming
635 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
636 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700637
638 Specify the real-time priority, or take the default if unsure.
639
640config RCU_BOOST_DELAY
641 int "Milliseconds to delay boosting after RCU grace-period start"
642 range 0 3000
643 depends on RCU_BOOST
644 default 500
645 help
646 This option specifies the time to wait after the beginning of
647 a given grace period before priority-boosting preempted RCU
648 readers blocking that grace period. Note that any RCU reader
649 blocking an expedited RCU grace period is boosted immediately.
650
651 Accept the default if unsure.
652
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700653config RCU_NOCB_CPU
654 bool "Offload RCU callback processing from boot-selected CPUs"
655 depends on TREE_RCU || TREE_PREEMPT_RCU
656 default n
657 help
658 Use this option to reduce OS jitter for aggressive HPC or
659 real-time workloads. It can also be used to offload RCU
660 callback invocation to energy-efficient CPUs in battery-powered
661 asymmetric multiprocessors.
662
663 This option offloads callback invocation from the set of
664 CPUs specified at boot time by the rcu_nocbs parameter.
665 For each such CPU, a kthread ("rcuoN") will be created to
666 invoke callbacks, where the "N" is the CPU being offloaded.
667 Nothing prevents this kthread from running on the specified
668 CPUs, but (1) the kthreads may be preempted between each
669 callback, and (2) affinity or cgroups can be used to force
670 the kthreads to run on whatever set of CPUs is desired.
671
672 Say Y here if you want reduced OS jitter on selected CPUs.
673 Say N here if you are unsure.
674
Mike Travisc903ff82009-01-15 12:28:29 -0800675endmenu # "RCU Subsystem"
676
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700678 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 ---help---
680 This option enables the complete Linux kernel ".config" file
681 contents to be saved in the kernel. It provides documentation
682 of which kernel options are used in a running kernel or in an
683 on-disk kernel. This information can be extracted from the kernel
684 image file with the script scripts/extract-ikconfig and used as
685 input to rebuild the current kernel or to build another kernel.
686 It can also be extracted from a running kernel by reading
687 /proc/config.gz if enabled (below).
688
689config IKCONFIG_PROC
690 bool "Enable access to .config through /proc/config.gz"
691 depends on IKCONFIG && PROC_FS
692 ---help---
693 This option enables access to the kernel configuration file
694 through /proc/config.gz.
695
Alistair John Strachan794543a2007-05-08 00:31:15 -0700696config LOG_BUF_SHIFT
697 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
698 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700699 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700700 help
701 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700702 Examples:
703 17 => 128 KB
704 16 => 64 KB
705 15 => 32 KB
706 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700707 13 => 8 KB
708 12 => 4 KB
709
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800710#
711# Architectures with an unreliable sched_clock() should select this:
712#
713config HAVE_UNSTABLE_SCHED_CLOCK
714 bool
715
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200716#
717# For architectures that want to enable the support for NUMA-affine scheduler
718# balancing logic:
719#
720config ARCH_SUPPORTS_NUMA_BALANCING
721 bool
722
723# For architectures that (ab)use NUMA to represent different memory regions
724# all cpu-local but of different latencies, such as SuperH.
725#
726config ARCH_WANT_NUMA_VARIABLE_LOCALITY
727 bool
728
729#
730# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
731config ARCH_WANTS_PROT_NUMA_PROT_NONE
732 bool
733
734config ARCH_USES_NUMA_PROT_NONE
735 bool
736 default y
737 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
738 depends on NUMA_BALANCING
739
Mel Gorman1a687c22012-11-22 11:16:36 +0000740config NUMA_BALANCING_DEFAULT_ENABLED
741 bool "Automatically enable NUMA aware memory/task placement"
742 default y
743 depends on NUMA_BALANCING
744 help
745 If set, autonumic NUMA balancing will be enabled if running on a NUMA
746 machine.
747
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200748config NUMA_BALANCING
749 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200750 depends on ARCH_SUPPORTS_NUMA_BALANCING
751 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
752 depends on SMP && NUMA && MIGRATION
753 help
754 This option adds support for automatic NUMA aware memory/task placement.
755 The mechanism is quite primitive and is based on migrating memory when
756 it is references to the node the task is running on.
757
758 This system will be inactive on UMA systems.
759
Li Zefan23964d22009-01-15 13:50:58 -0800760menuconfig CGROUPS
761 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800762 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700763 help
Li Zefan23964d22009-01-15 13:50:58 -0800764 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800765 use with process control subsystems such as Cpusets, CFS, memory
766 controls or device isolation.
767 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800768 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800769 - Documentation/cgroups/ (features for grouping, isolation
770 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700771
772 Say N if unsure.
773
Li Zefan23964d22009-01-15 13:50:58 -0800774if CGROUPS
775
Paul Menage006cb992007-10-18 23:39:43 -0700776config CGROUP_DEBUG
777 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700778 default n
Paul Menage006cb992007-10-18 23:39:43 -0700779 help
780 This option enables a simple cgroup subsystem that
781 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800782 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700783
Li Zefan23964d22009-01-15 13:50:58 -0800784 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700785
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700786config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800787 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800788 help
789 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700790 cgroup.
791
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700792config CGROUP_DEVICE
793 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700794 help
795 Provides a cgroup implementing whitelists for devices which
796 a process in the cgroup can mknod or open.
797
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798config CPUSETS
799 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700801 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 allow dynamically partitioning a system into sets of CPUs and
803 Memory Nodes and assigning tasks to run only within those sets.
804 This is primarily useful on large SMP or NUMA systems.
805
806 Say N if unsure.
807
Li Zefan23964d22009-01-15 13:50:58 -0800808config PROC_PID_CPUSET
809 bool "Include legacy /proc/<pid>/cpuset file"
810 depends on CPUSETS
811 default y
812
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100813config CGROUP_CPUACCT
814 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100815 help
816 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800817 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100818
Pavel Emelianove552b662008-02-07 00:13:49 -0800819config RESOURCE_COUNTERS
820 bool "Resource counters"
821 help
822 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800823 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800824
Andrew Mortonc255a452012-07-31 16:43:02 -0700825config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800826 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700827 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700828 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800829 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700830 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100831 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800832
833 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700834 associated with each page of memory in the system. By this,
835 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
836 usage tracking struct at boot. Total amount of this is printed out
837 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800838
839 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700840 sure you need the memory resource controller. Even when you enable
841 this, you can set "cgroup_disable=memory" at your boot option to
842 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800843 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800844
Balbir Singhcf475ad2008-04-29 01:00:16 -0700845 This config option also selects MM_OWNER config option, which
846 could in turn add some fork/exit overhead.
847
Andrew Mortonc255a452012-07-31 16:43:02 -0700848config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700849 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700850 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800851 help
852 Add swap management feature to memory resource controller. When you
853 enable this, you can limit mem+swap usage per cgroup. In other words,
854 when you disable this, memory resource controller has no cares to
855 usage of swap...a process can exhaust all of the swap. This extension
856 is useful when you want to avoid exhaustion swap but this itself
857 adds more overheads and consumes memory for remembering information.
858 Especially if you use 32bit system or small memory system, please
859 be careful about enabling this. When memory resource controller
860 is disabled by boot option, this will be automatically disabled and
861 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700862 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700863 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
864 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700865config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800866 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700867 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800868 default y
869 help
870 Memory Resource Controller Swap Extension comes with its price in
871 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700872 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800873 and let the user enable it by swapaccount boot command line
874 parameter should have this option unselected.
875 For those who want to have the feature enabled by default should
876 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700877 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700878config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700879 bool "Memory Resource Controller Kernel Memory accounting"
880 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800881 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000882 help
883 The Kernel Memory extension for Memory Resource Controller can limit
884 the amount of memory used by kernel objects in the system. Those are
885 fundamentally different from the entities handled by the standard
886 Memory Controller, which are page-based, and can be swapped. Users of
887 the kmem extension can use it to guarantee that no group of processes
888 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800889
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700890config CGROUP_HUGETLB
891 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700892 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700893 default n
894 help
895 Provides a cgroup Resource Controller for HugeTLB pages.
896 When you enable this, you can put a per cgroup limit on HugeTLB usage.
897 The limit is enforced during page fault. Since HugeTLB doesn't
898 support page reclaim, enforcing the limit at page fault time implies
899 that, the application will get SIGBUS signal if it tries to access
900 HugeTLB pages beyond its limit. This requires the application to know
901 beforehand how much HugeTLB pages it would require for its use. The
902 control group is tracked in the third page lru pointer. This means
903 that we cannot use the controller with huge page less than 3 pages.
904
Stephane Eraniane5d13672011-02-14 11:20:01 +0200905config CGROUP_PERF
906 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
907 depends on PERF_EVENTS && CGROUPS
908 help
909 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800910 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200911 designated cpu.
912
913 Say N if unsure.
914
Dhaval Giani7c941432010-01-20 13:26:18 +0100915menuconfig CGROUP_SCHED
916 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100917 default n
918 help
919 This feature lets CPU scheduler recognize task groups and control CPU
920 bandwidth allocation to such task groups. It uses cgroups to group
921 tasks.
922
923if CGROUP_SCHED
924config FAIR_GROUP_SCHED
925 bool "Group scheduling for SCHED_OTHER"
926 depends on CGROUP_SCHED
927 default CGROUP_SCHED
928
Paul Turnerab84d312011-07-21 09:43:28 -0700929config CFS_BANDWIDTH
930 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -0700931 depends on FAIR_GROUP_SCHED
932 default n
933 help
934 This option allows users to define CPU bandwidth rates (limits) for
935 tasks running within the fair group scheduler. Groups with no limit
936 set are considered to be unconstrained and will run with no
937 restriction.
938 See tip/Documentation/scheduler/sched-bwc.txt for more information.
939
Dhaval Giani7c941432010-01-20 13:26:18 +0100940config RT_GROUP_SCHED
941 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +0100942 depends on CGROUP_SCHED
943 default n
944 help
945 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800946 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100947 schedule realtime tasks for non-root users until you allocate
948 realtime bandwidth for them.
949 See Documentation/scheduler/sched-rt-group.txt for more information.
950
951endif #CGROUP_SCHED
952
Vivek Goyalafc24d42010-04-26 19:27:56 +0200953config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800954 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700955 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200956 default n
957 ---help---
958 Generic block IO controller cgroup interface. This is the common
959 cgroup interface which should be used by various IO controlling
960 policies.
961
962 Currently, CFQ IO scheduler uses it to recognize task groups and
963 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400964 to such task groups. It is also used by bio throttling logic in
965 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200966
967 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400968 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000969 enabling proportional weight division of disk bandwidth in CFQ, set
970 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000971 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200972
973 See Documentation/cgroups/blkio-controller.txt for more information.
974
975config DEBUG_BLK_CGROUP
976 bool "Enable Block IO controller debugging"
977 depends on BLK_CGROUP
978 default n
979 ---help---
980 Enable some debugging help. Currently it exports additional stat
981 files in a cgroup which can be useful for debugging.
982
Li Zefan23964d22009-01-15 13:50:58 -0800983endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800984
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800985config CHECKPOINT_RESTORE
986 bool "Checkpoint/restore support" if EXPERT
987 default n
988 help
989 Enables additional kernel features in a sake of checkpoint/restore.
990 In particular it adds auxiliary prctl codes to setup process text,
991 data and heap segment sizes, and a few additional /proc filesystem
992 entries.
993
994 If unsure, say N here.
995
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700996menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800997 bool "Namespaces support" if EXPERT
998 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800999 help
1000 Provides the way to make tasks work with different objects using
1001 the same id. For example same IPC id may refer to different objects
1002 or same user id or pid may refer to different tasks when used in
1003 different namespaces.
1004
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001005if NAMESPACES
1006
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001007config UTS_NS
1008 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001009 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001010 help
1011 In this namespace tasks see different info provided with the
1012 uname() system call
1013
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001014config IPC_NS
1015 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001016 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001017 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001018 help
1019 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001020 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001021
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001022config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001023 bool "User namespace"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001024 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001025 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001026
Eric W. Biederman5673a942011-11-17 10:23:55 -08001027 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001028 help
1029 This allows containers, i.e. vservers, to use user namespaces
1030 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001031
1032 When user namespaces are enabled in the kernel it is
1033 recommended that the MEMCG and MEMCG_KMEM options also be
1034 enabled and that user-space use the memory control groups to
1035 limit the amount of memory a memory unprivileged users can
1036 use.
1037
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001038 If unsure, say N.
1039
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001040config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001041 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001042 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001043 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001044 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001045 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001046 pid namespaces. This is a building block of containers.
1047
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001048config NET_NS
1049 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001050 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001051 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001052 help
1053 Allow user space to create what appear to be multiple instances
1054 of the network stack.
1055
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001056endif # NAMESPACES
1057
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001058config UIDGID_CONVERTED
1059 # True if all of the selected software conmponents are known
1060 # to have uid_t and gid_t converted to kuid_t and kgid_t
1061 # where appropriate and are otherwise safe to use with
1062 # the user namespace.
1063 bool
1064 default y
1065
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001066 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001067 depends on XFS_FS = n
1068
Eric W. Biederman5673a942011-11-17 10:23:55 -08001069config UIDGID_STRICT_TYPE_CHECKS
1070 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001071 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001072 default n
1073 help
1074 While the nececessary conversions are being added to all subsystems this option allows
1075 the code to continue to build for unconverted subsystems.
1076
1077 Say Y here if you want the strict type checking enabled
1078
Mike Galbraith5091faa2010-11-30 14:18:03 +01001079config SCHED_AUTOGROUP
1080 bool "Automatic process group scheduling"
1081 select EVENTFD
1082 select CGROUPS
1083 select CGROUP_SCHED
1084 select FAIR_GROUP_SCHED
1085 help
1086 This option optimizes the scheduler for common desktop workloads by
1087 automatically creating and populating task groups. This separation
1088 of workloads isolates aggressive CPU burners (like build jobs) from
1089 desktop applications. Task group autogeneration is currently based
1090 upon task session.
1091
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001092config MM_OWNER
1093 bool
1094
1095config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001096 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001097 depends on SYSFS
1098 default n
1099 help
1100 This option adds code that switches the layout of the "block" class
1101 devices, to not show up in /sys/class/block/, but only in
1102 /sys/block/.
1103
1104 This switch is only active when the sysfs.deprecated=1 boot option is
1105 passed or the SYSFS_DEPRECATED_V2 option is set.
1106
1107 This option allows new kernels to run on old distributions and tools,
1108 which might get confused by /sys/class/block/. Since 2007/2008 all
1109 major distributions and tools handle this just fine.
1110
1111 Recent distributions and userspace tools after 2009/2010 depend on
1112 the existence of /sys/class/block/, and will not work with this
1113 option enabled.
1114
1115 Only if you are using a new kernel on an old distribution, you might
1116 need to say Y here.
1117
1118config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001119 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001120 default n
1121 depends on SYSFS
1122 depends on SYSFS_DEPRECATED
1123 help
1124 Enable deprecated sysfs by default.
1125
1126 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1127 option.
1128
1129 Only if you are using a new kernel on an old distribution, you might
1130 need to say Y here. Even then, odds are you would not need it
1131 enabled, you can always pass the boot option if absolutely necessary.
1132
1133config RELAY
1134 bool "Kernel->user space relay support (formerly relayfs)"
1135 help
1136 This option enables support for relay interface support in
1137 certain file systems (such as debugfs).
1138 It is designed to provide an efficient mechanism for tools and
1139 facilities to relay large amounts of data from kernel space to
1140 user space.
1141
1142 If unsure, say N.
1143
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001144config BLK_DEV_INITRD
1145 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1146 depends on BROKEN || !FRV
1147 help
1148 The initial RAM filesystem is a ramfs which is loaded by the
1149 boot loader (loadlin or lilo) and that is mounted as root
1150 before the normal boot procedure. It is typically used to
1151 load modules needed to mount the "real" root file system,
1152 etc. See <file:Documentation/initrd.txt> for details.
1153
1154 If RAM disk support (BLK_DEV_RAM) is also included, this
1155 also enables initial RAM disk (initrd) support and adds
1156 15 Kbytes (more on some other architectures) to the kernel size.
1157
1158 If unsure say Y.
1159
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001160if BLK_DEV_INITRD
1161
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001162source "usr/Kconfig"
1163
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001164endif
1165
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001166config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001167 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001168 help
1169 Enabling this option will pass "-Os" instead of "-O2" to gcc
1170 resulting in a smaller kernel.
1171
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001172 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001173
Randy Dunlap08470622006-09-30 23:28:13 -07001174config SYSCTL
1175 bool
1176
Randy Dunlapb943c462009-03-10 12:55:46 -07001177config ANON_INODES
1178 bool
1179
David Rientjes6a108a12011-01-20 14:44:16 -08001180menuconfig EXPERT
1181 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001182 # Unhide debug options, to make the on-by-default options visible
1183 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184 help
1185 This option allows certain base kernel options and settings
1186 to be disabled or tweaked. This is for specialized
1187 environments which can tolerate a "non-standard" kernel.
1188 Only use this if you really know what you are doing.
1189
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001190config HAVE_UID16
1191 bool
1192
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001193config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001194 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001195 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001196 default y
1197 help
1198 This enables the legacy 16-bit UID syscall wrappers.
1199
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001200config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001201 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001202 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001203 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001204 select SYSCTL
1205 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001206 sys_sysctl uses binary paths that have been found challenging
1207 to properly maintain and use. The interface in /proc/sys
1208 using paths with ascii names is now the primary path to this
1209 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001210
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001211 Almost nothing using the binary sysctl interface so if you are
1212 trying to save some space it is probably safe to disable this,
1213 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001214
WANG Congc736de62011-11-02 13:39:25 -07001215 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001216
Catalin Marinas7ac57a82012-10-08 16:28:16 -07001217config SYSCTL_EXCEPTION_TRACE
1218 bool
1219 help
1220 Enable support for /proc/sys/debug/exception-trace.
1221
Vineet Guptab6fca722013-01-09 20:06:28 +05301222config SYSCTL_ARCH_UNALIGN_NO_WARN
1223 bool
1224 help
1225 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1226 Allows arch to define/use @no_unaligned_warning to possibly warn
1227 about unaligned access emulation going on under the hood.
1228
Vineet Guptabf14e3b2013-01-18 15:12:24 +05301229config SYSCTL_ARCH_UNALIGN_ALLOW
1230 bool
1231 help
1232 Enable support for /proc/sys/kernel/unaligned-trap
1233 Allows arches to define/use @unaligned_enabled to runtime toggle
1234 the unaligned access emulation.
1235 see arch/parisc/kernel/unaligned.c for reference
1236
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001238 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 default y
1240 help
1241 Say Y here to let the kernel print out symbolic crash information and
1242 symbolic stack backtraces. This increases the size of the kernel
1243 somewhat, as all symbols have to be loaded into the kernel image.
1244
1245config KALLSYMS_ALL
1246 bool "Include all symbols in kallsyms"
1247 depends on DEBUG_KERNEL && KALLSYMS
1248 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001249 Normally kallsyms only contains the symbols of functions for nicer
1250 OOPS messages and backtraces (i.e., symbols from the text and inittext
1251 sections). This is sufficient for most cases. And only in very rare
1252 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1253 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001255 This option makes sure that all symbols are loaded into the kernel
1256 image (i.e., symbols from all sections) in cost of increased kernel
1257 size (depending on the kernel configuration, it may be 300KiB or
1258 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001260 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001261
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001262config HOTPLUG
Greg Kroah-Hartman45f035a2012-09-04 17:01:08 -07001263 def_bool y
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001264
Matt Mackalld59745c2005-05-01 08:59:02 -07001265config PRINTK
1266 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001267 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001268 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001269 help
1270 This option enables normal printk support. Removing it
1271 eliminates most of the message strings from the kernel image
1272 and makes the kernel more or less silent. As this makes it
1273 very difficult to diagnose system problems, saying N here is
1274 strongly discouraged.
1275
Matt Mackallc8538a72005-05-01 08:59:01 -07001276config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001277 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001278 default y
1279 help
1280 Disabling this option eliminates support for BUG and WARN, reducing
1281 the size of your kernel image and potentially quietly ignoring
1282 numerous fatal conditions. You should only consider disabling this
1283 option for embedded systems with no facilities for reporting errors.
1284 Just say Y.
1285
Matt Mackall708e9a72006-01-08 01:05:25 -08001286config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001287 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001288 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001289 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001290 help
1291 Enable support for generating core dumps. Disabling saves about 4k.
1292
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001293
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001294config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001295 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001296 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001297 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001298 default y
1299 help
1300 This option allows to disable the internal PC-Speaker
1301 support, saving some memory.
1302
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001303config HAVE_PCSPKR_PLATFORM
1304 bool
1305
Linus Torvalds1da177e2005-04-16 15:20:36 -07001306config BASE_FULL
1307 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001308 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309 help
1310 Disabling this option reduces the size of miscellaneous core
1311 kernel data structures. This saves memory on small machines,
1312 but may reduce performance.
1313
1314config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001315 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001317 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318 help
1319 Disabling this option will cause the kernel to be built without
1320 support for "fast userspace mutexes". The resulting kernel may not
1321 run glibc-based applications correctly.
1322
1323config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001324 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001326 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 help
1328 Disabling this option will cause the kernel to be built without
1329 support for epoll family of system calls.
1330
Davide Libenzifba2afa2007-05-10 22:23:13 -07001331config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001332 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001333 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001334 default y
1335 help
1336 Enable the signalfd() system call that allows to receive signals
1337 on a file descriptor.
1338
1339 If unsure, say Y.
1340
Davide Libenzib215e282007-05-10 22:23:16 -07001341config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001342 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001343 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001344 default y
1345 help
1346 Enable the timerfd() system call that allows to receive timer
1347 events on a file descriptor.
1348
1349 If unsure, say Y.
1350
Davide Libenzie1ad7462007-05-10 22:23:19 -07001351config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001352 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001353 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001354 default y
1355 help
1356 Enable the eventfd() system call that allows to receive both
1357 kernel notification (ie. KAIO) or userspace notifications.
1358
1359 If unsure, say Y.
1360
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001362 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001363 default y
1364 depends on MMU
1365 help
1366 The shmem is an internal filesystem used to manage shared memory.
1367 It is backed by swap and manages resource limits. It is also exported
1368 to userspace as tmpfs if TMPFS is enabled. Disabling this
1369 option replaces shmem and tmpfs with the much simpler ramfs code,
1370 which may be appropriate on small systems without swap.
1371
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001372config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001373 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001374 default y
1375 help
1376 This option enables POSIX asynchronous I/O which may by used
1377 by some high performance threaded applications. Disabling
1378 this option saves about 7k.
1379
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001380config EMBEDDED
1381 bool "Embedded system"
1382 select EXPERT
1383 help
1384 This option should be enabled if compiling the kernel for
1385 an embedded system so certain expert options are available
1386 for configuration.
1387
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001388config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001389 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001390 help
1391 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001392
Peter Zijlstra906010b2009-09-21 16:08:49 +02001393config PERF_USE_VMALLOC
1394 bool
1395 help
1396 See tools/perf/design.txt for details
1397
Ingo Molnar57c0c152009-09-21 12:20:38 +02001398menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001399
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001400config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001401 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001402 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001403 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001404 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001405 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001406 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001407 Enable kernel support for various performance events provided
1408 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001409
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001410 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001411 use of generic tracepoints.
1412
1413 Most modern CPUs support performance events via performance
1414 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001415 types of hw events: such as instructions executed, cachemisses
1416 suffered, or branches mis-predicted - without slowing down the
1417 kernel or applications. These registers can also trigger interrupts
1418 when a threshold number of events have passed - and can thus be
1419 used to profile the code that runs on that CPU.
1420
Ingo Molnar57c0c152009-09-21 12:20:38 +02001421 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001422 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001423 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001424 provides per task and per CPU counters, and it provides event
1425 capabilities on top of those.
1426
1427 Say Y if unsure.
1428
Peter Zijlstra906010b2009-09-21 16:08:49 +02001429config DEBUG_PERF_USE_VMALLOC
1430 default n
1431 bool "Debug: use vmalloc to back perf mmap() buffers"
1432 depends on PERF_EVENTS && DEBUG_KERNEL
1433 select PERF_USE_VMALLOC
1434 help
1435 Use vmalloc memory to back perf mmap() buffers.
1436
1437 Mostly useful for debugging the vmalloc code on platforms
1438 that don't require it.
1439
1440 Say N if unsure.
1441
Thomas Gleixner0793a612008-12-04 20:12:29 +01001442endmenu
1443
Christoph Lameterf8891e52006-06-30 01:55:45 -07001444config VM_EVENT_COUNTERS
1445 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001446 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001447 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001448 VM event counters are needed for event counts to be shown.
1449 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001450 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001451 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001452
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001453config PCI_QUIRKS
1454 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001455 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001456 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001457 help
1458 This enables workarounds for various PCI chipset
1459 bugs/quirks. Disable this only if your target machine is
1460 unaffected by PCI quirks.
1461
Christoph Lameter41ecc552007-05-09 02:32:44 -07001462config SLUB_DEBUG
1463 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001464 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001465 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001466 help
1467 SLUB has extensive debug support features. Disabling these can
1468 result in significant savings in code size. This also disables
1469 SLUB sysfs support. /sys/slab will not exist and there will be
1470 no support for cache validation etc.
1471
Randy Dunlapb943c462009-03-10 12:55:46 -07001472config COMPAT_BRK
1473 bool "Disable heap randomization"
1474 default y
1475 help
1476 Randomizing heap placement makes heap exploits harder, but it
1477 also breaks ancient binaries (including anything libc5 based).
1478 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001479 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001480 /proc/sys/kernel/randomize_va_space to 2.
1481
1482 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1483
Christoph Lameter81819f02007-05-06 14:49:36 -07001484choice
1485 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001486 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001487 help
1488 This option allows to select a slab allocator.
1489
1490config SLAB
1491 bool "SLAB"
1492 help
1493 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001494 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001495 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001496
1497config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001498 bool "SLUB (Unqueued Allocator)"
1499 help
1500 SLUB is a slab allocator that minimizes cache line usage
1501 instead of managing queues of cached objects (SLAB approach).
1502 Per cpu caching is realized using slabs of objects instead
1503 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001504 and has enhanced diagnostics. SLUB is the default choice for
1505 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001506
1507config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001508 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001509 bool "SLOB (Simple Allocator)"
1510 help
Matt Mackall37291452008-02-04 22:29:38 -08001511 SLOB replaces the stock allocator with a drastically simpler
1512 allocator. SLOB is generally more space efficient but
1513 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001514
1515endchoice
1516
Jie Zhangea637632009-12-14 18:00:02 -08001517config MMAP_ALLOW_UNINITIALIZED
1518 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001519 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001520 default n
1521 help
1522 Normally, and according to the Linux spec, anonymous memory obtained
1523 from mmap() has it's contents cleared before it is passed to
1524 userspace. Enabling this config option allows you to request that
1525 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1526 providing a huge performance boost. If this option is not enabled,
1527 then the flag will be ignored.
1528
1529 This is taken advantage of by uClibc's malloc(), and also by
1530 ELF-FDPIC binfmt's brk and stack allocator.
1531
1532 Because of the obvious security issues, this option should only be
1533 enabled on embedded devices where you control what is run in
1534 userspace. Since that isn't generally a problem on no-MMU systems,
1535 it is normally safe to say Y here.
1536
1537 See Documentation/nommu-mmap.txt for more information.
1538
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001539config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001540 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001541 help
1542 Say Y here to enable the extended profiling support mechanisms used
1543 by profilers such as OProfile.
1544
Ingo Molnar5f87f112008-07-23 14:15:22 +02001545#
1546# Place an empty function call at each tracepoint site. Can be
1547# dynamically changed for a probe function.
1548#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001549config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001550 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001551
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001552source "arch/Kconfig"
1553
Linus Torvalds1da177e2005-04-16 15:20:36 -07001554endmenu # General setup
1555
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001556config HAVE_GENERIC_DMA_COHERENT
1557 bool
1558 default n
1559
Linus Torvalds158a9622008-01-02 13:04:48 -08001560config SLABINFO
1561 bool
1562 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001563 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001564 default y
1565
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001566config RT_MUTEXES
1567 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001568
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569config BASE_SMALL
1570 int
1571 default 0 if BASE_FULL
1572 default 1 if !BASE_FULL
1573
Jan Engelhardt66da5732007-07-15 23:39:29 -07001574menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001575 bool "Enable loadable module support"
1576 help
1577 Kernel modules are small pieces of compiled code which can
1578 be inserted in the running kernel, rather than being
1579 permanently built into the kernel. You use the "modprobe"
1580 tool to add (and sometimes remove) them. If you say Y here,
1581 many parts of the kernel can be built as modules (by
1582 answering M instead of Y where indicated): this is most
1583 useful for infrequently used options which are not required
1584 for booting. For more information, see the man pages for
1585 modprobe, lsmod, modinfo, insmod and rmmod.
1586
1587 If you say Y here, you will need to run "make
1588 modules_install" to put the modules under /lib/modules/
1589 where modprobe can find them (you may need to be root to do
1590 this).
1591
1592 If unsure, say Y.
1593
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001594if MODULES
1595
Linus Torvalds826e4502008-05-04 17:04:16 -07001596config MODULE_FORCE_LOAD
1597 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001598 default n
1599 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001600 Allow loading of modules without version information (ie. modprobe
1601 --force). Forced module loading sets the 'F' (forced) taint flag and
1602 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001603
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604config MODULE_UNLOAD
1605 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001606 help
1607 Without this option you will not be able to unload any
1608 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001609 anyway), which makes your kernel smaller, faster
1610 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001611
1612config MODULE_FORCE_UNLOAD
1613 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001614 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001615 help
1616 This option allows you to force a module to unload, even if the
1617 kernel believes it is unsafe: the kernel will remove the module
1618 without waiting for anyone to stop using it (using the -f option to
1619 rmmod). This is mainly for kernel developers and desperate users.
1620 If unsure, say N.
1621
Linus Torvalds1da177e2005-04-16 15:20:36 -07001622config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001623 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001624 help
1625 Usually, you have to use modules compiled with your kernel.
1626 Saying Y here makes it sometimes possible to use modules
1627 compiled for different kernels, by adding enough information
1628 to the modules to (hopefully) spot any changes which would
1629 make them incompatible with the kernel you are running. If
1630 unsure, say N.
1631
1632config MODULE_SRCVERSION_ALL
1633 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001634 help
1635 Modules which contain a MODULE_VERSION get an extra "srcversion"
1636 field inserted into their modinfo section, which contains a
1637 sum of the source files which made it. This helps maintainers
1638 see exactly which source was used to build a module (since
1639 others sometimes change the module source without updating
1640 the version). With this option, such a "srcversion" field
1641 will be created for all modules. If unsure, say N.
1642
Rusty Russell106a4ee2012-09-26 10:09:40 +01001643config MODULE_SIG
1644 bool "Module signature verification"
1645 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001646 select KEYS
1647 select CRYPTO
1648 select ASYMMETRIC_KEY_TYPE
1649 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1650 select PUBLIC_KEY_ALGO_RSA
1651 select ASN1
1652 select OID_REGISTRY
1653 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001654 help
1655 Check modules for valid signatures upon load: the signature
1656 is simply appended to the module. For more information see
1657 Documentation/module-signing.txt.
1658
David Howellsea0b6dc2012-09-26 10:09:50 +01001659 !!!WARNING!!! If you enable this option, you MUST make sure that the
1660 module DOES NOT get stripped after being signed. This includes the
1661 debuginfo strip done by some packagers (such as rpmbuild) and
1662 inclusion into an initramfs that wants the module size reduced.
1663
Rusty Russell106a4ee2012-09-26 10:09:40 +01001664config MODULE_SIG_FORCE
1665 bool "Require modules to be validly signed"
1666 depends on MODULE_SIG
1667 help
1668 Reject unsigned modules or signed modules for which we don't have a
1669 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001670
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301671config MODULE_SIG_ALL
1672 bool "Automatically sign all modules"
1673 default y
1674 depends on MODULE_SIG
1675 help
1676 Sign all modules during make modules_install. Without this option,
1677 modules must be signed manually, using the scripts/sign-file tool.
1678
1679comment "Do not forget to sign required modules with scripts/sign-file"
1680 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1681
David Howellsea0b6dc2012-09-26 10:09:50 +01001682choice
1683 prompt "Which hash algorithm should modules be signed with?"
1684 depends on MODULE_SIG
1685 help
1686 This determines which sort of hashing algorithm will be used during
1687 signature generation. This algorithm _must_ be built into the kernel
1688 directly so that signature verification can take place. It is not
1689 possible to load a signed module containing the algorithm to check
1690 the signature on that module.
1691
1692config MODULE_SIG_SHA1
1693 bool "Sign modules with SHA-1"
1694 select CRYPTO_SHA1
1695
1696config MODULE_SIG_SHA224
1697 bool "Sign modules with SHA-224"
1698 select CRYPTO_SHA256
1699
1700config MODULE_SIG_SHA256
1701 bool "Sign modules with SHA-256"
1702 select CRYPTO_SHA256
1703
1704config MODULE_SIG_SHA384
1705 bool "Sign modules with SHA-384"
1706 select CRYPTO_SHA512
1707
1708config MODULE_SIG_SHA512
1709 bool "Sign modules with SHA-512"
1710 select CRYPTO_SHA512
1711
1712endchoice
1713
Michal Marek22753672013-01-25 13:41:00 +10301714config MODULE_SIG_HASH
1715 string
1716 depends on MODULE_SIG
1717 default "sha1" if MODULE_SIG_SHA1
1718 default "sha224" if MODULE_SIG_SHA224
1719 default "sha256" if MODULE_SIG_SHA256
1720 default "sha384" if MODULE_SIG_SHA384
1721 default "sha512" if MODULE_SIG_SHA512
1722
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001723endif # MODULES
1724
Rusty Russell98a79d62008-12-13 21:19:41 +10301725config INIT_ALL_POSSIBLE
1726 bool
1727 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301728 Back when each arch used to define their own cpu_online_mask and
1729 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301730 with all 1s, and others with all 0s. When they were centralised,
1731 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001732 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301733
Linus Torvalds1da177e2005-04-16 15:20:36 -07001734config STOP_MACHINE
1735 bool
1736 default y
1737 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1738 help
1739 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001740
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001741source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001742
1743config PREEMPT_NOTIFIERS
1744 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001745
Steffen Klassert16295be2010-01-06 19:47:10 +11001746config PADATA
1747 depends on SMP
1748 bool
1749
Andi Kleen754b7b62012-10-04 17:11:27 -07001750# Can be selected by architectures with broken toolchains
1751# that get confused by correct const<->read_only section
1752# mappings
1753config BROKEN_RODATA
1754 bool
1755
David Howells4520c6a2012-09-21 23:31:13 +01001756config ASN1
1757 tristate
1758 help
1759 Build a simple ASN.1 grammar compiler that produces a bytecode output
1760 that can be interpreted by the ASN.1 stream decoder and used to
1761 inform it as to what tags are to be expected in a stream and what
1762 functions to call on what tags.
1763
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001764source "kernel/Kconfig.locks"