blob: 8a1dac2f80a98c268a571d7609038095fd126e0e [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
31config EXPERIMENTAL
Kees Cook5a958db2012-10-02 11:36:31 -070032 bool
33 default y
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Linus Torvalds1da177e2005-04-16 15:20:36 -070035config BROKEN
36 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
38config BROKEN_ON_SMP
39 bool
40 depends on BROKEN || !SMP
41 default y
42
Linus Torvalds1da177e2005-04-16 15:20:36 -070043config INIT_ENV_ARG_LIMIT
44 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070045 default 32 if !UML
46 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080048 Maximum of each of the number of arguments and environment
49 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Roland McGrath84336462009-12-21 16:24:06 -080052config CROSS_COMPILE
53 string "Cross-compiler tool prefix"
54 help
55 Same as running 'make CROSS_COMPILE=prefix-' but stored for
56 default make runs in this kernel build directory. You don't
57 need to set this unless you want the configured kernel build
58 directory to select the cross-compiler automatically.
59
Linus Torvalds1da177e2005-04-16 15:20:36 -070060config LOCALVERSION
61 string "Local version - append to kernel release"
62 help
63 Append an extra string to the end of your kernel version.
64 This will show up when you type uname, for example.
65 The string you set here will be appended after the contents of
66 any files with a filename matching localversion* in your
67 object and source tree, in that order. Your total string can
68 be a maximum of 64 characters.
69
Ryan Andersonaaebf432005-07-31 04:57:49 -040070config LOCALVERSION_AUTO
71 bool "Automatically append version information to the version string"
72 default y
73 help
74 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020075 release tree by looking for git tags that belong to the current
76 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040077
78 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020079 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040080 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020081 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -040082
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020083 (The actual string used here is the first eight characters produced
84 by running the command:
85
86 $ git rev-parse --verify HEAD
87
88 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -040089
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -080090config HAVE_KERNEL_GZIP
91 bool
92
93config HAVE_KERNEL_BZIP2
94 bool
95
96config HAVE_KERNEL_LZMA
97 bool
98
Lasse Collin3ebe1242011-01-12 17:01:23 -080099config HAVE_KERNEL_XZ
100 bool
101
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800102config HAVE_KERNEL_LZO
103 bool
104
Alain Knaff30d65db2009-01-04 22:46:17 +0100105choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800106 prompt "Kernel compression mode"
107 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800108 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 -0800109 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100110 The linux kernel is a kind of self-extracting executable.
111 Several compression algorithms are available, which differ
112 in efficiency, compression and decompression speed.
113 Compression speed is only relevant when building a kernel.
114 Decompression speed is relevant at each boot.
115
116 If you have any problems with bzip2 or lzma compressed
117 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
118 version of this functionality (bzip2 only), for 2.4, was
119 supplied by Christian Ludwig)
120
121 High compression options are mostly useful for users, who
122 are low on disk space (embedded systems), but for whom ram
123 size matters less.
124
125 If in doubt, select 'gzip'
126
127config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800128 bool "Gzip"
129 depends on HAVE_KERNEL_GZIP
130 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800131 The old and tried gzip compression. It provides a good balance
132 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100133
134config KERNEL_BZIP2
135 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800136 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100137 help
138 Its compression ratio and speed is intermediate.
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700139 Decompression speed is slowest among the choices. The kernel
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800140 size is about 10% smaller with bzip2, in comparison to gzip.
141 Bzip2 uses a large amount of memory. For modern kernels you
142 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100143
144config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800145 bool "LZMA"
146 depends on HAVE_KERNEL_LZMA
147 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700148 This compression algorithm's ratio is best. Decompression speed
149 is between gzip and bzip2. Compression is slowest.
150 The kernel size is about 33% smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100151
Lasse Collin3ebe1242011-01-12 17:01:23 -0800152config KERNEL_XZ
153 bool "XZ"
154 depends on HAVE_KERNEL_XZ
155 help
156 XZ uses the LZMA2 algorithm and instruction set specific
157 BCJ filters which can improve compression ratio of executable
158 code. The size of the kernel is about 30% smaller with XZ in
159 comparison to gzip. On architectures for which there is a BCJ
160 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
161 will create a few percent smaller kernel than plain LZMA.
162
163 The speed is about the same as with LZMA: The decompression
164 speed of XZ is better than that of bzip2 but worse than gzip
165 and LZO. Compression is slow.
166
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800167config KERNEL_LZO
168 bool "LZO"
169 depends on HAVE_KERNEL_LZO
170 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700171 Its compression ratio is the poorest among the choices. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200172 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800173 (both compression and decompression) is the fastest.
174
Alain Knaff30d65db2009-01-04 22:46:17 +0100175endchoice
176
Josh Triplettbd5dc172011-06-15 15:08:28 -0700177config DEFAULT_HOSTNAME
178 string "Default hostname"
179 default "(none)"
180 help
181 This option determines the default system hostname before userspace
182 calls sethostname(2). The kernel traditionally uses "(none)" here,
183 but you may wish to use a different default here to make a minimal
184 system more usable with less configuration.
185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186config SWAP
187 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200188 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 default y
190 help
191 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100192 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 used to provide more virtual memory than the actual RAM present
194 in your computer. If unsure say Y.
195
196config SYSVIPC
197 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 ---help---
199 Inter Process Communication is a suite of library functions and
200 system calls which let processes (running programs) synchronize and
201 exchange information. It is generally considered to be a good thing,
202 and some programs won't run unless you say Y here. In particular, if
203 you want to run the DOS emulator dosemu under Linux (read the
204 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
205 you'll need to say Y here.
206
207 You can find documentation about IPC with "info ipc" and also in
208 section 6.4 of the Linux Programmer's Guide, available from
209 <http://www.tldp.org/guides.html>.
210
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800211config SYSVIPC_SYSCTL
212 bool
213 depends on SYSVIPC
214 depends on SYSCTL
215 default y
216
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217config POSIX_MQUEUE
218 bool "POSIX Message Queues"
Kees Cook19c92392012-10-02 11:19:29 -0700219 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 ---help---
221 POSIX variant of message queues is a part of IPC. In POSIX message
222 queues every message has a priority which decides about succession
223 of receiving it by a process. If you want to compile and run
224 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200225 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227 POSIX message queues are visible as a filesystem called 'mqueue'
228 and can be mounted somewhere if you want to do filesystem
229 operations on message queues.
230
231 If unsure, say Y.
232
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700233config POSIX_MQUEUE_SYSCTL
234 bool
235 depends on POSIX_MQUEUE
236 depends on SYSCTL
237 default y
238
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530239config FHANDLE
240 bool "open by fhandle syscalls"
241 select EXPORTFS
242 help
243 If you say Y here, a user level program will be able to map
244 file names to handle and then later use the handle for
245 different file system operations. This is useful in implementing
246 userspace file servers, which now track files using handles instead
247 of names. The handle would remain the same even if file names
248 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
249 syscalls.
250
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251config AUDIT
252 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100253 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 help
255 Enable auditing infrastructure that can be used with another
256 kernel subsystem, such as SELinux (which requires this for
257 logging of avc messages output). Does not do system-call
258 auditing without CONFIG_AUDITSYSCALL.
259
260config AUDITSYSCALL
261 bool "Enable system-call auditing support"
Will Deacon8f827a12012-07-06 15:48:16 +0100262 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 default y if SECURITY_SELINUX
264 help
265 Enable low-overhead system-call auditing infrastructure that
266 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500267 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
Eric Paris939a67f2009-12-17 20:12:06 -0500269config AUDIT_WATCH
270 def_bool y
271 depends on AUDITSYSCALL
272 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
Al Viro74c3cbe2007-07-22 08:04:18 -0400274config AUDIT_TREE
275 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400276 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500277 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400278
Eric Paris633b4542012-01-03 14:23:08 -0500279config AUDIT_LOGINUID_IMMUTABLE
280 bool "Make audit loginuid immutable"
281 depends on AUDIT
282 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800283 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500284 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
285 but should instead only allow setting its loginuid if it was never
286 previously set. On systems which use systemd or a similar central
287 process to restart login services this should be set to true. On older
288 systems in which an admin would typically have to directly stop and
289 start processes this should be set to false. Setting this to true allows
290 one to drop potentially dangerous capabilites from the login tasks,
291 but may not be backwards compatible with older init systems.
292
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000293source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200294source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000295
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200296menu "CPU/Task time and stats accounting"
297
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200298config VIRT_CPU_ACCOUNTING
299 bool
300
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200301choice
302 prompt "Cputime accounting"
303 default TICK_CPU_ACCOUNTING if !PPC64
Stephen Rothwell02fc8d32013-02-08 14:19:38 +1100304 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200305
306# Kind of a stub config for the pure tick based cputime accounting
307config TICK_CPU_ACCOUNTING
308 bool "Simple tick based cputime accounting"
309 depends on !S390
310 help
311 This is the basic tick based cputime accounting that maintains
312 statistics about user, system and idle time spent on per jiffies
313 granularity.
314
315 If unsure, say Y.
316
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200317config VIRT_CPU_ACCOUNTING_NATIVE
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200318 bool "Deterministic task and CPU time accounting"
319 depends on HAVE_VIRT_CPU_ACCOUNTING
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200320 select VIRT_CPU_ACCOUNTING
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200321 help
322 Select this option to enable more accurate task and CPU time
323 accounting. This is done by reading a CPU counter on each
324 kernel entry and exit and on transitions within the kernel
325 between system, softirq and hardirq state, so there is a
326 small performance impact. In the case of s390 or IBM POWER > 5,
327 this also enables accounting of stolen time on logically-partitioned
328 systems.
329
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200330config VIRT_CPU_ACCOUNTING_GEN
331 bool "Full dynticks CPU time accounting"
332 depends on HAVE_CONTEXT_TRACKING && 64BIT
333 select VIRT_CPU_ACCOUNTING
334 select CONTEXT_TRACKING
335 help
336 Select this option to enable task and CPU time accounting on full
337 dynticks systems. This accounting is implemented by watching every
338 kernel-user boundaries using the context tracking subsystem.
339 The accounting is thus performed at the expense of some significant
340 overhead.
341
342 For now this is only useful if you are working on the full
343 dynticks subsystem development.
344
345 If unsure, say N.
346
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200347config IRQ_TIME_ACCOUNTING
348 bool "Fine granularity task level IRQ time accounting"
349 depends on HAVE_IRQ_TIME_ACCOUNTING
350 help
351 Select this option to enable fine granularity task irq time
352 accounting. This is done by reading a timestamp on each
353 transitions between softirq and hardirq state, so there can be a
354 small performance impact.
355
356 If in doubt, say N here.
357
358endchoice
359
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200360config BSD_PROCESS_ACCT
361 bool "BSD Process Accounting"
362 help
363 If you say Y here, a user level program will be able to instruct the
364 kernel (via a special system call) to write process accounting
365 information to a file: whenever a process exits, information about
366 that process will be appended to the file by the kernel. The
367 information includes things such as creation time, owning user,
368 command name, memory usage, controlling terminal etc. (the complete
369 list is in the struct acct in <file:include/linux/acct.h>). It is
370 up to the user level program to do useful things with this
371 information. This is generally a good idea, so say Y.
372
373config BSD_PROCESS_ACCT_V3
374 bool "BSD Process Accounting version 3 file format"
375 depends on BSD_PROCESS_ACCT
376 default n
377 help
378 If you say Y here, the process accounting information is written
379 in a new file format that also logs the process IDs of each
380 process and it's parent. Note that this file format is incompatible
381 with previous v0/v1/v2 file formats, so you will need updated tools
382 for processing it. A preliminary version of these tools is available
383 at <http://www.gnu.org/software/acct/>.
384
385config TASKSTATS
Kees Cook19c92392012-10-02 11:19:29 -0700386 bool "Export task/process statistics through netlink"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200387 depends on NET
388 default n
389 help
390 Export selected statistics for tasks/processes through the
391 generic netlink interface. Unlike BSD process accounting, the
392 statistics are available during the lifetime of tasks/processes as
393 responses to commands. Like BSD accounting, they are sent to user
394 space on task exit.
395
396 Say N if unsure.
397
398config TASK_DELAY_ACCT
Kees Cook19c92392012-10-02 11:19:29 -0700399 bool "Enable per-task delay accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200400 depends on TASKSTATS
401 help
402 Collect information on time spent by a task waiting for system
403 resources like cpu, synchronous block I/O completion and swapping
404 in pages. Such statistics can help in setting a task's priorities
405 relative to other tasks for cpu, io, rss limits etc.
406
407 Say N if unsure.
408
409config TASK_XACCT
Kees Cook19c92392012-10-02 11:19:29 -0700410 bool "Enable extended accounting over taskstats"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200411 depends on TASKSTATS
412 help
413 Collect extended task accounting data and send the data
414 to userland for processing over the taskstats interface.
415
416 Say N if unsure.
417
418config TASK_IO_ACCOUNTING
Kees Cook19c92392012-10-02 11:19:29 -0700419 bool "Enable per-task storage I/O accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200420 depends on TASK_XACCT
421 help
422 Collect information on the number of bytes of storage I/O which this
423 task has caused.
424
425 Say N if unsure.
426
427endmenu # "CPU/Task time and stats accounting"
428
Mike Travisc903ff82009-01-15 12:28:29 -0800429menu "RCU Subsystem"
430
431choice
432 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700433 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800434
Mike Travisc903ff82009-01-15 12:28:29 -0800435config TREE_RCU
436 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700437 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800438 help
439 This option selects the RCU implementation that is
440 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700441 thousands of CPUs. It also scales down nicely to
442 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800443
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700444config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700445 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800446 depends on PREEMPT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700447 help
448 This option selects the RCU implementation that is
449 designed for very large SMP systems with hundreds or
450 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700451 is also required. It also scales down nicely to
452 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700453
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800454 Select this option if you are unsure.
455
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700456config TINY_RCU
457 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700458 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700459 help
460 This option selects the RCU implementation that is
461 designed for UP systems from which real-time response
462 is not required. This option greatly reduces the
463 memory footprint of RCU.
464
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700465config TINY_PREEMPT_RCU
466 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700467 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700468 help
469 This option selects the RCU implementation that is designed
470 for real-time UP systems. This option greatly reduces the
471 memory footprint of RCU.
472
Mike Travisc903ff82009-01-15 12:28:29 -0800473endchoice
474
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700475config PREEMPT_RCU
476 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
477 help
478 This option enables preemptible-RCU code that is common between
479 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
480
Paul E. McKenney6bfc09e2012-10-19 12:49:17 -0700481config RCU_STALL_COMMON
482 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
483 help
484 This option enables RCU CPU stall code that is common between
485 the TINY and TREE variants of RCU. The purpose is to allow
486 the tiny variants to disable RCU CPU stall warnings, while
487 making these warnings mandatory for the tree variants.
488
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100489config CONTEXT_TRACKING
490 bool
491
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200492config RCU_USER_QS
493 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100494 depends on HAVE_CONTEXT_TRACKING && SMP
495 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200496 help
497 This option sets hooks on kernel / userspace boundaries and
498 puts RCU in extended quiescent state when the CPU runs in
499 userspace. It means that when a CPU runs in userspace, it is
500 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700501 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200502
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200503 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100504 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700505 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200506
507 If unsure say N
508
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100509config CONTEXT_TRACKING_FORCE
510 bool "Force context tracking"
511 depends on CONTEXT_TRACKING
Frederic Weisbecker8b438762013-02-26 15:37:59 +0100512 default CONTEXT_TRACKING
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200513 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100514 Probe on user/kernel boundaries by default in order to
515 test the features that rely on it such as userspace RCU extended
516 quiescent states.
517 This test is there for debugging until we have a real user like the
518 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200519
Mike Travisc903ff82009-01-15 12:28:29 -0800520config RCU_FANOUT
521 int "Tree-based hierarchical RCU fanout value"
522 range 2 64 if 64BIT
523 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700524 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800525 default 64 if 64BIT
526 default 32 if !64BIT
527 help
528 This option controls the fanout of hierarchical implementations
529 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700530 large numbers of CPUs. This value must be at least the fourth
531 root of NR_CPUS, which allows NR_CPUS to be insanely large.
532 The default value of RCU_FANOUT should be used for production
533 systems, but if you are stress-testing the RCU implementation
534 itself, small RCU_FANOUT values allow you to test large-system
535 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800536
537 Select a specific number if testing RCU itself.
538 Take the default if unsure.
539
Paul E. McKenney8932a632012-04-19 12:20:14 -0700540config RCU_FANOUT_LEAF
541 int "Tree-based hierarchical RCU leaf-level fanout value"
542 range 2 RCU_FANOUT if 64BIT
543 range 2 RCU_FANOUT if !64BIT
544 depends on TREE_RCU || TREE_PREEMPT_RCU
545 default 16
546 help
547 This option controls the leaf-level fanout of hierarchical
548 implementations of RCU, and allows trading off cache misses
549 against lock contention. Systems that synchronize their
550 scheduling-clock interrupts for energy-efficiency reasons will
551 want the default because the smaller leaf-level fanout keeps
552 lock contention levels acceptably low. Very large systems
553 (hundreds or thousands of CPUs) will instead want to set this
554 value to the maximum value possible in order to reduce the
555 number of cache misses incurred during RCU's grace-period
556 initialization. These systems tend to run CPU-bound, and thus
557 are not helped by synchronized interrupts, and thus tend to
558 skew them, which reduces lock contention enough that large
559 leaf-level fanouts work well.
560
561 Select a specific number if testing RCU itself.
562
563 Select the maximum permissible value for large systems.
564
565 Take the default if unsure.
566
Mike Travisc903ff82009-01-15 12:28:29 -0800567config RCU_FANOUT_EXACT
568 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700569 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800570 default n
571 help
572 This option forces use of the exact RCU_FANOUT value specified,
573 regardless of imbalances in the hierarchy. This is useful for
574 testing RCU itself, and might one day be useful on systems with
575 strong NUMA behavior.
576
577 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
578
579 Say N if unsure.
580
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800581config RCU_FAST_NO_HZ
582 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700583 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800584 default n
585 help
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700586 This option causes RCU to attempt to accelerate grace periods in
587 order to allow CPUs to enter dynticks-idle state more quickly.
588 On the other hand, this option increases the overhead of the
589 dynticks-idle checking, thus degrading scheduling latency.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800590
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700591 Say Y if energy efficiency is critically important, and you don't
592 care about real-time response.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800593
594 Say N if you are unsure.
595
Mike Travisc903ff82009-01-15 12:28:29 -0800596config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700597 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800598 select DEBUG_FS
599 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700600 This option provides tracing for the TREE_RCU and
601 TREE_PREEMPT_RCU implementations, permitting Makefile to
602 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800603
Paul E. McKenney24278d12010-09-27 17:25:23 -0700604config RCU_BOOST
605 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800606 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700607 default n
608 help
609 This option boosts the priority of preempted RCU readers that
610 block the current preemptible RCU grace period for too long.
611 This option also prevents heavy loads from blocking RCU
612 callback invocation for all flavors of RCU.
613
614 Say Y here if you are working with real-time apps or heavy loads
615 Say N here if you are unsure.
616
617config RCU_BOOST_PRIO
618 int "Real-time priority to boost RCU readers to"
619 range 1 99
620 depends on RCU_BOOST
621 default 1
622 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700623 This option specifies the real-time priority to which long-term
624 preempted RCU readers are to be boosted. If you are working
625 with a real-time application that has one or more CPU-bound
626 threads running at a real-time priority level, you should set
627 RCU_BOOST_PRIO to a priority higher then the highest-priority
628 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
629 of 1 is appropriate in the common case, which is real-time
630 applications that do not have any CPU-bound threads.
631
632 Some real-time applications might not have a single real-time
633 thread that saturates a given CPU, but instead might have
634 multiple real-time threads that, taken together, fully utilize
635 that CPU. In this case, you should set RCU_BOOST_PRIO to
636 a priority higher than the lowest-priority thread that is
637 conspiring to prevent the CPU from running any non-real-time
638 tasks. For example, if one thread at priority 10 and another
639 thread at priority 5 are between themselves fully consuming
640 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
641 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700642
643 Specify the real-time priority, or take the default if unsure.
644
645config RCU_BOOST_DELAY
646 int "Milliseconds to delay boosting after RCU grace-period start"
647 range 0 3000
648 depends on RCU_BOOST
649 default 500
650 help
651 This option specifies the time to wait after the beginning of
652 a given grace period before priority-boosting preempted RCU
653 readers blocking that grace period. Note that any RCU reader
654 blocking an expedited RCU grace period is boosted immediately.
655
656 Accept the default if unsure.
657
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700658config RCU_NOCB_CPU
659 bool "Offload RCU callback processing from boot-selected CPUs"
660 depends on TREE_RCU || TREE_PREEMPT_RCU
661 default n
662 help
663 Use this option to reduce OS jitter for aggressive HPC or
664 real-time workloads. It can also be used to offload RCU
665 callback invocation to energy-efficient CPUs in battery-powered
666 asymmetric multiprocessors.
667
668 This option offloads callback invocation from the set of
669 CPUs specified at boot time by the rcu_nocbs parameter.
670 For each such CPU, a kthread ("rcuoN") will be created to
671 invoke callbacks, where the "N" is the CPU being offloaded.
672 Nothing prevents this kthread from running on the specified
673 CPUs, but (1) the kthreads may be preempted between each
674 callback, and (2) affinity or cgroups can be used to force
675 the kthreads to run on whatever set of CPUs is desired.
676
677 Say Y here if you want reduced OS jitter on selected CPUs.
678 Say N here if you are unsure.
679
Mike Travisc903ff82009-01-15 12:28:29 -0800680endmenu # "RCU Subsystem"
681
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700683 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 ---help---
685 This option enables the complete Linux kernel ".config" file
686 contents to be saved in the kernel. It provides documentation
687 of which kernel options are used in a running kernel or in an
688 on-disk kernel. This information can be extracted from the kernel
689 image file with the script scripts/extract-ikconfig and used as
690 input to rebuild the current kernel or to build another kernel.
691 It can also be extracted from a running kernel by reading
692 /proc/config.gz if enabled (below).
693
694config IKCONFIG_PROC
695 bool "Enable access to .config through /proc/config.gz"
696 depends on IKCONFIG && PROC_FS
697 ---help---
698 This option enables access to the kernel configuration file
699 through /proc/config.gz.
700
Alistair John Strachan794543a2007-05-08 00:31:15 -0700701config LOG_BUF_SHIFT
702 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
703 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700704 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700705 help
706 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700707 Examples:
708 17 => 128 KB
709 16 => 64 KB
710 15 => 32 KB
711 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700712 13 => 8 KB
713 12 => 4 KB
714
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800715#
716# Architectures with an unreliable sched_clock() should select this:
717#
718config HAVE_UNSTABLE_SCHED_CLOCK
719 bool
720
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200721#
722# For architectures that want to enable the support for NUMA-affine scheduler
723# balancing logic:
724#
725config ARCH_SUPPORTS_NUMA_BALANCING
726 bool
727
728# For architectures that (ab)use NUMA to represent different memory regions
729# all cpu-local but of different latencies, such as SuperH.
730#
731config ARCH_WANT_NUMA_VARIABLE_LOCALITY
732 bool
733
734#
735# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
736config ARCH_WANTS_PROT_NUMA_PROT_NONE
737 bool
738
739config ARCH_USES_NUMA_PROT_NONE
740 bool
741 default y
742 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
743 depends on NUMA_BALANCING
744
Mel Gorman1a687c22012-11-22 11:16:36 +0000745config NUMA_BALANCING_DEFAULT_ENABLED
746 bool "Automatically enable NUMA aware memory/task placement"
747 default y
748 depends on NUMA_BALANCING
749 help
750 If set, autonumic NUMA balancing will be enabled if running on a NUMA
751 machine.
752
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200753config NUMA_BALANCING
754 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200755 depends on ARCH_SUPPORTS_NUMA_BALANCING
756 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
757 depends on SMP && NUMA && MIGRATION
758 help
759 This option adds support for automatic NUMA aware memory/task placement.
760 The mechanism is quite primitive and is based on migrating memory when
761 it is references to the node the task is running on.
762
763 This system will be inactive on UMA systems.
764
Li Zefan23964d22009-01-15 13:50:58 -0800765menuconfig CGROUPS
766 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800767 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700768 help
Li Zefan23964d22009-01-15 13:50:58 -0800769 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800770 use with process control subsystems such as Cpusets, CFS, memory
771 controls or device isolation.
772 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800773 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800774 - Documentation/cgroups/ (features for grouping, isolation
775 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700776
777 Say N if unsure.
778
Li Zefan23964d22009-01-15 13:50:58 -0800779if CGROUPS
780
Paul Menage006cb992007-10-18 23:39:43 -0700781config CGROUP_DEBUG
782 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700783 default n
Paul Menage006cb992007-10-18 23:39:43 -0700784 help
785 This option enables a simple cgroup subsystem that
786 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800787 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700788
Li Zefan23964d22009-01-15 13:50:58 -0800789 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700790
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700791config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800792 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800793 help
794 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700795 cgroup.
796
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700797config CGROUP_DEVICE
798 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700799 help
800 Provides a cgroup implementing whitelists for devices which
801 a process in the cgroup can mknod or open.
802
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803config CPUSETS
804 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700806 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 allow dynamically partitioning a system into sets of CPUs and
808 Memory Nodes and assigning tasks to run only within those sets.
809 This is primarily useful on large SMP or NUMA systems.
810
811 Say N if unsure.
812
Li Zefan23964d22009-01-15 13:50:58 -0800813config PROC_PID_CPUSET
814 bool "Include legacy /proc/<pid>/cpuset file"
815 depends on CPUSETS
816 default y
817
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100818config CGROUP_CPUACCT
819 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100820 help
821 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800822 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100823
Pavel Emelianove552b662008-02-07 00:13:49 -0800824config RESOURCE_COUNTERS
825 bool "Resource counters"
826 help
827 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800828 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800829
Andrew Mortonc255a452012-07-31 16:43:02 -0700830config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800831 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700832 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700833 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800834 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700835 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100836 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800837
838 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700839 associated with each page of memory in the system. By this,
840 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
841 usage tracking struct at boot. Total amount of this is printed out
842 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800843
844 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700845 sure you need the memory resource controller. Even when you enable
846 this, you can set "cgroup_disable=memory" at your boot option to
847 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800848 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800849
Balbir Singhcf475ad2008-04-29 01:00:16 -0700850 This config option also selects MM_OWNER config option, which
851 could in turn add some fork/exit overhead.
852
Andrew Mortonc255a452012-07-31 16:43:02 -0700853config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700854 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700855 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800856 help
857 Add swap management feature to memory resource controller. When you
858 enable this, you can limit mem+swap usage per cgroup. In other words,
859 when you disable this, memory resource controller has no cares to
860 usage of swap...a process can exhaust all of the swap. This extension
861 is useful when you want to avoid exhaustion swap but this itself
862 adds more overheads and consumes memory for remembering information.
863 Especially if you use 32bit system or small memory system, please
864 be careful about enabling this. When memory resource controller
865 is disabled by boot option, this will be automatically disabled and
866 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700867 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700868 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
869 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700870config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800871 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700872 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800873 default y
874 help
875 Memory Resource Controller Swap Extension comes with its price in
876 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700877 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800878 and let the user enable it by swapaccount boot command line
879 parameter should have this option unselected.
880 For those who want to have the feature enabled by default should
881 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700882 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700883config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700884 bool "Memory Resource Controller Kernel Memory accounting"
885 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800886 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000887 help
888 The Kernel Memory extension for Memory Resource Controller can limit
889 the amount of memory used by kernel objects in the system. Those are
890 fundamentally different from the entities handled by the standard
891 Memory Controller, which are page-based, and can be swapped. Users of
892 the kmem extension can use it to guarantee that no group of processes
893 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800894
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700895config CGROUP_HUGETLB
896 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700897 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700898 default n
899 help
900 Provides a cgroup Resource Controller for HugeTLB pages.
901 When you enable this, you can put a per cgroup limit on HugeTLB usage.
902 The limit is enforced during page fault. Since HugeTLB doesn't
903 support page reclaim, enforcing the limit at page fault time implies
904 that, the application will get SIGBUS signal if it tries to access
905 HugeTLB pages beyond its limit. This requires the application to know
906 beforehand how much HugeTLB pages it would require for its use. The
907 control group is tracked in the third page lru pointer. This means
908 that we cannot use the controller with huge page less than 3 pages.
909
Stephane Eraniane5d13672011-02-14 11:20:01 +0200910config CGROUP_PERF
911 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
912 depends on PERF_EVENTS && CGROUPS
913 help
914 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800915 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200916 designated cpu.
917
918 Say N if unsure.
919
Dhaval Giani7c941432010-01-20 13:26:18 +0100920menuconfig CGROUP_SCHED
921 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100922 default n
923 help
924 This feature lets CPU scheduler recognize task groups and control CPU
925 bandwidth allocation to such task groups. It uses cgroups to group
926 tasks.
927
928if CGROUP_SCHED
929config FAIR_GROUP_SCHED
930 bool "Group scheduling for SCHED_OTHER"
931 depends on CGROUP_SCHED
932 default CGROUP_SCHED
933
Paul Turnerab84d312011-07-21 09:43:28 -0700934config CFS_BANDWIDTH
935 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -0700936 depends on FAIR_GROUP_SCHED
937 default n
938 help
939 This option allows users to define CPU bandwidth rates (limits) for
940 tasks running within the fair group scheduler. Groups with no limit
941 set are considered to be unconstrained and will run with no
942 restriction.
943 See tip/Documentation/scheduler/sched-bwc.txt for more information.
944
Dhaval Giani7c941432010-01-20 13:26:18 +0100945config RT_GROUP_SCHED
946 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +0100947 depends on CGROUP_SCHED
948 default n
949 help
950 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800951 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100952 schedule realtime tasks for non-root users until you allocate
953 realtime bandwidth for them.
954 See Documentation/scheduler/sched-rt-group.txt for more information.
955
956endif #CGROUP_SCHED
957
Vivek Goyalafc24d42010-04-26 19:27:56 +0200958config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800959 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700960 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200961 default n
962 ---help---
963 Generic block IO controller cgroup interface. This is the common
964 cgroup interface which should be used by various IO controlling
965 policies.
966
967 Currently, CFQ IO scheduler uses it to recognize task groups and
968 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400969 to such task groups. It is also used by bio throttling logic in
970 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200971
972 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400973 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000974 enabling proportional weight division of disk bandwidth in CFQ, set
975 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000976 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200977
978 See Documentation/cgroups/blkio-controller.txt for more information.
979
980config DEBUG_BLK_CGROUP
981 bool "Enable Block IO controller debugging"
982 depends on BLK_CGROUP
983 default n
984 ---help---
985 Enable some debugging help. Currently it exports additional stat
986 files in a cgroup which can be useful for debugging.
987
Li Zefan23964d22009-01-15 13:50:58 -0800988endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800989
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800990config CHECKPOINT_RESTORE
991 bool "Checkpoint/restore support" if EXPERT
992 default n
993 help
994 Enables additional kernel features in a sake of checkpoint/restore.
995 In particular it adds auxiliary prctl codes to setup process text,
996 data and heap segment sizes, and a few additional /proc filesystem
997 entries.
998
999 If unsure, say N here.
1000
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001001menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001002 bool "Namespaces support" if EXPERT
1003 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001004 help
1005 Provides the way to make tasks work with different objects using
1006 the same id. For example same IPC id may refer to different objects
1007 or same user id or pid may refer to different tasks when used in
1008 different namespaces.
1009
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001010if NAMESPACES
1011
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001012config UTS_NS
1013 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001014 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001015 help
1016 In this namespace tasks see different info provided with the
1017 uname() system call
1018
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001019config IPC_NS
1020 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001021 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001022 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001023 help
1024 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001025 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001026
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001027config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001028 bool "User namespace"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001029 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001030 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001031
Eric W. Biederman5673a942011-11-17 10:23:55 -08001032 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001033 help
1034 This allows containers, i.e. vservers, to use user namespaces
1035 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001036
1037 When user namespaces are enabled in the kernel it is
1038 recommended that the MEMCG and MEMCG_KMEM options also be
1039 enabled and that user-space use the memory control groups to
1040 limit the amount of memory a memory unprivileged users can
1041 use.
1042
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001043 If unsure, say N.
1044
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001045config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001046 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001047 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001048 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001049 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001050 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001051 pid namespaces. This is a building block of containers.
1052
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001053config NET_NS
1054 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001055 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001056 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001057 help
1058 Allow user space to create what appear to be multiple instances
1059 of the network stack.
1060
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001061endif # NAMESPACES
1062
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001063config UIDGID_CONVERTED
1064 # True if all of the selected software conmponents are known
1065 # to have uid_t and gid_t converted to kuid_t and kgid_t
1066 # where appropriate and are otherwise safe to use with
1067 # the user namespace.
1068 bool
1069 default y
1070
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001071 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001072 depends on XFS_FS = n
1073
Eric W. Biederman5673a942011-11-17 10:23:55 -08001074config UIDGID_STRICT_TYPE_CHECKS
1075 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001076 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001077 default n
1078 help
1079 While the nececessary conversions are being added to all subsystems this option allows
1080 the code to continue to build for unconverted subsystems.
1081
1082 Say Y here if you want the strict type checking enabled
1083
Mike Galbraith5091faa2010-11-30 14:18:03 +01001084config SCHED_AUTOGROUP
1085 bool "Automatic process group scheduling"
1086 select EVENTFD
1087 select CGROUPS
1088 select CGROUP_SCHED
1089 select FAIR_GROUP_SCHED
1090 help
1091 This option optimizes the scheduler for common desktop workloads by
1092 automatically creating and populating task groups. This separation
1093 of workloads isolates aggressive CPU burners (like build jobs) from
1094 desktop applications. Task group autogeneration is currently based
1095 upon task session.
1096
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001097config MM_OWNER
1098 bool
1099
1100config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001101 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001102 depends on SYSFS
1103 default n
1104 help
1105 This option adds code that switches the layout of the "block" class
1106 devices, to not show up in /sys/class/block/, but only in
1107 /sys/block/.
1108
1109 This switch is only active when the sysfs.deprecated=1 boot option is
1110 passed or the SYSFS_DEPRECATED_V2 option is set.
1111
1112 This option allows new kernels to run on old distributions and tools,
1113 which might get confused by /sys/class/block/. Since 2007/2008 all
1114 major distributions and tools handle this just fine.
1115
1116 Recent distributions and userspace tools after 2009/2010 depend on
1117 the existence of /sys/class/block/, and will not work with this
1118 option enabled.
1119
1120 Only if you are using a new kernel on an old distribution, you might
1121 need to say Y here.
1122
1123config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001124 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001125 default n
1126 depends on SYSFS
1127 depends on SYSFS_DEPRECATED
1128 help
1129 Enable deprecated sysfs by default.
1130
1131 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1132 option.
1133
1134 Only if you are using a new kernel on an old distribution, you might
1135 need to say Y here. Even then, odds are you would not need it
1136 enabled, you can always pass the boot option if absolutely necessary.
1137
1138config RELAY
1139 bool "Kernel->user space relay support (formerly relayfs)"
1140 help
1141 This option enables support for relay interface support in
1142 certain file systems (such as debugfs).
1143 It is designed to provide an efficient mechanism for tools and
1144 facilities to relay large amounts of data from kernel space to
1145 user space.
1146
1147 If unsure, say N.
1148
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001149config BLK_DEV_INITRD
1150 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1151 depends on BROKEN || !FRV
1152 help
1153 The initial RAM filesystem is a ramfs which is loaded by the
1154 boot loader (loadlin or lilo) and that is mounted as root
1155 before the normal boot procedure. It is typically used to
1156 load modules needed to mount the "real" root file system,
1157 etc. See <file:Documentation/initrd.txt> for details.
1158
1159 If RAM disk support (BLK_DEV_RAM) is also included, this
1160 also enables initial RAM disk (initrd) support and adds
1161 15 Kbytes (more on some other architectures) to the kernel size.
1162
1163 If unsure say Y.
1164
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001165if BLK_DEV_INITRD
1166
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001167source "usr/Kconfig"
1168
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001169endif
1170
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001171config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001172 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001173 help
1174 Enabling this option will pass "-Os" instead of "-O2" to gcc
1175 resulting in a smaller kernel.
1176
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001177 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001178
Randy Dunlap08470622006-09-30 23:28:13 -07001179config SYSCTL
1180 bool
1181
Randy Dunlapb943c462009-03-10 12:55:46 -07001182config ANON_INODES
1183 bool
1184
David Rientjes6a108a12011-01-20 14:44:16 -08001185menuconfig EXPERT
1186 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001187 # Unhide debug options, to make the on-by-default options visible
1188 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 help
1190 This option allows certain base kernel options and settings
1191 to be disabled or tweaked. This is for specialized
1192 environments which can tolerate a "non-standard" kernel.
1193 Only use this if you really know what you are doing.
1194
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001195config HAVE_UID16
1196 bool
1197
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001198config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001199 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001200 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001201 default y
1202 help
1203 This enables the legacy 16-bit UID syscall wrappers.
1204
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001205config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001206 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001207 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001208 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001209 select SYSCTL
1210 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001211 sys_sysctl uses binary paths that have been found challenging
1212 to properly maintain and use. The interface in /proc/sys
1213 using paths with ascii names is now the primary path to this
1214 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001215
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001216 Almost nothing using the binary sysctl interface so if you are
1217 trying to save some space it is probably safe to disable this,
1218 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001219
WANG Congc736de62011-11-02 13:39:25 -07001220 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001221
Catalin Marinas7ac57a82012-10-08 16:28:16 -07001222config SYSCTL_EXCEPTION_TRACE
1223 bool
1224 help
1225 Enable support for /proc/sys/debug/exception-trace.
1226
Vineet Guptab6fca722013-01-09 20:06:28 +05301227config SYSCTL_ARCH_UNALIGN_NO_WARN
1228 bool
1229 help
1230 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1231 Allows arch to define/use @no_unaligned_warning to possibly warn
1232 about unaligned access emulation going on under the hood.
1233
Vineet Guptabf14e3b2013-01-18 15:12:24 +05301234config SYSCTL_ARCH_UNALIGN_ALLOW
1235 bool
1236 help
1237 Enable support for /proc/sys/kernel/unaligned-trap
1238 Allows arches to define/use @unaligned_enabled to runtime toggle
1239 the unaligned access emulation.
1240 see arch/parisc/kernel/unaligned.c for reference
1241
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001243 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 default y
1245 help
1246 Say Y here to let the kernel print out symbolic crash information and
1247 symbolic stack backtraces. This increases the size of the kernel
1248 somewhat, as all symbols have to be loaded into the kernel image.
1249
1250config KALLSYMS_ALL
1251 bool "Include all symbols in kallsyms"
1252 depends on DEBUG_KERNEL && KALLSYMS
1253 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001254 Normally kallsyms only contains the symbols of functions for nicer
1255 OOPS messages and backtraces (i.e., symbols from the text and inittext
1256 sections). This is sufficient for most cases. And only in very rare
1257 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1258 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001260 This option makes sure that all symbols are loaded into the kernel
1261 image (i.e., symbols from all sections) in cost of increased kernel
1262 size (depending on the kernel configuration, it may be 300KiB or
1263 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001264
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001265 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001266
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001267config HOTPLUG
Greg Kroah-Hartman45f035a2012-09-04 17:01:08 -07001268 def_bool y
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001269
Matt Mackalld59745c2005-05-01 08:59:02 -07001270config PRINTK
1271 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001272 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001273 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001274 help
1275 This option enables normal printk support. Removing it
1276 eliminates most of the message strings from the kernel image
1277 and makes the kernel more or less silent. As this makes it
1278 very difficult to diagnose system problems, saying N here is
1279 strongly discouraged.
1280
Matt Mackallc8538a72005-05-01 08:59:01 -07001281config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001282 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001283 default y
1284 help
1285 Disabling this option eliminates support for BUG and WARN, reducing
1286 the size of your kernel image and potentially quietly ignoring
1287 numerous fatal conditions. You should only consider disabling this
1288 option for embedded systems with no facilities for reporting errors.
1289 Just say Y.
1290
Matt Mackall708e9a72006-01-08 01:05:25 -08001291config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001292 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001293 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001294 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001295 help
1296 Enable support for generating core dumps. Disabling saves about 4k.
1297
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001298
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001299config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001300 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001301 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001302 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001303 default y
1304 help
1305 This option allows to disable the internal PC-Speaker
1306 support, saving some memory.
1307
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001308config HAVE_PCSPKR_PLATFORM
1309 bool
1310
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311config BASE_FULL
1312 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001313 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 help
1315 Disabling this option reduces the size of miscellaneous core
1316 kernel data structures. This saves memory on small machines,
1317 but may reduce performance.
1318
1319config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001320 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001322 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 help
1324 Disabling this option will cause the kernel to be built without
1325 support for "fast userspace mutexes". The resulting kernel may not
1326 run glibc-based applications correctly.
1327
1328config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001329 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001331 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 help
1333 Disabling this option will cause the kernel to be built without
1334 support for epoll family of system calls.
1335
Davide Libenzifba2afa2007-05-10 22:23:13 -07001336config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001337 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001338 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001339 default y
1340 help
1341 Enable the signalfd() system call that allows to receive signals
1342 on a file descriptor.
1343
1344 If unsure, say Y.
1345
Davide Libenzib215e282007-05-10 22:23:16 -07001346config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001347 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001348 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001349 default y
1350 help
1351 Enable the timerfd() system call that allows to receive timer
1352 events on a file descriptor.
1353
1354 If unsure, say Y.
1355
Davide Libenzie1ad7462007-05-10 22:23:19 -07001356config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001357 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001358 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001359 default y
1360 help
1361 Enable the eventfd() system call that allows to receive both
1362 kernel notification (ie. KAIO) or userspace notifications.
1363
1364 If unsure, say Y.
1365
Linus Torvalds1da177e2005-04-16 15:20:36 -07001366config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001367 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001368 default y
1369 depends on MMU
1370 help
1371 The shmem is an internal filesystem used to manage shared memory.
1372 It is backed by swap and manages resource limits. It is also exported
1373 to userspace as tmpfs if TMPFS is enabled. Disabling this
1374 option replaces shmem and tmpfs with the much simpler ramfs code,
1375 which may be appropriate on small systems without swap.
1376
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001377config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001378 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001379 default y
1380 help
1381 This option enables POSIX asynchronous I/O which may by used
1382 by some high performance threaded applications. Disabling
1383 this option saves about 7k.
1384
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001385config EMBEDDED
1386 bool "Embedded system"
1387 select EXPERT
1388 help
1389 This option should be enabled if compiling the kernel for
1390 an embedded system so certain expert options are available
1391 for configuration.
1392
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001393config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001394 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001395 help
1396 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001397
Peter Zijlstra906010b2009-09-21 16:08:49 +02001398config PERF_USE_VMALLOC
1399 bool
1400 help
1401 See tools/perf/design.txt for details
1402
Ingo Molnar57c0c152009-09-21 12:20:38 +02001403menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001404
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001405config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001406 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001407 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001408 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001409 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001410 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001411 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001412 Enable kernel support for various performance events provided
1413 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001414
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001415 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001416 use of generic tracepoints.
1417
1418 Most modern CPUs support performance events via performance
1419 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001420 types of hw events: such as instructions executed, cachemisses
1421 suffered, or branches mis-predicted - without slowing down the
1422 kernel or applications. These registers can also trigger interrupts
1423 when a threshold number of events have passed - and can thus be
1424 used to profile the code that runs on that CPU.
1425
Ingo Molnar57c0c152009-09-21 12:20:38 +02001426 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001427 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001428 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001429 provides per task and per CPU counters, and it provides event
1430 capabilities on top of those.
1431
1432 Say Y if unsure.
1433
Peter Zijlstra906010b2009-09-21 16:08:49 +02001434config DEBUG_PERF_USE_VMALLOC
1435 default n
1436 bool "Debug: use vmalloc to back perf mmap() buffers"
1437 depends on PERF_EVENTS && DEBUG_KERNEL
1438 select PERF_USE_VMALLOC
1439 help
1440 Use vmalloc memory to back perf mmap() buffers.
1441
1442 Mostly useful for debugging the vmalloc code on platforms
1443 that don't require it.
1444
1445 Say N if unsure.
1446
Thomas Gleixner0793a612008-12-04 20:12:29 +01001447endmenu
1448
Christoph Lameterf8891e52006-06-30 01:55:45 -07001449config VM_EVENT_COUNTERS
1450 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001451 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001452 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001453 VM event counters are needed for event counts to be shown.
1454 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001455 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001456 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001457
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001458config PCI_QUIRKS
1459 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001460 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001461 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001462 help
1463 This enables workarounds for various PCI chipset
1464 bugs/quirks. Disable this only if your target machine is
1465 unaffected by PCI quirks.
1466
Christoph Lameter41ecc552007-05-09 02:32:44 -07001467config SLUB_DEBUG
1468 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001469 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001470 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001471 help
1472 SLUB has extensive debug support features. Disabling these can
1473 result in significant savings in code size. This also disables
1474 SLUB sysfs support. /sys/slab will not exist and there will be
1475 no support for cache validation etc.
1476
Randy Dunlapb943c462009-03-10 12:55:46 -07001477config COMPAT_BRK
1478 bool "Disable heap randomization"
1479 default y
1480 help
1481 Randomizing heap placement makes heap exploits harder, but it
1482 also breaks ancient binaries (including anything libc5 based).
1483 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001484 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001485 /proc/sys/kernel/randomize_va_space to 2.
1486
1487 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1488
Christoph Lameter81819f02007-05-06 14:49:36 -07001489choice
1490 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001491 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001492 help
1493 This option allows to select a slab allocator.
1494
1495config SLAB
1496 bool "SLAB"
1497 help
1498 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001499 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001500 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001501
1502config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001503 bool "SLUB (Unqueued Allocator)"
1504 help
1505 SLUB is a slab allocator that minimizes cache line usage
1506 instead of managing queues of cached objects (SLAB approach).
1507 Per cpu caching is realized using slabs of objects instead
1508 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001509 and has enhanced diagnostics. SLUB is the default choice for
1510 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001511
1512config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001513 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001514 bool "SLOB (Simple Allocator)"
1515 help
Matt Mackall37291452008-02-04 22:29:38 -08001516 SLOB replaces the stock allocator with a drastically simpler
1517 allocator. SLOB is generally more space efficient but
1518 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001519
1520endchoice
1521
Jie Zhangea637632009-12-14 18:00:02 -08001522config MMAP_ALLOW_UNINITIALIZED
1523 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001524 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001525 default n
1526 help
1527 Normally, and according to the Linux spec, anonymous memory obtained
1528 from mmap() has it's contents cleared before it is passed to
1529 userspace. Enabling this config option allows you to request that
1530 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1531 providing a huge performance boost. If this option is not enabled,
1532 then the flag will be ignored.
1533
1534 This is taken advantage of by uClibc's malloc(), and also by
1535 ELF-FDPIC binfmt's brk and stack allocator.
1536
1537 Because of the obvious security issues, this option should only be
1538 enabled on embedded devices where you control what is run in
1539 userspace. Since that isn't generally a problem on no-MMU systems,
1540 it is normally safe to say Y here.
1541
1542 See Documentation/nommu-mmap.txt for more information.
1543
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001544config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001545 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001546 help
1547 Say Y here to enable the extended profiling support mechanisms used
1548 by profilers such as OProfile.
1549
Ingo Molnar5f87f112008-07-23 14:15:22 +02001550#
1551# Place an empty function call at each tracepoint site. Can be
1552# dynamically changed for a probe function.
1553#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001554config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001555 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001556
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001557source "arch/Kconfig"
1558
Linus Torvalds1da177e2005-04-16 15:20:36 -07001559endmenu # General setup
1560
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001561config HAVE_GENERIC_DMA_COHERENT
1562 bool
1563 default n
1564
Linus Torvalds158a9622008-01-02 13:04:48 -08001565config SLABINFO
1566 bool
1567 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001568 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001569 default y
1570
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001571config RT_MUTEXES
1572 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001573
Linus Torvalds1da177e2005-04-16 15:20:36 -07001574config BASE_SMALL
1575 int
1576 default 0 if BASE_FULL
1577 default 1 if !BASE_FULL
1578
Jan Engelhardt66da5732007-07-15 23:39:29 -07001579menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001580 bool "Enable loadable module support"
1581 help
1582 Kernel modules are small pieces of compiled code which can
1583 be inserted in the running kernel, rather than being
1584 permanently built into the kernel. You use the "modprobe"
1585 tool to add (and sometimes remove) them. If you say Y here,
1586 many parts of the kernel can be built as modules (by
1587 answering M instead of Y where indicated): this is most
1588 useful for infrequently used options which are not required
1589 for booting. For more information, see the man pages for
1590 modprobe, lsmod, modinfo, insmod and rmmod.
1591
1592 If you say Y here, you will need to run "make
1593 modules_install" to put the modules under /lib/modules/
1594 where modprobe can find them (you may need to be root to do
1595 this).
1596
1597 If unsure, say Y.
1598
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001599if MODULES
1600
Linus Torvalds826e4502008-05-04 17:04:16 -07001601config MODULE_FORCE_LOAD
1602 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001603 default n
1604 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001605 Allow loading of modules without version information (ie. modprobe
1606 --force). Forced module loading sets the 'F' (forced) taint flag and
1607 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001608
Linus Torvalds1da177e2005-04-16 15:20:36 -07001609config MODULE_UNLOAD
1610 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001611 help
1612 Without this option you will not be able to unload any
1613 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001614 anyway), which makes your kernel smaller, faster
1615 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001616
1617config MODULE_FORCE_UNLOAD
1618 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001619 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620 help
1621 This option allows you to force a module to unload, even if the
1622 kernel believes it is unsafe: the kernel will remove the module
1623 without waiting for anyone to stop using it (using the -f option to
1624 rmmod). This is mainly for kernel developers and desperate users.
1625 If unsure, say N.
1626
Linus Torvalds1da177e2005-04-16 15:20:36 -07001627config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001628 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629 help
1630 Usually, you have to use modules compiled with your kernel.
1631 Saying Y here makes it sometimes possible to use modules
1632 compiled for different kernels, by adding enough information
1633 to the modules to (hopefully) spot any changes which would
1634 make them incompatible with the kernel you are running. If
1635 unsure, say N.
1636
1637config MODULE_SRCVERSION_ALL
1638 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001639 help
1640 Modules which contain a MODULE_VERSION get an extra "srcversion"
1641 field inserted into their modinfo section, which contains a
1642 sum of the source files which made it. This helps maintainers
1643 see exactly which source was used to build a module (since
1644 others sometimes change the module source without updating
1645 the version). With this option, such a "srcversion" field
1646 will be created for all modules. If unsure, say N.
1647
Rusty Russell106a4ee2012-09-26 10:09:40 +01001648config MODULE_SIG
1649 bool "Module signature verification"
1650 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001651 select KEYS
1652 select CRYPTO
1653 select ASYMMETRIC_KEY_TYPE
1654 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1655 select PUBLIC_KEY_ALGO_RSA
1656 select ASN1
1657 select OID_REGISTRY
1658 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001659 help
1660 Check modules for valid signatures upon load: the signature
1661 is simply appended to the module. For more information see
1662 Documentation/module-signing.txt.
1663
David Howellsea0b6dc2012-09-26 10:09:50 +01001664 !!!WARNING!!! If you enable this option, you MUST make sure that the
1665 module DOES NOT get stripped after being signed. This includes the
1666 debuginfo strip done by some packagers (such as rpmbuild) and
1667 inclusion into an initramfs that wants the module size reduced.
1668
Rusty Russell106a4ee2012-09-26 10:09:40 +01001669config MODULE_SIG_FORCE
1670 bool "Require modules to be validly signed"
1671 depends on MODULE_SIG
1672 help
1673 Reject unsigned modules or signed modules for which we don't have a
1674 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001675
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301676config MODULE_SIG_ALL
1677 bool "Automatically sign all modules"
1678 default y
1679 depends on MODULE_SIG
1680 help
1681 Sign all modules during make modules_install. Without this option,
1682 modules must be signed manually, using the scripts/sign-file tool.
1683
1684comment "Do not forget to sign required modules with scripts/sign-file"
1685 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1686
David Howellsea0b6dc2012-09-26 10:09:50 +01001687choice
1688 prompt "Which hash algorithm should modules be signed with?"
1689 depends on MODULE_SIG
1690 help
1691 This determines which sort of hashing algorithm will be used during
1692 signature generation. This algorithm _must_ be built into the kernel
1693 directly so that signature verification can take place. It is not
1694 possible to load a signed module containing the algorithm to check
1695 the signature on that module.
1696
1697config MODULE_SIG_SHA1
1698 bool "Sign modules with SHA-1"
1699 select CRYPTO_SHA1
1700
1701config MODULE_SIG_SHA224
1702 bool "Sign modules with SHA-224"
1703 select CRYPTO_SHA256
1704
1705config MODULE_SIG_SHA256
1706 bool "Sign modules with SHA-256"
1707 select CRYPTO_SHA256
1708
1709config MODULE_SIG_SHA384
1710 bool "Sign modules with SHA-384"
1711 select CRYPTO_SHA512
1712
1713config MODULE_SIG_SHA512
1714 bool "Sign modules with SHA-512"
1715 select CRYPTO_SHA512
1716
1717endchoice
1718
Michal Marek22753672013-01-25 13:41:00 +10301719config MODULE_SIG_HASH
1720 string
1721 depends on MODULE_SIG
1722 default "sha1" if MODULE_SIG_SHA1
1723 default "sha224" if MODULE_SIG_SHA224
1724 default "sha256" if MODULE_SIG_SHA256
1725 default "sha384" if MODULE_SIG_SHA384
1726 default "sha512" if MODULE_SIG_SHA512
1727
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001728endif # MODULES
1729
Rusty Russell98a79d62008-12-13 21:19:41 +10301730config INIT_ALL_POSSIBLE
1731 bool
1732 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301733 Back when each arch used to define their own cpu_online_mask and
1734 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301735 with all 1s, and others with all 0s. When they were centralised,
1736 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001737 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301738
Linus Torvalds1da177e2005-04-16 15:20:36 -07001739config STOP_MACHINE
1740 bool
1741 default y
1742 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1743 help
1744 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001745
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001746source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001747
1748config PREEMPT_NOTIFIERS
1749 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001750
Steffen Klassert16295be2010-01-06 19:47:10 +11001751config PADATA
1752 depends on SMP
1753 bool
1754
Andi Kleen754b7b62012-10-04 17:11:27 -07001755# Can be selected by architectures with broken toolchains
1756# that get confused by correct const<->read_only section
1757# mappings
1758config BROKEN_RODATA
1759 bool
1760
David Howells4520c6a2012-09-21 23:31:13 +01001761config ASN1
1762 tristate
1763 help
1764 Build a simple ASN.1 grammar compiler that produces a bytecode output
1765 that can be interpreted by the ASN.1 stream decoder and used to
1766 inform it as to what tags are to be expected in a stream and what
1767 functions to call on what tags.
1768
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001769source "kernel/Kconfig.locks"