blob: 0a5e80fb9ba22beef93722f7bfe83ec33d81ee81 [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 Weisbecker1fd2b442012-07-11 20:26:40 +0200512 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100513 Probe on user/kernel boundaries by default in order to
514 test the features that rely on it such as userspace RCU extended
515 quiescent states.
516 This test is there for debugging until we have a real user like the
517 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200518
Mike Travisc903ff82009-01-15 12:28:29 -0800519config RCU_FANOUT
520 int "Tree-based hierarchical RCU fanout value"
521 range 2 64 if 64BIT
522 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700523 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800524 default 64 if 64BIT
525 default 32 if !64BIT
526 help
527 This option controls the fanout of hierarchical implementations
528 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700529 large numbers of CPUs. This value must be at least the fourth
530 root of NR_CPUS, which allows NR_CPUS to be insanely large.
531 The default value of RCU_FANOUT should be used for production
532 systems, but if you are stress-testing the RCU implementation
533 itself, small RCU_FANOUT values allow you to test large-system
534 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800535
536 Select a specific number if testing RCU itself.
537 Take the default if unsure.
538
Paul E. McKenney8932a632012-04-19 12:20:14 -0700539config RCU_FANOUT_LEAF
540 int "Tree-based hierarchical RCU leaf-level fanout value"
541 range 2 RCU_FANOUT if 64BIT
542 range 2 RCU_FANOUT if !64BIT
543 depends on TREE_RCU || TREE_PREEMPT_RCU
544 default 16
545 help
546 This option controls the leaf-level fanout of hierarchical
547 implementations of RCU, and allows trading off cache misses
548 against lock contention. Systems that synchronize their
549 scheduling-clock interrupts for energy-efficiency reasons will
550 want the default because the smaller leaf-level fanout keeps
551 lock contention levels acceptably low. Very large systems
552 (hundreds or thousands of CPUs) will instead want to set this
553 value to the maximum value possible in order to reduce the
554 number of cache misses incurred during RCU's grace-period
555 initialization. These systems tend to run CPU-bound, and thus
556 are not helped by synchronized interrupts, and thus tend to
557 skew them, which reduces lock contention enough that large
558 leaf-level fanouts work well.
559
560 Select a specific number if testing RCU itself.
561
562 Select the maximum permissible value for large systems.
563
564 Take the default if unsure.
565
Mike Travisc903ff82009-01-15 12:28:29 -0800566config RCU_FANOUT_EXACT
567 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700568 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800569 default n
570 help
571 This option forces use of the exact RCU_FANOUT value specified,
572 regardless of imbalances in the hierarchy. This is useful for
573 testing RCU itself, and might one day be useful on systems with
574 strong NUMA behavior.
575
576 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
577
578 Say N if unsure.
579
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800580config RCU_FAST_NO_HZ
581 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700582 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800583 default n
584 help
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700585 This option causes RCU to attempt to accelerate grace periods in
586 order to allow CPUs to enter dynticks-idle state more quickly.
587 On the other hand, this option increases the overhead of the
588 dynticks-idle checking, thus degrading scheduling latency.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800589
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700590 Say Y if energy efficiency is critically important, and you don't
591 care about real-time response.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800592
593 Say N if you are unsure.
594
Mike Travisc903ff82009-01-15 12:28:29 -0800595config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700596 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800597 select DEBUG_FS
598 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700599 This option provides tracing for the TREE_RCU and
600 TREE_PREEMPT_RCU implementations, permitting Makefile to
601 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800602
Paul E. McKenney24278d12010-09-27 17:25:23 -0700603config RCU_BOOST
604 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800605 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700606 default n
607 help
608 This option boosts the priority of preempted RCU readers that
609 block the current preemptible RCU grace period for too long.
610 This option also prevents heavy loads from blocking RCU
611 callback invocation for all flavors of RCU.
612
613 Say Y here if you are working with real-time apps or heavy loads
614 Say N here if you are unsure.
615
616config RCU_BOOST_PRIO
617 int "Real-time priority to boost RCU readers to"
618 range 1 99
619 depends on RCU_BOOST
620 default 1
621 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700622 This option specifies the real-time priority to which long-term
623 preempted RCU readers are to be boosted. If you are working
624 with a real-time application that has one or more CPU-bound
625 threads running at a real-time priority level, you should set
626 RCU_BOOST_PRIO to a priority higher then the highest-priority
627 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
628 of 1 is appropriate in the common case, which is real-time
629 applications that do not have any CPU-bound threads.
630
631 Some real-time applications might not have a single real-time
632 thread that saturates a given CPU, but instead might have
633 multiple real-time threads that, taken together, fully utilize
634 that CPU. In this case, you should set RCU_BOOST_PRIO to
635 a priority higher than the lowest-priority thread that is
636 conspiring to prevent the CPU from running any non-real-time
637 tasks. For example, if one thread at priority 10 and another
638 thread at priority 5 are between themselves fully consuming
639 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
640 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700641
642 Specify the real-time priority, or take the default if unsure.
643
644config RCU_BOOST_DELAY
645 int "Milliseconds to delay boosting after RCU grace-period start"
646 range 0 3000
647 depends on RCU_BOOST
648 default 500
649 help
650 This option specifies the time to wait after the beginning of
651 a given grace period before priority-boosting preempted RCU
652 readers blocking that grace period. Note that any RCU reader
653 blocking an expedited RCU grace period is boosted immediately.
654
655 Accept the default if unsure.
656
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700657config RCU_NOCB_CPU
658 bool "Offload RCU callback processing from boot-selected CPUs"
659 depends on TREE_RCU || TREE_PREEMPT_RCU
660 default n
661 help
662 Use this option to reduce OS jitter for aggressive HPC or
663 real-time workloads. It can also be used to offload RCU
664 callback invocation to energy-efficient CPUs in battery-powered
665 asymmetric multiprocessors.
666
667 This option offloads callback invocation from the set of
668 CPUs specified at boot time by the rcu_nocbs parameter.
669 For each such CPU, a kthread ("rcuoN") will be created to
670 invoke callbacks, where the "N" is the CPU being offloaded.
671 Nothing prevents this kthread from running on the specified
672 CPUs, but (1) the kthreads may be preempted between each
673 callback, and (2) affinity or cgroups can be used to force
674 the kthreads to run on whatever set of CPUs is desired.
675
676 Say Y here if you want reduced OS jitter on selected CPUs.
677 Say N here if you are unsure.
678
Mike Travisc903ff82009-01-15 12:28:29 -0800679endmenu # "RCU Subsystem"
680
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700682 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 ---help---
684 This option enables the complete Linux kernel ".config" file
685 contents to be saved in the kernel. It provides documentation
686 of which kernel options are used in a running kernel or in an
687 on-disk kernel. This information can be extracted from the kernel
688 image file with the script scripts/extract-ikconfig and used as
689 input to rebuild the current kernel or to build another kernel.
690 It can also be extracted from a running kernel by reading
691 /proc/config.gz if enabled (below).
692
693config IKCONFIG_PROC
694 bool "Enable access to .config through /proc/config.gz"
695 depends on IKCONFIG && PROC_FS
696 ---help---
697 This option enables access to the kernel configuration file
698 through /proc/config.gz.
699
Alistair John Strachan794543a2007-05-08 00:31:15 -0700700config LOG_BUF_SHIFT
701 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
702 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700703 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700704 help
705 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700706 Examples:
707 17 => 128 KB
708 16 => 64 KB
709 15 => 32 KB
710 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700711 13 => 8 KB
712 12 => 4 KB
713
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800714#
715# Architectures with an unreliable sched_clock() should select this:
716#
717config HAVE_UNSTABLE_SCHED_CLOCK
718 bool
719
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200720#
721# For architectures that want to enable the support for NUMA-affine scheduler
722# balancing logic:
723#
724config ARCH_SUPPORTS_NUMA_BALANCING
725 bool
726
727# For architectures that (ab)use NUMA to represent different memory regions
728# all cpu-local but of different latencies, such as SuperH.
729#
730config ARCH_WANT_NUMA_VARIABLE_LOCALITY
731 bool
732
733#
734# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
735config ARCH_WANTS_PROT_NUMA_PROT_NONE
736 bool
737
738config ARCH_USES_NUMA_PROT_NONE
739 bool
740 default y
741 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
742 depends on NUMA_BALANCING
743
Mel Gorman1a687c22012-11-22 11:16:36 +0000744config NUMA_BALANCING_DEFAULT_ENABLED
745 bool "Automatically enable NUMA aware memory/task placement"
746 default y
747 depends on NUMA_BALANCING
748 help
749 If set, autonumic NUMA balancing will be enabled if running on a NUMA
750 machine.
751
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200752config NUMA_BALANCING
753 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200754 depends on ARCH_SUPPORTS_NUMA_BALANCING
755 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
756 depends on SMP && NUMA && MIGRATION
757 help
758 This option adds support for automatic NUMA aware memory/task placement.
759 The mechanism is quite primitive and is based on migrating memory when
760 it is references to the node the task is running on.
761
762 This system will be inactive on UMA systems.
763
Li Zefan23964d22009-01-15 13:50:58 -0800764menuconfig CGROUPS
765 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800766 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700767 help
Li Zefan23964d22009-01-15 13:50:58 -0800768 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800769 use with process control subsystems such as Cpusets, CFS, memory
770 controls or device isolation.
771 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800772 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800773 - Documentation/cgroups/ (features for grouping, isolation
774 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700775
776 Say N if unsure.
777
Li Zefan23964d22009-01-15 13:50:58 -0800778if CGROUPS
779
Paul Menage006cb992007-10-18 23:39:43 -0700780config CGROUP_DEBUG
781 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700782 default n
Paul Menage006cb992007-10-18 23:39:43 -0700783 help
784 This option enables a simple cgroup subsystem that
785 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800786 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700787
Li Zefan23964d22009-01-15 13:50:58 -0800788 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700789
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700790config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800791 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800792 help
793 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700794 cgroup.
795
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700796config CGROUP_DEVICE
797 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700798 help
799 Provides a cgroup implementing whitelists for devices which
800 a process in the cgroup can mknod or open.
801
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802config CPUSETS
803 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700805 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 allow dynamically partitioning a system into sets of CPUs and
807 Memory Nodes and assigning tasks to run only within those sets.
808 This is primarily useful on large SMP or NUMA systems.
809
810 Say N if unsure.
811
Li Zefan23964d22009-01-15 13:50:58 -0800812config PROC_PID_CPUSET
813 bool "Include legacy /proc/<pid>/cpuset file"
814 depends on CPUSETS
815 default y
816
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100817config CGROUP_CPUACCT
818 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100819 help
820 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800821 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100822
Pavel Emelianove552b662008-02-07 00:13:49 -0800823config RESOURCE_COUNTERS
824 bool "Resource counters"
825 help
826 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800827 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800828
Andrew Mortonc255a452012-07-31 16:43:02 -0700829config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800830 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700831 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700832 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800833 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700834 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100835 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800836
837 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700838 associated with each page of memory in the system. By this,
839 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
840 usage tracking struct at boot. Total amount of this is printed out
841 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800842
843 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700844 sure you need the memory resource controller. Even when you enable
845 this, you can set "cgroup_disable=memory" at your boot option to
846 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800847 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800848
Balbir Singhcf475ad2008-04-29 01:00:16 -0700849 This config option also selects MM_OWNER config option, which
850 could in turn add some fork/exit overhead.
851
Andrew Mortonc255a452012-07-31 16:43:02 -0700852config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700853 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700854 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800855 help
856 Add swap management feature to memory resource controller. When you
857 enable this, you can limit mem+swap usage per cgroup. In other words,
858 when you disable this, memory resource controller has no cares to
859 usage of swap...a process can exhaust all of the swap. This extension
860 is useful when you want to avoid exhaustion swap but this itself
861 adds more overheads and consumes memory for remembering information.
862 Especially if you use 32bit system or small memory system, please
863 be careful about enabling this. When memory resource controller
864 is disabled by boot option, this will be automatically disabled and
865 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700866 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700867 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
868 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700869config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800870 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700871 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800872 default y
873 help
874 Memory Resource Controller Swap Extension comes with its price in
875 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700876 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800877 and let the user enable it by swapaccount boot command line
878 parameter should have this option unselected.
879 For those who want to have the feature enabled by default should
880 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700881 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700882config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700883 bool "Memory Resource Controller Kernel Memory accounting"
884 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800885 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000886 help
887 The Kernel Memory extension for Memory Resource Controller can limit
888 the amount of memory used by kernel objects in the system. Those are
889 fundamentally different from the entities handled by the standard
890 Memory Controller, which are page-based, and can be swapped. Users of
891 the kmem extension can use it to guarantee that no group of processes
892 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800893
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700894config CGROUP_HUGETLB
895 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700896 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700897 default n
898 help
899 Provides a cgroup Resource Controller for HugeTLB pages.
900 When you enable this, you can put a per cgroup limit on HugeTLB usage.
901 The limit is enforced during page fault. Since HugeTLB doesn't
902 support page reclaim, enforcing the limit at page fault time implies
903 that, the application will get SIGBUS signal if it tries to access
904 HugeTLB pages beyond its limit. This requires the application to know
905 beforehand how much HugeTLB pages it would require for its use. The
906 control group is tracked in the third page lru pointer. This means
907 that we cannot use the controller with huge page less than 3 pages.
908
Stephane Eraniane5d13672011-02-14 11:20:01 +0200909config CGROUP_PERF
910 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
911 depends on PERF_EVENTS && CGROUPS
912 help
913 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800914 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200915 designated cpu.
916
917 Say N if unsure.
918
Dhaval Giani7c941432010-01-20 13:26:18 +0100919menuconfig CGROUP_SCHED
920 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100921 default n
922 help
923 This feature lets CPU scheduler recognize task groups and control CPU
924 bandwidth allocation to such task groups. It uses cgroups to group
925 tasks.
926
927if CGROUP_SCHED
928config FAIR_GROUP_SCHED
929 bool "Group scheduling for SCHED_OTHER"
930 depends on CGROUP_SCHED
931 default CGROUP_SCHED
932
Paul Turnerab84d312011-07-21 09:43:28 -0700933config CFS_BANDWIDTH
934 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -0700935 depends on FAIR_GROUP_SCHED
936 default n
937 help
938 This option allows users to define CPU bandwidth rates (limits) for
939 tasks running within the fair group scheduler. Groups with no limit
940 set are considered to be unconstrained and will run with no
941 restriction.
942 See tip/Documentation/scheduler/sched-bwc.txt for more information.
943
Dhaval Giani7c941432010-01-20 13:26:18 +0100944config RT_GROUP_SCHED
945 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +0100946 depends on CGROUP_SCHED
947 default n
948 help
949 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800950 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100951 schedule realtime tasks for non-root users until you allocate
952 realtime bandwidth for them.
953 See Documentation/scheduler/sched-rt-group.txt for more information.
954
955endif #CGROUP_SCHED
956
Vivek Goyalafc24d42010-04-26 19:27:56 +0200957config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800958 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700959 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200960 default n
961 ---help---
962 Generic block IO controller cgroup interface. This is the common
963 cgroup interface which should be used by various IO controlling
964 policies.
965
966 Currently, CFQ IO scheduler uses it to recognize task groups and
967 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400968 to such task groups. It is also used by bio throttling logic in
969 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200970
971 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400972 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000973 enabling proportional weight division of disk bandwidth in CFQ, set
974 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000975 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200976
977 See Documentation/cgroups/blkio-controller.txt for more information.
978
979config DEBUG_BLK_CGROUP
980 bool "Enable Block IO controller debugging"
981 depends on BLK_CGROUP
982 default n
983 ---help---
984 Enable some debugging help. Currently it exports additional stat
985 files in a cgroup which can be useful for debugging.
986
Li Zefan23964d22009-01-15 13:50:58 -0800987endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800988
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800989config CHECKPOINT_RESTORE
990 bool "Checkpoint/restore support" if EXPERT
991 default n
992 help
993 Enables additional kernel features in a sake of checkpoint/restore.
994 In particular it adds auxiliary prctl codes to setup process text,
995 data and heap segment sizes, and a few additional /proc filesystem
996 entries.
997
998 If unsure, say N here.
999
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001000menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001001 bool "Namespaces support" if EXPERT
1002 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001003 help
1004 Provides the way to make tasks work with different objects using
1005 the same id. For example same IPC id may refer to different objects
1006 or same user id or pid may refer to different tasks when used in
1007 different namespaces.
1008
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001009if NAMESPACES
1010
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001011config UTS_NS
1012 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001013 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001014 help
1015 In this namespace tasks see different info provided with the
1016 uname() system call
1017
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001018config IPC_NS
1019 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001020 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001021 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001022 help
1023 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001024 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001025
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001026config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001027 bool "User namespace"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001028 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001029 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001030
Eric W. Biederman5673a942011-11-17 10:23:55 -08001031 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001032 help
1033 This allows containers, i.e. vservers, to use user namespaces
1034 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001035
1036 When user namespaces are enabled in the kernel it is
1037 recommended that the MEMCG and MEMCG_KMEM options also be
1038 enabled and that user-space use the memory control groups to
1039 limit the amount of memory a memory unprivileged users can
1040 use.
1041
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001042 If unsure, say N.
1043
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001044config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001045 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001046 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001047 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001048 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001049 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001050 pid namespaces. This is a building block of containers.
1051
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001052config NET_NS
1053 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001054 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001055 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001056 help
1057 Allow user space to create what appear to be multiple instances
1058 of the network stack.
1059
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001060endif # NAMESPACES
1061
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001062config UIDGID_CONVERTED
1063 # True if all of the selected software conmponents are known
1064 # to have uid_t and gid_t converted to kuid_t and kgid_t
1065 # where appropriate and are otherwise safe to use with
1066 # the user namespace.
1067 bool
1068 default y
1069
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001070 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001071 depends on XFS_FS = n
1072
Eric W. Biederman5673a942011-11-17 10:23:55 -08001073config UIDGID_STRICT_TYPE_CHECKS
1074 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001075 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001076 default n
1077 help
1078 While the nececessary conversions are being added to all subsystems this option allows
1079 the code to continue to build for unconverted subsystems.
1080
1081 Say Y here if you want the strict type checking enabled
1082
Mike Galbraith5091faa2010-11-30 14:18:03 +01001083config SCHED_AUTOGROUP
1084 bool "Automatic process group scheduling"
1085 select EVENTFD
1086 select CGROUPS
1087 select CGROUP_SCHED
1088 select FAIR_GROUP_SCHED
1089 help
1090 This option optimizes the scheduler for common desktop workloads by
1091 automatically creating and populating task groups. This separation
1092 of workloads isolates aggressive CPU burners (like build jobs) from
1093 desktop applications. Task group autogeneration is currently based
1094 upon task session.
1095
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001096config MM_OWNER
1097 bool
1098
1099config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001100 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001101 depends on SYSFS
1102 default n
1103 help
1104 This option adds code that switches the layout of the "block" class
1105 devices, to not show up in /sys/class/block/, but only in
1106 /sys/block/.
1107
1108 This switch is only active when the sysfs.deprecated=1 boot option is
1109 passed or the SYSFS_DEPRECATED_V2 option is set.
1110
1111 This option allows new kernels to run on old distributions and tools,
1112 which might get confused by /sys/class/block/. Since 2007/2008 all
1113 major distributions and tools handle this just fine.
1114
1115 Recent distributions and userspace tools after 2009/2010 depend on
1116 the existence of /sys/class/block/, and will not work with this
1117 option enabled.
1118
1119 Only if you are using a new kernel on an old distribution, you might
1120 need to say Y here.
1121
1122config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001123 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001124 default n
1125 depends on SYSFS
1126 depends on SYSFS_DEPRECATED
1127 help
1128 Enable deprecated sysfs by default.
1129
1130 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1131 option.
1132
1133 Only if you are using a new kernel on an old distribution, you might
1134 need to say Y here. Even then, odds are you would not need it
1135 enabled, you can always pass the boot option if absolutely necessary.
1136
1137config RELAY
1138 bool "Kernel->user space relay support (formerly relayfs)"
1139 help
1140 This option enables support for relay interface support in
1141 certain file systems (such as debugfs).
1142 It is designed to provide an efficient mechanism for tools and
1143 facilities to relay large amounts of data from kernel space to
1144 user space.
1145
1146 If unsure, say N.
1147
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001148config BLK_DEV_INITRD
1149 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1150 depends on BROKEN || !FRV
1151 help
1152 The initial RAM filesystem is a ramfs which is loaded by the
1153 boot loader (loadlin or lilo) and that is mounted as root
1154 before the normal boot procedure. It is typically used to
1155 load modules needed to mount the "real" root file system,
1156 etc. See <file:Documentation/initrd.txt> for details.
1157
1158 If RAM disk support (BLK_DEV_RAM) is also included, this
1159 also enables initial RAM disk (initrd) support and adds
1160 15 Kbytes (more on some other architectures) to the kernel size.
1161
1162 If unsure say Y.
1163
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001164if BLK_DEV_INITRD
1165
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001166source "usr/Kconfig"
1167
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001168endif
1169
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001170config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001171 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001172 help
1173 Enabling this option will pass "-Os" instead of "-O2" to gcc
1174 resulting in a smaller kernel.
1175
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001176 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001177
Randy Dunlap08470622006-09-30 23:28:13 -07001178config SYSCTL
1179 bool
1180
Randy Dunlapb943c462009-03-10 12:55:46 -07001181config ANON_INODES
1182 bool
1183
David Rientjes6a108a12011-01-20 14:44:16 -08001184menuconfig EXPERT
1185 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001186 # Unhide debug options, to make the on-by-default options visible
1187 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001188 help
1189 This option allows certain base kernel options and settings
1190 to be disabled or tweaked. This is for specialized
1191 environments which can tolerate a "non-standard" kernel.
1192 Only use this if you really know what you are doing.
1193
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001194config HAVE_UID16
1195 bool
1196
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001197config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001198 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001199 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001200 default y
1201 help
1202 This enables the legacy 16-bit UID syscall wrappers.
1203
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001204config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001205 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001206 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001207 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001208 select SYSCTL
1209 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001210 sys_sysctl uses binary paths that have been found challenging
1211 to properly maintain and use. The interface in /proc/sys
1212 using paths with ascii names is now the primary path to this
1213 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001214
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001215 Almost nothing using the binary sysctl interface so if you are
1216 trying to save some space it is probably safe to disable this,
1217 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001218
WANG Congc736de62011-11-02 13:39:25 -07001219 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001220
Catalin Marinas7ac57a82012-10-08 16:28:16 -07001221config SYSCTL_EXCEPTION_TRACE
1222 bool
1223 help
1224 Enable support for /proc/sys/debug/exception-trace.
1225
Vineet Guptab6fca722013-01-09 20:06:28 +05301226config SYSCTL_ARCH_UNALIGN_NO_WARN
1227 bool
1228 help
1229 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1230 Allows arch to define/use @no_unaligned_warning to possibly warn
1231 about unaligned access emulation going on under the hood.
1232
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001234 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 default y
1236 help
1237 Say Y here to let the kernel print out symbolic crash information and
1238 symbolic stack backtraces. This increases the size of the kernel
1239 somewhat, as all symbols have to be loaded into the kernel image.
1240
1241config KALLSYMS_ALL
1242 bool "Include all symbols in kallsyms"
1243 depends on DEBUG_KERNEL && KALLSYMS
1244 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001245 Normally kallsyms only contains the symbols of functions for nicer
1246 OOPS messages and backtraces (i.e., symbols from the text and inittext
1247 sections). This is sufficient for most cases. And only in very rare
1248 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1249 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001251 This option makes sure that all symbols are loaded into the kernel
1252 image (i.e., symbols from all sections) in cost of increased kernel
1253 size (depending on the kernel configuration, it may be 300KiB or
1254 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001256 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001257
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001258config HOTPLUG
Greg Kroah-Hartman45f035a2012-09-04 17:01:08 -07001259 def_bool y
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001260
Matt Mackalld59745c2005-05-01 08:59:02 -07001261config PRINTK
1262 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001263 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001264 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001265 help
1266 This option enables normal printk support. Removing it
1267 eliminates most of the message strings from the kernel image
1268 and makes the kernel more or less silent. As this makes it
1269 very difficult to diagnose system problems, saying N here is
1270 strongly discouraged.
1271
Matt Mackallc8538a72005-05-01 08:59:01 -07001272config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001273 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001274 default y
1275 help
1276 Disabling this option eliminates support for BUG and WARN, reducing
1277 the size of your kernel image and potentially quietly ignoring
1278 numerous fatal conditions. You should only consider disabling this
1279 option for embedded systems with no facilities for reporting errors.
1280 Just say Y.
1281
Matt Mackall708e9a72006-01-08 01:05:25 -08001282config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001283 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001284 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001285 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001286 help
1287 Enable support for generating core dumps. Disabling saves about 4k.
1288
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001289
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001290config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001291 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001292 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001293 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001294 default y
1295 help
1296 This option allows to disable the internal PC-Speaker
1297 support, saving some memory.
1298
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001299config HAVE_PCSPKR_PLATFORM
1300 bool
1301
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302config BASE_FULL
1303 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001304 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305 help
1306 Disabling this option reduces the size of miscellaneous core
1307 kernel data structures. This saves memory on small machines,
1308 but may reduce performance.
1309
1310config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001311 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001313 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 help
1315 Disabling this option will cause the kernel to be built without
1316 support for "fast userspace mutexes". The resulting kernel may not
1317 run glibc-based applications correctly.
1318
1319config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001320 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001322 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 help
1324 Disabling this option will cause the kernel to be built without
1325 support for epoll family of system calls.
1326
Davide Libenzifba2afa2007-05-10 22:23:13 -07001327config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001328 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001329 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001330 default y
1331 help
1332 Enable the signalfd() system call that allows to receive signals
1333 on a file descriptor.
1334
1335 If unsure, say Y.
1336
Davide Libenzib215e282007-05-10 22:23:16 -07001337config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001338 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001339 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001340 default y
1341 help
1342 Enable the timerfd() system call that allows to receive timer
1343 events on a file descriptor.
1344
1345 If unsure, say Y.
1346
Davide Libenzie1ad7462007-05-10 22:23:19 -07001347config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001348 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001349 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001350 default y
1351 help
1352 Enable the eventfd() system call that allows to receive both
1353 kernel notification (ie. KAIO) or userspace notifications.
1354
1355 If unsure, say Y.
1356
Linus Torvalds1da177e2005-04-16 15:20:36 -07001357config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001358 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359 default y
1360 depends on MMU
1361 help
1362 The shmem is an internal filesystem used to manage shared memory.
1363 It is backed by swap and manages resource limits. It is also exported
1364 to userspace as tmpfs if TMPFS is enabled. Disabling this
1365 option replaces shmem and tmpfs with the much simpler ramfs code,
1366 which may be appropriate on small systems without swap.
1367
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001368config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001369 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001370 default y
1371 help
1372 This option enables POSIX asynchronous I/O which may by used
1373 by some high performance threaded applications. Disabling
1374 this option saves about 7k.
1375
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001376config EMBEDDED
1377 bool "Embedded system"
1378 select EXPERT
1379 help
1380 This option should be enabled if compiling the kernel for
1381 an embedded system so certain expert options are available
1382 for configuration.
1383
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001384config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001385 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001386 help
1387 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001388
Peter Zijlstra906010b2009-09-21 16:08:49 +02001389config PERF_USE_VMALLOC
1390 bool
1391 help
1392 See tools/perf/design.txt for details
1393
Ingo Molnar57c0c152009-09-21 12:20:38 +02001394menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001395
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001396config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001397 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001398 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001399 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001400 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001401 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001402 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001403 Enable kernel support for various performance events provided
1404 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001405
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001406 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001407 use of generic tracepoints.
1408
1409 Most modern CPUs support performance events via performance
1410 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001411 types of hw events: such as instructions executed, cachemisses
1412 suffered, or branches mis-predicted - without slowing down the
1413 kernel or applications. These registers can also trigger interrupts
1414 when a threshold number of events have passed - and can thus be
1415 used to profile the code that runs on that CPU.
1416
Ingo Molnar57c0c152009-09-21 12:20:38 +02001417 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001418 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001419 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001420 provides per task and per CPU counters, and it provides event
1421 capabilities on top of those.
1422
1423 Say Y if unsure.
1424
Peter Zijlstra906010b2009-09-21 16:08:49 +02001425config DEBUG_PERF_USE_VMALLOC
1426 default n
1427 bool "Debug: use vmalloc to back perf mmap() buffers"
1428 depends on PERF_EVENTS && DEBUG_KERNEL
1429 select PERF_USE_VMALLOC
1430 help
1431 Use vmalloc memory to back perf mmap() buffers.
1432
1433 Mostly useful for debugging the vmalloc code on platforms
1434 that don't require it.
1435
1436 Say N if unsure.
1437
Thomas Gleixner0793a612008-12-04 20:12:29 +01001438endmenu
1439
Christoph Lameterf8891e52006-06-30 01:55:45 -07001440config VM_EVENT_COUNTERS
1441 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001442 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001443 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001444 VM event counters are needed for event counts to be shown.
1445 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001446 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001447 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001448
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001449config PCI_QUIRKS
1450 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001451 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001452 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001453 help
1454 This enables workarounds for various PCI chipset
1455 bugs/quirks. Disable this only if your target machine is
1456 unaffected by PCI quirks.
1457
Christoph Lameter41ecc552007-05-09 02:32:44 -07001458config SLUB_DEBUG
1459 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001460 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001461 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001462 help
1463 SLUB has extensive debug support features. Disabling these can
1464 result in significant savings in code size. This also disables
1465 SLUB sysfs support. /sys/slab will not exist and there will be
1466 no support for cache validation etc.
1467
Randy Dunlapb943c462009-03-10 12:55:46 -07001468config COMPAT_BRK
1469 bool "Disable heap randomization"
1470 default y
1471 help
1472 Randomizing heap placement makes heap exploits harder, but it
1473 also breaks ancient binaries (including anything libc5 based).
1474 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001475 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001476 /proc/sys/kernel/randomize_va_space to 2.
1477
1478 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1479
Christoph Lameter81819f02007-05-06 14:49:36 -07001480choice
1481 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001482 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001483 help
1484 This option allows to select a slab allocator.
1485
1486config SLAB
1487 bool "SLAB"
1488 help
1489 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001490 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001491 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001492
1493config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001494 bool "SLUB (Unqueued Allocator)"
1495 help
1496 SLUB is a slab allocator that minimizes cache line usage
1497 instead of managing queues of cached objects (SLAB approach).
1498 Per cpu caching is realized using slabs of objects instead
1499 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001500 and has enhanced diagnostics. SLUB is the default choice for
1501 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001502
1503config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001504 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001505 bool "SLOB (Simple Allocator)"
1506 help
Matt Mackall37291452008-02-04 22:29:38 -08001507 SLOB replaces the stock allocator with a drastically simpler
1508 allocator. SLOB is generally more space efficient but
1509 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001510
1511endchoice
1512
Jie Zhangea637632009-12-14 18:00:02 -08001513config MMAP_ALLOW_UNINITIALIZED
1514 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001515 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001516 default n
1517 help
1518 Normally, and according to the Linux spec, anonymous memory obtained
1519 from mmap() has it's contents cleared before it is passed to
1520 userspace. Enabling this config option allows you to request that
1521 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1522 providing a huge performance boost. If this option is not enabled,
1523 then the flag will be ignored.
1524
1525 This is taken advantage of by uClibc's malloc(), and also by
1526 ELF-FDPIC binfmt's brk and stack allocator.
1527
1528 Because of the obvious security issues, this option should only be
1529 enabled on embedded devices where you control what is run in
1530 userspace. Since that isn't generally a problem on no-MMU systems,
1531 it is normally safe to say Y here.
1532
1533 See Documentation/nommu-mmap.txt for more information.
1534
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001535config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001536 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001537 help
1538 Say Y here to enable the extended profiling support mechanisms used
1539 by profilers such as OProfile.
1540
Ingo Molnar5f87f112008-07-23 14:15:22 +02001541#
1542# Place an empty function call at each tracepoint site. Can be
1543# dynamically changed for a probe function.
1544#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001545config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001546 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001547
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001548source "arch/Kconfig"
1549
Linus Torvalds1da177e2005-04-16 15:20:36 -07001550endmenu # General setup
1551
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001552config HAVE_GENERIC_DMA_COHERENT
1553 bool
1554 default n
1555
Linus Torvalds158a9622008-01-02 13:04:48 -08001556config SLABINFO
1557 bool
1558 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001559 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001560 default y
1561
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001562config RT_MUTEXES
1563 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001564
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565config BASE_SMALL
1566 int
1567 default 0 if BASE_FULL
1568 default 1 if !BASE_FULL
1569
Jan Engelhardt66da5732007-07-15 23:39:29 -07001570menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571 bool "Enable loadable module support"
1572 help
1573 Kernel modules are small pieces of compiled code which can
1574 be inserted in the running kernel, rather than being
1575 permanently built into the kernel. You use the "modprobe"
1576 tool to add (and sometimes remove) them. If you say Y here,
1577 many parts of the kernel can be built as modules (by
1578 answering M instead of Y where indicated): this is most
1579 useful for infrequently used options which are not required
1580 for booting. For more information, see the man pages for
1581 modprobe, lsmod, modinfo, insmod and rmmod.
1582
1583 If you say Y here, you will need to run "make
1584 modules_install" to put the modules under /lib/modules/
1585 where modprobe can find them (you may need to be root to do
1586 this).
1587
1588 If unsure, say Y.
1589
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001590if MODULES
1591
Linus Torvalds826e4502008-05-04 17:04:16 -07001592config MODULE_FORCE_LOAD
1593 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001594 default n
1595 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001596 Allow loading of modules without version information (ie. modprobe
1597 --force). Forced module loading sets the 'F' (forced) taint flag and
1598 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001599
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600config MODULE_UNLOAD
1601 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001602 help
1603 Without this option you will not be able to unload any
1604 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001605 anyway), which makes your kernel smaller, faster
1606 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001607
1608config MODULE_FORCE_UNLOAD
1609 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001610 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001611 help
1612 This option allows you to force a module to unload, even if the
1613 kernel believes it is unsafe: the kernel will remove the module
1614 without waiting for anyone to stop using it (using the -f option to
1615 rmmod). This is mainly for kernel developers and desperate users.
1616 If unsure, say N.
1617
Linus Torvalds1da177e2005-04-16 15:20:36 -07001618config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001619 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620 help
1621 Usually, you have to use modules compiled with your kernel.
1622 Saying Y here makes it sometimes possible to use modules
1623 compiled for different kernels, by adding enough information
1624 to the modules to (hopefully) spot any changes which would
1625 make them incompatible with the kernel you are running. If
1626 unsure, say N.
1627
1628config MODULE_SRCVERSION_ALL
1629 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001630 help
1631 Modules which contain a MODULE_VERSION get an extra "srcversion"
1632 field inserted into their modinfo section, which contains a
1633 sum of the source files which made it. This helps maintainers
1634 see exactly which source was used to build a module (since
1635 others sometimes change the module source without updating
1636 the version). With this option, such a "srcversion" field
1637 will be created for all modules. If unsure, say N.
1638
Rusty Russell106a4ee2012-09-26 10:09:40 +01001639config MODULE_SIG
1640 bool "Module signature verification"
1641 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001642 select KEYS
1643 select CRYPTO
1644 select ASYMMETRIC_KEY_TYPE
1645 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1646 select PUBLIC_KEY_ALGO_RSA
1647 select ASN1
1648 select OID_REGISTRY
1649 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001650 help
1651 Check modules for valid signatures upon load: the signature
1652 is simply appended to the module. For more information see
1653 Documentation/module-signing.txt.
1654
David Howellsea0b6dc2012-09-26 10:09:50 +01001655 !!!WARNING!!! If you enable this option, you MUST make sure that the
1656 module DOES NOT get stripped after being signed. This includes the
1657 debuginfo strip done by some packagers (such as rpmbuild) and
1658 inclusion into an initramfs that wants the module size reduced.
1659
Rusty Russell106a4ee2012-09-26 10:09:40 +01001660config MODULE_SIG_FORCE
1661 bool "Require modules to be validly signed"
1662 depends on MODULE_SIG
1663 help
1664 Reject unsigned modules or signed modules for which we don't have a
1665 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001666
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301667config MODULE_SIG_ALL
1668 bool "Automatically sign all modules"
1669 default y
1670 depends on MODULE_SIG
1671 help
1672 Sign all modules during make modules_install. Without this option,
1673 modules must be signed manually, using the scripts/sign-file tool.
1674
1675comment "Do not forget to sign required modules with scripts/sign-file"
1676 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1677
David Howellsea0b6dc2012-09-26 10:09:50 +01001678choice
1679 prompt "Which hash algorithm should modules be signed with?"
1680 depends on MODULE_SIG
1681 help
1682 This determines which sort of hashing algorithm will be used during
1683 signature generation. This algorithm _must_ be built into the kernel
1684 directly so that signature verification can take place. It is not
1685 possible to load a signed module containing the algorithm to check
1686 the signature on that module.
1687
1688config MODULE_SIG_SHA1
1689 bool "Sign modules with SHA-1"
1690 select CRYPTO_SHA1
1691
1692config MODULE_SIG_SHA224
1693 bool "Sign modules with SHA-224"
1694 select CRYPTO_SHA256
1695
1696config MODULE_SIG_SHA256
1697 bool "Sign modules with SHA-256"
1698 select CRYPTO_SHA256
1699
1700config MODULE_SIG_SHA384
1701 bool "Sign modules with SHA-384"
1702 select CRYPTO_SHA512
1703
1704config MODULE_SIG_SHA512
1705 bool "Sign modules with SHA-512"
1706 select CRYPTO_SHA512
1707
1708endchoice
1709
Michal Marek22753672013-01-25 13:41:00 +10301710config MODULE_SIG_HASH
1711 string
1712 depends on MODULE_SIG
1713 default "sha1" if MODULE_SIG_SHA1
1714 default "sha224" if MODULE_SIG_SHA224
1715 default "sha256" if MODULE_SIG_SHA256
1716 default "sha384" if MODULE_SIG_SHA384
1717 default "sha512" if MODULE_SIG_SHA512
1718
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001719endif # MODULES
1720
Rusty Russell98a79d62008-12-13 21:19:41 +10301721config INIT_ALL_POSSIBLE
1722 bool
1723 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301724 Back when each arch used to define their own cpu_online_mask and
1725 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301726 with all 1s, and others with all 0s. When they were centralised,
1727 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001728 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301729
Linus Torvalds1da177e2005-04-16 15:20:36 -07001730config STOP_MACHINE
1731 bool
1732 default y
1733 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1734 help
1735 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001736
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001737source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001738
1739config PREEMPT_NOTIFIERS
1740 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001741
Steffen Klassert16295be2010-01-06 19:47:10 +11001742config PADATA
1743 depends on SMP
1744 bool
1745
Andi Kleen754b7b62012-10-04 17:11:27 -07001746# Can be selected by architectures with broken toolchains
1747# that get confused by correct const<->read_only section
1748# mappings
1749config BROKEN_RODATA
1750 bool
1751
David Howells4520c6a2012-09-21 23:31:13 +01001752config ASN1
1753 tristate
1754 help
1755 Build a simple ASN.1 grammar compiler that produces a bytecode output
1756 that can be interpreted by the ASN.1 stream decoder and used to
1757 inform it as to what tags are to be expected in a stream and what
1758 functions to call on what tags.
1759
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001760source "kernel/Kconfig.locks"