blob: 3020d81c05bc96c79111bd88a82fd03da8f2027b [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 HAVE_IRQ_WORK
24 bool
25
26config IRQ_WORK
27 bool
28 depends on HAVE_IRQ_WORK
29
David Daney1dbdc6f2012-04-19 14:59:57 -070030config BUILDTIME_EXTABLE_SORT
31 bool
32
Al Boldiff0cfc62007-07-31 00:39:23 -070033menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35config EXPERIMENTAL
Kees Cook5a958db2012-10-02 11:36:31 -070036 bool
37 default y
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
Linus Torvalds1da177e2005-04-16 15:20:36 -070039config BROKEN
40 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
42config BROKEN_ON_SMP
43 bool
44 depends on BROKEN || !SMP
45 default y
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047config INIT_ENV_ARG_LIMIT
48 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070049 default 32 if !UML
50 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080052 Maximum of each of the number of arguments and environment
53 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Roland McGrath84336462009-12-21 16:24:06 -080056config CROSS_COMPILE
57 string "Cross-compiler tool prefix"
58 help
59 Same as running 'make CROSS_COMPILE=prefix-' but stored for
60 default make runs in this kernel build directory. You don't
61 need to set this unless you want the configured kernel build
62 directory to select the cross-compiler automatically.
63
Linus Torvalds1da177e2005-04-16 15:20:36 -070064config LOCALVERSION
65 string "Local version - append to kernel release"
66 help
67 Append an extra string to the end of your kernel version.
68 This will show up when you type uname, for example.
69 The string you set here will be appended after the contents of
70 any files with a filename matching localversion* in your
71 object and source tree, in that order. Your total string can
72 be a maximum of 64 characters.
73
Ryan Andersonaaebf432005-07-31 04:57:49 -040074config LOCALVERSION_AUTO
75 bool "Automatically append version information to the version string"
76 default y
77 help
78 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020079 release tree by looking for git tags that belong to the current
80 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040081
82 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020083 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040084 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020085 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -040086
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020087 (The actual string used here is the first eight characters produced
88 by running the command:
89
90 $ git rev-parse --verify HEAD
91
92 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -040093
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -080094config HAVE_KERNEL_GZIP
95 bool
96
97config HAVE_KERNEL_BZIP2
98 bool
99
100config HAVE_KERNEL_LZMA
101 bool
102
Lasse Collin3ebe1242011-01-12 17:01:23 -0800103config HAVE_KERNEL_XZ
104 bool
105
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800106config HAVE_KERNEL_LZO
107 bool
108
Alain Knaff30d65db2009-01-04 22:46:17 +0100109choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800110 prompt "Kernel compression mode"
111 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800112 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 -0800113 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100114 The linux kernel is a kind of self-extracting executable.
115 Several compression algorithms are available, which differ
116 in efficiency, compression and decompression speed.
117 Compression speed is only relevant when building a kernel.
118 Decompression speed is relevant at each boot.
119
120 If you have any problems with bzip2 or lzma compressed
121 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
122 version of this functionality (bzip2 only), for 2.4, was
123 supplied by Christian Ludwig)
124
125 High compression options are mostly useful for users, who
126 are low on disk space (embedded systems), but for whom ram
127 size matters less.
128
129 If in doubt, select 'gzip'
130
131config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800132 bool "Gzip"
133 depends on HAVE_KERNEL_GZIP
134 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800135 The old and tried gzip compression. It provides a good balance
136 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100137
138config KERNEL_BZIP2
139 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800140 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100141 help
142 Its compression ratio and speed is intermediate.
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700143 Decompression speed is slowest among the choices. The kernel
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800144 size is about 10% smaller with bzip2, in comparison to gzip.
145 Bzip2 uses a large amount of memory. For modern kernels you
146 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100147
148config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800149 bool "LZMA"
150 depends on HAVE_KERNEL_LZMA
151 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700152 This compression algorithm's ratio is best. Decompression speed
153 is between gzip and bzip2. Compression is slowest.
154 The kernel size is about 33% smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100155
Lasse Collin3ebe1242011-01-12 17:01:23 -0800156config KERNEL_XZ
157 bool "XZ"
158 depends on HAVE_KERNEL_XZ
159 help
160 XZ uses the LZMA2 algorithm and instruction set specific
161 BCJ filters which can improve compression ratio of executable
162 code. The size of the kernel is about 30% smaller with XZ in
163 comparison to gzip. On architectures for which there is a BCJ
164 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
165 will create a few percent smaller kernel than plain LZMA.
166
167 The speed is about the same as with LZMA: The decompression
168 speed of XZ is better than that of bzip2 but worse than gzip
169 and LZO. Compression is slow.
170
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800171config KERNEL_LZO
172 bool "LZO"
173 depends on HAVE_KERNEL_LZO
174 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700175 Its compression ratio is the poorest among the choices. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200176 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800177 (both compression and decompression) is the fastest.
178
Alain Knaff30d65db2009-01-04 22:46:17 +0100179endchoice
180
Josh Triplettbd5dc172011-06-15 15:08:28 -0700181config DEFAULT_HOSTNAME
182 string "Default hostname"
183 default "(none)"
184 help
185 This option determines the default system hostname before userspace
186 calls sethostname(2). The kernel traditionally uses "(none)" here,
187 but you may wish to use a different default here to make a minimal
188 system more usable with less configuration.
189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190config SWAP
191 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200192 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 default y
194 help
195 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100196 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 used to provide more virtual memory than the actual RAM present
198 in your computer. If unsure say Y.
199
200config SYSVIPC
201 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 ---help---
203 Inter Process Communication is a suite of library functions and
204 system calls which let processes (running programs) synchronize and
205 exchange information. It is generally considered to be a good thing,
206 and some programs won't run unless you say Y here. In particular, if
207 you want to run the DOS emulator dosemu under Linux (read the
208 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
209 you'll need to say Y here.
210
211 You can find documentation about IPC with "info ipc" and also in
212 section 6.4 of the Linux Programmer's Guide, available from
213 <http://www.tldp.org/guides.html>.
214
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800215config SYSVIPC_SYSCTL
216 bool
217 depends on SYSVIPC
218 depends on SYSCTL
219 default y
220
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221config POSIX_MQUEUE
222 bool "POSIX Message Queues"
Kees Cook19c92392012-10-02 11:19:29 -0700223 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 ---help---
225 POSIX variant of message queues is a part of IPC. In POSIX message
226 queues every message has a priority which decides about succession
227 of receiving it by a process. If you want to compile and run
228 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200229 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230
231 POSIX message queues are visible as a filesystem called 'mqueue'
232 and can be mounted somewhere if you want to do filesystem
233 operations on message queues.
234
235 If unsure, say Y.
236
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700237config POSIX_MQUEUE_SYSCTL
238 bool
239 depends on POSIX_MQUEUE
240 depends on SYSCTL
241 default y
242
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530243config FHANDLE
244 bool "open by fhandle syscalls"
245 select EXPORTFS
246 help
247 If you say Y here, a user level program will be able to map
248 file names to handle and then later use the handle for
249 different file system operations. This is useful in implementing
250 userspace file servers, which now track files using handles instead
251 of names. The handle would remain the same even if file names
252 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
253 syscalls.
254
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255config AUDIT
256 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100257 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 help
259 Enable auditing infrastructure that can be used with another
260 kernel subsystem, such as SELinux (which requires this for
261 logging of avc messages output). Does not do system-call
262 auditing without CONFIG_AUDITSYSCALL.
263
264config AUDITSYSCALL
265 bool "Enable system-call auditing support"
Will Deacon8f827a12012-07-06 15:48:16 +0100266 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 default y if SECURITY_SELINUX
268 help
269 Enable low-overhead system-call auditing infrastructure that
270 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500271 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
Eric Paris939a67f2009-12-17 20:12:06 -0500273config AUDIT_WATCH
274 def_bool y
275 depends on AUDITSYSCALL
276 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277
Al Viro74c3cbe2007-07-22 08:04:18 -0400278config AUDIT_TREE
279 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400280 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500281 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400282
Eric Paris633b4542012-01-03 14:23:08 -0500283config AUDIT_LOGINUID_IMMUTABLE
284 bool "Make audit loginuid immutable"
285 depends on AUDIT
286 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800287 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500288 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
289 but should instead only allow setting its loginuid if it was never
290 previously set. On systems which use systemd or a similar central
291 process to restart login services this should be set to true. On older
292 systems in which an admin would typically have to directly stop and
293 start processes this should be set to false. Setting this to true allows
294 one to drop potentially dangerous capabilites from the login tasks,
295 but may not be backwards compatible with older init systems.
296
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000297source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200298source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000299
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200300menu "CPU/Task time and stats accounting"
301
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200302choice
303 prompt "Cputime accounting"
304 default TICK_CPU_ACCOUNTING if !PPC64
305 default VIRT_CPU_ACCOUNTING if PPC64
306
307# Kind of a stub config for the pure tick based cputime accounting
308config TICK_CPU_ACCOUNTING
309 bool "Simple tick based cputime accounting"
310 depends on !S390
311 help
312 This is the basic tick based cputime accounting that maintains
313 statistics about user, system and idle time spent on per jiffies
314 granularity.
315
316 If unsure, say Y.
317
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200318config VIRT_CPU_ACCOUNTING
319 bool "Deterministic task and CPU time accounting"
320 depends on HAVE_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 Weisbeckerfdf9c352012-09-09 14:56:31 +0200330config IRQ_TIME_ACCOUNTING
331 bool "Fine granularity task level IRQ time accounting"
332 depends on HAVE_IRQ_TIME_ACCOUNTING
333 help
334 Select this option to enable fine granularity task irq time
335 accounting. This is done by reading a timestamp on each
336 transitions between softirq and hardirq state, so there can be a
337 small performance impact.
338
339 If in doubt, say N here.
340
341endchoice
342
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200343config BSD_PROCESS_ACCT
344 bool "BSD Process Accounting"
345 help
346 If you say Y here, a user level program will be able to instruct the
347 kernel (via a special system call) to write process accounting
348 information to a file: whenever a process exits, information about
349 that process will be appended to the file by the kernel. The
350 information includes things such as creation time, owning user,
351 command name, memory usage, controlling terminal etc. (the complete
352 list is in the struct acct in <file:include/linux/acct.h>). It is
353 up to the user level program to do useful things with this
354 information. This is generally a good idea, so say Y.
355
356config BSD_PROCESS_ACCT_V3
357 bool "BSD Process Accounting version 3 file format"
358 depends on BSD_PROCESS_ACCT
359 default n
360 help
361 If you say Y here, the process accounting information is written
362 in a new file format that also logs the process IDs of each
363 process and it's parent. Note that this file format is incompatible
364 with previous v0/v1/v2 file formats, so you will need updated tools
365 for processing it. A preliminary version of these tools is available
366 at <http://www.gnu.org/software/acct/>.
367
368config TASKSTATS
Kees Cook19c92392012-10-02 11:19:29 -0700369 bool "Export task/process statistics through netlink"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200370 depends on NET
371 default n
372 help
373 Export selected statistics for tasks/processes through the
374 generic netlink interface. Unlike BSD process accounting, the
375 statistics are available during the lifetime of tasks/processes as
376 responses to commands. Like BSD accounting, they are sent to user
377 space on task exit.
378
379 Say N if unsure.
380
381config TASK_DELAY_ACCT
Kees Cook19c92392012-10-02 11:19:29 -0700382 bool "Enable per-task delay accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200383 depends on TASKSTATS
384 help
385 Collect information on time spent by a task waiting for system
386 resources like cpu, synchronous block I/O completion and swapping
387 in pages. Such statistics can help in setting a task's priorities
388 relative to other tasks for cpu, io, rss limits etc.
389
390 Say N if unsure.
391
392config TASK_XACCT
Kees Cook19c92392012-10-02 11:19:29 -0700393 bool "Enable extended accounting over taskstats"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200394 depends on TASKSTATS
395 help
396 Collect extended task accounting data and send the data
397 to userland for processing over the taskstats interface.
398
399 Say N if unsure.
400
401config TASK_IO_ACCOUNTING
Kees Cook19c92392012-10-02 11:19:29 -0700402 bool "Enable per-task storage I/O accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200403 depends on TASK_XACCT
404 help
405 Collect information on the number of bytes of storage I/O which this
406 task has caused.
407
408 Say N if unsure.
409
410endmenu # "CPU/Task time and stats accounting"
411
Mike Travisc903ff82009-01-15 12:28:29 -0800412menu "RCU Subsystem"
413
414choice
415 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700416 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800417
Mike Travisc903ff82009-01-15 12:28:29 -0800418config TREE_RCU
419 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700420 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800421 help
422 This option selects the RCU implementation that is
423 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700424 thousands of CPUs. It also scales down nicely to
425 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800426
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700427config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700428 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700429 depends on PREEMPT && SMP
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700430 help
431 This option selects the RCU implementation that is
432 designed for very large SMP systems with hundreds or
433 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700434 is also required. It also scales down nicely to
435 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700436
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700437config TINY_RCU
438 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700439 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700440 help
441 This option selects the RCU implementation that is
442 designed for UP systems from which real-time response
443 is not required. This option greatly reduces the
444 memory footprint of RCU.
445
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700446config TINY_PREEMPT_RCU
447 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700448 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700449 help
450 This option selects the RCU implementation that is designed
451 for real-time UP systems. This option greatly reduces the
452 memory footprint of RCU.
453
Mike Travisc903ff82009-01-15 12:28:29 -0800454endchoice
455
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700456config PREEMPT_RCU
457 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
458 help
459 This option enables preemptible-RCU code that is common between
460 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
461
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100462config CONTEXT_TRACKING
463 bool
464
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200465config RCU_USER_QS
466 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100467 depends on HAVE_CONTEXT_TRACKING && SMP
468 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200469 help
470 This option sets hooks on kernel / userspace boundaries and
471 puts RCU in extended quiescent state when the CPU runs in
472 userspace. It means that when a CPU runs in userspace, it is
473 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700474 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200475
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200476 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100477 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700478 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200479
480 If unsure say N
481
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100482config CONTEXT_TRACKING_FORCE
483 bool "Force context tracking"
484 depends on CONTEXT_TRACKING
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200485 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100486 Probe on user/kernel boundaries by default in order to
487 test the features that rely on it such as userspace RCU extended
488 quiescent states.
489 This test is there for debugging until we have a real user like the
490 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200491
Mike Travisc903ff82009-01-15 12:28:29 -0800492config RCU_FANOUT
493 int "Tree-based hierarchical RCU fanout value"
494 range 2 64 if 64BIT
495 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700496 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800497 default 64 if 64BIT
498 default 32 if !64BIT
499 help
500 This option controls the fanout of hierarchical implementations
501 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700502 large numbers of CPUs. This value must be at least the fourth
503 root of NR_CPUS, which allows NR_CPUS to be insanely large.
504 The default value of RCU_FANOUT should be used for production
505 systems, but if you are stress-testing the RCU implementation
506 itself, small RCU_FANOUT values allow you to test large-system
507 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800508
509 Select a specific number if testing RCU itself.
510 Take the default if unsure.
511
Paul E. McKenney8932a632012-04-19 12:20:14 -0700512config RCU_FANOUT_LEAF
513 int "Tree-based hierarchical RCU leaf-level fanout value"
514 range 2 RCU_FANOUT if 64BIT
515 range 2 RCU_FANOUT if !64BIT
516 depends on TREE_RCU || TREE_PREEMPT_RCU
517 default 16
518 help
519 This option controls the leaf-level fanout of hierarchical
520 implementations of RCU, and allows trading off cache misses
521 against lock contention. Systems that synchronize their
522 scheduling-clock interrupts for energy-efficiency reasons will
523 want the default because the smaller leaf-level fanout keeps
524 lock contention levels acceptably low. Very large systems
525 (hundreds or thousands of CPUs) will instead want to set this
526 value to the maximum value possible in order to reduce the
527 number of cache misses incurred during RCU's grace-period
528 initialization. These systems tend to run CPU-bound, and thus
529 are not helped by synchronized interrupts, and thus tend to
530 skew them, which reduces lock contention enough that large
531 leaf-level fanouts work well.
532
533 Select a specific number if testing RCU itself.
534
535 Select the maximum permissible value for large systems.
536
537 Take the default if unsure.
538
Mike Travisc903ff82009-01-15 12:28:29 -0800539config RCU_FANOUT_EXACT
540 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700541 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800542 default n
543 help
544 This option forces use of the exact RCU_FANOUT value specified,
545 regardless of imbalances in the hierarchy. This is useful for
546 testing RCU itself, and might one day be useful on systems with
547 strong NUMA behavior.
548
549 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
550
551 Say N if unsure.
552
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800553config RCU_FAST_NO_HZ
554 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700555 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800556 default n
557 help
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700558 This option causes RCU to attempt to accelerate grace periods in
559 order to allow CPUs to enter dynticks-idle state more quickly.
560 On the other hand, this option increases the overhead of the
561 dynticks-idle checking, thus degrading scheduling latency.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800562
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700563 Say Y if energy efficiency is critically important, and you don't
564 care about real-time response.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800565
566 Say N if you are unsure.
567
Mike Travisc903ff82009-01-15 12:28:29 -0800568config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700569 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800570 select DEBUG_FS
571 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700572 This option provides tracing for the TREE_RCU and
573 TREE_PREEMPT_RCU implementations, permitting Makefile to
574 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800575
Paul E. McKenney24278d12010-09-27 17:25:23 -0700576config RCU_BOOST
577 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800578 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700579 default n
580 help
581 This option boosts the priority of preempted RCU readers that
582 block the current preemptible RCU grace period for too long.
583 This option also prevents heavy loads from blocking RCU
584 callback invocation for all flavors of RCU.
585
586 Say Y here if you are working with real-time apps or heavy loads
587 Say N here if you are unsure.
588
589config RCU_BOOST_PRIO
590 int "Real-time priority to boost RCU readers to"
591 range 1 99
592 depends on RCU_BOOST
593 default 1
594 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700595 This option specifies the real-time priority to which long-term
596 preempted RCU readers are to be boosted. If you are working
597 with a real-time application that has one or more CPU-bound
598 threads running at a real-time priority level, you should set
599 RCU_BOOST_PRIO to a priority higher then the highest-priority
600 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
601 of 1 is appropriate in the common case, which is real-time
602 applications that do not have any CPU-bound threads.
603
604 Some real-time applications might not have a single real-time
605 thread that saturates a given CPU, but instead might have
606 multiple real-time threads that, taken together, fully utilize
607 that CPU. In this case, you should set RCU_BOOST_PRIO to
608 a priority higher than the lowest-priority thread that is
609 conspiring to prevent the CPU from running any non-real-time
610 tasks. For example, if one thread at priority 10 and another
611 thread at priority 5 are between themselves fully consuming
612 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
613 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700614
615 Specify the real-time priority, or take the default if unsure.
616
617config RCU_BOOST_DELAY
618 int "Milliseconds to delay boosting after RCU grace-period start"
619 range 0 3000
620 depends on RCU_BOOST
621 default 500
622 help
623 This option specifies the time to wait after the beginning of
624 a given grace period before priority-boosting preempted RCU
625 readers blocking that grace period. Note that any RCU reader
626 blocking an expedited RCU grace period is boosted immediately.
627
628 Accept the default if unsure.
629
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700630config RCU_NOCB_CPU
631 bool "Offload RCU callback processing from boot-selected CPUs"
632 depends on TREE_RCU || TREE_PREEMPT_RCU
633 default n
634 help
635 Use this option to reduce OS jitter for aggressive HPC or
636 real-time workloads. It can also be used to offload RCU
637 callback invocation to energy-efficient CPUs in battery-powered
638 asymmetric multiprocessors.
639
640 This option offloads callback invocation from the set of
641 CPUs specified at boot time by the rcu_nocbs parameter.
642 For each such CPU, a kthread ("rcuoN") will be created to
643 invoke callbacks, where the "N" is the CPU being offloaded.
644 Nothing prevents this kthread from running on the specified
645 CPUs, but (1) the kthreads may be preempted between each
646 callback, and (2) affinity or cgroups can be used to force
647 the kthreads to run on whatever set of CPUs is desired.
648
649 Say Y here if you want reduced OS jitter on selected CPUs.
650 Say N here if you are unsure.
651
Mike Travisc903ff82009-01-15 12:28:29 -0800652endmenu # "RCU Subsystem"
653
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700655 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 ---help---
657 This option enables the complete Linux kernel ".config" file
658 contents to be saved in the kernel. It provides documentation
659 of which kernel options are used in a running kernel or in an
660 on-disk kernel. This information can be extracted from the kernel
661 image file with the script scripts/extract-ikconfig and used as
662 input to rebuild the current kernel or to build another kernel.
663 It can also be extracted from a running kernel by reading
664 /proc/config.gz if enabled (below).
665
666config IKCONFIG_PROC
667 bool "Enable access to .config through /proc/config.gz"
668 depends on IKCONFIG && PROC_FS
669 ---help---
670 This option enables access to the kernel configuration file
671 through /proc/config.gz.
672
Alistair John Strachan794543a2007-05-08 00:31:15 -0700673config LOG_BUF_SHIFT
674 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
675 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700676 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700677 help
678 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700679 Examples:
680 17 => 128 KB
681 16 => 64 KB
682 15 => 32 KB
683 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700684 13 => 8 KB
685 12 => 4 KB
686
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800687#
688# Architectures with an unreliable sched_clock() should select this:
689#
690config HAVE_UNSTABLE_SCHED_CLOCK
691 bool
692
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200693#
694# For architectures that want to enable the support for NUMA-affine scheduler
695# balancing logic:
696#
697config ARCH_SUPPORTS_NUMA_BALANCING
698 bool
699
700# For architectures that (ab)use NUMA to represent different memory regions
701# all cpu-local but of different latencies, such as SuperH.
702#
703config ARCH_WANT_NUMA_VARIABLE_LOCALITY
704 bool
705
706#
707# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
708config ARCH_WANTS_PROT_NUMA_PROT_NONE
709 bool
710
711config ARCH_USES_NUMA_PROT_NONE
712 bool
713 default y
714 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
715 depends on NUMA_BALANCING
716
Mel Gorman1a687c22012-11-22 11:16:36 +0000717config NUMA_BALANCING_DEFAULT_ENABLED
718 bool "Automatically enable NUMA aware memory/task placement"
719 default y
720 depends on NUMA_BALANCING
721 help
722 If set, autonumic NUMA balancing will be enabled if running on a NUMA
723 machine.
724
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200725config NUMA_BALANCING
726 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200727 depends on ARCH_SUPPORTS_NUMA_BALANCING
728 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
729 depends on SMP && NUMA && MIGRATION
730 help
731 This option adds support for automatic NUMA aware memory/task placement.
732 The mechanism is quite primitive and is based on migrating memory when
733 it is references to the node the task is running on.
734
735 This system will be inactive on UMA systems.
736
Li Zefan23964d22009-01-15 13:50:58 -0800737menuconfig CGROUPS
738 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800739 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700740 help
Li Zefan23964d22009-01-15 13:50:58 -0800741 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800742 use with process control subsystems such as Cpusets, CFS, memory
743 controls or device isolation.
744 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800745 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800746 - Documentation/cgroups/ (features for grouping, isolation
747 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700748
749 Say N if unsure.
750
Li Zefan23964d22009-01-15 13:50:58 -0800751if CGROUPS
752
Paul Menage006cb992007-10-18 23:39:43 -0700753config CGROUP_DEBUG
754 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700755 default n
Paul Menage006cb992007-10-18 23:39:43 -0700756 help
757 This option enables a simple cgroup subsystem that
758 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800759 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700760
Li Zefan23964d22009-01-15 13:50:58 -0800761 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700762
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700763config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800764 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800765 help
766 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700767 cgroup.
768
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700769config CGROUP_DEVICE
770 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700771 help
772 Provides a cgroup implementing whitelists for devices which
773 a process in the cgroup can mknod or open.
774
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775config CPUSETS
776 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700778 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 allow dynamically partitioning a system into sets of CPUs and
780 Memory Nodes and assigning tasks to run only within those sets.
781 This is primarily useful on large SMP or NUMA systems.
782
783 Say N if unsure.
784
Li Zefan23964d22009-01-15 13:50:58 -0800785config PROC_PID_CPUSET
786 bool "Include legacy /proc/<pid>/cpuset file"
787 depends on CPUSETS
788 default y
789
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100790config CGROUP_CPUACCT
791 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100792 help
793 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800794 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100795
Pavel Emelianove552b662008-02-07 00:13:49 -0800796config RESOURCE_COUNTERS
797 bool "Resource counters"
798 help
799 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800800 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800801
Andrew Mortonc255a452012-07-31 16:43:02 -0700802config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800803 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700804 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700805 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800806 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700807 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100808 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800809
810 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700811 associated with each page of memory in the system. By this,
812 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
813 usage tracking struct at boot. Total amount of this is printed out
814 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800815
816 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700817 sure you need the memory resource controller. Even when you enable
818 this, you can set "cgroup_disable=memory" at your boot option to
819 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800820 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800821
Balbir Singhcf475ad2008-04-29 01:00:16 -0700822 This config option also selects MM_OWNER config option, which
823 could in turn add some fork/exit overhead.
824
Andrew Mortonc255a452012-07-31 16:43:02 -0700825config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700826 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700827 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800828 help
829 Add swap management feature to memory resource controller. When you
830 enable this, you can limit mem+swap usage per cgroup. In other words,
831 when you disable this, memory resource controller has no cares to
832 usage of swap...a process can exhaust all of the swap. This extension
833 is useful when you want to avoid exhaustion swap but this itself
834 adds more overheads and consumes memory for remembering information.
835 Especially if you use 32bit system or small memory system, please
836 be careful about enabling this. When memory resource controller
837 is disabled by boot option, this will be automatically disabled and
838 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700839 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700840 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
841 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700842config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800843 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700844 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800845 default y
846 help
847 Memory Resource Controller Swap Extension comes with its price in
848 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700849 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800850 and let the user enable it by swapaccount boot command line
851 parameter should have this option unselected.
852 For those who want to have the feature enabled by default should
853 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700854 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700855config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700856 bool "Memory Resource Controller Kernel Memory accounting"
857 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800858 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000859 help
860 The Kernel Memory extension for Memory Resource Controller can limit
861 the amount of memory used by kernel objects in the system. Those are
862 fundamentally different from the entities handled by the standard
863 Memory Controller, which are page-based, and can be swapped. Users of
864 the kmem extension can use it to guarantee that no group of processes
865 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800866
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700867config CGROUP_HUGETLB
868 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700869 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700870 default n
871 help
872 Provides a cgroup Resource Controller for HugeTLB pages.
873 When you enable this, you can put a per cgroup limit on HugeTLB usage.
874 The limit is enforced during page fault. Since HugeTLB doesn't
875 support page reclaim, enforcing the limit at page fault time implies
876 that, the application will get SIGBUS signal if it tries to access
877 HugeTLB pages beyond its limit. This requires the application to know
878 beforehand how much HugeTLB pages it would require for its use. The
879 control group is tracked in the third page lru pointer. This means
880 that we cannot use the controller with huge page less than 3 pages.
881
Stephane Eraniane5d13672011-02-14 11:20:01 +0200882config CGROUP_PERF
883 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
884 depends on PERF_EVENTS && CGROUPS
885 help
886 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800887 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200888 designated cpu.
889
890 Say N if unsure.
891
Dhaval Giani7c941432010-01-20 13:26:18 +0100892menuconfig CGROUP_SCHED
893 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100894 default n
895 help
896 This feature lets CPU scheduler recognize task groups and control CPU
897 bandwidth allocation to such task groups. It uses cgroups to group
898 tasks.
899
900if CGROUP_SCHED
901config FAIR_GROUP_SCHED
902 bool "Group scheduling for SCHED_OTHER"
903 depends on CGROUP_SCHED
904 default CGROUP_SCHED
905
Paul Turnerab84d312011-07-21 09:43:28 -0700906config CFS_BANDWIDTH
907 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -0700908 depends on FAIR_GROUP_SCHED
909 default n
910 help
911 This option allows users to define CPU bandwidth rates (limits) for
912 tasks running within the fair group scheduler. Groups with no limit
913 set are considered to be unconstrained and will run with no
914 restriction.
915 See tip/Documentation/scheduler/sched-bwc.txt for more information.
916
Dhaval Giani7c941432010-01-20 13:26:18 +0100917config RT_GROUP_SCHED
918 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +0100919 depends on CGROUP_SCHED
920 default n
921 help
922 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800923 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100924 schedule realtime tasks for non-root users until you allocate
925 realtime bandwidth for them.
926 See Documentation/scheduler/sched-rt-group.txt for more information.
927
928endif #CGROUP_SCHED
929
Vivek Goyalafc24d42010-04-26 19:27:56 +0200930config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800931 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700932 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200933 default n
934 ---help---
935 Generic block IO controller cgroup interface. This is the common
936 cgroup interface which should be used by various IO controlling
937 policies.
938
939 Currently, CFQ IO scheduler uses it to recognize task groups and
940 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400941 to such task groups. It is also used by bio throttling logic in
942 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200943
944 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400945 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000946 enabling proportional weight division of disk bandwidth in CFQ, set
947 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000948 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200949
950 See Documentation/cgroups/blkio-controller.txt for more information.
951
952config DEBUG_BLK_CGROUP
953 bool "Enable Block IO controller debugging"
954 depends on BLK_CGROUP
955 default n
956 ---help---
957 Enable some debugging help. Currently it exports additional stat
958 files in a cgroup which can be useful for debugging.
959
Li Zefan23964d22009-01-15 13:50:58 -0800960endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800961
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800962config CHECKPOINT_RESTORE
963 bool "Checkpoint/restore support" if EXPERT
964 default n
965 help
966 Enables additional kernel features in a sake of checkpoint/restore.
967 In particular it adds auxiliary prctl codes to setup process text,
968 data and heap segment sizes, and a few additional /proc filesystem
969 entries.
970
971 If unsure, say N here.
972
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700973menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800974 bool "Namespaces support" if EXPERT
975 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800976 help
977 Provides the way to make tasks work with different objects using
978 the same id. For example same IPC id may refer to different objects
979 or same user id or pid may refer to different tasks when used in
980 different namespaces.
981
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700982if NAMESPACES
983
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800984config UTS_NS
985 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700986 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800987 help
988 In this namespace tasks see different info provided with the
989 uname() system call
990
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800991config IPC_NS
992 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700993 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700994 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800995 help
996 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700997 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800998
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800999config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001000 bool "User namespace"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001001 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001002 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001003
Eric W. Biederman5673a942011-11-17 10:23:55 -08001004 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001005 help
1006 This allows containers, i.e. vservers, to use user namespaces
1007 to provide different user info for different servers.
1008 If unsure, say N.
1009
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001010config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001011 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001012 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001013 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001014 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001015 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001016 pid namespaces. This is a building block of containers.
1017
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001018config NET_NS
1019 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001020 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001021 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001022 help
1023 Allow user space to create what appear to be multiple instances
1024 of the network stack.
1025
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001026endif # NAMESPACES
1027
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001028config UIDGID_CONVERTED
1029 # True if all of the selected software conmponents are known
1030 # to have uid_t and gid_t converted to kuid_t and kgid_t
1031 # where appropriate and are otherwise safe to use with
1032 # the user namespace.
1033 bool
1034 default y
1035
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001036 # Networking
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001037 depends on NET_9P = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001038
1039 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001040 depends on 9P_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001041 depends on AFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001042 depends on CEPH_FS = n
1043 depends on CIFS = n
1044 depends on CODA_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001045 depends on GFS2_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001046 depends on NCP_FS = n
1047 depends on NFSD = n
1048 depends on NFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001049 depends on OCFS2_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001050 depends on XFS_FS = n
1051
Eric W. Biederman5673a942011-11-17 10:23:55 -08001052config UIDGID_STRICT_TYPE_CHECKS
1053 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001054 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001055 default n
1056 help
1057 While the nececessary conversions are being added to all subsystems this option allows
1058 the code to continue to build for unconverted subsystems.
1059
1060 Say Y here if you want the strict type checking enabled
1061
Mike Galbraith5091faa2010-11-30 14:18:03 +01001062config SCHED_AUTOGROUP
1063 bool "Automatic process group scheduling"
1064 select EVENTFD
1065 select CGROUPS
1066 select CGROUP_SCHED
1067 select FAIR_GROUP_SCHED
1068 help
1069 This option optimizes the scheduler for common desktop workloads by
1070 automatically creating and populating task groups. This separation
1071 of workloads isolates aggressive CPU burners (like build jobs) from
1072 desktop applications. Task group autogeneration is currently based
1073 upon task session.
1074
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001075config MM_OWNER
1076 bool
1077
1078config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001079 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001080 depends on SYSFS
1081 default n
1082 help
1083 This option adds code that switches the layout of the "block" class
1084 devices, to not show up in /sys/class/block/, but only in
1085 /sys/block/.
1086
1087 This switch is only active when the sysfs.deprecated=1 boot option is
1088 passed or the SYSFS_DEPRECATED_V2 option is set.
1089
1090 This option allows new kernels to run on old distributions and tools,
1091 which might get confused by /sys/class/block/. Since 2007/2008 all
1092 major distributions and tools handle this just fine.
1093
1094 Recent distributions and userspace tools after 2009/2010 depend on
1095 the existence of /sys/class/block/, and will not work with this
1096 option enabled.
1097
1098 Only if you are using a new kernel on an old distribution, you might
1099 need to say Y here.
1100
1101config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001102 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001103 default n
1104 depends on SYSFS
1105 depends on SYSFS_DEPRECATED
1106 help
1107 Enable deprecated sysfs by default.
1108
1109 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1110 option.
1111
1112 Only if you are using a new kernel on an old distribution, you might
1113 need to say Y here. Even then, odds are you would not need it
1114 enabled, you can always pass the boot option if absolutely necessary.
1115
1116config RELAY
1117 bool "Kernel->user space relay support (formerly relayfs)"
1118 help
1119 This option enables support for relay interface support in
1120 certain file systems (such as debugfs).
1121 It is designed to provide an efficient mechanism for tools and
1122 facilities to relay large amounts of data from kernel space to
1123 user space.
1124
1125 If unsure, say N.
1126
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001127config BLK_DEV_INITRD
1128 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1129 depends on BROKEN || !FRV
1130 help
1131 The initial RAM filesystem is a ramfs which is loaded by the
1132 boot loader (loadlin or lilo) and that is mounted as root
1133 before the normal boot procedure. It is typically used to
1134 load modules needed to mount the "real" root file system,
1135 etc. See <file:Documentation/initrd.txt> for details.
1136
1137 If RAM disk support (BLK_DEV_RAM) is also included, this
1138 also enables initial RAM disk (initrd) support and adds
1139 15 Kbytes (more on some other architectures) to the kernel size.
1140
1141 If unsure say Y.
1142
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001143if BLK_DEV_INITRD
1144
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001145source "usr/Kconfig"
1146
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001147endif
1148
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001149config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001150 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001151 help
1152 Enabling this option will pass "-Os" instead of "-O2" to gcc
1153 resulting in a smaller kernel.
1154
jkacur775a7222008-07-16 00:31:16 +02001155 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001156
Randy Dunlap08470622006-09-30 23:28:13 -07001157config SYSCTL
1158 bool
1159
Randy Dunlapb943c462009-03-10 12:55:46 -07001160config ANON_INODES
1161 bool
1162
David Rientjes6a108a12011-01-20 14:44:16 -08001163menuconfig EXPERT
1164 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001165 # Unhide debug options, to make the on-by-default options visible
1166 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 help
1168 This option allows certain base kernel options and settings
1169 to be disabled or tweaked. This is for specialized
1170 environments which can tolerate a "non-standard" kernel.
1171 Only use this if you really know what you are doing.
1172
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001173config HAVE_UID16
1174 bool
1175
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001176config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001177 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001178 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001179 default y
1180 help
1181 This enables the legacy 16-bit UID syscall wrappers.
1182
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001183config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001184 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001185 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001186 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001187 select SYSCTL
1188 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001189 sys_sysctl uses binary paths that have been found challenging
1190 to properly maintain and use. The interface in /proc/sys
1191 using paths with ascii names is now the primary path to this
1192 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001193
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001194 Almost nothing using the binary sysctl interface so if you are
1195 trying to save some space it is probably safe to disable this,
1196 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001197
WANG Congc736de62011-11-02 13:39:25 -07001198 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001199
Catalin Marinas7ac57a82012-10-08 16:28:16 -07001200config SYSCTL_EXCEPTION_TRACE
1201 bool
1202 help
1203 Enable support for /proc/sys/debug/exception-trace.
1204
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001206 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207 default y
1208 help
1209 Say Y here to let the kernel print out symbolic crash information and
1210 symbolic stack backtraces. This increases the size of the kernel
1211 somewhat, as all symbols have to be loaded into the kernel image.
1212
1213config KALLSYMS_ALL
1214 bool "Include all symbols in kallsyms"
1215 depends on DEBUG_KERNEL && KALLSYMS
1216 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001217 Normally kallsyms only contains the symbols of functions for nicer
1218 OOPS messages and backtraces (i.e., symbols from the text and inittext
1219 sections). This is sufficient for most cases. And only in very rare
1220 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1221 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001223 This option makes sure that all symbols are loaded into the kernel
1224 image (i.e., symbols from all sections) in cost of increased kernel
1225 size (depending on the kernel configuration, it may be 300KiB or
1226 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001228 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001229
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001230config HOTPLUG
Greg Kroah-Hartman45f035a2012-09-04 17:01:08 -07001231 def_bool y
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001232
Matt Mackalld59745c2005-05-01 08:59:02 -07001233config PRINTK
1234 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001235 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001236 help
1237 This option enables normal printk support. Removing it
1238 eliminates most of the message strings from the kernel image
1239 and makes the kernel more or less silent. As this makes it
1240 very difficult to diagnose system problems, saying N here is
1241 strongly discouraged.
1242
Matt Mackallc8538a72005-05-01 08:59:01 -07001243config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001244 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001245 default y
1246 help
1247 Disabling this option eliminates support for BUG and WARN, reducing
1248 the size of your kernel image and potentially quietly ignoring
1249 numerous fatal conditions. You should only consider disabling this
1250 option for embedded systems with no facilities for reporting errors.
1251 Just say Y.
1252
Matt Mackall708e9a72006-01-08 01:05:25 -08001253config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001254 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001255 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001256 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001257 help
1258 Enable support for generating core dumps. Disabling saves about 4k.
1259
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001260
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001261config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001262 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001263 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001264 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001265 default y
1266 help
1267 This option allows to disable the internal PC-Speaker
1268 support, saving some memory.
1269
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001270config HAVE_PCSPKR_PLATFORM
1271 bool
1272
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273config BASE_FULL
1274 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001275 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 help
1277 Disabling this option reduces the size of miscellaneous core
1278 kernel data structures. This saves memory on small machines,
1279 but may reduce performance.
1280
1281config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001282 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001284 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001285 help
1286 Disabling this option will cause the kernel to be built without
1287 support for "fast userspace mutexes". The resulting kernel may not
1288 run glibc-based applications correctly.
1289
1290config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001291 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001293 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294 help
1295 Disabling this option will cause the kernel to be built without
1296 support for epoll family of system calls.
1297
Davide Libenzifba2afa2007-05-10 22:23:13 -07001298config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001299 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001300 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001301 default y
1302 help
1303 Enable the signalfd() system call that allows to receive signals
1304 on a file descriptor.
1305
1306 If unsure, say Y.
1307
Davide Libenzib215e282007-05-10 22:23:16 -07001308config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001309 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001310 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001311 default y
1312 help
1313 Enable the timerfd() system call that allows to receive timer
1314 events on a file descriptor.
1315
1316 If unsure, say Y.
1317
Davide Libenzie1ad7462007-05-10 22:23:19 -07001318config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001319 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001320 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001321 default y
1322 help
1323 Enable the eventfd() system call that allows to receive both
1324 kernel notification (ie. KAIO) or userspace notifications.
1325
1326 If unsure, say Y.
1327
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001329 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 default y
1331 depends on MMU
1332 help
1333 The shmem is an internal filesystem used to manage shared memory.
1334 It is backed by swap and manages resource limits. It is also exported
1335 to userspace as tmpfs if TMPFS is enabled. Disabling this
1336 option replaces shmem and tmpfs with the much simpler ramfs code,
1337 which may be appropriate on small systems without swap.
1338
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001339config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001340 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001341 default y
1342 help
1343 This option enables POSIX asynchronous I/O which may by used
1344 by some high performance threaded applications. Disabling
1345 this option saves about 7k.
1346
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001347config EMBEDDED
1348 bool "Embedded system"
1349 select EXPERT
1350 help
1351 This option should be enabled if compiling the kernel for
1352 an embedded system so certain expert options are available
1353 for configuration.
1354
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001355config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001356 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001357 help
1358 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001359
Peter Zijlstra906010b2009-09-21 16:08:49 +02001360config PERF_USE_VMALLOC
1361 bool
1362 help
1363 See tools/perf/design.txt for details
1364
Ingo Molnar57c0c152009-09-21 12:20:38 +02001365menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001366
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001367config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001368 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001369 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001370 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001371 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001372 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001373 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001374 Enable kernel support for various performance events provided
1375 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001376
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001377 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001378 use of generic tracepoints.
1379
1380 Most modern CPUs support performance events via performance
1381 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001382 types of hw events: such as instructions executed, cachemisses
1383 suffered, or branches mis-predicted - without slowing down the
1384 kernel or applications. These registers can also trigger interrupts
1385 when a threshold number of events have passed - and can thus be
1386 used to profile the code that runs on that CPU.
1387
Ingo Molnar57c0c152009-09-21 12:20:38 +02001388 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001389 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001390 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001391 provides per task and per CPU counters, and it provides event
1392 capabilities on top of those.
1393
1394 Say Y if unsure.
1395
Peter Zijlstra906010b2009-09-21 16:08:49 +02001396config DEBUG_PERF_USE_VMALLOC
1397 default n
1398 bool "Debug: use vmalloc to back perf mmap() buffers"
1399 depends on PERF_EVENTS && DEBUG_KERNEL
1400 select PERF_USE_VMALLOC
1401 help
1402 Use vmalloc memory to back perf mmap() buffers.
1403
1404 Mostly useful for debugging the vmalloc code on platforms
1405 that don't require it.
1406
1407 Say N if unsure.
1408
Thomas Gleixner0793a612008-12-04 20:12:29 +01001409endmenu
1410
Christoph Lameterf8891e52006-06-30 01:55:45 -07001411config VM_EVENT_COUNTERS
1412 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001413 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001414 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001415 VM event counters are needed for event counts to be shown.
1416 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001417 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001418 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001419
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001420config PCI_QUIRKS
1421 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001422 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001423 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001424 help
1425 This enables workarounds for various PCI chipset
1426 bugs/quirks. Disable this only if your target machine is
1427 unaffected by PCI quirks.
1428
Christoph Lameter41ecc552007-05-09 02:32:44 -07001429config SLUB_DEBUG
1430 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001431 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001432 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001433 help
1434 SLUB has extensive debug support features. Disabling these can
1435 result in significant savings in code size. This also disables
1436 SLUB sysfs support. /sys/slab will not exist and there will be
1437 no support for cache validation etc.
1438
Randy Dunlapb943c462009-03-10 12:55:46 -07001439config COMPAT_BRK
1440 bool "Disable heap randomization"
1441 default y
1442 help
1443 Randomizing heap placement makes heap exploits harder, but it
1444 also breaks ancient binaries (including anything libc5 based).
1445 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001446 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001447 /proc/sys/kernel/randomize_va_space to 2.
1448
1449 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1450
Christoph Lameter81819f02007-05-06 14:49:36 -07001451choice
1452 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001453 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001454 help
1455 This option allows to select a slab allocator.
1456
1457config SLAB
1458 bool "SLAB"
1459 help
1460 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001461 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001462 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001463
1464config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001465 bool "SLUB (Unqueued Allocator)"
1466 help
1467 SLUB is a slab allocator that minimizes cache line usage
1468 instead of managing queues of cached objects (SLAB approach).
1469 Per cpu caching is realized using slabs of objects instead
1470 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001471 and has enhanced diagnostics. SLUB is the default choice for
1472 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001473
1474config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001475 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001476 bool "SLOB (Simple Allocator)"
1477 help
Matt Mackall37291452008-02-04 22:29:38 -08001478 SLOB replaces the stock allocator with a drastically simpler
1479 allocator. SLOB is generally more space efficient but
1480 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001481
1482endchoice
1483
Jie Zhangea637632009-12-14 18:00:02 -08001484config MMAP_ALLOW_UNINITIALIZED
1485 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001486 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001487 default n
1488 help
1489 Normally, and according to the Linux spec, anonymous memory obtained
1490 from mmap() has it's contents cleared before it is passed to
1491 userspace. Enabling this config option allows you to request that
1492 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1493 providing a huge performance boost. If this option is not enabled,
1494 then the flag will be ignored.
1495
1496 This is taken advantage of by uClibc's malloc(), and also by
1497 ELF-FDPIC binfmt's brk and stack allocator.
1498
1499 Because of the obvious security issues, this option should only be
1500 enabled on embedded devices where you control what is run in
1501 userspace. Since that isn't generally a problem on no-MMU systems,
1502 it is normally safe to say Y here.
1503
1504 See Documentation/nommu-mmap.txt for more information.
1505
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001506config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001507 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001508 help
1509 Say Y here to enable the extended profiling support mechanisms used
1510 by profilers such as OProfile.
1511
Ingo Molnar5f87f112008-07-23 14:15:22 +02001512#
1513# Place an empty function call at each tracepoint site. Can be
1514# dynamically changed for a probe function.
1515#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001516config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001517 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001518
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001519source "arch/Kconfig"
1520
Linus Torvalds1da177e2005-04-16 15:20:36 -07001521endmenu # General setup
1522
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001523config HAVE_GENERIC_DMA_COHERENT
1524 bool
1525 default n
1526
Linus Torvalds158a9622008-01-02 13:04:48 -08001527config SLABINFO
1528 bool
1529 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001530 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001531 default y
1532
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001533config RT_MUTEXES
1534 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001535
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536config BASE_SMALL
1537 int
1538 default 0 if BASE_FULL
1539 default 1 if !BASE_FULL
1540
Jan Engelhardt66da5732007-07-15 23:39:29 -07001541menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542 bool "Enable loadable module support"
1543 help
1544 Kernel modules are small pieces of compiled code which can
1545 be inserted in the running kernel, rather than being
1546 permanently built into the kernel. You use the "modprobe"
1547 tool to add (and sometimes remove) them. If you say Y here,
1548 many parts of the kernel can be built as modules (by
1549 answering M instead of Y where indicated): this is most
1550 useful for infrequently used options which are not required
1551 for booting. For more information, see the man pages for
1552 modprobe, lsmod, modinfo, insmod and rmmod.
1553
1554 If you say Y here, you will need to run "make
1555 modules_install" to put the modules under /lib/modules/
1556 where modprobe can find them (you may need to be root to do
1557 this).
1558
1559 If unsure, say Y.
1560
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001561if MODULES
1562
Linus Torvalds826e4502008-05-04 17:04:16 -07001563config MODULE_FORCE_LOAD
1564 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001565 default n
1566 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001567 Allow loading of modules without version information (ie. modprobe
1568 --force). Forced module loading sets the 'F' (forced) taint flag and
1569 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001570
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571config MODULE_UNLOAD
1572 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001573 help
1574 Without this option you will not be able to unload any
1575 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001576 anyway), which makes your kernel smaller, faster
1577 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578
1579config MODULE_FORCE_UNLOAD
1580 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001581 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582 help
1583 This option allows you to force a module to unload, even if the
1584 kernel believes it is unsafe: the kernel will remove the module
1585 without waiting for anyone to stop using it (using the -f option to
1586 rmmod). This is mainly for kernel developers and desperate users.
1587 If unsure, say N.
1588
Linus Torvalds1da177e2005-04-16 15:20:36 -07001589config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001590 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001591 help
1592 Usually, you have to use modules compiled with your kernel.
1593 Saying Y here makes it sometimes possible to use modules
1594 compiled for different kernels, by adding enough information
1595 to the modules to (hopefully) spot any changes which would
1596 make them incompatible with the kernel you are running. If
1597 unsure, say N.
1598
1599config MODULE_SRCVERSION_ALL
1600 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001601 help
1602 Modules which contain a MODULE_VERSION get an extra "srcversion"
1603 field inserted into their modinfo section, which contains a
1604 sum of the source files which made it. This helps maintainers
1605 see exactly which source was used to build a module (since
1606 others sometimes change the module source without updating
1607 the version). With this option, such a "srcversion" field
1608 will be created for all modules. If unsure, say N.
1609
Rusty Russell106a4ee2012-09-26 10:09:40 +01001610config MODULE_SIG
1611 bool "Module signature verification"
1612 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001613 select KEYS
1614 select CRYPTO
1615 select ASYMMETRIC_KEY_TYPE
1616 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1617 select PUBLIC_KEY_ALGO_RSA
1618 select ASN1
1619 select OID_REGISTRY
1620 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001621 help
1622 Check modules for valid signatures upon load: the signature
1623 is simply appended to the module. For more information see
1624 Documentation/module-signing.txt.
1625
David Howellsea0b6dc2012-09-26 10:09:50 +01001626 !!!WARNING!!! If you enable this option, you MUST make sure that the
1627 module DOES NOT get stripped after being signed. This includes the
1628 debuginfo strip done by some packagers (such as rpmbuild) and
1629 inclusion into an initramfs that wants the module size reduced.
1630
Rusty Russell106a4ee2012-09-26 10:09:40 +01001631config MODULE_SIG_FORCE
1632 bool "Require modules to be validly signed"
1633 depends on MODULE_SIG
1634 help
1635 Reject unsigned modules or signed modules for which we don't have a
1636 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001637
1638choice
1639 prompt "Which hash algorithm should modules be signed with?"
1640 depends on MODULE_SIG
1641 help
1642 This determines which sort of hashing algorithm will be used during
1643 signature generation. This algorithm _must_ be built into the kernel
1644 directly so that signature verification can take place. It is not
1645 possible to load a signed module containing the algorithm to check
1646 the signature on that module.
1647
1648config MODULE_SIG_SHA1
1649 bool "Sign modules with SHA-1"
1650 select CRYPTO_SHA1
1651
1652config MODULE_SIG_SHA224
1653 bool "Sign modules with SHA-224"
1654 select CRYPTO_SHA256
1655
1656config MODULE_SIG_SHA256
1657 bool "Sign modules with SHA-256"
1658 select CRYPTO_SHA256
1659
1660config MODULE_SIG_SHA384
1661 bool "Sign modules with SHA-384"
1662 select CRYPTO_SHA512
1663
1664config MODULE_SIG_SHA512
1665 bool "Sign modules with SHA-512"
1666 select CRYPTO_SHA512
1667
1668endchoice
1669
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001670endif # MODULES
1671
Rusty Russell98a79d62008-12-13 21:19:41 +10301672config INIT_ALL_POSSIBLE
1673 bool
1674 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301675 Back when each arch used to define their own cpu_online_mask and
1676 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301677 with all 1s, and others with all 0s. When they were centralised,
1678 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001679 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301680
Linus Torvalds1da177e2005-04-16 15:20:36 -07001681config STOP_MACHINE
1682 bool
1683 default y
1684 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1685 help
1686 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001687
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001688source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001689
1690config PREEMPT_NOTIFIERS
1691 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001692
Steffen Klassert16295be2010-01-06 19:47:10 +11001693config PADATA
1694 depends on SMP
1695 bool
1696
Andi Kleen754b7b62012-10-04 17:11:27 -07001697# Can be selected by architectures with broken toolchains
1698# that get confused by correct const<->read_only section
1699# mappings
1700config BROKEN_RODATA
1701 bool
1702
David Howells4520c6a2012-09-21 23:31:13 +01001703config ASN1
1704 tristate
1705 help
1706 Build a simple ASN.1 grammar compiler that produces a bytecode output
1707 that can be interpreted by the ASN.1 stream decoder and used to
1708 inform it as to what tags are to be expected in a stream and what
1709 functions to call on what tags.
1710
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001711source "kernel/Kconfig.locks"