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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
22 default y
23
Al Boldiff0cfc62007-07-31 00:39:23 -070024menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26config EXPERIMENTAL
27 bool "Prompt for development and/or incomplete code/drivers"
28 ---help---
29 Some of the various things that Linux supports (such as network
30 drivers, file systems, network protocols, etc.) can be in a state
31 of development where the functionality, stability, or the level of
32 testing is not yet high enough for general use. This is usually
33 known as the "alpha-test" phase among developers. If a feature is
34 currently in alpha-test, then the developers usually discourage
35 uninformed widespread use of this feature by the general public to
36 avoid "Why doesn't this work?" type mail messages. However, active
37 testing and use of these systems is welcomed. Just be aware that it
38 may not meet the normal level of reliability or it may fail to work
39 in some special cases. Detailed bug reports from people familiar
40 with the kernel internals are usually welcomed by the developers
41 (before submitting bug reports, please read the documents
42 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
43 <file:Documentation/BUG-HUNTING>, and
44 <file:Documentation/oops-tracing.txt> in the kernel source).
45
46 This option will also make obsoleted drivers available. These are
47 drivers that have been replaced by something else, and/or are
48 scheduled to be removed in a future kernel release.
49
50 Unless you intend to help test and develop a feature or driver that
51 falls into this category, or you have a situation that requires
52 using these features, you should probably say N here, which will
53 cause the configurator to present you with fewer choices. If
54 you say Y here, you will be offered the choice of using features or
55 drivers that are currently considered to be in the alpha-test phase.
56
Linus Torvalds1da177e2005-04-16 15:20:36 -070057config BROKEN
58 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60config BROKEN_ON_SMP
61 bool
62 depends on BROKEN || !SMP
63 default y
64
65config LOCK_KERNEL
66 bool
67 depends on SMP || PREEMPT
68 default y
69
70config INIT_ENV_ARG_LIMIT
71 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070072 default 32 if !UML
73 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080075 Maximum of each of the number of arguments and environment
76 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
79config LOCALVERSION
80 string "Local version - append to kernel release"
81 help
82 Append an extra string to the end of your kernel version.
83 This will show up when you type uname, for example.
84 The string you set here will be appended after the contents of
85 any files with a filename matching localversion* in your
86 object and source tree, in that order. Your total string can
87 be a maximum of 64 characters.
88
Ryan Andersonaaebf432005-07-31 04:57:49 -040089config LOCALVERSION_AUTO
90 bool "Automatically append version information to the version string"
91 default y
92 help
93 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020094 release tree by looking for git tags that belong to the current
95 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040096
97 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020098 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040099 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200100 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400101
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200102 (The actual string used here is the first eight characters produced
103 by running the command:
104
105 $ git rev-parse --verify HEAD
106
107 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400108
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800109config HAVE_KERNEL_GZIP
110 bool
111
112config HAVE_KERNEL_BZIP2
113 bool
114
115config HAVE_KERNEL_LZMA
116 bool
117
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800118config HAVE_KERNEL_LZO
119 bool
120
Alain Knaff30d65db2009-01-04 22:46:17 +0100121choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800122 prompt "Kernel compression mode"
123 default KERNEL_GZIP
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800124 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_LZO
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800125 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100126 The linux kernel is a kind of self-extracting executable.
127 Several compression algorithms are available, which differ
128 in efficiency, compression and decompression speed.
129 Compression speed is only relevant when building a kernel.
130 Decompression speed is relevant at each boot.
131
132 If you have any problems with bzip2 or lzma compressed
133 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
134 version of this functionality (bzip2 only), for 2.4, was
135 supplied by Christian Ludwig)
136
137 High compression options are mostly useful for users, who
138 are low on disk space (embedded systems), but for whom ram
139 size matters less.
140
141 If in doubt, select 'gzip'
142
143config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800144 bool "Gzip"
145 depends on HAVE_KERNEL_GZIP
146 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800147 The old and tried gzip compression. It provides a good balance
148 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100149
150config KERNEL_BZIP2
151 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800152 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100153 help
154 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800155 Decompression speed is slowest among the three. The kernel
156 size is about 10% smaller with bzip2, in comparison to gzip.
157 Bzip2 uses a large amount of memory. For modern kernels you
158 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100159
160config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800161 bool "LZMA"
162 depends on HAVE_KERNEL_LZMA
163 help
164 The most recent compression algorithm.
165 Its ratio is best, decompression speed is between the other
166 two. Compression is slowest. The kernel size is about 33%
167 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100168
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800169config KERNEL_LZO
170 bool "LZO"
171 depends on HAVE_KERNEL_LZO
172 help
173 Its compression ratio is the poorest among the 4. The kernel
174 size is about about 10% bigger than gzip; however its speed
175 (both compression and decompression) is the fastest.
176
Alain Knaff30d65db2009-01-04 22:46:17 +0100177endchoice
178
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179config SWAP
180 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200181 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 default y
183 help
184 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100185 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 used to provide more virtual memory than the actual RAM present
187 in your computer. If unsure say Y.
188
189config SYSVIPC
190 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 ---help---
192 Inter Process Communication is a suite of library functions and
193 system calls which let processes (running programs) synchronize and
194 exchange information. It is generally considered to be a good thing,
195 and some programs won't run unless you say Y here. In particular, if
196 you want to run the DOS emulator dosemu under Linux (read the
197 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
198 you'll need to say Y here.
199
200 You can find documentation about IPC with "info ipc" and also in
201 section 6.4 of the Linux Programmer's Guide, available from
202 <http://www.tldp.org/guides.html>.
203
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800204config SYSVIPC_SYSCTL
205 bool
206 depends on SYSVIPC
207 depends on SYSCTL
208 default y
209
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210config POSIX_MQUEUE
211 bool "POSIX Message Queues"
212 depends on NET && EXPERIMENTAL
213 ---help---
214 POSIX variant of message queues is a part of IPC. In POSIX message
215 queues every message has a priority which decides about succession
216 of receiving it by a process. If you want to compile and run
217 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200218 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
220 POSIX message queues are visible as a filesystem called 'mqueue'
221 and can be mounted somewhere if you want to do filesystem
222 operations on message queues.
223
224 If unsure, say Y.
225
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700226config POSIX_MQUEUE_SYSCTL
227 bool
228 depends on POSIX_MQUEUE
229 depends on SYSCTL
230 default y
231
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232config BSD_PROCESS_ACCT
233 bool "BSD Process Accounting"
234 help
235 If you say Y here, a user level program will be able to instruct the
236 kernel (via a special system call) to write process accounting
237 information to a file: whenever a process exits, information about
238 that process will be appended to the file by the kernel. The
239 information includes things such as creation time, owning user,
240 command name, memory usage, controlling terminal etc. (the complete
241 list is in the struct acct in <file:include/linux/acct.h>). It is
242 up to the user level program to do useful things with this
243 information. This is generally a good idea, so say Y.
244
245config BSD_PROCESS_ACCT_V3
246 bool "BSD Process Accounting version 3 file format"
247 depends on BSD_PROCESS_ACCT
248 default n
249 help
250 If you say Y here, the process accounting information is written
251 in a new file format that also logs the process IDs of each
252 process and it's parent. Note that this file format is incompatible
253 with previous v0/v1/v2 file formats, so you will need updated tools
254 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300255 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
Shailabh Nagarc7572492006-07-14 00:24:40 -0700257config TASKSTATS
258 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
259 depends on NET
260 default n
261 help
262 Export selected statistics for tasks/processes through the
263 generic netlink interface. Unlike BSD process accounting, the
264 statistics are available during the lifetime of tasks/processes as
265 responses to commands. Like BSD accounting, they are sent to user
266 space on task exit.
267
268 Say N if unsure.
269
Shailabh Nagarca74e922006-07-14 00:24:36 -0700270config TASK_DELAY_ACCT
271 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700272 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700273 help
274 Collect information on time spent by a task waiting for system
275 resources like cpu, synchronous block I/O completion and swapping
276 in pages. Such statistics can help in setting a task's priorities
277 relative to other tasks for cpu, io, rss limits etc.
278
279 Say N if unsure.
280
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800281config TASK_XACCT
282 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
283 depends on TASKSTATS
284 help
285 Collect extended task accounting data and send the data
286 to userland for processing over the taskstats interface.
287
288 Say N if unsure.
289
290config TASK_IO_ACCOUNTING
291 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
292 depends on TASK_XACCT
293 help
294 Collect information on the number of bytes of storage I/O which this
295 task has caused.
296
297 Say N if unsure.
298
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299config AUDIT
300 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100301 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 help
303 Enable auditing infrastructure that can be used with another
304 kernel subsystem, such as SELinux (which requires this for
305 logging of avc messages output). Does not do system-call
306 auditing without CONFIG_AUDITSYSCALL.
307
308config AUDITSYSCALL
309 bool "Enable system-call auditing support"
Kumar Gala022382a2009-10-16 07:21:37 +0000310 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 default y if SECURITY_SELINUX
312 help
313 Enable low-overhead system-call auditing infrastructure that
314 can be used independently or with another kernel subsystem,
Amy Griffisf368c07d2006-04-07 16:55:56 -0400315 such as SELinux. To use audit's filesystem watch feature, please
316 ensure that INOTIFY is configured.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317
Al Viro74c3cbe2007-07-22 08:04:18 -0400318config AUDIT_TREE
319 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400320 depends on AUDITSYSCALL
321 select INOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400322
Mike Travisc903ff82009-01-15 12:28:29 -0800323menu "RCU Subsystem"
324
325choice
326 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700327 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800328
Mike Travisc903ff82009-01-15 12:28:29 -0800329config TREE_RCU
330 bool "Tree-based hierarchical RCU"
331 help
332 This option selects the RCU implementation that is
333 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700334 thousands of CPUs. It also scales down nicely to
335 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800336
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700337config TREE_PREEMPT_RCU
338 bool "Preemptable tree-based hierarchical RCU"
339 depends on PREEMPT
340 help
341 This option selects the RCU implementation that is
342 designed for very large SMP systems with hundreds or
343 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700344 is also required. It also scales down nicely to
345 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700346
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700347config TINY_RCU
348 bool "UP-only small-memory-footprint RCU"
349 depends on !SMP
350 help
351 This option selects the RCU implementation that is
352 designed for UP systems from which real-time response
353 is not required. This option greatly reduces the
354 memory footprint of RCU.
355
Mike Travisc903ff82009-01-15 12:28:29 -0800356endchoice
357
358config RCU_TRACE
359 bool "Enable tracing for RCU"
Paul E. McKenney6b3ef482009-08-22 13:56:53 -0700360 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800361 help
362 This option provides tracing in RCU which presents stats
363 in debugfs for debugging RCU implementation.
364
365 Say Y here if you want to enable RCU tracing
366 Say N if you are unsure.
367
368config RCU_FANOUT
369 int "Tree-based hierarchical RCU fanout value"
370 range 2 64 if 64BIT
371 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700372 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800373 default 64 if 64BIT
374 default 32 if !64BIT
375 help
376 This option controls the fanout of hierarchical implementations
377 of RCU, allowing RCU to work efficiently on machines with
378 large numbers of CPUs. This value must be at least the cube
379 root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
380 systems and up to 262,144 for 64-bit systems.
381
382 Select a specific number if testing RCU itself.
383 Take the default if unsure.
384
385config RCU_FANOUT_EXACT
386 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700387 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800388 default n
389 help
390 This option forces use of the exact RCU_FANOUT value specified,
391 regardless of imbalances in the hierarchy. This is useful for
392 testing RCU itself, and might one day be useful on systems with
393 strong NUMA behavior.
394
395 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
396
397 Say N if unsure.
398
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800399config RCU_FAST_NO_HZ
400 bool "Accelerate last non-dyntick-idle CPU's grace periods"
401 depends on TREE_RCU && NO_HZ && SMP
402 default n
403 help
404 This option causes RCU to attempt to accelerate grace periods
405 in order to allow the final CPU to enter dynticks-idle state
406 more quickly. On the other hand, this option increases the
407 overhead of the dynticks-idle checking, particularly on systems
408 with large numbers of CPUs.
409
410 Say Y if energy efficiency is critically important, particularly
411 if you have relatively few CPUs.
412
413 Say N if you are unsure.
414
Mike Travisc903ff82009-01-15 12:28:29 -0800415config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700416 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800417 select DEBUG_FS
418 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700419 This option provides tracing for the TREE_RCU and
420 TREE_PREEMPT_RCU implementations, permitting Makefile to
421 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800422
Mike Travisc903ff82009-01-15 12:28:29 -0800423endmenu # "RCU Subsystem"
424
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700426 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 ---help---
428 This option enables the complete Linux kernel ".config" file
429 contents to be saved in the kernel. It provides documentation
430 of which kernel options are used in a running kernel or in an
431 on-disk kernel. This information can be extracted from the kernel
432 image file with the script scripts/extract-ikconfig and used as
433 input to rebuild the current kernel or to build another kernel.
434 It can also be extracted from a running kernel by reading
435 /proc/config.gz if enabled (below).
436
437config IKCONFIG_PROC
438 bool "Enable access to .config through /proc/config.gz"
439 depends on IKCONFIG && PROC_FS
440 ---help---
441 This option enables access to the kernel configuration file
442 through /proc/config.gz.
443
Alistair John Strachan794543a2007-05-08 00:31:15 -0700444config LOG_BUF_SHIFT
445 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
446 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700447 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700448 help
449 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700450 Examples:
451 17 => 128 KB
452 16 => 64 KB
453 15 => 32 KB
454 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700455 13 => 8 KB
456 12 => 4 KB
457
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800458#
459# Architectures with an unreliable sched_clock() should select this:
460#
461config HAVE_UNSTABLE_SCHED_CLOCK
462 bool
463
Li Zefan23964d22009-01-15 13:50:58 -0800464menuconfig CGROUPS
465 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800466 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700467 help
Li Zefan23964d22009-01-15 13:50:58 -0800468 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800469 use with process control subsystems such as Cpusets, CFS, memory
470 controls or device isolation.
471 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800472 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800473 - Documentation/cgroups/ (features for grouping, isolation
474 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700475
476 Say N if unsure.
477
Li Zefan23964d22009-01-15 13:50:58 -0800478if CGROUPS
479
Paul Menage006cb992007-10-18 23:39:43 -0700480config CGROUP_DEBUG
481 bool "Example debug cgroup subsystem"
482 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700483 default n
Paul Menage006cb992007-10-18 23:39:43 -0700484 help
485 This option enables a simple cgroup subsystem that
486 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800487 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700488
Li Zefan23964d22009-01-15 13:50:58 -0800489 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700490
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700491config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800492 bool "Namespace cgroup subsystem"
493 depends on CGROUPS
494 help
495 Provides a simple namespace cgroup subsystem to
496 provide hierarchical naming of sets of namespaces,
497 for instance virtual servers and checkpoint/restart
498 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700499
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700500config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800501 bool "Freezer cgroup subsystem"
502 depends on CGROUPS
503 help
504 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700505 cgroup.
506
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700507config CGROUP_DEVICE
508 bool "Device controller for cgroups"
509 depends on CGROUPS && EXPERIMENTAL
510 help
511 Provides a cgroup implementing whitelists for devices which
512 a process in the cgroup can mknod or open.
513
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514config CPUSETS
515 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700516 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700518 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 allow dynamically partitioning a system into sets of CPUs and
520 Memory Nodes and assigning tasks to run only within those sets.
521 This is primarily useful on large SMP or NUMA systems.
522
523 Say N if unsure.
524
Li Zefan23964d22009-01-15 13:50:58 -0800525config PROC_PID_CPUSET
526 bool "Include legacy /proc/<pid>/cpuset file"
527 depends on CPUSETS
528 default y
529
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100530config CGROUP_CPUACCT
531 bool "Simple CPU accounting cgroup subsystem"
532 depends on CGROUPS
533 help
534 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800535 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100536
Pavel Emelianove552b662008-02-07 00:13:49 -0800537config RESOURCE_COUNTERS
538 bool "Resource counters"
539 help
540 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800541 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800542 depends on CGROUPS
543
Balbir Singh00f0b822008-03-04 14:28:39 -0800544config CGROUP_MEM_RES_CTLR
545 bool "Memory Resource Controller for Control Groups"
546 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700547 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800548 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700549 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100550 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800551
552 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700553 associated with each page of memory in the system. By this,
554 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
555 usage tracking struct at boot. Total amount of this is printed out
556 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800557
558 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700559 sure you need the memory resource controller. Even when you enable
560 this, you can set "cgroup_disable=memory" at your boot option to
561 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800562 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800563
Balbir Singhcf475ad2008-04-29 01:00:16 -0700564 This config option also selects MM_OWNER config option, which
565 could in turn add some fork/exit overhead.
566
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800567config CGROUP_MEM_RES_CTLR_SWAP
568 bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
569 depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
570 help
571 Add swap management feature to memory resource controller. When you
572 enable this, you can limit mem+swap usage per cgroup. In other words,
573 when you disable this, memory resource controller has no cares to
574 usage of swap...a process can exhaust all of the swap. This extension
575 is useful when you want to avoid exhaustion swap but this itself
576 adds more overheads and consumes memory for remembering information.
577 Especially if you use 32bit system or small memory system, please
578 be careful about enabling this. When memory resource controller
579 is disabled by boot option, this will be automatically disabled and
580 there will be no overhead from this. Even when you set this config=y,
581 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700582 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
583 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800584
Dhaval Giani7c941432010-01-20 13:26:18 +0100585menuconfig CGROUP_SCHED
586 bool "Group CPU scheduler"
587 depends on EXPERIMENTAL && CGROUPS
588 default n
589 help
590 This feature lets CPU scheduler recognize task groups and control CPU
591 bandwidth allocation to such task groups. It uses cgroups to group
592 tasks.
593
594if CGROUP_SCHED
595config FAIR_GROUP_SCHED
596 bool "Group scheduling for SCHED_OTHER"
597 depends on CGROUP_SCHED
598 default CGROUP_SCHED
599
600config RT_GROUP_SCHED
601 bool "Group scheduling for SCHED_RR/FIFO"
602 depends on EXPERIMENTAL
603 depends on CGROUP_SCHED
604 default n
605 help
606 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800607 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100608 schedule realtime tasks for non-root users until you allocate
609 realtime bandwidth for them.
610 See Documentation/scheduler/sched-rt-group.txt for more information.
611
612endif #CGROUP_SCHED
613
Vivek Goyalafc24d42010-04-26 19:27:56 +0200614config BLK_CGROUP
615 tristate "Block IO controller"
616 depends on CGROUPS && BLOCK
617 default n
618 ---help---
619 Generic block IO controller cgroup interface. This is the common
620 cgroup interface which should be used by various IO controlling
621 policies.
622
623 Currently, CFQ IO scheduler uses it to recognize task groups and
624 control disk bandwidth allocation (proportional time slice allocation)
625 to such task groups.
626
627 This option only enables generic Block IO controller infrastructure.
628 One needs to also enable actual IO controlling logic in CFQ for it
629 to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).
630
631 See Documentation/cgroups/blkio-controller.txt for more information.
632
633config DEBUG_BLK_CGROUP
634 bool "Enable Block IO controller debugging"
635 depends on BLK_CGROUP
636 default n
637 ---help---
638 Enable some debugging help. Currently it exports additional stat
639 files in a cgroup which can be useful for debugging.
640
Li Zefan23964d22009-01-15 13:50:58 -0800641endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800642
Li Zefan23964d22009-01-15 13:50:58 -0800643config MM_OWNER
644 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800645
Kay Sievers88a22c92006-09-14 11:23:28 +0200646config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100647 bool
648
649config SYSFS_DEPRECATED_V2
Uwe Kleine-König9e9868a2009-12-03 19:58:00 +0100650 bool "enable deprecated sysfs features to support old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800651 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200652 default n
Ingo Molnard47846c2008-03-04 14:54:47 +0100653 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200654 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100655 This option switches the layout of sysfs to the deprecated
Kay Sieversf6ee6492009-04-16 19:56:37 +0200656 version. Do not use it on recent distributions.
Kay Sievers88a22c92006-09-14 11:23:28 +0200657
Kay Sieversfce3e802008-11-01 14:03:00 +0100658 The current sysfs layout features a unified device tree at
659 /sys/devices/, which is able to express a hierarchy between
660 class devices. If the deprecated option is set to Y, the
661 unified device tree is split into a bus device tree at
662 /sys/devices/ and several individual class device trees at
663 /sys/class/. The class and bus devices will be connected by
664 "<subsystem>:<name>" and the "device" links. The "block"
665 class devices, will not show up in /sys/class/block/. Some
666 subsystems will suppress the creation of some devices which
667 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200668
Kay Sieversfce3e802008-11-01 14:03:00 +0100669 This option is not a pure compatibility option that can
670 be safely enabled on newer distributions. It will change the
671 layout of sysfs to the non-extensible deprecated version,
672 and disable some features, which can not be exported without
673 confusing older userspace tools. Since 2007/2008 all major
674 distributions do not enable this option, and ship no tools which
675 depend on the deprecated layout or this option.
676
677 If you are using a new kernel on an older distribution, or use
678 older userspace tools, you might need to say Y here. Do not say Y,
679 if the original kernel, that came with your distribution, has
680 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200681
Jens Axboeb86ff9812006-03-23 19:56:55 +0100682config RELAY
683 bool "Kernel->user space relay support (formerly relayfs)"
684 help
685 This option enables support for relay interface support in
686 certain file systems (such as debugfs).
687 It is designed to provide an efficient mechanism for tools and
688 facilities to relay large amounts of data from kernel space to
689 user space.
690
691 If unsure, say N.
692
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800693config NAMESPACES
694 bool "Namespaces support" if EMBEDDED
695 default !EMBEDDED
696 help
697 Provides the way to make tasks work with different objects using
698 the same id. For example same IPC id may refer to different objects
699 or same user id or pid may refer to different tasks when used in
700 different namespaces.
701
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800702config UTS_NS
703 bool "UTS namespace"
704 depends on NAMESPACES
705 help
706 In this namespace tasks see different info provided with the
707 uname() system call
708
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800709config IPC_NS
710 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700711 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800712 help
713 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700714 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800715
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800716config USER_NS
717 bool "User namespace (EXPERIMENTAL)"
718 depends on NAMESPACES && EXPERIMENTAL
719 help
720 This allows containers, i.e. vservers, to use user namespaces
721 to provide different user info for different servers.
722 If unsure, say N.
723
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800724config PID_NS
725 bool "PID Namespaces (EXPERIMENTAL)"
726 default n
727 depends on NAMESPACES && EXPERIMENTAL
728 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300729 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100730 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800731 pid namespaces. This is a building block of containers.
732
733 Unless you want to work with an experimental feature
734 say N here.
735
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800736config NET_NS
737 bool "Network namespace"
738 default n
739 depends on NAMESPACES && EXPERIMENTAL && NET
740 help
741 Allow user space to create what appear to be multiple instances
742 of the network stack.
743
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800744config BLK_DEV_INITRD
745 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
746 depends on BROKEN || !FRV
747 help
748 The initial RAM filesystem is a ramfs which is loaded by the
749 boot loader (loadlin or lilo) and that is mounted as root
750 before the normal boot procedure. It is typically used to
751 load modules needed to mount the "real" root file system,
752 etc. See <file:Documentation/initrd.txt> for details.
753
754 If RAM disk support (BLK_DEV_RAM) is also included, this
755 also enables initial RAM disk (initrd) support and adds
756 15 Kbytes (more on some other architectures) to the kernel size.
757
758 If unsure say Y.
759
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800760if BLK_DEV_INITRD
761
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200762source "usr/Kconfig"
763
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800764endif
765
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800766config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200767 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800768 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800769 help
770 Enabling this option will pass "-Os" instead of "-O2" to gcc
771 resulting in a smaller kernel.
772
jkacur775a7222008-07-16 00:31:16 +0200773 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800774
Randy Dunlap08470622006-09-30 23:28:13 -0700775config SYSCTL
776 bool
777
Randy Dunlapb943c462009-03-10 12:55:46 -0700778config ANON_INODES
779 bool
780
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781menuconfig EMBEDDED
782 bool "Configure standard kernel features (for small systems)"
783 help
784 This option allows certain base kernel options and settings
785 to be disabled or tweaked. This is for specialized
786 environments which can tolerate a "non-standard" kernel.
787 Only use this if you really know what you are doing.
788
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700789config UID16
790 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700791 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700792 default y
793 help
794 This enables the legacy 16-bit UID syscall wrappers.
795
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700796config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700797 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman26a70342009-11-05 05:26:41 -0800798 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800799 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700800 select SYSCTL
801 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800802 sys_sysctl uses binary paths that have been found challenging
803 to properly maintain and use. The interface in /proc/sys
804 using paths with ascii names is now the primary path to this
805 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700806
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800807 Almost nothing using the binary sysctl interface so if you are
808 trying to save some space it is probably safe to disable this,
809 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700810
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800811 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700812
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100814 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 default y
816 help
817 Say Y here to let the kernel print out symbolic crash information and
818 symbolic stack backtraces. This increases the size of the kernel
819 somewhat, as all symbols have to be loaded into the kernel image.
820
821config KALLSYMS_ALL
822 bool "Include all symbols in kallsyms"
823 depends on DEBUG_KERNEL && KALLSYMS
824 help
825 Normally kallsyms only contains the symbols of functions, for nicer
826 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200827 symbols too: say Y here to include all symbols, if you need them
828 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829
830 Say N.
831
832config KALLSYMS_EXTRA_PASS
833 bool "Do an extra kallsyms pass"
834 depends on KALLSYMS
835 help
836 If kallsyms is not working correctly, the build will fail with
837 inconsistent kallsyms data. If that occurs, log a bug report and
838 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
839 Always say N here unless you find a bug in kallsyms, which must be
840 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
841 you wait for kallsyms to be fixed.
842
Matt Mackalld59745c2005-05-01 08:59:02 -0700843
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800844config HOTPLUG
845 bool "Support for hot-pluggable devices" if EMBEDDED
846 default y
847 help
848 This option is provided for the case where no hotplug or uevent
849 capabilities is wanted by the kernel. You should only consider
850 disabling this option for embedded systems that do not use modules, a
851 dynamic /dev tree, or dynamic device discovery. Just say Y.
852
Matt Mackalld59745c2005-05-01 08:59:02 -0700853config PRINTK
854 default y
855 bool "Enable support for printk" if EMBEDDED
856 help
857 This option enables normal printk support. Removing it
858 eliminates most of the message strings from the kernel image
859 and makes the kernel more or less silent. As this makes it
860 very difficult to diagnose system problems, saying N here is
861 strongly discouraged.
862
Matt Mackallc8538a72005-05-01 08:59:01 -0700863config BUG
864 bool "BUG() support" if EMBEDDED
865 default y
866 help
867 Disabling this option eliminates support for BUG and WARN, reducing
868 the size of your kernel image and potentially quietly ignoring
869 numerous fatal conditions. You should only consider disabling this
870 option for embedded systems with no facilities for reporting errors.
871 Just say Y.
872
Matt Mackall708e9a72006-01-08 01:05:25 -0800873config ELF_CORE
874 default y
875 bool "Enable ELF core dumps" if EMBEDDED
876 help
877 Enable support for generating core dumps. Disabling saves about 4k.
878
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200879config PCSPKR_PLATFORM
880 bool "Enable PC-Speaker support" if EMBEDDED
881 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
882 default y
883 help
884 This option allows to disable the internal PC-Speaker
885 support, saving some memory.
886
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887config BASE_FULL
888 default y
889 bool "Enable full-sized data structures for core" if EMBEDDED
890 help
891 Disabling this option reduces the size of miscellaneous core
892 kernel data structures. This saves memory on small machines,
893 but may reduce performance.
894
895config FUTEX
896 bool "Enable futex support" if EMBEDDED
897 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700898 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 help
900 Disabling this option will cause the kernel to be built without
901 support for "fast userspace mutexes". The resulting kernel may not
902 run glibc-based applications correctly.
903
904config EPOLL
905 bool "Enable eventpoll support" if EMBEDDED
906 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700907 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 help
909 Disabling this option will cause the kernel to be built without
910 support for epoll family of system calls.
911
Davide Libenzifba2afa2007-05-10 22:23:13 -0700912config SIGNALFD
913 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700914 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700915 default y
916 help
917 Enable the signalfd() system call that allows to receive signals
918 on a file descriptor.
919
920 If unsure, say Y.
921
Davide Libenzib215e282007-05-10 22:23:16 -0700922config TIMERFD
923 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700924 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700925 default y
926 help
927 Enable the timerfd() system call that allows to receive timer
928 events on a file descriptor.
929
930 If unsure, say Y.
931
Davide Libenzie1ad7462007-05-10 22:23:19 -0700932config EVENTFD
933 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700934 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700935 default y
936 help
937 Enable the eventfd() system call that allows to receive both
938 kernel notification (ie. KAIO) or userspace notifications.
939
940 If unsure, say Y.
941
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942config SHMEM
943 bool "Use full shmem filesystem" if EMBEDDED
944 default y
945 depends on MMU
946 help
947 The shmem is an internal filesystem used to manage shared memory.
948 It is backed by swap and manages resource limits. It is also exported
949 to userspace as tmpfs if TMPFS is enabled. Disabling this
950 option replaces shmem and tmpfs with the much simpler ramfs code,
951 which may be appropriate on small systems without swap.
952
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700953config AIO
954 bool "Enable AIO support" if EMBEDDED
955 default y
956 help
957 This option enables POSIX asynchronous I/O which may by used
958 by some high performance threaded applications. Disabling
959 this option saves about 7k.
960
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200961config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +0100962 bool
Mike Frysinger018df722009-06-12 13:17:43 -0400963 help
964 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100965
Peter Zijlstra906010b2009-09-21 16:08:49 +0200966config PERF_USE_VMALLOC
967 bool
968 help
969 See tools/perf/design.txt for details
970
Ingo Molnar57c0c152009-09-21 12:20:38 +0200971menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +0100972
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200973config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +0200974 bool "Kernel performance events and counters"
975 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200976 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +0100977 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +0100978 help
Ingo Molnar57c0c152009-09-21 12:20:38 +0200979 Enable kernel support for various performance events provided
980 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100981
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -0200982 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +0200983 use of generic tracepoints.
984
985 Most modern CPUs support performance events via performance
986 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +0100987 types of hw events: such as instructions executed, cachemisses
988 suffered, or branches mis-predicted - without slowing down the
989 kernel or applications. These registers can also trigger interrupts
990 when a threshold number of events have passed - and can thus be
991 used to profile the code that runs on that CPU.
992
Ingo Molnar57c0c152009-09-21 12:20:38 +0200993 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -0200994 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +0200995 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +0100996 provides per task and per CPU counters, and it provides event
997 capabilities on top of those.
998
999 Say Y if unsure.
1000
Ingo Molnar57c0c152009-09-21 12:20:38 +02001001config PERF_COUNTERS
1002 bool "Kernel performance counters (old config option)"
1003 depends on HAVE_PERF_EVENTS
1004 help
1005 This config has been obsoleted by the PERF_EVENTS
1006 config option - please see that one for details.
1007
1008 It has no effect on the kernel whether you enable
1009 it or not, it is a compatibility placeholder.
1010
1011 Say N if unsure.
1012
Peter Zijlstra906010b2009-09-21 16:08:49 +02001013config DEBUG_PERF_USE_VMALLOC
1014 default n
1015 bool "Debug: use vmalloc to back perf mmap() buffers"
1016 depends on PERF_EVENTS && DEBUG_KERNEL
1017 select PERF_USE_VMALLOC
1018 help
1019 Use vmalloc memory to back perf mmap() buffers.
1020
1021 Mostly useful for debugging the vmalloc code on platforms
1022 that don't require it.
1023
1024 Say N if unsure.
1025
Thomas Gleixner0793a612008-12-04 20:12:29 +01001026endmenu
1027
Christoph Lameterf8891e52006-06-30 01:55:45 -07001028config VM_EVENT_COUNTERS
1029 default y
1030 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
1031 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001032 VM event counters are needed for event counts to be shown.
1033 This option allows the disabling of the VM event counters
1034 on EMBEDDED systems. /proc/vmstat will only show page counts
1035 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001036
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001037config PCI_QUIRKS
1038 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001039 bool "Enable PCI quirk workarounds" if EMBEDDED
1040 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001041 help
1042 This enables workarounds for various PCI chipset
1043 bugs/quirks. Disable this only if your target machine is
1044 unaffected by PCI quirks.
1045
Christoph Lameter41ecc552007-05-09 02:32:44 -07001046config SLUB_DEBUG
1047 default y
1048 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -07001049 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001050 help
1051 SLUB has extensive debug support features. Disabling these can
1052 result in significant savings in code size. This also disables
1053 SLUB sysfs support. /sys/slab will not exist and there will be
1054 no support for cache validation etc.
1055
Randy Dunlapb943c462009-03-10 12:55:46 -07001056config COMPAT_BRK
1057 bool "Disable heap randomization"
1058 default y
1059 help
1060 Randomizing heap placement makes heap exploits harder, but it
1061 also breaks ancient binaries (including anything libc5 based).
1062 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001063 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001064 /proc/sys/kernel/randomize_va_space to 2.
1065
1066 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1067
Christoph Lameter81819f02007-05-06 14:49:36 -07001068choice
1069 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001070 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001071 help
1072 This option allows to select a slab allocator.
1073
1074config SLAB
1075 bool "SLAB"
1076 help
1077 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001078 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001079 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001080
1081config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001082 bool "SLUB (Unqueued Allocator)"
1083 help
1084 SLUB is a slab allocator that minimizes cache line usage
1085 instead of managing queues of cached objects (SLAB approach).
1086 Per cpu caching is realized using slabs of objects instead
1087 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001088 and has enhanced diagnostics. SLUB is the default choice for
1089 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001090
1091config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001092 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001093 bool "SLOB (Simple Allocator)"
1094 help
Matt Mackall37291452008-02-04 22:29:38 -08001095 SLOB replaces the stock allocator with a drastically simpler
1096 allocator. SLOB is generally more space efficient but
1097 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001098
1099endchoice
1100
Jie Zhangea637632009-12-14 18:00:02 -08001101config MMAP_ALLOW_UNINITIALIZED
1102 bool "Allow mmapped anonymous memory to be uninitialized"
1103 depends on EMBEDDED && !MMU
1104 default n
1105 help
1106 Normally, and according to the Linux spec, anonymous memory obtained
1107 from mmap() has it's contents cleared before it is passed to
1108 userspace. Enabling this config option allows you to request that
1109 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1110 providing a huge performance boost. If this option is not enabled,
1111 then the flag will be ignored.
1112
1113 This is taken advantage of by uClibc's malloc(), and also by
1114 ELF-FDPIC binfmt's brk and stack allocator.
1115
1116 Because of the obvious security issues, this option should only be
1117 enabled on embedded devices where you control what is run in
1118 userspace. Since that isn't generally a problem on no-MMU systems,
1119 it is normally safe to say Y here.
1120
1121 See Documentation/nommu-mmap.txt for more information.
1122
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001123config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001124 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001125 help
1126 Say Y here to enable the extended profiling support mechanisms used
1127 by profilers such as OProfile.
1128
Ingo Molnar5f87f112008-07-23 14:15:22 +02001129#
1130# Place an empty function call at each tracepoint site. Can be
1131# dynamically changed for a probe function.
1132#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001133config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001134 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001135
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001136source "arch/Kconfig"
1137
David Howells07fe7cb2009-04-03 16:42:35 +01001138config SLOW_WORK
1139 default n
David Howells1c2d0082009-04-06 15:47:25 +01001140 bool
David Howells07fe7cb2009-04-03 16:42:35 +01001141 help
1142 The slow work thread pool provides a number of dynamically allocated
1143 threads that can be used by the kernel to perform operations that
1144 take a relatively long time.
1145
1146 An example of this would be CacheFiles doing a path lookup followed
1147 by a series of mkdirs and a create call, all of which have to touch
1148 disk.
1149
David Howells1c2d0082009-04-06 15:47:25 +01001150 See Documentation/slow-work.txt.
1151
David Howellsf13a48b2009-12-01 15:36:11 +00001152config SLOW_WORK_DEBUG
1153 bool "Slow work debugging through debugfs"
David Howells8fba10a2009-11-19 18:10:51 +00001154 default n
David Howellsf13a48b2009-12-01 15:36:11 +00001155 depends on SLOW_WORK && DEBUG_FS
David Howells8fba10a2009-11-19 18:10:51 +00001156 help
David Howellsf13a48b2009-12-01 15:36:11 +00001157 Display the contents of the slow work run queue through debugfs,
David Howells8fba10a2009-11-19 18:10:51 +00001158 including items currently executing.
1159
1160 See Documentation/slow-work.txt.
1161
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162endmenu # General setup
1163
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001164config HAVE_GENERIC_DMA_COHERENT
1165 bool
1166 default n
1167
Linus Torvalds158a9622008-01-02 13:04:48 -08001168config SLABINFO
1169 bool
1170 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001171 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001172 default y
1173
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001174config RT_MUTEXES
1175 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001176
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177config BASE_SMALL
1178 int
1179 default 0 if BASE_FULL
1180 default 1 if !BASE_FULL
1181
Jan Engelhardt66da5732007-07-15 23:39:29 -07001182menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183 bool "Enable loadable module support"
1184 help
1185 Kernel modules are small pieces of compiled code which can
1186 be inserted in the running kernel, rather than being
1187 permanently built into the kernel. You use the "modprobe"
1188 tool to add (and sometimes remove) them. If you say Y here,
1189 many parts of the kernel can be built as modules (by
1190 answering M instead of Y where indicated): this is most
1191 useful for infrequently used options which are not required
1192 for booting. For more information, see the man pages for
1193 modprobe, lsmod, modinfo, insmod and rmmod.
1194
1195 If you say Y here, you will need to run "make
1196 modules_install" to put the modules under /lib/modules/
1197 where modprobe can find them (you may need to be root to do
1198 this).
1199
1200 If unsure, say Y.
1201
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001202if MODULES
1203
Linus Torvalds826e4502008-05-04 17:04:16 -07001204config MODULE_FORCE_LOAD
1205 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001206 default n
1207 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001208 Allow loading of modules without version information (ie. modprobe
1209 --force). Forced module loading sets the 'F' (forced) taint flag and
1210 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001211
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212config MODULE_UNLOAD
1213 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 help
1215 Without this option you will not be able to unload any
1216 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001217 anyway), which makes your kernel smaller, faster
1218 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219
1220config MODULE_FORCE_UNLOAD
1221 bool "Forced module unloading"
1222 depends on MODULE_UNLOAD && EXPERIMENTAL
1223 help
1224 This option allows you to force a module to unload, even if the
1225 kernel believes it is unsafe: the kernel will remove the module
1226 without waiting for anyone to stop using it (using the -f option to
1227 rmmod). This is mainly for kernel developers and desperate users.
1228 If unsure, say N.
1229
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001231 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232 help
1233 Usually, you have to use modules compiled with your kernel.
1234 Saying Y here makes it sometimes possible to use modules
1235 compiled for different kernels, by adding enough information
1236 to the modules to (hopefully) spot any changes which would
1237 make them incompatible with the kernel you are running. If
1238 unsure, say N.
1239
1240config MODULE_SRCVERSION_ALL
1241 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242 help
1243 Modules which contain a MODULE_VERSION get an extra "srcversion"
1244 field inserted into their modinfo section, which contains a
1245 sum of the source files which made it. This helps maintainers
1246 see exactly which source was used to build a module (since
1247 others sometimes change the module source without updating
1248 the version). With this option, such a "srcversion" field
1249 will be created for all modules. If unsure, say N.
1250
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001251endif # MODULES
1252
Rusty Russell98a79d62008-12-13 21:19:41 +10301253config INIT_ALL_POSSIBLE
1254 bool
1255 help
1256 Back when each arch used to define their own cpu_online_map and
1257 cpu_possible_map, some of them chose to initialize cpu_possible_map
1258 with all 1s, and others with all 0s. When they were centralised,
1259 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001260 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301261
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262config STOP_MACHINE
1263 bool
1264 default y
1265 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1266 help
1267 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001268
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001269source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001270
1271config PREEMPT_NOTIFIERS
1272 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001273
Steffen Klassert16295be2010-01-06 19:47:10 +11001274config PADATA
1275 depends on SMP
1276 bool
1277
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001278source "kernel/Kconfig.locks"