blob: e9fa3007a6fc12cf079f085a0bae9f231b309b0a [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 Oberparleiterb99b87f72009-06-17 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47 drivers that have been replaced by something else, and/or are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 Dunlap34ad92c22005-10-30 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
Alain Knaff30d65db2009-01-04 22:46:17 +0100118choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800119 prompt "Kernel compression mode"
120 default KERNEL_GZIP
121 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA
122 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100123 The linux kernel is a kind of self-extracting executable.
124 Several compression algorithms are available, which differ
125 in efficiency, compression and decompression speed.
126 Compression speed is only relevant when building a kernel.
127 Decompression speed is relevant at each boot.
128
129 If you have any problems with bzip2 or lzma compressed
130 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
131 version of this functionality (bzip2 only), for 2.4, was
132 supplied by Christian Ludwig)
133
134 High compression options are mostly useful for users, who
135 are low on disk space (embedded systems), but for whom ram
136 size matters less.
137
138 If in doubt, select 'gzip'
139
140config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800141 bool "Gzip"
142 depends on HAVE_KERNEL_GZIP
143 help
144 The old and tried gzip compression. Its compression ratio is
145 the poorest among the 3 choices; however its speed (both
146 compression and decompression) is the fastest.
Alain Knaff30d65db2009-01-04 22:46:17 +0100147
148config KERNEL_BZIP2
149 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800150 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100151 help
152 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800153 Decompression speed is slowest among the three. The kernel
154 size is about 10% smaller with bzip2, in comparison to gzip.
155 Bzip2 uses a large amount of memory. For modern kernels you
156 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100157
158config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800159 bool "LZMA"
160 depends on HAVE_KERNEL_LZMA
161 help
162 The most recent compression algorithm.
163 Its ratio is best, decompression speed is between the other
164 two. Compression is slowest. The kernel size is about 33%
165 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100166
167endchoice
168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169config SWAP
170 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200171 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 default y
173 help
174 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100175 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 used to provide more virtual memory than the actual RAM present
177 in your computer. If unsure say Y.
178
179config SYSVIPC
180 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 ---help---
182 Inter Process Communication is a suite of library functions and
183 system calls which let processes (running programs) synchronize and
184 exchange information. It is generally considered to be a good thing,
185 and some programs won't run unless you say Y here. In particular, if
186 you want to run the DOS emulator dosemu under Linux (read the
187 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
188 you'll need to say Y here.
189
190 You can find documentation about IPC with "info ipc" and also in
191 section 6.4 of the Linux Programmer's Guide, available from
192 <http://www.tldp.org/guides.html>.
193
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800194config SYSVIPC_SYSCTL
195 bool
196 depends on SYSVIPC
197 depends on SYSCTL
198 default y
199
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200config POSIX_MQUEUE
201 bool "POSIX Message Queues"
202 depends on NET && EXPERIMENTAL
203 ---help---
204 POSIX variant of message queues is a part of IPC. In POSIX message
205 queues every message has a priority which decides about succession
206 of receiving it by a process. If you want to compile and run
207 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200208 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210 POSIX message queues are visible as a filesystem called 'mqueue'
211 and can be mounted somewhere if you want to do filesystem
212 operations on message queues.
213
214 If unsure, say Y.
215
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700216config POSIX_MQUEUE_SYSCTL
217 bool
218 depends on POSIX_MQUEUE
219 depends on SYSCTL
220 default y
221
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222config BSD_PROCESS_ACCT
223 bool "BSD Process Accounting"
224 help
225 If you say Y here, a user level program will be able to instruct the
226 kernel (via a special system call) to write process accounting
227 information to a file: whenever a process exits, information about
228 that process will be appended to the file by the kernel. The
229 information includes things such as creation time, owning user,
230 command name, memory usage, controlling terminal etc. (the complete
231 list is in the struct acct in <file:include/linux/acct.h>). It is
232 up to the user level program to do useful things with this
233 information. This is generally a good idea, so say Y.
234
235config BSD_PROCESS_ACCT_V3
236 bool "BSD Process Accounting version 3 file format"
237 depends on BSD_PROCESS_ACCT
238 default n
239 help
240 If you say Y here, the process accounting information is written
241 in a new file format that also logs the process IDs of each
242 process and it's parent. Note that this file format is incompatible
243 with previous v0/v1/v2 file formats, so you will need updated tools
244 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300245 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
Shailabh Nagarc7572492006-07-14 00:24:40 -0700247config TASKSTATS
248 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
249 depends on NET
250 default n
251 help
252 Export selected statistics for tasks/processes through the
253 generic netlink interface. Unlike BSD process accounting, the
254 statistics are available during the lifetime of tasks/processes as
255 responses to commands. Like BSD accounting, they are sent to user
256 space on task exit.
257
258 Say N if unsure.
259
Shailabh Nagarca74e922006-07-14 00:24:36 -0700260config TASK_DELAY_ACCT
261 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700262 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700263 help
264 Collect information on time spent by a task waiting for system
265 resources like cpu, synchronous block I/O completion and swapping
266 in pages. Such statistics can help in setting a task's priorities
267 relative to other tasks for cpu, io, rss limits etc.
268
269 Say N if unsure.
270
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800271config TASK_XACCT
272 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
273 depends on TASKSTATS
274 help
275 Collect extended task accounting data and send the data
276 to userland for processing over the taskstats interface.
277
278 Say N if unsure.
279
280config TASK_IO_ACCOUNTING
281 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
282 depends on TASK_XACCT
283 help
284 Collect information on the number of bytes of storage I/O which this
285 task has caused.
286
287 Say N if unsure.
288
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289config AUDIT
290 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100291 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 help
293 Enable auditing infrastructure that can be used with another
294 kernel subsystem, such as SELinux (which requires this for
295 logging of avc messages output). Does not do system-call
296 auditing without CONFIG_AUDITSYSCALL.
297
298config AUDITSYSCALL
299 bool "Enable system-call auditing support"
Kumar Gala022382a2009-10-16 07:21:37 +0000300 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 default y if SECURITY_SELINUX
302 help
303 Enable low-overhead system-call auditing infrastructure that
304 can be used independently or with another kernel subsystem,
Amy Griffisf368c07d2006-04-07 16:55:56 -0400305 such as SELinux. To use audit's filesystem watch feature, please
306 ensure that INOTIFY is configured.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
Al Viro74c3cbe2007-07-22 08:04:18 -0400308config AUDIT_TREE
309 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400310 depends on AUDITSYSCALL
311 select INOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400312
Mike Travisc903ff82009-01-15 12:28:29 -0800313menu "RCU Subsystem"
314
315choice
316 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700317 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800318
Mike Travisc903ff82009-01-15 12:28:29 -0800319config TREE_RCU
320 bool "Tree-based hierarchical RCU"
321 help
322 This option selects the RCU implementation that is
323 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700324 thousands of CPUs. It also scales down nicely to
325 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800326
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700327config TREE_PREEMPT_RCU
328 bool "Preemptable tree-based hierarchical RCU"
329 depends on PREEMPT
330 help
331 This option selects the RCU implementation that is
332 designed for very large SMP systems with hundreds or
333 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700334 is also required. It also scales down nicely to
335 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700336
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700337config TINY_RCU
338 bool "UP-only small-memory-footprint RCU"
339 depends on !SMP
340 help
341 This option selects the RCU implementation that is
342 designed for UP systems from which real-time response
343 is not required. This option greatly reduces the
344 memory footprint of RCU.
345
Mike Travisc903ff82009-01-15 12:28:29 -0800346endchoice
347
348config RCU_TRACE
349 bool "Enable tracing for RCU"
Paul E. McKenney6b3ef482009-08-22 13:56:53 -0700350 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800351 help
352 This option provides tracing in RCU which presents stats
353 in debugfs for debugging RCU implementation.
354
355 Say Y here if you want to enable RCU tracing
356 Say N if you are unsure.
357
358config RCU_FANOUT
359 int "Tree-based hierarchical RCU fanout value"
360 range 2 64 if 64BIT
361 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700362 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800363 default 64 if 64BIT
364 default 32 if !64BIT
365 help
366 This option controls the fanout of hierarchical implementations
367 of RCU, allowing RCU to work efficiently on machines with
368 large numbers of CPUs. This value must be at least the cube
369 root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
370 systems and up to 262,144 for 64-bit systems.
371
372 Select a specific number if testing RCU itself.
373 Take the default if unsure.
374
375config RCU_FANOUT_EXACT
376 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700377 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800378 default n
379 help
380 This option forces use of the exact RCU_FANOUT value specified,
381 regardless of imbalances in the hierarchy. This is useful for
382 testing RCU itself, and might one day be useful on systems with
383 strong NUMA behavior.
384
385 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
386
387 Say N if unsure.
388
389config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700390 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800391 select DEBUG_FS
392 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700393 This option provides tracing for the TREE_RCU and
394 TREE_PREEMPT_RCU implementations, permitting Makefile to
395 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800396
Mike Travisc903ff82009-01-15 12:28:29 -0800397endmenu # "RCU Subsystem"
398
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700400 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 ---help---
402 This option enables the complete Linux kernel ".config" file
403 contents to be saved in the kernel. It provides documentation
404 of which kernel options are used in a running kernel or in an
405 on-disk kernel. This information can be extracted from the kernel
406 image file with the script scripts/extract-ikconfig and used as
407 input to rebuild the current kernel or to build another kernel.
408 It can also be extracted from a running kernel by reading
409 /proc/config.gz if enabled (below).
410
411config IKCONFIG_PROC
412 bool "Enable access to .config through /proc/config.gz"
413 depends on IKCONFIG && PROC_FS
414 ---help---
415 This option enables access to the kernel configuration file
416 through /proc/config.gz.
417
Alistair John Strachan794543a2007-05-08 00:31:15 -0700418config LOG_BUF_SHIFT
419 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
420 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700421 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700422 help
423 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700424 Examples:
425 17 => 128 KB
426 16 => 64 KB
427 15 => 32 KB
428 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700429 13 => 8 KB
430 12 => 4 KB
431
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800432#
433# Architectures with an unreliable sched_clock() should select this:
434#
435config HAVE_UNSTABLE_SCHED_CLOCK
436 bool
437
Li Zefan23964d22009-01-15 13:50:58 -0800438menuconfig CGROUPS
439 boolean "Control Group support"
Paul Menageddbcc7e2007-10-18 23:39:30 -0700440 help
Li Zefan23964d22009-01-15 13:50:58 -0800441 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800442 use with process control subsystems such as Cpusets, CFS, memory
443 controls or device isolation.
444 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800445 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800446 - Documentation/cgroups/ (features for grouping, isolation
447 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700448
449 Say N if unsure.
450
Li Zefan23964d22009-01-15 13:50:58 -0800451if CGROUPS
452
Paul Menage006cb992007-10-18 23:39:43 -0700453config CGROUP_DEBUG
454 bool "Example debug cgroup subsystem"
455 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700456 default n
Paul Menage006cb992007-10-18 23:39:43 -0700457 help
458 This option enables a simple cgroup subsystem that
459 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800460 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700461
Li Zefan23964d22009-01-15 13:50:58 -0800462 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700463
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700464config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800465 bool "Namespace cgroup subsystem"
466 depends on CGROUPS
467 help
468 Provides a simple namespace cgroup subsystem to
469 provide hierarchical naming of sets of namespaces,
470 for instance virtual servers and checkpoint/restart
471 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700472
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700473config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800474 bool "Freezer cgroup subsystem"
475 depends on CGROUPS
476 help
477 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700478 cgroup.
479
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700480config CGROUP_DEVICE
481 bool "Device controller for cgroups"
482 depends on CGROUPS && EXPERIMENTAL
483 help
484 Provides a cgroup implementing whitelists for devices which
485 a process in the cgroup can mknod or open.
486
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487config CPUSETS
488 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700489 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700491 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 allow dynamically partitioning a system into sets of CPUs and
493 Memory Nodes and assigning tasks to run only within those sets.
494 This is primarily useful on large SMP or NUMA systems.
495
496 Say N if unsure.
497
Li Zefan23964d22009-01-15 13:50:58 -0800498config PROC_PID_CPUSET
499 bool "Include legacy /proc/<pid>/cpuset file"
500 depends on CPUSETS
501 default y
502
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100503config CGROUP_CPUACCT
504 bool "Simple CPU accounting cgroup subsystem"
505 depends on CGROUPS
506 help
507 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800508 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100509
Pavel Emelianove552b662008-02-07 00:13:49 -0800510config RESOURCE_COUNTERS
511 bool "Resource counters"
512 help
513 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800514 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800515 depends on CGROUPS
516
Balbir Singh00f0b822008-03-04 14:28:39 -0800517config CGROUP_MEM_RES_CTLR
518 bool "Memory Resource Controller for Control Groups"
519 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700520 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800521 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700522 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100523 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800524
525 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700526 associated with each page of memory in the system. By this,
527 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
528 usage tracking struct at boot. Total amount of this is printed out
529 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800530
531 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700532 sure you need the memory resource controller. Even when you enable
533 this, you can set "cgroup_disable=memory" at your boot option to
534 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800535 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800536
Balbir Singhcf475ad2008-04-29 01:00:16 -0700537 This config option also selects MM_OWNER config option, which
538 could in turn add some fork/exit overhead.
539
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800540config CGROUP_MEM_RES_CTLR_SWAP
541 bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
542 depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
543 help
544 Add swap management feature to memory resource controller. When you
545 enable this, you can limit mem+swap usage per cgroup. In other words,
546 when you disable this, memory resource controller has no cares to
547 usage of swap...a process can exhaust all of the swap. This extension
548 is useful when you want to avoid exhaustion swap but this itself
549 adds more overheads and consumes memory for remembering information.
550 Especially if you use 32bit system or small memory system, please
551 be careful about enabling this. When memory resource controller
552 is disabled by boot option, this will be automatically disabled and
553 there will be no overhead from this. Even when you set this config=y,
554 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700555 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
556 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800557
Dhaval Giani7c941432010-01-20 13:26:18 +0100558menuconfig CGROUP_SCHED
559 bool "Group CPU scheduler"
560 depends on EXPERIMENTAL && CGROUPS
561 default n
562 help
563 This feature lets CPU scheduler recognize task groups and control CPU
564 bandwidth allocation to such task groups. It uses cgroups to group
565 tasks.
566
567if CGROUP_SCHED
568config FAIR_GROUP_SCHED
569 bool "Group scheduling for SCHED_OTHER"
570 depends on CGROUP_SCHED
571 default CGROUP_SCHED
572
573config RT_GROUP_SCHED
574 bool "Group scheduling for SCHED_RR/FIFO"
575 depends on EXPERIMENTAL
576 depends on CGROUP_SCHED
577 default n
578 help
579 This feature lets you explicitly allocate real CPU bandwidth
580 to users or control groups (depending on the "Basis for grouping tasks"
581 setting below. If enabled, it will also make it impossible to
582 schedule realtime tasks for non-root users until you allocate
583 realtime bandwidth for them.
584 See Documentation/scheduler/sched-rt-group.txt for more information.
585
586endif #CGROUP_SCHED
587
Li Zefan23964d22009-01-15 13:50:58 -0800588endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800589
Li Zefan23964d22009-01-15 13:50:58 -0800590config MM_OWNER
591 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800592
Kay Sievers88a22c92006-09-14 11:23:28 +0200593config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100594 bool
595
596config SYSFS_DEPRECATED_V2
Uwe Kleine-König9e9868a2009-12-03 19:58:00 +0100597 bool "enable deprecated sysfs features to support old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800598 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200599 default n
Ingo Molnard47846c2008-03-04 14:54:47 +0100600 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200601 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100602 This option switches the layout of sysfs to the deprecated
Kay Sieversf6ee6492009-04-16 19:56:37 +0200603 version. Do not use it on recent distributions.
Kay Sievers88a22c92006-09-14 11:23:28 +0200604
Kay Sieversfce3e802008-11-01 14:03:00 +0100605 The current sysfs layout features a unified device tree at
606 /sys/devices/, which is able to express a hierarchy between
607 class devices. If the deprecated option is set to Y, the
608 unified device tree is split into a bus device tree at
609 /sys/devices/ and several individual class device trees at
610 /sys/class/. The class and bus devices will be connected by
611 "<subsystem>:<name>" and the "device" links. The "block"
612 class devices, will not show up in /sys/class/block/. Some
613 subsystems will suppress the creation of some devices which
614 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200615
Kay Sieversfce3e802008-11-01 14:03:00 +0100616 This option is not a pure compatibility option that can
617 be safely enabled on newer distributions. It will change the
618 layout of sysfs to the non-extensible deprecated version,
619 and disable some features, which can not be exported without
620 confusing older userspace tools. Since 2007/2008 all major
621 distributions do not enable this option, and ship no tools which
622 depend on the deprecated layout or this option.
623
624 If you are using a new kernel on an older distribution, or use
625 older userspace tools, you might need to say Y here. Do not say Y,
626 if the original kernel, that came with your distribution, has
627 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200628
Jens Axboeb86ff9812006-03-23 19:56:55 +0100629config RELAY
630 bool "Kernel->user space relay support (formerly relayfs)"
631 help
632 This option enables support for relay interface support in
633 certain file systems (such as debugfs).
634 It is designed to provide an efficient mechanism for tools and
635 facilities to relay large amounts of data from kernel space to
636 user space.
637
638 If unsure, say N.
639
Pavel Emelyanovc5289a692008-02-08 04:18:19 -0800640config NAMESPACES
641 bool "Namespaces support" if EMBEDDED
642 default !EMBEDDED
643 help
644 Provides the way to make tasks work with different objects using
645 the same id. For example same IPC id may refer to different objects
646 or same user id or pid may refer to different tasks when used in
647 different namespaces.
648
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800649config UTS_NS
650 bool "UTS namespace"
651 depends on NAMESPACES
652 help
653 In this namespace tasks see different info provided with the
654 uname() system call
655
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800656config IPC_NS
657 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700658 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800659 help
660 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700661 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800662
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800663config USER_NS
664 bool "User namespace (EXPERIMENTAL)"
665 depends on NAMESPACES && EXPERIMENTAL
666 help
667 This allows containers, i.e. vservers, to use user namespaces
668 to provide different user info for different servers.
669 If unsure, say N.
670
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800671config PID_NS
672 bool "PID Namespaces (EXPERIMENTAL)"
673 default n
674 depends on NAMESPACES && EXPERIMENTAL
675 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300676 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100677 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800678 pid namespaces. This is a building block of containers.
679
680 Unless you want to work with an experimental feature
681 say N here.
682
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800683config NET_NS
684 bool "Network namespace"
685 default n
686 depends on NAMESPACES && EXPERIMENTAL && NET
687 help
688 Allow user space to create what appear to be multiple instances
689 of the network stack.
690
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800691config BLK_DEV_INITRD
692 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
693 depends on BROKEN || !FRV
694 help
695 The initial RAM filesystem is a ramfs which is loaded by the
696 boot loader (loadlin or lilo) and that is mounted as root
697 before the normal boot procedure. It is typically used to
698 load modules needed to mount the "real" root file system,
699 etc. See <file:Documentation/initrd.txt> for details.
700
701 If RAM disk support (BLK_DEV_RAM) is also included, this
702 also enables initial RAM disk (initrd) support and adds
703 15 Kbytes (more on some other architectures) to the kernel size.
704
705 If unsure say Y.
706
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800707if BLK_DEV_INITRD
708
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200709source "usr/Kconfig"
710
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800711endif
712
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800713config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200714 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800715 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800716 help
717 Enabling this option will pass "-Os" instead of "-O2" to gcc
718 resulting in a smaller kernel.
719
jkacur775a7222008-07-16 00:31:16 +0200720 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800721
Randy Dunlap08470622006-09-30 23:28:13 -0700722config SYSCTL
723 bool
724
Randy Dunlapb943c462009-03-10 12:55:46 -0700725config ANON_INODES
726 bool
727
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728menuconfig EMBEDDED
729 bool "Configure standard kernel features (for small systems)"
730 help
731 This option allows certain base kernel options and settings
732 to be disabled or tweaked. This is for specialized
733 environments which can tolerate a "non-standard" kernel.
734 Only use this if you really know what you are doing.
735
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700736config UID16
737 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700738 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 -0700739 default y
740 help
741 This enables the legacy 16-bit UID syscall wrappers.
742
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700743config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700744 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman26a70342009-11-05 05:26:41 -0800745 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800746 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700747 select SYSCTL
748 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800749 sys_sysctl uses binary paths that have been found challenging
750 to properly maintain and use. The interface in /proc/sys
751 using paths with ascii names is now the primary path to this
752 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700753
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800754 Almost nothing using the binary sysctl interface so if you are
755 trying to save some space it is probably safe to disable this,
756 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700757
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800758 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700759
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100761 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 default y
763 help
764 Say Y here to let the kernel print out symbolic crash information and
765 symbolic stack backtraces. This increases the size of the kernel
766 somewhat, as all symbols have to be loaded into the kernel image.
767
768config KALLSYMS_ALL
769 bool "Include all symbols in kallsyms"
770 depends on DEBUG_KERNEL && KALLSYMS
771 help
772 Normally kallsyms only contains the symbols of functions, for nicer
773 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200774 symbols too: say Y here to include all symbols, if you need them
775 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776
777 Say N.
778
779config KALLSYMS_EXTRA_PASS
780 bool "Do an extra kallsyms pass"
781 depends on KALLSYMS
782 help
783 If kallsyms is not working correctly, the build will fail with
784 inconsistent kallsyms data. If that occurs, log a bug report and
785 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
786 Always say N here unless you find a bug in kallsyms, which must be
787 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
788 you wait for kallsyms to be fixed.
789
Matt Mackalld59745c2005-05-01 08:59:02 -0700790
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800791config HOTPLUG
792 bool "Support for hot-pluggable devices" if EMBEDDED
793 default y
794 help
795 This option is provided for the case where no hotplug or uevent
796 capabilities is wanted by the kernel. You should only consider
797 disabling this option for embedded systems that do not use modules, a
798 dynamic /dev tree, or dynamic device discovery. Just say Y.
799
Matt Mackalld59745c2005-05-01 08:59:02 -0700800config PRINTK
801 default y
802 bool "Enable support for printk" if EMBEDDED
803 help
804 This option enables normal printk support. Removing it
805 eliminates most of the message strings from the kernel image
806 and makes the kernel more or less silent. As this makes it
807 very difficult to diagnose system problems, saying N here is
808 strongly discouraged.
809
Matt Mackallc8538a72005-05-01 08:59:01 -0700810config BUG
811 bool "BUG() support" if EMBEDDED
812 default y
813 help
814 Disabling this option eliminates support for BUG and WARN, reducing
815 the size of your kernel image and potentially quietly ignoring
816 numerous fatal conditions. You should only consider disabling this
817 option for embedded systems with no facilities for reporting errors.
818 Just say Y.
819
Matt Mackall708e9a72006-01-08 01:05:25 -0800820config ELF_CORE
821 default y
822 bool "Enable ELF core dumps" if EMBEDDED
823 help
824 Enable support for generating core dumps. Disabling saves about 4k.
825
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200826config PCSPKR_PLATFORM
827 bool "Enable PC-Speaker support" if EMBEDDED
828 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
829 default y
830 help
831 This option allows to disable the internal PC-Speaker
832 support, saving some memory.
833
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834config BASE_FULL
835 default y
836 bool "Enable full-sized data structures for core" if EMBEDDED
837 help
838 Disabling this option reduces the size of miscellaneous core
839 kernel data structures. This saves memory on small machines,
840 but may reduce performance.
841
842config FUTEX
843 bool "Enable futex support" if EMBEDDED
844 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700845 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 help
847 Disabling this option will cause the kernel to be built without
848 support for "fast userspace mutexes". The resulting kernel may not
849 run glibc-based applications correctly.
850
851config EPOLL
852 bool "Enable eventpoll support" if EMBEDDED
853 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700854 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 help
856 Disabling this option will cause the kernel to be built without
857 support for epoll family of system calls.
858
Davide Libenzifba2afa2007-05-10 22:23:13 -0700859config SIGNALFD
860 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700861 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700862 default y
863 help
864 Enable the signalfd() system call that allows to receive signals
865 on a file descriptor.
866
867 If unsure, say Y.
868
Davide Libenzib215e282007-05-10 22:23:16 -0700869config TIMERFD
870 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700871 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700872 default y
873 help
874 Enable the timerfd() system call that allows to receive timer
875 events on a file descriptor.
876
877 If unsure, say Y.
878
Davide Libenzie1ad7462007-05-10 22:23:19 -0700879config EVENTFD
880 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700881 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700882 default y
883 help
884 Enable the eventfd() system call that allows to receive both
885 kernel notification (ie. KAIO) or userspace notifications.
886
887 If unsure, say Y.
888
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889config SHMEM
890 bool "Use full shmem filesystem" if EMBEDDED
891 default y
892 depends on MMU
893 help
894 The shmem is an internal filesystem used to manage shared memory.
895 It is backed by swap and manages resource limits. It is also exported
896 to userspace as tmpfs if TMPFS is enabled. Disabling this
897 option replaces shmem and tmpfs with the much simpler ramfs code,
898 which may be appropriate on small systems without swap.
899
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700900config AIO
901 bool "Enable AIO support" if EMBEDDED
902 default y
903 help
904 This option enables POSIX asynchronous I/O which may by used
905 by some high performance threaded applications. Disabling
906 this option saves about 7k.
907
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200908config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +0100909 bool
Mike Frysinger018df722009-06-12 13:17:43 -0400910 help
911 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100912
Peter Zijlstra906010b2009-09-21 16:08:49 +0200913config PERF_USE_VMALLOC
914 bool
915 help
916 See tools/perf/design.txt for details
917
Ingo Molnar57c0c152009-09-21 12:20:38 +0200918menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +0100919
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200920config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +0200921 bool "Kernel performance events and counters"
922 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200923 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +0100924 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +0100925 help
Ingo Molnar57c0c152009-09-21 12:20:38 +0200926 Enable kernel support for various performance events provided
927 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100928
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -0200929 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +0200930 use of generic tracepoints.
931
932 Most modern CPUs support performance events via performance
933 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +0100934 types of hw events: such as instructions executed, cachemisses
935 suffered, or branches mis-predicted - without slowing down the
936 kernel or applications. These registers can also trigger interrupts
937 when a threshold number of events have passed - and can thus be
938 used to profile the code that runs on that CPU.
939
Ingo Molnar57c0c152009-09-21 12:20:38 +0200940 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -0200941 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +0200942 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +0100943 provides per task and per CPU counters, and it provides event
944 capabilities on top of those.
945
946 Say Y if unsure.
947
Peter Zijlstrae077df42009-03-19 20:26:17 +0100948config EVENT_PROFILE
Peter Zijlstra470a1392009-07-29 10:50:09 +0200949 bool "Tracepoint profiling sources"
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200950 depends on PERF_EVENTS && EVENT_TRACING
Peter Zijlstrae077df42009-03-19 20:26:17 +0100951 default y
Peter Zijlstra470a1392009-07-29 10:50:09 +0200952 help
Ingo Molnar57c0c152009-09-21 12:20:38 +0200953 Allow the use of tracepoints as software performance events.
Peter Zijlstra470a1392009-07-29 10:50:09 +0200954
Ingo Molnar57c0c152009-09-21 12:20:38 +0200955 When this is enabled, you can create perf events based on
Peter Zijlstra470a1392009-07-29 10:50:09 +0200956 tracepoints using PERF_TYPE_TRACEPOINT and the tracepoint ID
957 found in debugfs://tracing/events/*/*/id. (The -e/--events
958 option to the perf tool can parse and interpret symbolic
959 tracepoints, in the subsystem:tracepoint_name format.)
Peter Zijlstrae077df42009-03-19 20:26:17 +0100960
Ingo Molnar57c0c152009-09-21 12:20:38 +0200961config PERF_COUNTERS
962 bool "Kernel performance counters (old config option)"
963 depends on HAVE_PERF_EVENTS
964 help
965 This config has been obsoleted by the PERF_EVENTS
966 config option - please see that one for details.
967
968 It has no effect on the kernel whether you enable
969 it or not, it is a compatibility placeholder.
970
971 Say N if unsure.
972
Peter Zijlstra906010b2009-09-21 16:08:49 +0200973config DEBUG_PERF_USE_VMALLOC
974 default n
975 bool "Debug: use vmalloc to back perf mmap() buffers"
976 depends on PERF_EVENTS && DEBUG_KERNEL
977 select PERF_USE_VMALLOC
978 help
979 Use vmalloc memory to back perf mmap() buffers.
980
981 Mostly useful for debugging the vmalloc code on platforms
982 that don't require it.
983
984 Say N if unsure.
985
Thomas Gleixner0793a612008-12-04 20:12:29 +0100986endmenu
987
Christoph Lameterf8891e52006-06-30 01:55:45 -0700988config VM_EVENT_COUNTERS
989 default y
990 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
991 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -0800992 VM event counters are needed for event counts to be shown.
993 This option allows the disabling of the VM event counters
994 on EMBEDDED systems. /proc/vmstat will only show page counts
995 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -0700996
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200997config PCI_QUIRKS
998 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +0200999 bool "Enable PCI quirk workarounds" if EMBEDDED
1000 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001001 help
1002 This enables workarounds for various PCI chipset
1003 bugs/quirks. Disable this only if your target machine is
1004 unaffected by PCI quirks.
1005
Christoph Lameter41ecc552007-05-09 02:32:44 -07001006config SLUB_DEBUG
1007 default y
1008 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -07001009 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001010 help
1011 SLUB has extensive debug support features. Disabling these can
1012 result in significant savings in code size. This also disables
1013 SLUB sysfs support. /sys/slab will not exist and there will be
1014 no support for cache validation etc.
1015
Randy Dunlapb943c462009-03-10 12:55:46 -07001016config COMPAT_BRK
1017 bool "Disable heap randomization"
1018 default y
1019 help
1020 Randomizing heap placement makes heap exploits harder, but it
1021 also breaks ancient binaries (including anything libc5 based).
1022 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001023 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001024 /proc/sys/kernel/randomize_va_space to 2.
1025
1026 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1027
Christoph Lameter81819f02007-05-06 14:49:36 -07001028choice
1029 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001030 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001031 help
1032 This option allows to select a slab allocator.
1033
1034config SLAB
1035 bool "SLAB"
1036 help
1037 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001038 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001039 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001040
1041config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001042 bool "SLUB (Unqueued Allocator)"
1043 help
1044 SLUB is a slab allocator that minimizes cache line usage
1045 instead of managing queues of cached objects (SLAB approach).
1046 Per cpu caching is realized using slabs of objects instead
1047 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001048 and has enhanced diagnostics. SLUB is the default choice for
1049 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001050
1051config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001052 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001053 bool "SLOB (Simple Allocator)"
1054 help
Matt Mackall37291452008-02-04 22:29:38 -08001055 SLOB replaces the stock allocator with a drastically simpler
1056 allocator. SLOB is generally more space efficient but
1057 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001058
1059endchoice
1060
Jie Zhangea637632009-12-14 18:00:02 -08001061config MMAP_ALLOW_UNINITIALIZED
1062 bool "Allow mmapped anonymous memory to be uninitialized"
1063 depends on EMBEDDED && !MMU
1064 default n
1065 help
1066 Normally, and according to the Linux spec, anonymous memory obtained
1067 from mmap() has it's contents cleared before it is passed to
1068 userspace. Enabling this config option allows you to request that
1069 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1070 providing a huge performance boost. If this option is not enabled,
1071 then the flag will be ignored.
1072
1073 This is taken advantage of by uClibc's malloc(), and also by
1074 ELF-FDPIC binfmt's brk and stack allocator.
1075
1076 Because of the obvious security issues, this option should only be
1077 enabled on embedded devices where you control what is run in
1078 userspace. Since that isn't generally a problem on no-MMU systems,
1079 it is normally safe to say Y here.
1080
1081 See Documentation/nommu-mmap.txt for more information.
1082
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001083config PROFILING
1084 bool "Profiling support (EXPERIMENTAL)"
1085 help
1086 Say Y here to enable the extended profiling support mechanisms used
1087 by profilers such as OProfile.
1088
Ingo Molnar5f87f112008-07-23 14:15:22 +02001089#
1090# Place an empty function call at each tracepoint site. Can be
1091# dynamically changed for a probe function.
1092#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001093config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001094 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001095
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001096source "arch/Kconfig"
1097
David Howells07fe7cb2009-04-03 16:42:35 +01001098config SLOW_WORK
1099 default n
David Howells1c2d0082009-04-06 15:47:25 +01001100 bool
David Howells07fe7cb2009-04-03 16:42:35 +01001101 help
1102 The slow work thread pool provides a number of dynamically allocated
1103 threads that can be used by the kernel to perform operations that
1104 take a relatively long time.
1105
1106 An example of this would be CacheFiles doing a path lookup followed
1107 by a series of mkdirs and a create call, all of which have to touch
1108 disk.
1109
David Howells1c2d0082009-04-06 15:47:25 +01001110 See Documentation/slow-work.txt.
1111
David Howellsf13a48b2009-12-01 15:36:11 +00001112config SLOW_WORK_DEBUG
1113 bool "Slow work debugging through debugfs"
David Howells8fba10a2009-11-19 18:10:51 +00001114 default n
David Howellsf13a48b2009-12-01 15:36:11 +00001115 depends on SLOW_WORK && DEBUG_FS
David Howells8fba10a2009-11-19 18:10:51 +00001116 help
David Howellsf13a48b2009-12-01 15:36:11 +00001117 Display the contents of the slow work run queue through debugfs,
David Howells8fba10a2009-11-19 18:10:51 +00001118 including items currently executing.
1119
1120 See Documentation/slow-work.txt.
1121
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122endmenu # General setup
1123
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001124config HAVE_GENERIC_DMA_COHERENT
1125 bool
1126 default n
1127
Linus Torvalds158a9622008-01-02 13:04:48 -08001128config SLABINFO
1129 bool
1130 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001131 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001132 default y
1133
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001134config RT_MUTEXES
1135 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001136
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137config BASE_SMALL
1138 int
1139 default 0 if BASE_FULL
1140 default 1 if !BASE_FULL
1141
Jan Engelhardt66da5732007-07-15 23:39:29 -07001142menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 bool "Enable loadable module support"
1144 help
1145 Kernel modules are small pieces of compiled code which can
1146 be inserted in the running kernel, rather than being
1147 permanently built into the kernel. You use the "modprobe"
1148 tool to add (and sometimes remove) them. If you say Y here,
1149 many parts of the kernel can be built as modules (by
1150 answering M instead of Y where indicated): this is most
1151 useful for infrequently used options which are not required
1152 for booting. For more information, see the man pages for
1153 modprobe, lsmod, modinfo, insmod and rmmod.
1154
1155 If you say Y here, you will need to run "make
1156 modules_install" to put the modules under /lib/modules/
1157 where modprobe can find them (you may need to be root to do
1158 this).
1159
1160 If unsure, say Y.
1161
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001162if MODULES
1163
Linus Torvalds826e4502008-05-04 17:04:16 -07001164config MODULE_FORCE_LOAD
1165 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001166 default n
1167 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001168 Allow loading of modules without version information (ie. modprobe
1169 --force). Forced module loading sets the 'F' (forced) taint flag and
1170 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001171
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172config MODULE_UNLOAD
1173 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 help
1175 Without this option you will not be able to unload any
1176 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001177 anyway), which makes your kernel smaller, faster
1178 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179
1180config MODULE_FORCE_UNLOAD
1181 bool "Forced module unloading"
1182 depends on MODULE_UNLOAD && EXPERIMENTAL
1183 help
1184 This option allows you to force a module to unload, even if the
1185 kernel believes it is unsafe: the kernel will remove the module
1186 without waiting for anyone to stop using it (using the -f option to
1187 rmmod). This is mainly for kernel developers and desperate users.
1188 If unsure, say N.
1189
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001191 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 help
1193 Usually, you have to use modules compiled with your kernel.
1194 Saying Y here makes it sometimes possible to use modules
1195 compiled for different kernels, by adding enough information
1196 to the modules to (hopefully) spot any changes which would
1197 make them incompatible with the kernel you are running. If
1198 unsure, say N.
1199
1200config MODULE_SRCVERSION_ALL
1201 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202 help
1203 Modules which contain a MODULE_VERSION get an extra "srcversion"
1204 field inserted into their modinfo section, which contains a
1205 sum of the source files which made it. This helps maintainers
1206 see exactly which source was used to build a module (since
1207 others sometimes change the module source without updating
1208 the version). With this option, such a "srcversion" field
1209 will be created for all modules. If unsure, say N.
1210
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001211endif # MODULES
1212
Rusty Russell98a79d62008-12-13 21:19:41 +10301213config INIT_ALL_POSSIBLE
1214 bool
1215 help
1216 Back when each arch used to define their own cpu_online_map and
1217 cpu_possible_map, some of them chose to initialize cpu_possible_map
1218 with all 1s, and others with all 0s. When they were centralised,
1219 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001220 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301221
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222config STOP_MACHINE
1223 bool
1224 default y
1225 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1226 help
1227 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001228
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001229source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001230
1231config PREEMPT_NOTIFIERS
1232 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001233
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001234source "kernel/Kconfig.locks"