51cc31f515447fd0d9b202b393f98c235d6c5310
[openwrt/svn-archive/archive.git] / config / Config-kernel.in
1 # Copyright (C) 2006-2014 OpenWrt.org
2 #
3 # This is free software, licensed under the GNU General Public License v2.
4 # See /LICENSE for more information.
5 #
6
7 config KERNEL_PRINTK
8 bool "Enable support for printk"
9 default y
10
11 config KERNEL_CRASHLOG
12 bool "Crash logging"
13 depends on !(arm || powerpc || sparc || TARGET_uml)
14 default y
15
16 config KERNEL_SWAP
17 bool "Support for paging of anonymous memory (swap)"
18 default y
19
20 config KERNEL_DEBUG_FS
21 bool "Compile the kernel with debug filesystem enabled"
22 default y
23 help
24 debugfs is a virtual file system that kernel developers use to put
25 debugging files into. Enable this option to be able to read and
26 write to these files. Many common debugging facilities, such as
27 ftrace, require the existence of debugfs.
28
29 config KERNEL_PERF_EVENTS
30 bool
31 default n
32
33 config KERNEL_PROFILING
34 bool "Compile the kernel with profiling enabled"
35 default n
36 select KERNEL_PERF_EVENTS
37 help
38 Enable the extended profiling support mechanisms used by profilers such
39 as OProfile.
40
41 config KERNEL_KALLSYMS
42 bool "Compile the kernel with symbol table information"
43 default y
44 help
45 This will give you more information in stack traces from kernel oopses.
46
47 config KERNEL_FTRACE
48 bool "Compile the kernel with tracing support"
49 default n
50
51 config KERNEL_FTRACE_SYSCALLS
52 bool "Trace system calls"
53 depends on KERNEL_FTRACE
54 default n
55
56 config KERNEL_ENABLE_DEFAULT_TRACERS
57 bool "Trace process context switches and events"
58 depends on KERNEL_FTRACE
59 default n
60
61 config KERNEL_DEBUG_KERNEL
62 bool
63 default n
64
65 config KERNEL_DEBUG_INFO
66 bool "Compile the kernel with debug information"
67 default y
68 select KERNEL_DEBUG_KERNEL
69 help
70 This will compile your kernel and modules with debug information.
71
72 config KERNEL_DEBUG_LL_UART_NONE
73 bool
74 default n
75 depends on arm
76
77 config KERNEL_DEBUG_LL
78 bool
79 default n
80 depends on arm
81 select KERNEL_DEBUG_LL_UART_NONE
82 help
83 ARM low level debugging.
84
85 config KERNEL_DYNAMIC_DEBUG
86 bool "Compile the kernel with dynamic printk"
87 select KERNEL_DEBUG_FS
88 default n
89 help
90 Compiles debug level messages into the kernel, which would not
91 otherwise be available at runtime. These messages can then be
92 enabled/disabled based on various levels of scope - per source file,
93 function, module, format string, and line number. This mechanism
94 implicitly compiles in all pr_debug() and dev_dbg() calls, which
95 enlarges the kernel text size by about 2%.
96
97 config KERNEL_EARLY_PRINTK
98 bool "Compile the kernel with early printk"
99 default n
100 depends on arm
101 select KERNEL_DEBUG_KERNEL
102 select KERNEL_DEBUG_LL if arm
103 help
104 Compile the kernel with early printk support. This is only useful for
105 debugging purposes to send messages over the serial console in early boot.
106 Enable this to debug early boot problems.
107
108 config KERNEL_AIO
109 bool "Compile the kernel with asynchronous IO support"
110 default n
111
112 config KERNEL_DIRECT_IO
113 bool "Compile the kernel with direct IO support"
114 default n
115
116 config KERNEL_MAGIC_SYSRQ
117 bool "Compile the kernel with SysRq support"
118 default y
119
120 config KERNEL_COREDUMP
121 bool
122
123 config KERNEL_ELF_CORE
124 bool "Enable process core dump support"
125 select KERNEL_COREDUMP
126 default y
127
128 config KERNEL_PROVE_LOCKING
129 bool "Enable kernel lock checking"
130 select KERNEL_DEBUG_KERNEL
131 default n
132
133 config KERNEL_PRINTK_TIME
134 bool "Enable printk timestamps"
135 default y
136
137 config KERNEL_SLUB_DEBUG
138 bool
139
140 config KERNEL_SLUB_DEBUG_ON
141 bool
142
143 config KERNEL_SLABINFO
144 select KERNEL_SLUB_DEBUG
145 select KERNEL_SLUB_DEBUG_ON
146 bool "Enable /proc slab debug info"
147
148 config KERNEL_PROC_PAGE_MONITOR
149 bool "Enable /proc page monitoring"
150
151 config KERNEL_RELAY
152 bool
153
154 config KERNEL_KEXEC
155 bool "Enable kexec support"
156
157 config USE_RFKILL
158 bool "Enable rfkill support"
159 default RFKILL_SUPPORT
160
161 config USE_SPARSE
162 bool "Enable sparse check during kernel build"
163 default n
164
165 #
166 # CGROUP support symbols
167 #
168
169 config KERNEL_CGROUPS
170 bool "Enable kernel cgroups"
171 default n
172
173 if KERNEL_CGROUPS
174
175 config KERNEL_CGROUP_DEBUG
176 bool "Example debug cgroup subsystem"
177 default n
178 help
179 This option enables a simple cgroup subsystem that
180 exports useful debugging information about the cgroups
181 framework.
182
183 config KERNEL_FREEZER
184 bool
185 default y if KERNEL_CGROUP_FREEZER
186
187 config KERNEL_CGROUP_FREEZER
188 bool "Freezer cgroup subsystem"
189 default y
190 help
191 Provides a way to freeze and unfreeze all tasks in a
192 cgroup.
193
194 config KERNEL_CGROUP_DEVICE
195 bool "Device controller for cgroups"
196 default y
197 help
198 Provides a cgroup implementing whitelists for devices which
199 a process in the cgroup can mknod or open.
200
201 config KERNEL_CPUSETS
202 bool "Cpuset support"
203 default n
204 help
205 This option will let you create and manage CPUSETs which
206 allow dynamically partitioning a system into sets of CPUs and
207 Memory Nodes and assigning tasks to run only within those sets.
208 This is primarily useful on large SMP or NUMA systems.
209
210 config KERNEL_PROC_PID_CPUSET
211 bool "Include legacy /proc/<pid>/cpuset file"
212 default n
213 depends on KERNEL_CPUSETS
214
215 config KERNEL_CGROUP_CPUACCT
216 bool "Simple CPU accounting cgroup subsystem"
217 default n
218 help
219 Provides a simple Resource Controller for monitoring the
220 total CPU consumed by the tasks in a cgroup.
221
222 config KERNEL_RESOURCE_COUNTERS
223 bool "Resource counters"
224 default n
225 help
226 This option enables controller independent resource accounting
227 infrastructure that works with cgroups.
228
229 config KERNEL_MM_OWNER
230 bool
231 default y if KERNEL_MEMCG
232
233 config KERNEL_MEMCG
234 bool "Memory Resource Controller for Control Groups"
235 default n
236 depends on KERNEL_RESOURCE_COUNTERS
237 help
238 Provides a memory resource controller that manages both anonymous
239 memory and page cache. (See Documentation/cgroups/memory.txt)
240
241 Note that setting this option increases fixed memory overhead
242 associated with each page of memory in the system. By this,
243 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
244 usage tracking struct at boot. Total amount of this is printed out
245 at boot.
246
247 Only enable when you're ok with these tradeoffs and really
248 sure you need the memory resource controller. Even when you enable
249 this, you can set "cgroup_disable=memory" at your boot option to
250 disable memory resource controller and you can avoid overheads
251 (but lose benefits of memory resource controller).
252
253 This config option also selects MM_OWNER config option, which
254 could in turn add some fork/exit overhead.
255
256 config KERNEL_MEMCG_SWAP
257 bool "Memory Resource Controller Swap Extension"
258 default n
259 depends on KERNEL_MEMCG
260 help
261 Add swap management feature to memory resource controller. When you
262 enable this, you can limit mem+swap usage per cgroup. In other words,
263 when you disable this, memory resource controller has no cares to
264 usage of swap...a process can exhaust all of the swap. This extension
265 is useful when you want to avoid exhaustion swap but this itself
266 adds more overheads and consumes memory for remembering information.
267 Especially if you use 32bit system or small memory system, please
268 be careful about enabling this. When memory resource controller
269 is disabled by boot option, this will be automatically disabled and
270 there will be no overhead from this. Even when you set this config=y,
271 if boot option "swapaccount=0" is set, swap will not be accounted.
272 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
273 size is 4096bytes, 512k per 1Gbytes of swap.
274
275 config KERNEL_MEMCG_SWAP_ENABLED
276 bool "Memory Resource Controller Swap Extension enabled by default"
277 default n
278 depends on KERNEL_MEMCG_SWAP
279 help
280 Memory Resource Controller Swap Extension comes with its price in
281 a bigger memory consumption. General purpose distribution kernels
282 which want to enable the feature but keep it disabled by default
283 and let the user enable it by swapaccount boot command line
284 parameter should have this option unselected.
285
286 Those who want to have the feature enabled by default should
287 select this option (if, for some reason, they need to disable it,
288 then swapaccount=0 does the trick).
289
290
291 config KERNEL_MEMCG_KMEM
292 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
293 default n
294 depends on KERNEL_MEMCG
295 help
296 The Kernel Memory extension for Memory Resource Controller can limit
297 the amount of memory used by kernel objects in the system. Those are
298 fundamentally different from the entities handled by the standard
299 Memory Controller, which are page-based, and can be swapped. Users of
300 the kmem extension can use it to guarantee that no group of processes
301 will ever exhaust kernel resources alone.
302
303 config KERNEL_CGROUP_PERF
304 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
305 select KERNEL_PERF_EVENTS
306 default n
307 help
308 This option extends the per-cpu mode to restrict monitoring to
309 threads which belong to the cgroup specified and run on the
310 designated cpu.
311
312 menuconfig KERNEL_CGROUP_SCHED
313 bool "Group CPU scheduler"
314 default n
315 help
316 This feature lets CPU scheduler recognize task groups and control CPU
317 bandwidth allocation to such task groups. It uses cgroups to group
318 tasks.
319
320 if KERNEL_CGROUP_SCHED
321
322 config KERNEL_FAIR_GROUP_SCHED
323 bool "Group scheduling for SCHED_OTHER"
324 default n
325
326 config KERNEL_CFS_BANDWIDTH
327 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
328 default n
329 depends on KERNEL_FAIR_GROUP_SCHED
330 help
331 This option allows users to define CPU bandwidth rates (limits) for
332 tasks running within the fair group scheduler. Groups with no limit
333 set are considered to be unconstrained and will run with no
334 restriction.
335 See tip/Documentation/scheduler/sched-bwc.txt for more information.
336
337 config KERNEL_RT_GROUP_SCHED
338 bool "Group scheduling for SCHED_RR/FIFO"
339 default n
340 help
341 This feature lets you explicitly allocate real CPU bandwidth
342 to task groups. If enabled, it will also make it impossible to
343 schedule realtime tasks for non-root users until you allocate
344 realtime bandwidth for them.
345
346 endif
347
348 config KERNEL_BLK_CGROUP
349 bool "Block IO controller"
350 default y
351 help
352 Generic block IO controller cgroup interface. This is the common
353 cgroup interface which should be used by various IO controlling
354 policies.
355
356 Currently, CFQ IO scheduler uses it to recognize task groups and
357 control disk bandwidth allocation (proportional time slice allocation)
358 to such task groups. It is also used by bio throttling logic in
359 block layer to implement upper limit in IO rates on a device.
360
361 This option only enables generic Block IO controller infrastructure.
362 One needs to also enable actual IO controlling logic/policy. For
363 enabling proportional weight division of disk bandwidth in CFQ, set
364 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
365 CONFIG_BLK_DEV_THROTTLING=y.
366
367 config KERNEL_DEBUG_BLK_CGROUP
368 bool "Enable Block IO controller debugging"
369 default n
370 depends on KERNEL_BLK_CGROUP
371 help
372 Enable some debugging help. Currently it exports additional stat
373 files in a cgroup which can be useful for debugging.
374
375 config KERNEL_NET_CLS_CGROUP
376 bool "Control Group Classifier"
377 default y
378
379 config KERNEL_NETPRIO_CGROUP
380 bool "Network priority cgroup"
381 default y
382
383 endif
384
385 #
386 # Namespace support symbols
387 #
388
389 config KERNEL_NAMESPACES
390 bool "Enable kernel namespaces"
391 default n
392
393 if KERNEL_NAMESPACES
394
395 config KERNEL_UTS_NS
396 bool "UTS namespace"
397 default y
398 help
399 In this namespace, tasks see different info provided
400 with the uname() system call.
401
402 config KERNEL_IPC_NS
403 bool "IPC namespace"
404 default y
405 help
406 In this namespace, tasks work with IPC ids which correspond to
407 different IPC objects in different namespaces.
408
409 config KERNEL_USER_NS
410 bool "User namespace (EXPERIMENTAL)"
411 default y
412 help
413 This allows containers, i.e. vservers, to use user namespaces
414 to provide different user info for different servers.
415
416 config KERNEL_PID_NS
417 bool "PID Namespaces"
418 default y
419 help
420 Support process id namespaces. This allows having multiple
421 processes with the same pid as long as they are in different
422 pid namespaces. This is a building block of containers.
423
424 config KERNEL_NET_NS
425 bool "Network namespace"
426 default y
427 help
428 Allow user space to create what appear to be multiple instances
429 of the network stack.
430
431 endif
432
433 #
434 # LXC related symbols
435 #
436
437 config KERNEL_LXC_MISC
438 bool "Enable miscellaneous LXC related options"
439 default n
440
441 if KERNEL_LXC_MISC
442
443 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
444 bool "Support multiple instances of devpts"
445 default y
446 help
447 Enable support for multiple instances of devpts filesystem.
448 If you want to have isolated PTY namespaces (eg: in containers),
449 say Y here. Otherwise, say N. If enabled, each mount of devpts
450 filesystem with the '-o newinstance' option will create an
451 independent PTY namespace.
452
453 config KERNEL_POSIX_MQUEUE
454 bool "POSIX Message Queues"
455 default y
456 help
457 POSIX variant of message queues is a part of IPC. In POSIX message
458 queues every message has a priority which decides about succession
459 of receiving it by a process. If you want to compile and run
460 programs written e.g. for Solaris with use of its POSIX message
461 queues (functions mq_*) say Y here.
462
463 POSIX message queues are visible as a filesystem called 'mqueue'
464 and can be mounted somewhere if you want to do filesystem
465 operations on message queues.
466
467 endif