d5b565ea5e0affa63946edc8802a49cb132b2ce3
[openwrt/openwrt.git] / config / Config-kernel.in
1 # Copyright (C) 2006-2013 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_DEBUG_FS
8 bool "Compile the kernel with Debug FileSystem enabled"
9 default y
10 help
11 debugfs is a virtual file system that kernel developers use to put
12 debugging files into. Enable this option to be able to read and
13 write to these files.
14
15 config KERNEL_PERF_EVENTS
16 bool
17 default n
18
19 config KERNEL_PROFILING
20 bool "Compile the kernel with profiling enabled"
21 default n
22 select KERNEL_PERF_EVENTS
23 help
24 Enable the extended profiling support mechanisms used by profilers such
25 as OProfile.
26
27 config KERNEL_KALLSYMS
28 bool "Compile the kernel with symbol table information"
29 default y
30 help
31 This will give you more information in stack traces from kernel oopses
32
33 config KERNEL_FTRACE
34 bool "Compile the kernel with tracing support"
35 default n
36
37 config KERNEL_FTRACE_SYSCALLS
38 bool "Trace system calls"
39 depends on KERNEL_FTRACE
40 default n
41
42 config KERNEL_ENABLE_DEFAULT_TRACERS
43 bool "Trace process context switches and events"
44 depends on KERNEL_FTRACE
45 default n
46
47 config KERNEL_DEBUG_KERNEL
48 bool
49 default n
50
51 config KERNEL_DEBUG_INFO
52 bool "Compile the kernel with debug information"
53 default y
54 select KERNEL_DEBUG_KERNEL
55 help
56 This will compile your kernel and modules with debug information.
57
58 config KERNEL_DEBUG_LL_UART_NONE
59 bool
60 default n
61 depends on arm
62
63 config KERNEL_DEBUG_LL
64 bool
65 default n
66 depends on arm
67 select KERNEL_DEBUG_LL_UART_NONE
68 help
69 ARM low level debugging
70
71 config KERNEL_EARLY_PRINTK
72 bool "Compile the kernel with early printk"
73 default n
74 depends on arm
75 select KERNEL_DEBUG_KERNEL
76 select KERNEL_DEBUG_LL if arm
77 help
78 Compile the kernel with early printk support.
79 This is only useful for debugging purposes to send messages
80 over the serial console in early boot.
81 Enable this to debug early boot problems.
82
83 config KERNEL_AIO
84 bool "Compile the kernel with asynchronous IO support"
85 default n
86
87 config KERNEL_DIRECT_IO
88 bool "Compile the kernel with direct IO support"
89 default n
90
91 config KERNEL_MAGIC_SYSRQ
92 bool "Compile the kernel with SysRq support"
93 default y
94
95 config KERNEL_COREDUMP
96 bool
97
98 config KERNEL_ELF_CORE
99 bool "Enable process core dump support"
100 select KERNEL_COREDUMP
101 default y
102
103 config KERNEL_PROVE_LOCKING
104 bool "Enable kernel lock checking"
105 select KERNEL_DEBUG_KERNEL
106 default n
107
108 config KERNEL_PRINTK_TIME
109 bool "Enable printk timestamps"
110 default y
111
112 config KERNEL_RELAY
113 bool
114
115 config KERNEL_KEXEC
116 bool "Enable kexec support"
117
118 config USE_RFKILL
119 bool "Enable rfkill support"
120 default RFKILL_SUPPORT
121
122 #
123 # CGROUP support symbols
124 #
125
126 config KERNEL_CGROUPS
127 bool "Enable kernel cgroups"
128 default n
129
130 if KERNEL_CGROUPS
131
132 config KERNEL_CGROUP_DEBUG
133 bool "Example debug cgroup subsystem"
134 default n
135 help
136 This option enables a simple cgroup subsystem that
137 exports useful debugging information about the cgroups
138 framework.
139
140 config KERNEL_FREEZER
141 bool
142 default y if KERNEL_CGROUP_FREEZER
143
144 config KERNEL_CGROUP_FREEZER
145 bool "Freezer cgroup subsystem"
146 default n
147 help
148 Provides a way to freeze and unfreeze all tasks in a
149 cgroup.
150
151 config KERNEL_CGROUP_DEVICE
152 bool "Device controller for cgroups"
153 default y
154 help
155 Provides a cgroup implementing whitelists for devices which
156 a process in the cgroup can mknod or open.
157
158 config KERNEL_CPUSETS
159 bool "Cpuset support"
160 default n
161 help
162 This option will let you create and manage CPUSETs which
163 allow dynamically partitioning a system into sets of CPUs and
164 Memory Nodes and assigning tasks to run only within those sets.
165 This is primarily useful on large SMP or NUMA systems.
166
167 config KERNEL_PROC_PID_CPUSET
168 bool "Include legacy /proc/<pid>/cpuset file"
169 default n
170 depends on KERNEL_CPUSETS
171
172 config KERNEL_CGROUP_CPUACCT
173 bool "Simple CPU accounting cgroup subsystem"
174 default n
175 help
176 Provides a simple Resource Controller for monitoring the
177 total CPU consumed by the tasks in a cgroup.
178
179 config KERNEL_RESOURCE_COUNTERS
180 bool "Resource counters"
181 default n
182 help
183 This option enables controller independent resource accounting
184 infrastructure that works with cgroups.
185
186 config KERNEL_MM_OWNER
187 bool
188 default y if KERNEL_MEMCG
189
190 config KERNEL_MEMCG
191 bool "Memory Resource Controller for Control Groups"
192 default n
193 depends on KERNEL_RESOURCE_COUNTERS
194 help
195 Provides a memory resource controller that manages both anonymous
196 memory and page cache. (See Documentation/cgroups/memory.txt)
197
198 Note that setting this option increases fixed memory overhead
199 associated with each page of memory in the system. By this,
200 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
201 usage tracking struct at boot. Total amount of this is printed out
202 at boot.
203
204 Only enable when you're ok with these trade offs and really
205 sure you need the memory resource controller. Even when you enable
206 this, you can set "cgroup_disable=memory" at your boot option to
207 disable memory resource controller and you can avoid overheads.
208 (and lose benefits of memory resource controller)
209
210 This config option also selects MM_OWNER config option, which
211 could in turn add some fork/exit overhead.
212
213 config KERNEL_MEMCG_SWAP
214 bool "Memory Resource Controller Swap Extension"
215 default n
216 depends on KERNEL_MEMCG
217 help
218 Add swap management feature to memory resource controller. When you
219 enable this, you can limit mem+swap usage per cgroup. In other words,
220 when you disable this, memory resource controller has no cares to
221 usage of swap...a process can exhaust all of the swap. This extension
222 is useful when you want to avoid exhaustion swap but this itself
223 adds more overheads and consumes memory for remembering information.
224 Especially if you use 32bit system or small memory system, please
225 be careful about enabling this. When memory resource controller
226 is disabled by boot option, this will be automatically disabled and
227 there will be no overhead from this. Even when you set this config=y,
228 if boot option "swapaccount=0" is set, swap will not be accounted.
229 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
230 size is 4096bytes, 512k per 1Gbytes of swap.
231
232 config KERNEL_MEMCG_SWAP_ENABLED
233 bool "Memory Resource Controller Swap Extension enabled by default"
234 default n
235 depends on KERNEL_MEMCG_SWAP
236 help
237 Memory Resource Controller Swap Extension comes with its price in
238 a bigger memory consumption. General purpose distribution kernels
239 which want to enable the feature but keep it disabled by default
240 and let the user enable it by swapaccount boot command line
241 parameter should have this option unselected.
242 For those who want to have the feature enabled by default should
243 select this option (if, for some reason, they need to disable it
244 then swapaccount=0 does the trick).
245
246
247 config KERNEL_MEMCG_KMEM
248 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
249 default n
250 depends on KERNEL_MEMCG
251 help
252 The Kernel Memory extension for Memory Resource Controller can limit
253 the amount of memory used by kernel objects in the system. Those are
254 fundamentally different from the entities handled by the standard
255 Memory Controller, which are page-based, and can be swapped. Users of
256 the kmem extension can use it to guarantee that no group of processes
257 will ever exhaust kernel resources alone.
258
259 config KERNEL_PERF_EVENTS
260 bool
261 default y if KERNEL_CGROUP_PERF
262
263 config KERNEL_CGROUP_PERF
264 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
265 default n
266 help
267 This option extends the per-cpu mode to restrict monitoring to
268 threads which belong to the cgroup specified and run on the
269 designated cpu.
270
271 menuconfig KERNEL_CGROUP_SCHED
272 bool "Group CPU scheduler"
273 default n
274 help
275 This feature lets CPU scheduler recognize task groups and control CPU
276 bandwidth allocation to such task groups. It uses cgroups to group
277 tasks.
278
279 if KERNEL_CGROUP_SCHED
280
281 config KERNEL_FAIR_GROUP_SCHED
282 bool "Group scheduling for SCHED_OTHER"
283 default n
284
285 config KERNEL_CFS_BANDWIDTH
286 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
287 default n
288 depends on KERNEL_FAIR_GROUP_SCHED
289 help
290 This option allows users to define CPU bandwidth rates (limits) for
291 tasks running within the fair group scheduler. Groups with no limit
292 set are considered to be unconstrained and will run with no
293 restriction.
294 See tip/Documentation/scheduler/sched-bwc.txt for more information.
295
296 config KERNEL_RT_GROUP_SCHED
297 bool "Group scheduling for SCHED_RR/FIFO"
298 default n
299 help
300 This feature lets you explicitly allocate real CPU bandwidth
301 to task groups. If enabled, it will also make it impossible to
302 schedule realtime tasks for non-root users until you allocate
303 realtime bandwidth for them.
304
305 endif
306
307 config KERNEL_BLK_CGROUP
308 bool "Block IO controller"
309 default y
310 help
311 Generic block IO controller cgroup interface. This is the common
312 cgroup interface which should be used by various IO controlling
313 policies.
314
315 Currently, CFQ IO scheduler uses it to recognize task groups and
316 control disk bandwidth allocation (proportional time slice allocation)
317 to such task groups. It is also used by bio throttling logic in
318 block layer to implement upper limit in IO rates on a device.
319
320 This option only enables generic Block IO controller infrastructure.
321 One needs to also enable actual IO controlling logic/policy. For
322 enabling proportional weight division of disk bandwidth in CFQ, set
323 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
324 CONFIG_BLK_DEV_THROTTLING=y.
325
326 config KERNEL_DEBUG_BLK_CGROUP
327 bool "Enable Block IO controller debugging"
328 default n
329 depends on KERNEL_BLK_CGROUP
330 help
331 Enable some debugging help. Currently it exports additional stat
332 files in a cgroup which can be useful for debugging.
333
334 config KERNEL_NET_CLS_CGROUP
335 bool "Control Group Classifier"
336 default y
337
338 config KERNEL_NETPRIO_CGROUP
339 bool "Network priority cgroup"
340 default y
341
342 endif
343
344 #
345 # Namespace support symbols
346 #
347
348 config KERNEL_NAMESPACES
349 bool "Enable kernel namespaces"
350 default n
351
352 if KERNEL_NAMESPACES
353
354 config KERNEL_UTS_NS
355 bool "UTS namespace"
356 default y
357 help
358 In this namespace tasks see different info provided
359 with the uname() system call
360
361 config KERNEL_IPC_NS
362 bool "IPC namespace"
363 default y
364 help
365 In this namespace tasks work with IPC ids which correspond to
366 different IPC objects in different namespaces.
367
368 config KERNEL_USER_NS
369 bool "User namespace (EXPERIMENTAL)"
370 default y
371 help
372 This allows containers, i.e. vservers, to use user namespaces
373 to provide different user info for different servers.
374
375 config KERNEL_PID_NS
376 bool "PID Namespaces"
377 default y
378 help
379 Support process id namespaces. This allows having multiple
380 processes with the same pid as long as they are in different
381 pid namespaces. This is a building block of containers.
382
383 config KERNEL_NET_NS
384 bool "Network namespace"
385 default y
386 help
387 Allow user space to create what appear to be multiple instances
388 of the network stack.
389
390 endif
391
392 #
393 # LXC related symbols
394 #
395
396 config KERNEL_LXC_MISC
397 bool "Enable miscellaneous LXC related options"
398 default n
399
400 if KERNEL_LXC_MISC
401
402 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
403 bool "Support multiple instances of devpts"
404 default y
405 help
406 Enable support for multiple instances of devpts filesystem.
407 If you want to have isolated PTY namespaces (eg: in containers),
408 say Y here. Otherwise, say N. If enabled, each mount of devpts
409 filesystem with the '-o newinstance' option will create an
410 independent PTY namespace.
411
412 config KERNEL_POSIX_MQUEUE
413 bool "POSIX Message Queues"
414 default n
415 help
416 POSIX variant of message queues is a part of IPC. In POSIX message
417 queues every message has a priority which decides about succession
418 of receiving it by a process. If you want to compile and run
419 programs written e.g. for Solaris with use of its POSIX message
420 queues (functions mq_*) say Y here.
421
422 POSIX message queues are visible as a filesystem called 'mqueue'
423 and can be mounted somewhere if you want to do filesystem
424 operations on message queues.
425
426 endif