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