1 # Copyright (C) 2006-2014 OpenWrt.org
3 # This is free software, licensed under the GNU General Public License v2.
4 # See /LICENSE for more information.
8 bool "Enable support for printk"
11 config KERNEL_CRASHLOG
13 depends on !(arm || powerpc || sparc)
17 bool "Support for paging of anonymous memory (swap)"
20 config KERNEL_DEBUG_FS
21 bool "Compile the kernel with Debug FileSystem enabled"
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
28 config KERNEL_PERF_EVENTS
32 config KERNEL_PROFILING
33 bool "Compile the kernel with profiling enabled"
35 select KERNEL_PERF_EVENTS
37 Enable the extended profiling support mechanisms used by profilers such
40 config KERNEL_KALLSYMS
41 bool "Compile the kernel with symbol table information"
44 This will give you more information in stack traces from kernel oopses
47 bool "Compile the kernel with tracing support"
50 config KERNEL_FTRACE_SYSCALLS
51 bool "Trace system calls"
52 depends on KERNEL_FTRACE
55 config KERNEL_ENABLE_DEFAULT_TRACERS
56 bool "Trace process context switches and events"
57 depends on KERNEL_FTRACE
60 config KERNEL_DEBUG_KERNEL
64 config KERNEL_DEBUG_INFO
65 bool "Compile the kernel with debug information"
67 select KERNEL_DEBUG_KERNEL
69 This will compile your kernel and modules with debug information.
71 config KERNEL_DEBUG_LL_UART_NONE
76 config KERNEL_DEBUG_LL
80 select KERNEL_DEBUG_LL_UART_NONE
82 ARM low level debugging
84 config KERNEL_DYNAMIC_DEBUG
85 bool "Compile the kernel with dynamic printk"
86 select KERNEL_DEBUG_FS
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%.
96 config KERNEL_EARLY_PRINTK
97 bool "Compile the kernel with early printk"
100 select KERNEL_DEBUG_KERNEL
101 select KERNEL_DEBUG_LL if arm
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.
109 bool "Compile the kernel with asynchronous IO support"
112 config KERNEL_DIRECT_IO
113 bool "Compile the kernel with direct IO support"
116 config KERNEL_MAGIC_SYSRQ
117 bool "Compile the kernel with SysRq support"
120 config KERNEL_COREDUMP
123 config KERNEL_ELF_CORE
124 bool "Enable process core dump support"
125 select KERNEL_COREDUMP
128 config KERNEL_PROVE_LOCKING
129 bool "Enable kernel lock checking"
130 select KERNEL_DEBUG_KERNEL
133 config KERNEL_PRINTK_TIME
134 bool "Enable printk timestamps"
141 bool "Enable kexec support"
144 bool "Enable rfkill support"
145 default RFKILL_SUPPORT
148 # CGROUP support symbols
151 config KERNEL_CGROUPS
152 bool "Enable kernel cgroups"
157 config KERNEL_CGROUP_DEBUG
158 bool "Example debug cgroup subsystem"
161 This option enables a simple cgroup subsystem that
162 exports useful debugging information about the cgroups
165 config KERNEL_FREEZER
167 default y if KERNEL_CGROUP_FREEZER
169 config KERNEL_CGROUP_FREEZER
170 bool "Freezer cgroup subsystem"
173 Provides a way to freeze and unfreeze all tasks in a
176 config KERNEL_CGROUP_DEVICE
177 bool "Device controller for cgroups"
180 Provides a cgroup implementing whitelists for devices which
181 a process in the cgroup can mknod or open.
183 config KERNEL_CPUSETS
184 bool "Cpuset support"
187 This option will let you create and manage CPUSETs which
188 allow dynamically partitioning a system into sets of CPUs and
189 Memory Nodes and assigning tasks to run only within those sets.
190 This is primarily useful on large SMP or NUMA systems.
192 config KERNEL_PROC_PID_CPUSET
193 bool "Include legacy /proc/<pid>/cpuset file"
195 depends on KERNEL_CPUSETS
197 config KERNEL_CGROUP_CPUACCT
198 bool "Simple CPU accounting cgroup subsystem"
201 Provides a simple Resource Controller for monitoring the
202 total CPU consumed by the tasks in a cgroup.
204 config KERNEL_RESOURCE_COUNTERS
205 bool "Resource counters"
208 This option enables controller independent resource accounting
209 infrastructure that works with cgroups.
211 config KERNEL_MM_OWNER
213 default y if KERNEL_MEMCG
216 bool "Memory Resource Controller for Control Groups"
218 depends on KERNEL_RESOURCE_COUNTERS
220 Provides a memory resource controller that manages both anonymous
221 memory and page cache. (See Documentation/cgroups/memory.txt)
223 Note that setting this option increases fixed memory overhead
224 associated with each page of memory in the system. By this,
225 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
226 usage tracking struct at boot. Total amount of this is printed out
229 Only enable when you're ok with these trade offs and really
230 sure you need the memory resource controller. Even when you enable
231 this, you can set "cgroup_disable=memory" at your boot option to
232 disable memory resource controller and you can avoid overheads.
233 (and lose benefits of memory resource controller)
235 This config option also selects MM_OWNER config option, which
236 could in turn add some fork/exit overhead.
238 config KERNEL_MEMCG_SWAP
239 bool "Memory Resource Controller Swap Extension"
241 depends on KERNEL_MEMCG
243 Add swap management feature to memory resource controller. When you
244 enable this, you can limit mem+swap usage per cgroup. In other words,
245 when you disable this, memory resource controller has no cares to
246 usage of swap...a process can exhaust all of the swap. This extension
247 is useful when you want to avoid exhaustion swap but this itself
248 adds more overheads and consumes memory for remembering information.
249 Especially if you use 32bit system or small memory system, please
250 be careful about enabling this. When memory resource controller
251 is disabled by boot option, this will be automatically disabled and
252 there will be no overhead from this. Even when you set this config=y,
253 if boot option "swapaccount=0" is set, swap will not be accounted.
254 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
255 size is 4096bytes, 512k per 1Gbytes of swap.
257 config KERNEL_MEMCG_SWAP_ENABLED
258 bool "Memory Resource Controller Swap Extension enabled by default"
260 depends on KERNEL_MEMCG_SWAP
262 Memory Resource Controller Swap Extension comes with its price in
263 a bigger memory consumption. General purpose distribution kernels
264 which want to enable the feature but keep it disabled by default
265 and let the user enable it by swapaccount boot command line
266 parameter should have this option unselected.
267 For those who want to have the feature enabled by default should
268 select this option (if, for some reason, they need to disable it
269 then swapaccount=0 does the trick).
272 config KERNEL_MEMCG_KMEM
273 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
275 depends on KERNEL_MEMCG
277 The Kernel Memory extension for Memory Resource Controller can limit
278 the amount of memory used by kernel objects in the system. Those are
279 fundamentally different from the entities handled by the standard
280 Memory Controller, which are page-based, and can be swapped. Users of
281 the kmem extension can use it to guarantee that no group of processes
282 will ever exhaust kernel resources alone.
284 config KERNEL_PERF_EVENTS
286 default y if KERNEL_CGROUP_PERF
288 config KERNEL_CGROUP_PERF
289 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
292 This option extends the per-cpu mode to restrict monitoring to
293 threads which belong to the cgroup specified and run on the
296 menuconfig KERNEL_CGROUP_SCHED
297 bool "Group CPU scheduler"
300 This feature lets CPU scheduler recognize task groups and control CPU
301 bandwidth allocation to such task groups. It uses cgroups to group
304 if KERNEL_CGROUP_SCHED
306 config KERNEL_FAIR_GROUP_SCHED
307 bool "Group scheduling for SCHED_OTHER"
310 config KERNEL_CFS_BANDWIDTH
311 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
313 depends on KERNEL_FAIR_GROUP_SCHED
315 This option allows users to define CPU bandwidth rates (limits) for
316 tasks running within the fair group scheduler. Groups with no limit
317 set are considered to be unconstrained and will run with no
319 See tip/Documentation/scheduler/sched-bwc.txt for more information.
321 config KERNEL_RT_GROUP_SCHED
322 bool "Group scheduling for SCHED_RR/FIFO"
325 This feature lets you explicitly allocate real CPU bandwidth
326 to task groups. If enabled, it will also make it impossible to
327 schedule realtime tasks for non-root users until you allocate
328 realtime bandwidth for them.
332 config KERNEL_BLK_CGROUP
333 bool "Block IO controller"
336 Generic block IO controller cgroup interface. This is the common
337 cgroup interface which should be used by various IO controlling
340 Currently, CFQ IO scheduler uses it to recognize task groups and
341 control disk bandwidth allocation (proportional time slice allocation)
342 to such task groups. It is also used by bio throttling logic in
343 block layer to implement upper limit in IO rates on a device.
345 This option only enables generic Block IO controller infrastructure.
346 One needs to also enable actual IO controlling logic/policy. For
347 enabling proportional weight division of disk bandwidth in CFQ, set
348 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
349 CONFIG_BLK_DEV_THROTTLING=y.
351 config KERNEL_DEBUG_BLK_CGROUP
352 bool "Enable Block IO controller debugging"
354 depends on KERNEL_BLK_CGROUP
356 Enable some debugging help. Currently it exports additional stat
357 files in a cgroup which can be useful for debugging.
359 config KERNEL_NET_CLS_CGROUP
360 bool "Control Group Classifier"
363 config KERNEL_NETPRIO_CGROUP
364 bool "Network priority cgroup"
370 # Namespace support symbols
373 config KERNEL_NAMESPACES
374 bool "Enable kernel namespaces"
383 In this namespace tasks see different info provided
384 with the uname() system call
390 In this namespace tasks work with IPC ids which correspond to
391 different IPC objects in different namespaces.
393 config KERNEL_USER_NS
394 bool "User namespace (EXPERIMENTAL)"
397 This allows containers, i.e. vservers, to use user namespaces
398 to provide different user info for different servers.
401 bool "PID Namespaces"
404 Support process id namespaces. This allows having multiple
405 processes with the same pid as long as they are in different
406 pid namespaces. This is a building block of containers.
409 bool "Network namespace"
412 Allow user space to create what appear to be multiple instances
413 of the network stack.
418 # LXC related symbols
421 config KERNEL_LXC_MISC
422 bool "Enable miscellaneous LXC related options"
427 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
428 bool "Support multiple instances of devpts"
431 Enable support for multiple instances of devpts filesystem.
432 If you want to have isolated PTY namespaces (eg: in containers),
433 say Y here. Otherwise, say N. If enabled, each mount of devpts
434 filesystem with the '-o newinstance' option will create an
435 independent PTY namespace.
437 config KERNEL_POSIX_MQUEUE
438 bool "POSIX Message Queues"
441 POSIX variant of message queues is a part of IPC. In POSIX message
442 queues every message has a priority which decides about succession
443 of receiving it by a process. If you want to compile and run
444 programs written e.g. for Solaris with use of its POSIX message
445 queues (functions mq_*) say Y here.
447 POSIX message queues are visible as a filesystem called 'mqueue'
448 and can be mounted somewhere if you want to do filesystem
449 operations on message queues.