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"
137 config KERNEL_PROC_PAGE_MONITOR
138 bool "Enable /proc page monitoring"
144 bool "Enable kexec support"
147 bool "Enable rfkill support"
148 default RFKILL_SUPPORT
151 bool "Enable sparse check during kernel build"
155 # CGROUP support symbols
158 config KERNEL_CGROUPS
159 bool "Enable kernel cgroups"
164 config KERNEL_CGROUP_DEBUG
165 bool "Example debug cgroup subsystem"
168 This option enables a simple cgroup subsystem that
169 exports useful debugging information about the cgroups
172 config KERNEL_FREEZER
174 default y if KERNEL_CGROUP_FREEZER
176 config KERNEL_CGROUP_FREEZER
177 bool "Freezer cgroup subsystem"
180 Provides a way to freeze and unfreeze all tasks in a
183 config KERNEL_CGROUP_DEVICE
184 bool "Device controller for cgroups"
187 Provides a cgroup implementing whitelists for devices which
188 a process in the cgroup can mknod or open.
190 config KERNEL_CPUSETS
191 bool "Cpuset support"
194 This option will let you create and manage CPUSETs which
195 allow dynamically partitioning a system into sets of CPUs and
196 Memory Nodes and assigning tasks to run only within those sets.
197 This is primarily useful on large SMP or NUMA systems.
199 config KERNEL_PROC_PID_CPUSET
200 bool "Include legacy /proc/<pid>/cpuset file"
202 depends on KERNEL_CPUSETS
204 config KERNEL_CGROUP_CPUACCT
205 bool "Simple CPU accounting cgroup subsystem"
208 Provides a simple Resource Controller for monitoring the
209 total CPU consumed by the tasks in a cgroup.
211 config KERNEL_RESOURCE_COUNTERS
212 bool "Resource counters"
215 This option enables controller independent resource accounting
216 infrastructure that works with cgroups.
218 config KERNEL_MM_OWNER
220 default y if KERNEL_MEMCG
223 bool "Memory Resource Controller for Control Groups"
225 depends on KERNEL_RESOURCE_COUNTERS
227 Provides a memory resource controller that manages both anonymous
228 memory and page cache. (See Documentation/cgroups/memory.txt)
230 Note that setting this option increases fixed memory overhead
231 associated with each page of memory in the system. By this,
232 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
233 usage tracking struct at boot. Total amount of this is printed out
236 Only enable when you're ok with these trade offs and really
237 sure you need the memory resource controller. Even when you enable
238 this, you can set "cgroup_disable=memory" at your boot option to
239 disable memory resource controller and you can avoid overheads.
240 (and lose benefits of memory resource controller)
242 This config option also selects MM_OWNER config option, which
243 could in turn add some fork/exit overhead.
245 config KERNEL_MEMCG_SWAP
246 bool "Memory Resource Controller Swap Extension"
248 depends on KERNEL_MEMCG
250 Add swap management feature to memory resource controller. When you
251 enable this, you can limit mem+swap usage per cgroup. In other words,
252 when you disable this, memory resource controller has no cares to
253 usage of swap...a process can exhaust all of the swap. This extension
254 is useful when you want to avoid exhaustion swap but this itself
255 adds more overheads and consumes memory for remembering information.
256 Especially if you use 32bit system or small memory system, please
257 be careful about enabling this. When memory resource controller
258 is disabled by boot option, this will be automatically disabled and
259 there will be no overhead from this. Even when you set this config=y,
260 if boot option "swapaccount=0" is set, swap will not be accounted.
261 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
262 size is 4096bytes, 512k per 1Gbytes of swap.
264 config KERNEL_MEMCG_SWAP_ENABLED
265 bool "Memory Resource Controller Swap Extension enabled by default"
267 depends on KERNEL_MEMCG_SWAP
269 Memory Resource Controller Swap Extension comes with its price in
270 a bigger memory consumption. General purpose distribution kernels
271 which want to enable the feature but keep it disabled by default
272 and let the user enable it by swapaccount boot command line
273 parameter should have this option unselected.
274 For those who want to have the feature enabled by default should
275 select this option (if, for some reason, they need to disable it
276 then swapaccount=0 does the trick).
279 config KERNEL_MEMCG_KMEM
280 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
282 depends on KERNEL_MEMCG
284 The Kernel Memory extension for Memory Resource Controller can limit
285 the amount of memory used by kernel objects in the system. Those are
286 fundamentally different from the entities handled by the standard
287 Memory Controller, which are page-based, and can be swapped. Users of
288 the kmem extension can use it to guarantee that no group of processes
289 will ever exhaust kernel resources alone.
291 config KERNEL_PERF_EVENTS
293 default y if KERNEL_CGROUP_PERF
295 config KERNEL_CGROUP_PERF
296 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
299 This option extends the per-cpu mode to restrict monitoring to
300 threads which belong to the cgroup specified and run on the
303 menuconfig KERNEL_CGROUP_SCHED
304 bool "Group CPU scheduler"
307 This feature lets CPU scheduler recognize task groups and control CPU
308 bandwidth allocation to such task groups. It uses cgroups to group
311 if KERNEL_CGROUP_SCHED
313 config KERNEL_FAIR_GROUP_SCHED
314 bool "Group scheduling for SCHED_OTHER"
317 config KERNEL_CFS_BANDWIDTH
318 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
320 depends on KERNEL_FAIR_GROUP_SCHED
322 This option allows users to define CPU bandwidth rates (limits) for
323 tasks running within the fair group scheduler. Groups with no limit
324 set are considered to be unconstrained and will run with no
326 See tip/Documentation/scheduler/sched-bwc.txt for more information.
328 config KERNEL_RT_GROUP_SCHED
329 bool "Group scheduling for SCHED_RR/FIFO"
332 This feature lets you explicitly allocate real CPU bandwidth
333 to task groups. If enabled, it will also make it impossible to
334 schedule realtime tasks for non-root users until you allocate
335 realtime bandwidth for them.
339 config KERNEL_BLK_CGROUP
340 bool "Block IO controller"
343 Generic block IO controller cgroup interface. This is the common
344 cgroup interface which should be used by various IO controlling
347 Currently, CFQ IO scheduler uses it to recognize task groups and
348 control disk bandwidth allocation (proportional time slice allocation)
349 to such task groups. It is also used by bio throttling logic in
350 block layer to implement upper limit in IO rates on a device.
352 This option only enables generic Block IO controller infrastructure.
353 One needs to also enable actual IO controlling logic/policy. For
354 enabling proportional weight division of disk bandwidth in CFQ, set
355 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
356 CONFIG_BLK_DEV_THROTTLING=y.
358 config KERNEL_DEBUG_BLK_CGROUP
359 bool "Enable Block IO controller debugging"
361 depends on KERNEL_BLK_CGROUP
363 Enable some debugging help. Currently it exports additional stat
364 files in a cgroup which can be useful for debugging.
366 config KERNEL_NET_CLS_CGROUP
367 bool "Control Group Classifier"
370 config KERNEL_NETPRIO_CGROUP
371 bool "Network priority cgroup"
377 # Namespace support symbols
380 config KERNEL_NAMESPACES
381 bool "Enable kernel namespaces"
390 In this namespace tasks see different info provided
391 with the uname() system call
397 In this namespace tasks work with IPC ids which correspond to
398 different IPC objects in different namespaces.
400 config KERNEL_USER_NS
401 bool "User namespace (EXPERIMENTAL)"
404 This allows containers, i.e. vservers, to use user namespaces
405 to provide different user info for different servers.
408 bool "PID Namespaces"
411 Support process id namespaces. This allows having multiple
412 processes with the same pid as long as they are in different
413 pid namespaces. This is a building block of containers.
416 bool "Network namespace"
419 Allow user space to create what appear to be multiple instances
420 of the network stack.
425 # LXC related symbols
428 config KERNEL_LXC_MISC
429 bool "Enable miscellaneous LXC related options"
434 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
435 bool "Support multiple instances of devpts"
438 Enable support for multiple instances of devpts filesystem.
439 If you want to have isolated PTY namespaces (eg: in containers),
440 say Y here. Otherwise, say N. If enabled, each mount of devpts
441 filesystem with the '-o newinstance' option will create an
442 independent PTY namespace.
444 config KERNEL_POSIX_MQUEUE
445 bool "POSIX Message Queues"
448 POSIX variant of message queues is a part of IPC. In POSIX message
449 queues every message has a priority which decides about succession
450 of receiving it by a process. If you want to compile and run
451 programs written e.g. for Solaris with use of its POSIX message
452 queues (functions mq_*) say Y here.
454 POSIX message queues are visible as a filesystem called 'mqueue'
455 and can be mounted somewhere if you want to do filesystem
456 operations on message queues.