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 bool "Enable sparse check during kernel build"
152 # CGROUP support symbols
155 config KERNEL_CGROUPS
156 bool "Enable kernel cgroups"
161 config KERNEL_CGROUP_DEBUG
162 bool "Example debug cgroup subsystem"
165 This option enables a simple cgroup subsystem that
166 exports useful debugging information about the cgroups
169 config KERNEL_FREEZER
171 default y if KERNEL_CGROUP_FREEZER
173 config KERNEL_CGROUP_FREEZER
174 bool "Freezer cgroup subsystem"
177 Provides a way to freeze and unfreeze all tasks in a
180 config KERNEL_CGROUP_DEVICE
181 bool "Device controller for cgroups"
184 Provides a cgroup implementing whitelists for devices which
185 a process in the cgroup can mknod or open.
187 config KERNEL_CPUSETS
188 bool "Cpuset support"
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.
196 config KERNEL_PROC_PID_CPUSET
197 bool "Include legacy /proc/<pid>/cpuset file"
199 depends on KERNEL_CPUSETS
201 config KERNEL_CGROUP_CPUACCT
202 bool "Simple CPU accounting cgroup subsystem"
205 Provides a simple Resource Controller for monitoring the
206 total CPU consumed by the tasks in a cgroup.
208 config KERNEL_RESOURCE_COUNTERS
209 bool "Resource counters"
212 This option enables controller independent resource accounting
213 infrastructure that works with cgroups.
215 config KERNEL_MM_OWNER
217 default y if KERNEL_MEMCG
220 bool "Memory Resource Controller for Control Groups"
222 depends on KERNEL_RESOURCE_COUNTERS
224 Provides a memory resource controller that manages both anonymous
225 memory and page cache. (See Documentation/cgroups/memory.txt)
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
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)
239 This config option also selects MM_OWNER config option, which
240 could in turn add some fork/exit overhead.
242 config KERNEL_MEMCG_SWAP
243 bool "Memory Resource Controller Swap Extension"
245 depends on KERNEL_MEMCG
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.
261 config KERNEL_MEMCG_SWAP_ENABLED
262 bool "Memory Resource Controller Swap Extension enabled by default"
264 depends on KERNEL_MEMCG_SWAP
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).
276 config KERNEL_MEMCG_KMEM
277 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
279 depends on KERNEL_MEMCG
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.
288 config KERNEL_PERF_EVENTS
290 default y if KERNEL_CGROUP_PERF
292 config KERNEL_CGROUP_PERF
293 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
296 This option extends the per-cpu mode to restrict monitoring to
297 threads which belong to the cgroup specified and run on the
300 menuconfig KERNEL_CGROUP_SCHED
301 bool "Group CPU scheduler"
304 This feature lets CPU scheduler recognize task groups and control CPU
305 bandwidth allocation to such task groups. It uses cgroups to group
308 if KERNEL_CGROUP_SCHED
310 config KERNEL_FAIR_GROUP_SCHED
311 bool "Group scheduling for SCHED_OTHER"
314 config KERNEL_CFS_BANDWIDTH
315 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
317 depends on KERNEL_FAIR_GROUP_SCHED
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
323 See tip/Documentation/scheduler/sched-bwc.txt for more information.
325 config KERNEL_RT_GROUP_SCHED
326 bool "Group scheduling for SCHED_RR/FIFO"
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.
336 config KERNEL_BLK_CGROUP
337 bool "Block IO controller"
340 Generic block IO controller cgroup interface. This is the common
341 cgroup interface which should be used by various IO controlling
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.
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.
355 config KERNEL_DEBUG_BLK_CGROUP
356 bool "Enable Block IO controller debugging"
358 depends on KERNEL_BLK_CGROUP
360 Enable some debugging help. Currently it exports additional stat
361 files in a cgroup which can be useful for debugging.
363 config KERNEL_NET_CLS_CGROUP
364 bool "Control Group Classifier"
367 config KERNEL_NETPRIO_CGROUP
368 bool "Network priority cgroup"
374 # Namespace support symbols
377 config KERNEL_NAMESPACES
378 bool "Enable kernel namespaces"
387 In this namespace tasks see different info provided
388 with the uname() system call
394 In this namespace tasks work with IPC ids which correspond to
395 different IPC objects in different namespaces.
397 config KERNEL_USER_NS
398 bool "User namespace (EXPERIMENTAL)"
401 This allows containers, i.e. vservers, to use user namespaces
402 to provide different user info for different servers.
405 bool "PID Namespaces"
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.
413 bool "Network namespace"
416 Allow user space to create what appear to be multiple instances
417 of the network stack.
422 # LXC related symbols
425 config KERNEL_LXC_MISC
426 bool "Enable miscellaneous LXC related options"
431 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
432 bool "Support multiple instances of devpts"
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.
441 config KERNEL_POSIX_MQUEUE
442 bool "POSIX Message Queues"
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.
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.