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 || TARGET_uml)
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
26 write to these files. Many common debugging facilities, such as
27 ftrace, require the existence of debugfs.
29 config KERNEL_PERF_EVENTS
33 config KERNEL_PROFILING
34 bool "Compile the kernel with profiling enabled"
36 select KERNEL_PERF_EVENTS
38 Enable the extended profiling support mechanisms used by profilers such
41 config KERNEL_KALLSYMS
42 bool "Compile the kernel with symbol table information"
45 This will give you more information in stack traces from kernel oopses.
48 bool "Compile the kernel with tracing support"
49 depends on !TARGET_uml
52 config KERNEL_FTRACE_SYSCALLS
53 bool "Trace system calls"
54 depends on KERNEL_FTRACE
57 config KERNEL_ENABLE_DEFAULT_TRACERS
58 bool "Trace process context switches and events"
59 depends on KERNEL_FTRACE
62 config KERNEL_FUNCTION_TRACER
63 bool "Function tracer"
64 depends on KERNEL_FTRACE
67 config KERNEL_FUNCTION_GRAPH_TRACER
68 bool "Function graph tracer"
69 depends on KERNEL_FUNCTION_TRACER
72 config KERNEL_DYNAMIC_FTRACE
73 bool "Enable/disable function tracing dynamically"
74 depends on KERNEL_FUNCTION_TRACER
77 config KERNEL_FUNCTION_PROFILER
78 bool "Function profiler"
79 depends on KERNEL_FUNCTION_TRACER
82 config KERNEL_DEBUG_KERNEL
86 config KERNEL_DEBUG_INFO
87 bool "Compile the kernel with debug information"
89 select KERNEL_DEBUG_KERNEL
91 This will compile your kernel and modules with debug information.
93 config KERNEL_DEBUG_LL_UART_NONE
98 config KERNEL_DEBUG_LL
102 select KERNEL_DEBUG_LL_UART_NONE
104 ARM low level debugging.
106 config KERNEL_DYNAMIC_DEBUG
107 bool "Compile the kernel with dynamic printk"
108 select KERNEL_DEBUG_FS
111 Compiles debug level messages into the kernel, which would not
112 otherwise be available at runtime. These messages can then be
113 enabled/disabled based on various levels of scope - per source file,
114 function, module, format string, and line number. This mechanism
115 implicitly compiles in all pr_debug() and dev_dbg() calls, which
116 enlarges the kernel text size by about 2%.
118 config KERNEL_EARLY_PRINTK
119 bool "Compile the kernel with early printk"
120 default y if TARGET_bcm53xx
123 select KERNEL_DEBUG_KERNEL
124 select KERNEL_DEBUG_LL if arm
126 Compile the kernel with early printk support. This is only useful for
127 debugging purposes to send messages over the serial console in early boot.
128 Enable this to debug early boot problems.
130 config KERNEL_KPROBES
131 bool "Compile the kernel with kprobes support"
134 select KERNEL_PERF_EVENTS
136 Compiles the kernel with KPROBES support, which allows you to trap
137 at almost any kernel address and execute a callback function.
138 register_kprobe() establishes a probepoint and specifies the
139 callback. Kprobes is useful for kernel debugging, non-intrusive
140 instrumentation and testing.
141 If in doubt, say "N".
143 config KERNEL_KPROBE_EVENT
145 default y if KERNEL_KPROBES
148 bool "Compile the kernel with asynchronous IO support"
151 config KERNEL_DIRECT_IO
152 bool "Compile the kernel with direct IO support"
155 config KERNEL_FHANDLE
156 bool "Compile the kernel with support for fhandle syscalls"
159 config KERNEL_FANOTIFY
160 bool "Compile the kernel with modern file notification support"
163 config KERNEL_BLK_DEV_BSG
164 bool "Compile the kernel with SCSI generic v4 support for any block device"
167 config KERNEL_MAGIC_SYSRQ
168 bool "Compile the kernel with SysRq support"
171 config KERNEL_COREDUMP
174 config KERNEL_ELF_CORE
175 bool "Enable process core dump support"
176 select KERNEL_COREDUMP
179 config KERNEL_PROVE_LOCKING
180 bool "Enable kernel lock checking"
181 select KERNEL_DEBUG_KERNEL
184 config KERNEL_PRINTK_TIME
185 bool "Enable printk timestamps"
188 config KERNEL_SLUB_DEBUG
191 config KERNEL_SLUB_DEBUG_ON
194 config KERNEL_SLABINFO
195 select KERNEL_SLUB_DEBUG
196 select KERNEL_SLUB_DEBUG_ON
197 bool "Enable /proc slab debug info"
199 config KERNEL_PROC_PAGE_MONITOR
200 bool "Enable /proc page monitoring"
206 bool "Enable kexec support"
209 bool "Enable rfkill support"
210 default RFKILL_SUPPORT
213 bool "Enable sparse check during kernel build"
216 config KERNEL_DEVTMPFS
217 bool "Compile the kernel with device tmpfs enabled"
220 devtmpfs is a simple, kernel-managed /dev filesystem. The kernel creates
221 devices nodes for all registered devices ti simplify boot, but leaves more
222 complex tasks to userspace (e.g. udev).
226 config KERNEL_DEVTMPFS_MOUNT
227 bool "Automatically mount devtmpfs after root filesystem is mounted"
233 # CGROUP support symbols
236 config KERNEL_CGROUPS
237 bool "Enable kernel cgroups"
242 config KERNEL_CGROUP_DEBUG
243 bool "Example debug cgroup subsystem"
246 This option enables a simple cgroup subsystem that
247 exports useful debugging information about the cgroups
250 config KERNEL_FREEZER
252 default y if KERNEL_CGROUP_FREEZER
254 config KERNEL_CGROUP_FREEZER
255 bool "Freezer cgroup subsystem"
258 Provides a way to freeze and unfreeze all tasks in a
261 config KERNEL_CGROUP_DEVICE
262 bool "Device controller for cgroups"
265 Provides a cgroup implementing whitelists for devices which
266 a process in the cgroup can mknod or open.
268 config KERNEL_CGROUP_PIDS
269 bool "PIDs cgroup subsystem"
272 Provides enforcement of process number limits in the scope of a
275 config KERNEL_CPUSETS
276 bool "Cpuset support"
279 This option will let you create and manage CPUSETs which
280 allow dynamically partitioning a system into sets of CPUs and
281 Memory Nodes and assigning tasks to run only within those sets.
282 This is primarily useful on large SMP or NUMA systems.
284 config KERNEL_PROC_PID_CPUSET
285 bool "Include legacy /proc/<pid>/cpuset file"
287 depends on KERNEL_CPUSETS
289 config KERNEL_CGROUP_CPUACCT
290 bool "Simple CPU accounting cgroup subsystem"
293 Provides a simple Resource Controller for monitoring the
294 total CPU consumed by the tasks in a cgroup.
296 config KERNEL_RESOURCE_COUNTERS
297 bool "Resource counters"
300 This option enables controller independent resource accounting
301 infrastructure that works with cgroups.
303 config KERNEL_MM_OWNER
305 default y if KERNEL_MEMCG
308 bool "Memory Resource Controller for Control Groups"
310 depends on KERNEL_RESOURCE_COUNTERS || !LINUX_3_18
312 Provides a memory resource controller that manages both anonymous
313 memory and page cache. (See Documentation/cgroups/memory.txt)
315 Note that setting this option increases fixed memory overhead
316 associated with each page of memory in the system. By this,
317 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
318 usage tracking struct at boot. Total amount of this is printed out
321 Only enable when you're ok with these tradeoffs and really
322 sure you need the memory resource controller. Even when you enable
323 this, you can set "cgroup_disable=memory" at your boot option to
324 disable memory resource controller and you can avoid overheads
325 (but lose benefits of memory resource controller).
327 This config option also selects MM_OWNER config option, which
328 could in turn add some fork/exit overhead.
330 config KERNEL_MEMCG_SWAP
331 bool "Memory Resource Controller Swap Extension"
333 depends on KERNEL_MEMCG
335 Add swap management feature to memory resource controller. When you
336 enable this, you can limit mem+swap usage per cgroup. In other words,
337 when you disable this, memory resource controller has no cares to
338 usage of swap...a process can exhaust all of the swap. This extension
339 is useful when you want to avoid exhaustion swap but this itself
340 adds more overheads and consumes memory for remembering information.
341 Especially if you use 32bit system or small memory system, please
342 be careful about enabling this. When memory resource controller
343 is disabled by boot option, this will be automatically disabled and
344 there will be no overhead from this. Even when you set this config=y,
345 if boot option "swapaccount=0" is set, swap will not be accounted.
346 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
347 size is 4096bytes, 512k per 1Gbytes of swap.
349 config KERNEL_MEMCG_SWAP_ENABLED
350 bool "Memory Resource Controller Swap Extension enabled by default"
352 depends on KERNEL_MEMCG_SWAP
354 Memory Resource Controller Swap Extension comes with its price in
355 a bigger memory consumption. General purpose distribution kernels
356 which want to enable the feature but keep it disabled by default
357 and let the user enable it by swapaccount boot command line
358 parameter should have this option unselected.
360 Those who want to have the feature enabled by default should
361 select this option (if, for some reason, they need to disable it,
362 then swapaccount=0 does the trick).
365 config KERNEL_MEMCG_KMEM
366 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
368 depends on KERNEL_MEMCG
370 The Kernel Memory extension for Memory Resource Controller can limit
371 the amount of memory used by kernel objects in the system. Those are
372 fundamentally different from the entities handled by the standard
373 Memory Controller, which are page-based, and can be swapped. Users of
374 the kmem extension can use it to guarantee that no group of processes
375 will ever exhaust kernel resources alone.
377 config KERNEL_CGROUP_PERF
378 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
379 select KERNEL_PERF_EVENTS
382 This option extends the per-cpu mode to restrict monitoring to
383 threads which belong to the cgroup specified and run on the
386 menuconfig KERNEL_CGROUP_SCHED
387 bool "Group CPU scheduler"
390 This feature lets CPU scheduler recognize task groups and control CPU
391 bandwidth allocation to such task groups. It uses cgroups to group
394 if KERNEL_CGROUP_SCHED
396 config KERNEL_FAIR_GROUP_SCHED
397 bool "Group scheduling for SCHED_OTHER"
400 config KERNEL_CFS_BANDWIDTH
401 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
403 depends on KERNEL_FAIR_GROUP_SCHED
405 This option allows users to define CPU bandwidth rates (limits) for
406 tasks running within the fair group scheduler. Groups with no limit
407 set are considered to be unconstrained and will run with no
409 See tip/Documentation/scheduler/sched-bwc.txt for more information.
411 config KERNEL_RT_GROUP_SCHED
412 bool "Group scheduling for SCHED_RR/FIFO"
415 This feature lets you explicitly allocate real CPU bandwidth
416 to task groups. If enabled, it will also make it impossible to
417 schedule realtime tasks for non-root users until you allocate
418 realtime bandwidth for them.
422 config KERNEL_BLK_CGROUP
423 bool "Block IO controller"
426 Generic block IO controller cgroup interface. This is the common
427 cgroup interface which should be used by various IO controlling
430 Currently, CFQ IO scheduler uses it to recognize task groups and
431 control disk bandwidth allocation (proportional time slice allocation)
432 to such task groups. It is also used by bio throttling logic in
433 block layer to implement upper limit in IO rates on a device.
435 This option only enables generic Block IO controller infrastructure.
436 One needs to also enable actual IO controlling logic/policy. For
437 enabling proportional weight division of disk bandwidth in CFQ, set
438 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
439 CONFIG_BLK_DEV_THROTTLING=y.
441 config KERNEL_DEBUG_BLK_CGROUP
442 bool "Enable Block IO controller debugging"
444 depends on KERNEL_BLK_CGROUP
446 Enable some debugging help. Currently it exports additional stat
447 files in a cgroup which can be useful for debugging.
449 config KERNEL_NET_CLS_CGROUP
450 bool "Control Group Classifier"
453 config KERNEL_NETPRIO_CGROUP
454 bool "Network priority cgroup"
460 # Namespace support symbols
463 config KERNEL_NAMESPACES
464 bool "Enable kernel namespaces"
473 In this namespace, tasks see different info provided
474 with the uname() system call.
480 In this namespace, tasks work with IPC ids which correspond to
481 different IPC objects in different namespaces.
483 config KERNEL_USER_NS
484 bool "User namespace (EXPERIMENTAL)"
487 This allows containers, i.e. vservers, to use user namespaces
488 to provide different user info for different servers.
491 bool "PID Namespaces"
494 Support process id namespaces. This allows having multiple
495 processes with the same pid as long as they are in different
496 pid namespaces. This is a building block of containers.
499 bool "Network namespace"
502 Allow user space to create what appear to be multiple instances
503 of the network stack.
508 # LXC related symbols
511 config KERNEL_LXC_MISC
512 bool "Enable miscellaneous LXC related options"
517 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
518 bool "Support multiple instances of devpts"
521 Enable support for multiple instances of devpts filesystem.
522 If you want to have isolated PTY namespaces (eg: in containers),
523 say Y here. Otherwise, say N. If enabled, each mount of devpts
524 filesystem with the '-o newinstance' option will create an
525 independent PTY namespace.
527 config KERNEL_POSIX_MQUEUE
528 bool "POSIX Message Queues"
531 POSIX variant of message queues is a part of IPC. In POSIX message
532 queues every message has a priority which decides about succession
533 of receiving it by a process. If you want to compile and run
534 programs written e.g. for Solaris with use of its POSIX message
535 queues (functions mq_*) say Y here.
537 POSIX message queues are visible as a filesystem called 'mqueue'
538 and can be mounted somewhere if you want to do filesystem
539 operations on message queues.
543 config KERNEL_SECCOMP_FILTER
547 config KERNEL_SECCOMP
548 bool "Enable seccomp support"
549 depends on !(TARGET_uml)
550 select KERNEL_SECCOMP_FILTER
553 Build kernel with support for seccomp.