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 || TARGET_uml)
  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. Many common debugging facilities, such as
  27           ftrace, require the existence of debugfs.
  28
  29 config KERNEL_PERF_EVENTS
  30         bool
  31         default n
  32
  33 config KERNEL_PROFILING
  34         bool "Compile the kernel with profiling enabled"
  35         default n
  36         select KERNEL_PERF_EVENTS
  37         help
  38           Enable the extended profiling support mechanisms used by profilers such
  39           as OProfile.
  40
  41 config KERNEL_KALLSYMS
  42         bool "Compile the kernel with symbol table information"
  43         default y
  44         help
  45           This will give you more information in stack traces from kernel oopses.
  46
  47 config KERNEL_FTRACE
  48         bool "Compile the kernel with tracing support"
  49         default n
  50
  51 config KERNEL_FTRACE_SYSCALLS
  52         bool "Trace system calls"
  53         depends on KERNEL_FTRACE
  54         default n
  55
  56 config KERNEL_ENABLE_DEFAULT_TRACERS
  57         bool "Trace process context switches and events"
  58         depends on KERNEL_FTRACE
  59         default n
  60
  61 config KERNEL_DEBUG_KERNEL
  62         bool
  63         default n
  64
  65 config KERNEL_DEBUG_INFO
  66         bool "Compile the kernel with debug information"
  67         default y
  68         select KERNEL_DEBUG_KERNEL
  69         help
  70           This will compile your kernel and modules with debug information.
  71
  72 config KERNEL_DEBUG_LL_UART_NONE
  73         bool
  74         default n
  75         depends on arm
  76
  77 config KERNEL_DEBUG_LL
  78         bool
  79         default n
  80         depends on arm
  81         select KERNEL_DEBUG_LL_UART_NONE
  82         help
  83           ARM low level debugging.
  84
  85 config KERNEL_DYNAMIC_DEBUG
  86         bool "Compile the kernel with dynamic printk"
  87         select KERNEL_DEBUG_FS
  88         default n
  89         help
  90           Compiles debug level messages into the kernel, which would not
  91           otherwise be available at runtime. These messages can then be
  92           enabled/disabled based on various levels of scope - per source file,
  93           function, module, format string, and line number. This mechanism
  94           implicitly compiles in all pr_debug() and dev_dbg() calls, which
  95           enlarges the kernel text size by about 2%.
  96
  97 config KERNEL_EARLY_PRINTK
  98         bool "Compile the kernel with early printk"
  99         default n
 100         depends on arm
 101         select KERNEL_DEBUG_KERNEL
 102         select KERNEL_DEBUG_LL if arm
 103         help
 104           Compile the kernel with early printk support.  This is only useful for
 105           debugging purposes to send messages 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_SLUB_DEBUG
 138         bool
 139
 140 config KERNEL_SLUB_DEBUG_ON
 141         bool
 142
 143 config KERNEL_SLABINFO
 144         select KERNEL_SLUB_DEBUG
 145         select KERNEL_SLUB_DEBUG_ON
 146         bool "Enable /proc slab debug info"
 147
 148 config KERNEL_PROC_PAGE_MONITOR
 149         bool "Enable /proc page monitoring"
 150
 151 config KERNEL_RELAY
 152         bool
 153
 154 config KERNEL_KEXEC
 155         bool "Enable kexec support"
 156
 157 config USE_RFKILL
 158         bool "Enable rfkill support"
 159         default RFKILL_SUPPORT
 160
 161 config USE_SPARSE
 162         bool "Enable sparse check during kernel build"
 163         default n
 164
 165 #
 166 # CGROUP support symbols
 167 #
 168
 169 config KERNEL_CGROUPS
 170         bool "Enable kernel cgroups"
 171         default n
 172
 173 if KERNEL_CGROUPS
 174
 175         config KERNEL_CGROUP_DEBUG
 176                 bool "Example debug cgroup subsystem"
 177                 default n
 178                 help
 179                   This option enables a simple cgroup subsystem that
 180                   exports useful debugging information about the cgroups
 181                   framework.
 182
 183         config KERNEL_FREEZER
 184                 bool
 185                 default y if KERNEL_CGROUP_FREEZER
 186
 187         config KERNEL_CGROUP_FREEZER
 188                 bool "Freezer cgroup subsystem"
 189                 default y
 190                 help
 191                   Provides a way to freeze and unfreeze all tasks in a
 192                   cgroup.
 193
 194         config KERNEL_CGROUP_DEVICE
 195                 bool "Device controller for cgroups"
 196                 default y
 197                 help
 198                   Provides a cgroup implementing whitelists for devices which
 199                   a process in the cgroup can mknod or open.
 200
 201         config KERNEL_CPUSETS
 202                 bool "Cpuset support"
 203                 default n
 204                 help
 205                   This option will let you create and manage CPUSETs which
 206                   allow dynamically partitioning a system into sets of CPUs and
 207                   Memory Nodes and assigning tasks to run only within those sets.
 208                   This is primarily useful on large SMP or NUMA systems.
 209
 210         config KERNEL_PROC_PID_CPUSET
 211                 bool "Include legacy /proc/<pid>/cpuset file"
 212                 default n
 213                 depends on KERNEL_CPUSETS
 214
 215         config KERNEL_CGROUP_CPUACCT
 216                 bool "Simple CPU accounting cgroup subsystem"
 217                 default n
 218                 help
 219                   Provides a simple Resource Controller for monitoring the
 220                   total CPU consumed by the tasks in a cgroup.
 221
 222         config KERNEL_RESOURCE_COUNTERS
 223                 bool "Resource counters"
 224                 default n
 225                 help
 226                   This option enables controller independent resource accounting
 227                   infrastructure that works with cgroups.
 228
 229         config KERNEL_MM_OWNER
 230                 bool
 231                 default y if KERNEL_MEMCG
 232
 233         config KERNEL_MEMCG
 234                 bool "Memory Resource Controller for Control Groups"
 235                 default n
 236                 depends on KERNEL_RESOURCE_COUNTERS
 237                 help
 238                   Provides a memory resource controller that manages both anonymous
 239                   memory and page cache. (See Documentation/cgroups/memory.txt)
 240
 241                   Note that setting this option increases fixed memory overhead
 242                   associated with each page of memory in the system. By this,
 243                   20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
 244                   usage tracking struct at boot. Total amount of this is printed out
 245                   at boot.
 246
 247                   Only enable when you're ok with these tradeoffs and really
 248                   sure you need the memory resource controller. Even when you enable
 249                   this, you can set "cgroup_disable=memory" at your boot option to
 250                   disable memory resource controller and you can avoid overheads
 251                   (but lose benefits of memory resource controller).
 252
 253                   This config option also selects MM_OWNER config option, which
 254                   could in turn add some fork/exit overhead.
 255
 256         config KERNEL_MEMCG_SWAP
 257                 bool "Memory Resource Controller Swap Extension"
 258                 default n
 259                 depends on KERNEL_MEMCG
 260                 help
 261                   Add swap management feature to memory resource controller. When you
 262                   enable this, you can limit mem+swap usage per cgroup. In other words,
 263                   when you disable this, memory resource controller has no cares to
 264                   usage of swap...a process can exhaust all of the swap. This extension
 265                   is useful when you want to avoid exhaustion swap but this itself
 266                   adds more overheads and consumes memory for remembering information.
 267                   Especially if you use 32bit system or small memory system, please
 268                   be careful about enabling this. When memory resource controller
 269                   is disabled by boot option, this will be automatically disabled and
 270                   there will be no overhead from this. Even when you set this config=y,
 271                   if boot option "swapaccount=0" is set, swap will not be accounted.
 272                   Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
 273                   size is 4096bytes, 512k per 1Gbytes of swap.
 274
 275         config KERNEL_MEMCG_SWAP_ENABLED
 276                 bool "Memory Resource Controller Swap Extension enabled by default"
 277                 default n
 278                 depends on KERNEL_MEMCG_SWAP
 279                 help
 280                   Memory Resource Controller Swap Extension comes with its price in
 281                   a bigger memory consumption. General purpose distribution kernels
 282                   which want to enable the feature but keep it disabled by default
 283                   and let the user enable it by swapaccount boot command line
 284                   parameter should have this option unselected.
 285
 286                   Those who want to have the feature enabled by default should
 287                   select this option (if, for some reason, they need to disable it,
 288                   then swapaccount=0 does the trick).
 289
 290
 291         config KERNEL_MEMCG_KMEM
 292                 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
 293                 default n
 294                 depends on KERNEL_MEMCG
 295                 help
 296                   The Kernel Memory extension for Memory Resource Controller can limit
 297                   the amount of memory used by kernel objects in the system. Those are
 298                   fundamentally different from the entities handled by the standard
 299                   Memory Controller, which are page-based, and can be swapped. Users of
 300                   the kmem extension can use it to guarantee that no group of processes
 301                   will ever exhaust kernel resources alone.
 302
 303         config KERNEL_CGROUP_PERF
 304                 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
 305                 select KERNEL_PERF_EVENTS
 306                 default n
 307                 help
 308                   This option extends the per-cpu mode to restrict monitoring to
 309                   threads which belong to the cgroup specified and run on the
 310                   designated cpu.
 311
 312         menuconfig KERNEL_CGROUP_SCHED
 313                 bool "Group CPU scheduler"
 314                 default n
 315                 help
 316                   This feature lets CPU scheduler recognize task groups and control CPU
 317                   bandwidth allocation to such task groups. It uses cgroups to group
 318                   tasks.
 319
 320         if KERNEL_CGROUP_SCHED
 321
 322                 config KERNEL_FAIR_GROUP_SCHED
 323                         bool "Group scheduling for SCHED_OTHER"
 324                         default n
 325
 326                 config KERNEL_CFS_BANDWIDTH
 327                         bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
 328                         default n
 329                         depends on KERNEL_FAIR_GROUP_SCHED
 330                         help
 331                           This option allows users to define CPU bandwidth rates (limits) for
 332                           tasks running within the fair group scheduler.  Groups with no limit
 333                           set are considered to be unconstrained and will run with no
 334                           restriction.
 335                           See tip/Documentation/scheduler/sched-bwc.txt for more information.
 336
 337                 config KERNEL_RT_GROUP_SCHED
 338                         bool "Group scheduling for SCHED_RR/FIFO"
 339                         default n
 340                         help
 341                           This feature lets you explicitly allocate real CPU bandwidth
 342                           to task groups. If enabled, it will also make it impossible to
 343                           schedule realtime tasks for non-root users until you allocate
 344                           realtime bandwidth for them.
 345
 346         endif
 347
 348         config KERNEL_BLK_CGROUP
 349                 bool "Block IO controller"
 350                 default y
 351                 help
 352                   Generic block IO controller cgroup interface. This is the common
 353                   cgroup interface which should be used by various IO controlling
 354                   policies.
 355
 356                   Currently, CFQ IO scheduler uses it to recognize task groups and
 357                   control disk bandwidth allocation (proportional time slice allocation)
 358                   to such task groups. It is also used by bio throttling logic in
 359                   block layer to implement upper limit in IO rates on a device.
 360
 361                   This option only enables generic Block IO controller infrastructure.
 362                   One needs to also enable actual IO controlling logic/policy. For
 363                   enabling proportional weight division of disk bandwidth in CFQ, set
 364                   CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
 365                   CONFIG_BLK_DEV_THROTTLING=y.
 366
 367         config KERNEL_DEBUG_BLK_CGROUP
 368                 bool "Enable Block IO controller debugging"
 369                 default n
 370                 depends on KERNEL_BLK_CGROUP
 371                 help
 372                   Enable some debugging help. Currently it exports additional stat
 373                   files in a cgroup which can be useful for debugging.
 374
 375         config KERNEL_NET_CLS_CGROUP
 376                 bool "Control Group Classifier"
 377                 default y
 378
 379         config KERNEL_NETPRIO_CGROUP
 380                 bool "Network priority cgroup"
 381                 default y
 382
 383 endif
 384
 385 #
 386 # Namespace support symbols
 387 #
 388
 389 config KERNEL_NAMESPACES
 390         bool "Enable kernel namespaces"
 391         default n
 392
 393 if KERNEL_NAMESPACES
 394
 395         config KERNEL_UTS_NS
 396                 bool "UTS namespace"
 397                 default y
 398                 help
 399                   In this namespace, tasks see different info provided
 400                   with the uname() system call.
 401
 402         config KERNEL_IPC_NS
 403                 bool "IPC namespace"
 404                 default y
 405                 help
 406                   In this namespace, tasks work with IPC ids which correspond to
 407                   different IPC objects in different namespaces.
 408
 409         config KERNEL_USER_NS
 410                 bool "User namespace (EXPERIMENTAL)"
 411                 default y
 412                 help
 413                   This allows containers, i.e. vservers, to use user namespaces
 414                   to provide different user info for different servers.
 415
 416         config KERNEL_PID_NS
 417                 bool "PID Namespaces"
 418                 default y
 419                 help
 420                   Support process id namespaces. This allows having multiple
 421                   processes with the same pid as long as they are in different
 422                   pid namespaces. This is a building block of containers.
 423
 424         config KERNEL_NET_NS
 425                 bool "Network namespace"
 426                 default y
 427                 help
 428                   Allow user space to create what appear to be multiple instances
 429                   of the network stack.
 430
 431 endif
 432
 433 #
 434 # LXC related symbols
 435 #
 436
 437 config KERNEL_LXC_MISC
 438         bool "Enable miscellaneous LXC related options"
 439         default n
 440
 441 if KERNEL_LXC_MISC
 442
 443         config KERNEL_DEVPTS_MULTIPLE_INSTANCES
 444                 bool "Support multiple instances of devpts"
 445                 default y
 446                 help
 447                   Enable support for multiple instances of devpts filesystem.
 448                   If you want to have isolated PTY namespaces (eg: in containers),
 449                   say Y here. Otherwise, say N. If enabled, each mount of devpts
 450                   filesystem with the '-o newinstance' option will create an
 451                   independent PTY namespace.
 452
 453         config KERNEL_POSIX_MQUEUE
 454                 bool "POSIX Message Queues"
 455                 default y
 456                 help
 457                   POSIX variant of message queues is a part of IPC. In POSIX message
 458                   queues every message has a priority which decides about succession
 459                   of receiving it by a process. If you want to compile and run
 460                   programs written e.g. for Solaris with use of its POSIX message
 461                   queues (functions mq_*) say Y here.
 462
 463                   POSIX message queues are visible as a filesystem called 'mqueue'
 464                   and can be mounted somewhere if you want to do filesystem
 465                   operations on message queues.
 466
 467 endif