| 1 | config ARCH |
| 2 | string |
| 3 | option env="ARCH" |
| 4 | |
| 5 | config KERNELVERSION |
| 6 | string |
| 7 | option env="KERNELVERSION" |
| 8 | |
| 9 | config DEFCONFIG_LIST |
| 10 | string |
| 11 | depends on !UML |
| 12 | option defconfig_list |
| 13 | default "/lib/modules/$UNAME_RELEASE/.config" |
| 14 | default "/etc/kernel-config" |
| 15 | default "/boot/config-$UNAME_RELEASE" |
| 16 | default "arch/$ARCH/defconfig" |
| 17 | |
| 18 | menu "General setup" |
| 19 | |
| 20 | config EXPERIMENTAL |
| 21 | bool "Prompt for development and/or incomplete code/drivers" |
| 22 | ---help--- |
| 23 | Some of the various things that Linux supports (such as network |
| 24 | drivers, file systems, network protocols, etc.) can be in a state |
| 25 | of development where the functionality, stability, or the level of |
| 26 | testing is not yet high enough for general use. This is usually |
| 27 | known as the "alpha-test" phase among developers. If a feature is |
| 28 | currently in alpha-test, then the developers usually discourage |
| 29 | uninformed widespread use of this feature by the general public to |
| 30 | avoid "Why doesn't this work?" type mail messages. However, active |
| 31 | testing and use of these systems is welcomed. Just be aware that it |
| 32 | may not meet the normal level of reliability or it may fail to work |
| 33 | in some special cases. Detailed bug reports from people familiar |
| 34 | with the kernel internals are usually welcomed by the developers |
| 35 | (before submitting bug reports, please read the documents |
| 36 | <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, |
| 37 | <file:Documentation/BUG-HUNTING>, and |
| 38 | <file:Documentation/oops-tracing.txt> in the kernel source). |
| 39 | |
| 40 | This option will also make obsoleted drivers available. These are |
| 41 | drivers that have been replaced by something else, and/or are |
| 42 | scheduled to be removed in a future kernel release. |
| 43 | |
| 44 | Unless you intend to help test and develop a feature or driver that |
| 45 | falls into this category, or you have a situation that requires |
| 46 | using these features, you should probably say N here, which will |
| 47 | cause the configurator to present you with fewer choices. If |
| 48 | you say Y here, you will be offered the choice of using features or |
| 49 | drivers that are currently considered to be in the alpha-test phase. |
| 50 | |
| 51 | config BROKEN |
| 52 | bool |
| 53 | |
| 54 | config BROKEN_ON_SMP |
| 55 | bool |
| 56 | depends on BROKEN || !SMP |
| 57 | default y |
| 58 | |
| 59 | config LOCK_KERNEL |
| 60 | bool |
| 61 | depends on SMP || PREEMPT |
| 62 | default y |
| 63 | |
| 64 | config INIT_ENV_ARG_LIMIT |
| 65 | int |
| 66 | default 32 if !UML |
| 67 | default 128 if UML |
| 68 | help |
| 69 | Maximum of each of the number of arguments and environment |
| 70 | variables passed to init from the kernel command line. |
| 71 | |
| 72 | |
| 73 | config LOCALVERSION |
| 74 | string "Local version - append to kernel release" |
| 75 | help |
| 76 | Append an extra string to the end of your kernel version. |
| 77 | This will show up when you type uname, for example. |
| 78 | The string you set here will be appended after the contents of |
| 79 | any files with a filename matching localversion* in your |
| 80 | object and source tree, in that order. Your total string can |
| 81 | be a maximum of 64 characters. |
| 82 | |
| 83 | config LOCALVERSION_AUTO |
| 84 | bool "Automatically append version information to the version string" |
| 85 | default y |
| 86 | help |
| 87 | This will try to automatically determine if the current tree is a |
| 88 | release tree by looking for git tags that belong to the current |
| 89 | top of tree revision. |
| 90 | |
| 91 | A string of the format -gxxxxxxxx will be added to the localversion |
| 92 | if a git-based tree is found. The string generated by this will be |
| 93 | appended after any matching localversion* files, and after the value |
| 94 | set in CONFIG_LOCALVERSION. |
| 95 | |
| 96 | (The actual string used here is the first eight characters produced |
| 97 | by running the command: |
| 98 | |
| 99 | $ git rev-parse --verify HEAD |
| 100 | |
| 101 | which is done within the script "scripts/setlocalversion".) |
| 102 | |
| 103 | config SWAP |
| 104 | bool "Support for paging of anonymous memory (swap)" |
| 105 | depends on MMU && BLOCK |
| 106 | default y |
| 107 | help |
| 108 | This option allows you to choose whether you want to have support |
| 109 | for so called swap devices or swap files in your kernel that are |
| 110 | used to provide more virtual memory than the actual RAM present |
| 111 | in your computer. If unsure say Y. |
| 112 | |
| 113 | config SYSVIPC |
| 114 | bool "System V IPC" |
| 115 | ---help--- |
| 116 | Inter Process Communication is a suite of library functions and |
| 117 | system calls which let processes (running programs) synchronize and |
| 118 | exchange information. It is generally considered to be a good thing, |
| 119 | and some programs won't run unless you say Y here. In particular, if |
| 120 | you want to run the DOS emulator dosemu under Linux (read the |
| 121 | DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), |
| 122 | you'll need to say Y here. |
| 123 | |
| 124 | You can find documentation about IPC with "info ipc" and also in |
| 125 | section 6.4 of the Linux Programmer's Guide, available from |
| 126 | <http://www.tldp.org/guides.html>. |
| 127 | |
| 128 | config SYSVIPC_SYSCTL |
| 129 | bool |
| 130 | depends on SYSVIPC |
| 131 | depends on SYSCTL |
| 132 | default y |
| 133 | |
| 134 | config POSIX_MQUEUE |
| 135 | bool "POSIX Message Queues" |
| 136 | depends on NET && EXPERIMENTAL |
| 137 | ---help--- |
| 138 | POSIX variant of message queues is a part of IPC. In POSIX message |
| 139 | queues every message has a priority which decides about succession |
| 140 | of receiving it by a process. If you want to compile and run |
| 141 | programs written e.g. for Solaris with use of its POSIX message |
| 142 | queues (functions mq_*) say Y here. |
| 143 | |
| 144 | POSIX message queues are visible as a filesystem called 'mqueue' |
| 145 | and can be mounted somewhere if you want to do filesystem |
| 146 | operations on message queues. |
| 147 | |
| 148 | If unsure, say Y. |
| 149 | |
| 150 | config BSD_PROCESS_ACCT |
| 151 | bool "BSD Process Accounting" |
| 152 | help |
| 153 | If you say Y here, a user level program will be able to instruct the |
| 154 | kernel (via a special system call) to write process accounting |
| 155 | information to a file: whenever a process exits, information about |
| 156 | that process will be appended to the file by the kernel. The |
| 157 | information includes things such as creation time, owning user, |
| 158 | command name, memory usage, controlling terminal etc. (the complete |
| 159 | list is in the struct acct in <file:include/linux/acct.h>). It is |
| 160 | up to the user level program to do useful things with this |
| 161 | information. This is generally a good idea, so say Y. |
| 162 | |
| 163 | config BSD_PROCESS_ACCT_V3 |
| 164 | bool "BSD Process Accounting version 3 file format" |
| 165 | depends on BSD_PROCESS_ACCT |
| 166 | default n |
| 167 | help |
| 168 | If you say Y here, the process accounting information is written |
| 169 | in a new file format that also logs the process IDs of each |
| 170 | process and it's parent. Note that this file format is incompatible |
| 171 | with previous v0/v1/v2 file formats, so you will need updated tools |
| 172 | for processing it. A preliminary version of these tools is available |
| 173 | at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>. |
| 174 | |
| 175 | config TASKSTATS |
| 176 | bool "Export task/process statistics through netlink (EXPERIMENTAL)" |
| 177 | depends on NET |
| 178 | default n |
| 179 | help |
| 180 | Export selected statistics for tasks/processes through the |
| 181 | generic netlink interface. Unlike BSD process accounting, the |
| 182 | statistics are available during the lifetime of tasks/processes as |
| 183 | responses to commands. Like BSD accounting, they are sent to user |
| 184 | space on task exit. |
| 185 | |
| 186 | Say N if unsure. |
| 187 | |
| 188 | config TASK_DELAY_ACCT |
| 189 | bool "Enable per-task delay accounting (EXPERIMENTAL)" |
| 190 | depends on TASKSTATS |
| 191 | help |
| 192 | Collect information on time spent by a task waiting for system |
| 193 | resources like cpu, synchronous block I/O completion and swapping |
| 194 | in pages. Such statistics can help in setting a task's priorities |
| 195 | relative to other tasks for cpu, io, rss limits etc. |
| 196 | |
| 197 | Say N if unsure. |
| 198 | |
| 199 | config TASK_XACCT |
| 200 | bool "Enable extended accounting over taskstats (EXPERIMENTAL)" |
| 201 | depends on TASKSTATS |
| 202 | help |
| 203 | Collect extended task accounting data and send the data |
| 204 | to userland for processing over the taskstats interface. |
| 205 | |
| 206 | Say N if unsure. |
| 207 | |
| 208 | config TASK_IO_ACCOUNTING |
| 209 | bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" |
| 210 | depends on TASK_XACCT |
| 211 | help |
| 212 | Collect information on the number of bytes of storage I/O which this |
| 213 | task has caused. |
| 214 | |
| 215 | Say N if unsure. |
| 216 | |
| 217 | config AUDIT |
| 218 | bool "Auditing support" |
| 219 | depends on NET |
| 220 | help |
| 221 | Enable auditing infrastructure that can be used with another |
| 222 | kernel subsystem, such as SELinux (which requires this for |
| 223 | logging of avc messages output). Does not do system-call |
| 224 | auditing without CONFIG_AUDITSYSCALL. |
| 225 | |
| 226 | config AUDITSYSCALL |
| 227 | bool "Enable system-call auditing support" |
| 228 | depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH) |
| 229 | default y if SECURITY_SELINUX |
| 230 | help |
| 231 | Enable low-overhead system-call auditing infrastructure that |
| 232 | can be used independently or with another kernel subsystem, |
| 233 | such as SELinux. To use audit's filesystem watch feature, please |
| 234 | ensure that INOTIFY is configured. |
| 235 | |
| 236 | config AUDIT_TREE |
| 237 | def_bool y |
| 238 | depends on AUDITSYSCALL && INOTIFY |
| 239 | |
| 240 | config IKCONFIG |
| 241 | tristate "Kernel .config support" |
| 242 | ---help--- |
| 243 | This option enables the complete Linux kernel ".config" file |
| 244 | contents to be saved in the kernel. It provides documentation |
| 245 | of which kernel options are used in a running kernel or in an |
| 246 | on-disk kernel. This information can be extracted from the kernel |
| 247 | image file with the script scripts/extract-ikconfig and used as |
| 248 | input to rebuild the current kernel or to build another kernel. |
| 249 | It can also be extracted from a running kernel by reading |
| 250 | /proc/config.gz if enabled (below). |
| 251 | |
| 252 | config IKCONFIG_PROC |
| 253 | bool "Enable access to .config through /proc/config.gz" |
| 254 | depends on IKCONFIG && PROC_FS |
| 255 | ---help--- |
| 256 | This option enables access to the kernel configuration file |
| 257 | through /proc/config.gz. |
| 258 | |
| 259 | config LOG_BUF_SHIFT |
| 260 | int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" |
| 261 | range 12 21 |
| 262 | default 17 |
| 263 | help |
| 264 | Select kernel log buffer size as a power of 2. |
| 265 | Examples: |
| 266 | 17 => 128 KB |
| 267 | 16 => 64 KB |
| 268 | 15 => 32 KB |
| 269 | 14 => 16 KB |
| 270 | 13 => 8 KB |
| 271 | 12 => 4 KB |
| 272 | |
| 273 | config CGROUPS |
| 274 | bool "Control Group support" |
| 275 | help |
| 276 | This option will let you use process cgroup subsystems |
| 277 | such as Cpusets |
| 278 | |
| 279 | Say N if unsure. |
| 280 | |
| 281 | config CGROUP_DEBUG |
| 282 | bool "Example debug cgroup subsystem" |
| 283 | depends on CGROUPS |
| 284 | default n |
| 285 | help |
| 286 | This option enables a simple cgroup subsystem that |
| 287 | exports useful debugging information about the cgroups |
| 288 | framework |
| 289 | |
| 290 | Say N if unsure |
| 291 | |
| 292 | config CGROUP_NS |
| 293 | bool "Namespace cgroup subsystem" |
| 294 | depends on CGROUPS |
| 295 | help |
| 296 | Provides a simple namespace cgroup subsystem to |
| 297 | provide hierarchical naming of sets of namespaces, |
| 298 | for instance virtual servers and checkpoint/restart |
| 299 | jobs. |
| 300 | |
| 301 | config CGROUP_DEVICE |
| 302 | bool "Device controller for cgroups" |
| 303 | depends on CGROUPS && EXPERIMENTAL |
| 304 | help |
| 305 | Provides a cgroup implementing whitelists for devices which |
| 306 | a process in the cgroup can mknod or open. |
| 307 | |
| 308 | config CPUSETS |
| 309 | bool "Cpuset support" |
| 310 | depends on SMP && CGROUPS |
| 311 | help |
| 312 | This option will let you create and manage CPUSETs which |
| 313 | allow dynamically partitioning a system into sets of CPUs and |
| 314 | Memory Nodes and assigning tasks to run only within those sets. |
| 315 | This is primarily useful on large SMP or NUMA systems. |
| 316 | |
| 317 | Say N if unsure. |
| 318 | |
| 319 | config GROUP_SCHED |
| 320 | bool "Group CPU scheduler" |
| 321 | default y |
| 322 | help |
| 323 | This feature lets CPU scheduler recognize task groups and control CPU |
| 324 | bandwidth allocation to such task groups. |
| 325 | |
| 326 | config FAIR_GROUP_SCHED |
| 327 | bool "Group scheduling for SCHED_OTHER" |
| 328 | depends on GROUP_SCHED |
| 329 | default y |
| 330 | |
| 331 | config RT_GROUP_SCHED |
| 332 | bool "Group scheduling for SCHED_RR/FIFO" |
| 333 | depends on EXPERIMENTAL |
| 334 | depends on GROUP_SCHED |
| 335 | default n |
| 336 | help |
| 337 | This feature lets you explicitly allocate real CPU bandwidth |
| 338 | to users or control groups (depending on the "Basis for grouping tasks" |
| 339 | setting below. If enabled, it will also make it impossible to |
| 340 | schedule realtime tasks for non-root users until you allocate |
| 341 | realtime bandwidth for them. |
| 342 | See Documentation/sched-rt-group.txt for more information. |
| 343 | |
| 344 | choice |
| 345 | depends on GROUP_SCHED |
| 346 | prompt "Basis for grouping tasks" |
| 347 | default USER_SCHED |
| 348 | |
| 349 | config USER_SCHED |
| 350 | bool "user id" |
| 351 | help |
| 352 | This option will choose userid as the basis for grouping |
| 353 | tasks, thus providing equal CPU bandwidth to each user. |
| 354 | |
| 355 | config CGROUP_SCHED |
| 356 | bool "Control groups" |
| 357 | depends on CGROUPS |
| 358 | help |
| 359 | This option allows you to create arbitrary task groups |
| 360 | using the "cgroup" pseudo filesystem and control |
| 361 | the cpu bandwidth allocated to each such task group. |
| 362 | Refer to Documentation/cgroups.txt for more information |
| 363 | on "cgroup" pseudo filesystem. |
| 364 | |
| 365 | endchoice |
| 366 | |
| 367 | config CGROUP_CPUACCT |
| 368 | bool "Simple CPU accounting cgroup subsystem" |
| 369 | depends on CGROUPS |
| 370 | help |
| 371 | Provides a simple Resource Controller for monitoring the |
| 372 | total CPU consumed by the tasks in a cgroup |
| 373 | |
| 374 | config RESOURCE_COUNTERS |
| 375 | bool "Resource counters" |
| 376 | help |
| 377 | This option enables controller independent resource accounting |
| 378 | infrastructure that works with cgroups |
| 379 | depends on CGROUPS |
| 380 | |
| 381 | config MM_OWNER |
| 382 | bool |
| 383 | |
| 384 | config CGROUP_MEM_RES_CTLR |
| 385 | bool "Memory Resource Controller for Control Groups" |
| 386 | depends on CGROUPS && RESOURCE_COUNTERS |
| 387 | select MM_OWNER |
| 388 | help |
| 389 | Provides a memory resource controller that manages both page cache and |
| 390 | RSS memory. |
| 391 | |
| 392 | Note that setting this option increases fixed memory overhead |
| 393 | associated with each page of memory in the system by 4/8 bytes |
| 394 | and also increases cache misses because struct page on many 64bit |
| 395 | systems will not fit into a single cache line anymore. |
| 396 | |
| 397 | Only enable when you're ok with these trade offs and really |
| 398 | sure you need the memory resource controller. |
| 399 | |
| 400 | This config option also selects MM_OWNER config option, which |
| 401 | could in turn add some fork/exit overhead. |
| 402 | |
| 403 | config SYSFS_DEPRECATED |
| 404 | bool |
| 405 | |
| 406 | config SYSFS_DEPRECATED_V2 |
| 407 | bool "Create deprecated sysfs files" |
| 408 | depends on SYSFS |
| 409 | default y |
| 410 | select SYSFS_DEPRECATED |
| 411 | help |
| 412 | This option creates deprecated symlinks such as the |
| 413 | "device"-link, the <subsystem>:<name>-link, and the |
| 414 | "bus"-link. It may also add deprecated key in the |
| 415 | uevent environment. |
| 416 | None of these features or values should be used today, as |
| 417 | they export driver core implementation details to userspace |
| 418 | or export properties which can't be kept stable across kernel |
| 419 | releases. |
| 420 | |
| 421 | If enabled, this option will also move any device structures |
| 422 | that belong to a class, back into the /sys/class hierarchy, in |
| 423 | order to support older versions of udev and some userspace |
| 424 | programs. |
| 425 | |
| 426 | If you are using a distro with the most recent userspace |
| 427 | packages, it should be safe to say N here. |
| 428 | |
| 429 | config PROC_PID_CPUSET |
| 430 | bool "Include legacy /proc/<pid>/cpuset file" |
| 431 | depends on CPUSETS |
| 432 | default y |
| 433 | |
| 434 | config RELAY |
| 435 | bool "Kernel->user space relay support (formerly relayfs)" |
| 436 | help |
| 437 | This option enables support for relay interface support in |
| 438 | certain file systems (such as debugfs). |
| 439 | It is designed to provide an efficient mechanism for tools and |
| 440 | facilities to relay large amounts of data from kernel space to |
| 441 | user space. |
| 442 | |
| 443 | If unsure, say N. |
| 444 | |
| 445 | config NAMESPACES |
| 446 | bool "Namespaces support" if EMBEDDED |
| 447 | default !EMBEDDED |
| 448 | help |
| 449 | Provides the way to make tasks work with different objects using |
| 450 | the same id. For example same IPC id may refer to different objects |
| 451 | or same user id or pid may refer to different tasks when used in |
| 452 | different namespaces. |
| 453 | |
| 454 | config UTS_NS |
| 455 | bool "UTS namespace" |
| 456 | depends on NAMESPACES |
| 457 | help |
| 458 | In this namespace tasks see different info provided with the |
| 459 | uname() system call |
| 460 | |
| 461 | config IPC_NS |
| 462 | bool "IPC namespace" |
| 463 | depends on NAMESPACES && SYSVIPC |
| 464 | help |
| 465 | In this namespace tasks work with IPC ids which correspond to |
| 466 | different IPC objects in different namespaces |
| 467 | |
| 468 | config USER_NS |
| 469 | bool "User namespace (EXPERIMENTAL)" |
| 470 | depends on NAMESPACES && EXPERIMENTAL |
| 471 | help |
| 472 | This allows containers, i.e. vservers, to use user namespaces |
| 473 | to provide different user info for different servers. |
| 474 | If unsure, say N. |
| 475 | |
| 476 | config PID_NS |
| 477 | bool "PID Namespaces (EXPERIMENTAL)" |
| 478 | default n |
| 479 | depends on NAMESPACES && EXPERIMENTAL |
| 480 | help |
| 481 | Suport process id namespaces. This allows having multiple |
| 482 | process with the same pid as long as they are in different |
| 483 | pid namespaces. This is a building block of containers. |
| 484 | |
| 485 | Unless you want to work with an experimental feature |
| 486 | say N here. |
| 487 | |
| 488 | config BLK_DEV_INITRD |
| 489 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" |
| 490 | depends on BROKEN || !FRV |
| 491 | help |
| 492 | The initial RAM filesystem is a ramfs which is loaded by the |
| 493 | boot loader (loadlin or lilo) and that is mounted as root |
| 494 | before the normal boot procedure. It is typically used to |
| 495 | load modules needed to mount the "real" root file system, |
| 496 | etc. See <file:Documentation/initrd.txt> for details. |
| 497 | |
| 498 | If RAM disk support (BLK_DEV_RAM) is also included, this |
| 499 | also enables initial RAM disk (initrd) support and adds |
| 500 | 15 Kbytes (more on some other architectures) to the kernel size. |
| 501 | |
| 502 | If unsure say Y. |
| 503 | |
| 504 | if BLK_DEV_INITRD |
| 505 | |
| 506 | source "usr/Kconfig" |
| 507 | |
| 508 | endif |
| 509 | |
| 510 | config CC_OPTIMIZE_FOR_SIZE |
| 511 | bool "Optimize for size" |
| 512 | default y |
| 513 | help |
| 514 | Enabling this option will pass "-Os" instead of "-O2" to gcc |
| 515 | resulting in a smaller kernel. |
| 516 | |
| 517 | If unsure, say N. |
| 518 | |
| 519 | config SYSCTL |
| 520 | bool |
| 521 | |
| 522 | menuconfig EMBEDDED |
| 523 | bool "Configure standard kernel features (for small systems)" |
| 524 | help |
| 525 | This option allows certain base kernel options and settings |
| 526 | to be disabled or tweaked. This is for specialized |
| 527 | environments which can tolerate a "non-standard" kernel. |
| 528 | Only use this if you really know what you are doing. |
| 529 | |
| 530 | config UID16 |
| 531 | bool "Enable 16-bit UID system calls" if EMBEDDED |
| 532 | depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION) |
| 533 | default y |
| 534 | help |
| 535 | This enables the legacy 16-bit UID syscall wrappers. |
| 536 | |
| 537 | config SYSCTL_SYSCALL |
| 538 | bool "Sysctl syscall support" if EMBEDDED |
| 539 | default y |
| 540 | select SYSCTL |
| 541 | ---help--- |
| 542 | sys_sysctl uses binary paths that have been found challenging |
| 543 | to properly maintain and use. The interface in /proc/sys |
| 544 | using paths with ascii names is now the primary path to this |
| 545 | information. |
| 546 | |
| 547 | Almost nothing using the binary sysctl interface so if you are |
| 548 | trying to save some space it is probably safe to disable this, |
| 549 | making your kernel marginally smaller. |
| 550 | |
| 551 | If unsure say Y here. |
| 552 | |
| 553 | config SYSCTL_SYSCALL_CHECK |
| 554 | bool "Sysctl checks" if EMBEDDED |
| 555 | depends on SYSCTL_SYSCALL |
| 556 | default y |
| 557 | ---help--- |
| 558 | sys_sysctl uses binary paths that have been found challenging |
| 559 | to properly maintain and use. This enables checks that help |
| 560 | you to keep things correct. |
| 561 | |
| 562 | If unsure say Y here. |
| 563 | |
| 564 | config KALLSYMS |
| 565 | bool "Load all symbols for debugging/ksymoops" if EMBEDDED |
| 566 | default y |
| 567 | help |
| 568 | Say Y here to let the kernel print out symbolic crash information and |
| 569 | symbolic stack backtraces. This increases the size of the kernel |
| 570 | somewhat, as all symbols have to be loaded into the kernel image. |
| 571 | |
| 572 | config KALLSYMS_ALL |
| 573 | bool "Include all symbols in kallsyms" |
| 574 | depends on DEBUG_KERNEL && KALLSYMS |
| 575 | help |
| 576 | Normally kallsyms only contains the symbols of functions, for nicer |
| 577 | OOPS messages. Some debuggers can use kallsyms for other |
| 578 | symbols too: say Y here to include all symbols, if you need them |
| 579 | and you don't care about adding 300k to the size of your kernel. |
| 580 | |
| 581 | Say N. |
| 582 | |
| 583 | config KALLSYMS_EXTRA_PASS |
| 584 | bool "Do an extra kallsyms pass" |
| 585 | depends on KALLSYMS |
| 586 | help |
| 587 | If kallsyms is not working correctly, the build will fail with |
| 588 | inconsistent kallsyms data. If that occurs, log a bug report and |
| 589 | turn on KALLSYMS_EXTRA_PASS which should result in a stable build. |
| 590 | Always say N here unless you find a bug in kallsyms, which must be |
| 591 | reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while |
| 592 | you wait for kallsyms to be fixed. |
| 593 | |
| 594 | |
| 595 | config HOTPLUG |
| 596 | bool "Support for hot-pluggable devices" if EMBEDDED |
| 597 | default y |
| 598 | help |
| 599 | This option is provided for the case where no hotplug or uevent |
| 600 | capabilities is wanted by the kernel. You should only consider |
| 601 | disabling this option for embedded systems that do not use modules, a |
| 602 | dynamic /dev tree, or dynamic device discovery. Just say Y. |
| 603 | |
| 604 | config PRINTK |
| 605 | default y |
| 606 | bool "Enable support for printk" if EMBEDDED |
| 607 | help |
| 608 | This option enables normal printk support. Removing it |
| 609 | eliminates most of the message strings from the kernel image |
| 610 | and makes the kernel more or less silent. As this makes it |
| 611 | very difficult to diagnose system problems, saying N here is |
| 612 | strongly discouraged. |
| 613 | |
| 614 | config BUG |
| 615 | bool "BUG() support" if EMBEDDED |
| 616 | default y |
| 617 | help |
| 618 | Disabling this option eliminates support for BUG and WARN, reducing |
| 619 | the size of your kernel image and potentially quietly ignoring |
| 620 | numerous fatal conditions. You should only consider disabling this |
| 621 | option for embedded systems with no facilities for reporting errors. |
| 622 | Just say Y. |
| 623 | |
| 624 | config ELF_CORE |
| 625 | default y |
| 626 | bool "Enable ELF core dumps" if EMBEDDED |
| 627 | help |
| 628 | Enable support for generating core dumps. Disabling saves about 4k. |
| 629 | |
| 630 | config COMPAT_BRK |
| 631 | bool "Disable heap randomization" |
| 632 | default y |
| 633 | help |
| 634 | Randomizing heap placement makes heap exploits harder, but it |
| 635 | also breaks ancient binaries (including anything libc5 based). |
| 636 | This option changes the bootup default to heap randomization |
| 637 | disabled, and can be overriden runtime by setting |
| 638 | /proc/sys/kernel/randomize_va_space to 2. |
| 639 | |
| 640 | On non-ancient distros (post-2000 ones) N is usually a safe choice. |
| 641 | |
| 642 | config BASE_FULL |
| 643 | default y |
| 644 | bool "Enable full-sized data structures for core" if EMBEDDED |
| 645 | help |
| 646 | Disabling this option reduces the size of miscellaneous core |
| 647 | kernel data structures. This saves memory on small machines, |
| 648 | but may reduce performance. |
| 649 | |
| 650 | config FUTEX |
| 651 | bool "Enable futex support" if EMBEDDED |
| 652 | default y |
| 653 | select RT_MUTEXES |
| 654 | help |
| 655 | Disabling this option will cause the kernel to be built without |
| 656 | support for "fast userspace mutexes". The resulting kernel may not |
| 657 | run glibc-based applications correctly. |
| 658 | |
| 659 | config ANON_INODES |
| 660 | bool |
| 661 | |
| 662 | config EPOLL |
| 663 | bool "Enable eventpoll support" if EMBEDDED |
| 664 | default y |
| 665 | select ANON_INODES |
| 666 | help |
| 667 | Disabling this option will cause the kernel to be built without |
| 668 | support for epoll family of system calls. |
| 669 | |
| 670 | config SIGNALFD |
| 671 | bool "Enable signalfd() system call" if EMBEDDED |
| 672 | select ANON_INODES |
| 673 | default y |
| 674 | help |
| 675 | Enable the signalfd() system call that allows to receive signals |
| 676 | on a file descriptor. |
| 677 | |
| 678 | If unsure, say Y. |
| 679 | |
| 680 | config TIMERFD |
| 681 | bool "Enable timerfd() system call" if EMBEDDED |
| 682 | select ANON_INODES |
| 683 | default y |
| 684 | help |
| 685 | Enable the timerfd() system call that allows to receive timer |
| 686 | events on a file descriptor. |
| 687 | |
| 688 | If unsure, say Y. |
| 689 | |
| 690 | config EVENTFD |
| 691 | bool "Enable eventfd() system call" if EMBEDDED |
| 692 | select ANON_INODES |
| 693 | default y |
| 694 | help |
| 695 | Enable the eventfd() system call that allows to receive both |
| 696 | kernel notification (ie. KAIO) or userspace notifications. |
| 697 | |
| 698 | If unsure, say Y. |
| 699 | |
| 700 | config SHMEM |
| 701 | bool "Use full shmem filesystem" if EMBEDDED |
| 702 | default y |
| 703 | depends on MMU |
| 704 | help |
| 705 | The shmem is an internal filesystem used to manage shared memory. |
| 706 | It is backed by swap and manages resource limits. It is also exported |
| 707 | to userspace as tmpfs if TMPFS is enabled. Disabling this |
| 708 | option replaces shmem and tmpfs with the much simpler ramfs code, |
| 709 | which may be appropriate on small systems without swap. |
| 710 | |
| 711 | config VM_EVENT_COUNTERS |
| 712 | default y |
| 713 | bool "Enable VM event counters for /proc/vmstat" if EMBEDDED |
| 714 | help |
| 715 | VM event counters are needed for event counts to be shown. |
| 716 | This option allows the disabling of the VM event counters |
| 717 | on EMBEDDED systems. /proc/vmstat will only show page counts |
| 718 | if VM event counters are disabled. |
| 719 | |
| 720 | config SLUB_DEBUG |
| 721 | default y |
| 722 | bool "Enable SLUB debugging support" if EMBEDDED |
| 723 | depends on SLUB |
| 724 | help |
| 725 | SLUB has extensive debug support features. Disabling these can |
| 726 | result in significant savings in code size. This also disables |
| 727 | SLUB sysfs support. /sys/slab will not exist and there will be |
| 728 | no support for cache validation etc. |
| 729 | |
| 730 | choice |
| 731 | prompt "Choose SLAB allocator" |
| 732 | default SLUB |
| 733 | help |
| 734 | This option allows to select a slab allocator. |
| 735 | |
| 736 | config SLAB |
| 737 | bool "SLAB" |
| 738 | help |
| 739 | The regular slab allocator that is established and known to work |
| 740 | well in all environments. It organizes cache hot objects in |
| 741 | per cpu and per node queues. SLAB is the default choice for |
| 742 | a slab allocator. |
| 743 | |
| 744 | config SLUB |
| 745 | bool "SLUB (Unqueued Allocator)" |
| 746 | help |
| 747 | SLUB is a slab allocator that minimizes cache line usage |
| 748 | instead of managing queues of cached objects (SLAB approach). |
| 749 | Per cpu caching is realized using slabs of objects instead |
| 750 | of queues of objects. SLUB can use memory efficiently |
| 751 | and has enhanced diagnostics. |
| 752 | |
| 753 | config SLOB |
| 754 | depends on EMBEDDED |
| 755 | bool "SLOB (Simple Allocator)" |
| 756 | help |
| 757 | SLOB replaces the stock allocator with a drastically simpler |
| 758 | allocator. SLOB is generally more space efficient but |
| 759 | does not perform as well on large systems. |
| 760 | |
| 761 | endchoice |
| 762 | |
| 763 | config PROFILING |
| 764 | bool "Profiling support (EXPERIMENTAL)" |
| 765 | help |
| 766 | Say Y here to enable the extended profiling support mechanisms used |
| 767 | by profilers such as OProfile. |
| 768 | |
| 769 | config MARKERS |
| 770 | bool "Activate markers" |
| 771 | help |
| 772 | Place an empty function call at each marker site. Can be |
| 773 | dynamically changed for a probe function. |
| 774 | |
| 775 | source "arch/Kconfig" |
| 776 | |
| 777 | config PROC_PAGE_MONITOR |
| 778 | default y |
| 779 | depends on PROC_FS && MMU |
| 780 | bool "Enable /proc page monitoring" if EMBEDDED |
| 781 | help |
| 782 | Various /proc files exist to monitor process memory utilization: |
| 783 | /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap, |
| 784 | /proc/kpagecount, and /proc/kpageflags. Disabling these |
| 785 | interfaces will reduce the size of the kernel by approximately 4kb. |
| 786 | |
| 787 | endmenu # General setup |
| 788 | |
| 789 | config SLABINFO |
| 790 | bool |
| 791 | depends on PROC_FS |
| 792 | depends on SLAB || SLUB_DEBUG |
| 793 | default y |
| 794 | |
| 795 | config RT_MUTEXES |
| 796 | boolean |
| 797 | select PLIST |
| 798 | |
| 799 | config TINY_SHMEM |
| 800 | default !SHMEM |
| 801 | bool |
| 802 | |
| 803 | config BASE_SMALL |
| 804 | int |
| 805 | default 0 if BASE_FULL |
| 806 | default 1 if !BASE_FULL |
| 807 | |
| 808 | menuconfig MODULES |
| 809 | bool "Enable loadable module support" |
| 810 | help |
| 811 | Kernel modules are small pieces of compiled code which can |
| 812 | be inserted in the running kernel, rather than being |
| 813 | permanently built into the kernel. You use the "modprobe" |
| 814 | tool to add (and sometimes remove) them. If you say Y here, |
| 815 | many parts of the kernel can be built as modules (by |
| 816 | answering M instead of Y where indicated): this is most |
| 817 | useful for infrequently used options which are not required |
| 818 | for booting. For more information, see the man pages for |
| 819 | modprobe, lsmod, modinfo, insmod and rmmod. |
| 820 | |
| 821 | If you say Y here, you will need to run "make |
| 822 | modules_install" to put the modules under /lib/modules/ |
| 823 | where modprobe can find them (you may need to be root to do |
| 824 | this). |
| 825 | |
| 826 | If unsure, say Y. |
| 827 | |
| 828 | config MODULE_UNLOAD |
| 829 | bool "Module unloading" |
| 830 | depends on MODULES |
| 831 | help |
| 832 | Without this option you will not be able to unload any |
| 833 | modules (note that some modules may not be unloadable |
| 834 | anyway), which makes your kernel slightly smaller and |
| 835 | simpler. If unsure, say Y. |
| 836 | |
| 837 | config MODULE_FORCE_UNLOAD |
| 838 | bool "Forced module unloading" |
| 839 | depends on MODULE_UNLOAD && EXPERIMENTAL |
| 840 | help |
| 841 | This option allows you to force a module to unload, even if the |
| 842 | kernel believes it is unsafe: the kernel will remove the module |
| 843 | without waiting for anyone to stop using it (using the -f option to |
| 844 | rmmod). This is mainly for kernel developers and desperate users. |
| 845 | If unsure, say N. |
| 846 | |
| 847 | config MODVERSIONS |
| 848 | bool "Module versioning support" |
| 849 | depends on MODULES |
| 850 | help |
| 851 | Usually, you have to use modules compiled with your kernel. |
| 852 | Saying Y here makes it sometimes possible to use modules |
| 853 | compiled for different kernels, by adding enough information |
| 854 | to the modules to (hopefully) spot any changes which would |
| 855 | make them incompatible with the kernel you are running. If |
| 856 | unsure, say N. |
| 857 | |
| 858 | config MODULE_SRCVERSION_ALL |
| 859 | bool "Source checksum for all modules" |
| 860 | depends on MODULES |
| 861 | help |
| 862 | Modules which contain a MODULE_VERSION get an extra "srcversion" |
| 863 | field inserted into their modinfo section, which contains a |
| 864 | sum of the source files which made it. This helps maintainers |
| 865 | see exactly which source was used to build a module (since |
| 866 | others sometimes change the module source without updating |
| 867 | the version). With this option, such a "srcversion" field |
| 868 | will be created for all modules. If unsure, say N. |
| 869 | |
| 870 | config KMOD |
| 871 | bool "Automatic kernel module loading" |
| 872 | depends on MODULES |
| 873 | help |
| 874 | Normally when you have selected some parts of the kernel to |
| 875 | be created as kernel modules, you must load them (using the |
| 876 | "modprobe" command) before you can use them. If you say Y |
| 877 | here, some parts of the kernel will be able to load modules |
| 878 | automatically: when a part of the kernel needs a module, it |
| 879 | runs modprobe with the appropriate arguments, thereby |
| 880 | loading the module if it is available. If unsure, say Y. |
| 881 | |
| 882 | config STOP_MACHINE |
| 883 | bool |
| 884 | default y |
| 885 | depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU |
| 886 | help |
| 887 | Need stop_machine() primitive. |
| 888 | |
| 889 | source "block/Kconfig" |
| 890 | |
| 891 | config PREEMPT_NOTIFIERS |
| 892 | bool |
| 893 | |
| 894 | config CLASSIC_RCU |
| 895 | def_bool !PREEMPT_RCU |
| 896 | help |
| 897 | This option selects the classic RCU implementation that is |
| 898 | designed for best read-side performance on non-realtime |
| 899 | systems. Classic RCU is the default. Note that the |
| 900 | PREEMPT_RCU symbol is used to select/deselect this option. |