1config ARCH 2 string 3 option env="ARCH" 4 5config KERNELVERSION 6 string 7 option env="KERNELVERSION" 8 9config 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 "$ARCH_DEFCONFIG" 17 default "arch/$ARCH/defconfig" 18 19menu "General setup" 20 21config EXPERIMENTAL 22 bool "Prompt for development and/or incomplete code/drivers" 23 ---help--- 24 Some of the various things that Linux supports (such as network 25 drivers, file systems, network protocols, etc.) can be in a state 26 of development where the functionality, stability, or the level of 27 testing is not yet high enough for general use. This is usually 28 known as the "alpha-test" phase among developers. If a feature is 29 currently in alpha-test, then the developers usually discourage 30 uninformed widespread use of this feature by the general public to 31 avoid "Why doesn't this work?" type mail messages. However, active 32 testing and use of these systems is welcomed. Just be aware that it 33 may not meet the normal level of reliability or it may fail to work 34 in some special cases. Detailed bug reports from people familiar 35 with the kernel internals are usually welcomed by the developers 36 (before submitting bug reports, please read the documents 37 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, 38 <file:Documentation/BUG-HUNTING>, and 39 <file:Documentation/oops-tracing.txt> in the kernel source). 40 41 This option will also make obsoleted drivers available. These are 42 drivers that have been replaced by something else, and/or are 43 scheduled to be removed in a future kernel release. 44 45 Unless you intend to help test and develop a feature or driver that 46 falls into this category, or you have a situation that requires 47 using these features, you should probably say N here, which will 48 cause the configurator to present you with fewer choices. If 49 you say Y here, you will be offered the choice of using features or 50 drivers that are currently considered to be in the alpha-test phase. 51 52config BROKEN 53 bool 54 55config BROKEN_ON_SMP 56 bool 57 depends on BROKEN || !SMP 58 default y 59 60config LOCK_KERNEL 61 bool 62 depends on SMP || PREEMPT 63 default y 64 65config INIT_ENV_ARG_LIMIT 66 int 67 default 32 if !UML 68 default 128 if UML 69 help 70 Maximum of each of the number of arguments and environment 71 variables passed to init from the kernel command line. 72 73 74config LOCALVERSION 75 string "Local version - append to kernel release" 76 help 77 Append an extra string to the end of your kernel version. 78 This will show up when you type uname, for example. 79 The string you set here will be appended after the contents of 80 any files with a filename matching localversion* in your 81 object and source tree, in that order. Your total string can 82 be a maximum of 64 characters. 83 84config LOCALVERSION_AUTO 85 bool "Automatically append version information to the version string" 86 default y 87 help 88 This will try to automatically determine if the current tree is a 89 release tree by looking for git tags that belong to the current 90 top of tree revision. 91 92 A string of the format -gxxxxxxxx will be added to the localversion 93 if a git-based tree is found. The string generated by this will be 94 appended after any matching localversion* files, and after the value 95 set in CONFIG_LOCALVERSION. 96 97 (The actual string used here is the first eight characters produced 98 by running the command: 99 100 $ git rev-parse --verify HEAD 101 102 which is done within the script "scripts/setlocalversion".) 103 104config SWAP 105 bool "Support for paging of anonymous memory (swap)" 106 depends on MMU && BLOCK 107 default y 108 help 109 This option allows you to choose whether you want to have support 110 for so called swap devices or swap files in your kernel that are 111 used to provide more virtual memory than the actual RAM present 112 in your computer. If unsure say Y. 113 114config SYSVIPC 115 bool "System V IPC" 116 ---help--- 117 Inter Process Communication is a suite of library functions and 118 system calls which let processes (running programs) synchronize and 119 exchange information. It is generally considered to be a good thing, 120 and some programs won't run unless you say Y here. In particular, if 121 you want to run the DOS emulator dosemu under Linux (read the 122 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), 123 you'll need to say Y here. 124 125 You can find documentation about IPC with "info ipc" and also in 126 section 6.4 of the Linux Programmer's Guide, available from 127 <http://www.tldp.org/guides.html>. 128 129config SYSVIPC_SYSCTL 130 bool 131 depends on SYSVIPC 132 depends on SYSCTL 133 default y 134 135config POSIX_MQUEUE 136 bool "POSIX Message Queues" 137 depends on NET && EXPERIMENTAL 138 ---help--- 139 POSIX variant of message queues is a part of IPC. In POSIX message 140 queues every message has a priority which decides about succession 141 of receiving it by a process. If you want to compile and run 142 programs written e.g. for Solaris with use of its POSIX message 143 queues (functions mq_*) say Y here. 144 145 POSIX message queues are visible as a filesystem called 'mqueue' 146 and can be mounted somewhere if you want to do filesystem 147 operations on message queues. 148 149 If unsure, say Y. 150 151config BSD_PROCESS_ACCT 152 bool "BSD Process Accounting" 153 help 154 If you say Y here, a user level program will be able to instruct the 155 kernel (via a special system call) to write process accounting 156 information to a file: whenever a process exits, information about 157 that process will be appended to the file by the kernel. The 158 information includes things such as creation time, owning user, 159 command name, memory usage, controlling terminal etc. (the complete 160 list is in the struct acct in <file:include/linux/acct.h>). It is 161 up to the user level program to do useful things with this 162 information. This is generally a good idea, so say Y. 163 164config BSD_PROCESS_ACCT_V3 165 bool "BSD Process Accounting version 3 file format" 166 depends on BSD_PROCESS_ACCT 167 default n 168 help 169 If you say Y here, the process accounting information is written 170 in a new file format that also logs the process IDs of each 171 process and it's parent. Note that this file format is incompatible 172 with previous v0/v1/v2 file formats, so you will need updated tools 173 for processing it. A preliminary version of these tools is available 174 at <http://www.gnu.org/software/acct/>. 175 176config TASKSTATS 177 bool "Export task/process statistics through netlink (EXPERIMENTAL)" 178 depends on NET 179 default n 180 help 181 Export selected statistics for tasks/processes through the 182 generic netlink interface. Unlike BSD process accounting, the 183 statistics are available during the lifetime of tasks/processes as 184 responses to commands. Like BSD accounting, they are sent to user 185 space on task exit. 186 187 Say N if unsure. 188 189config TASK_DELAY_ACCT 190 bool "Enable per-task delay accounting (EXPERIMENTAL)" 191 depends on TASKSTATS 192 help 193 Collect information on time spent by a task waiting for system 194 resources like cpu, synchronous block I/O completion and swapping 195 in pages. Such statistics can help in setting a task's priorities 196 relative to other tasks for cpu, io, rss limits etc. 197 198 Say N if unsure. 199 200config TASK_XACCT 201 bool "Enable extended accounting over taskstats (EXPERIMENTAL)" 202 depends on TASKSTATS 203 help 204 Collect extended task accounting data and send the data 205 to userland for processing over the taskstats interface. 206 207 Say N if unsure. 208 209config TASK_IO_ACCOUNTING 210 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" 211 depends on TASK_XACCT 212 help 213 Collect information on the number of bytes of storage I/O which this 214 task has caused. 215 216 Say N if unsure. 217 218config AUDIT 219 bool "Auditing support" 220 depends on NET 221 help 222 Enable auditing infrastructure that can be used with another 223 kernel subsystem, such as SELinux (which requires this for 224 logging of avc messages output). Does not do system-call 225 auditing without CONFIG_AUDITSYSCALL. 226 227config AUDITSYSCALL 228 bool "Enable system-call auditing support" 229 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH) 230 default y if SECURITY_SELINUX 231 help 232 Enable low-overhead system-call auditing infrastructure that 233 can be used independently or with another kernel subsystem, 234 such as SELinux. To use audit's filesystem watch feature, please 235 ensure that INOTIFY is configured. 236 237config AUDIT_TREE 238 def_bool y 239 depends on AUDITSYSCALL && INOTIFY 240 241config IKCONFIG 242 tristate "Kernel .config support" 243 ---help--- 244 This option enables the complete Linux kernel ".config" file 245 contents to be saved in the kernel. It provides documentation 246 of which kernel options are used in a running kernel or in an 247 on-disk kernel. This information can be extracted from the kernel 248 image file with the script scripts/extract-ikconfig and used as 249 input to rebuild the current kernel or to build another kernel. 250 It can also be extracted from a running kernel by reading 251 /proc/config.gz if enabled (below). 252 253config IKCONFIG_PROC 254 bool "Enable access to .config through /proc/config.gz" 255 depends on IKCONFIG && PROC_FS 256 ---help--- 257 This option enables access to the kernel configuration file 258 through /proc/config.gz. 259 260config LOG_BUF_SHIFT 261 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" 262 range 12 21 263 default 17 264 help 265 Select kernel log buffer size as a power of 2. 266 Examples: 267 17 => 128 KB 268 16 => 64 KB 269 15 => 32 KB 270 14 => 16 KB 271 13 => 8 KB 272 12 => 4 KB 273 274config CGROUPS 275 bool "Control Group support" 276 help 277 This option will let you use process cgroup subsystems 278 such as Cpusets 279 280 Say N if unsure. 281 282config CGROUP_DEBUG 283 bool "Example debug cgroup subsystem" 284 depends on CGROUPS 285 default n 286 help 287 This option enables a simple cgroup subsystem that 288 exports useful debugging information about the cgroups 289 framework 290 291 Say N if unsure 292 293config CGROUP_NS 294 bool "Namespace cgroup subsystem" 295 depends on CGROUPS 296 help 297 Provides a simple namespace cgroup subsystem to 298 provide hierarchical naming of sets of namespaces, 299 for instance virtual servers and checkpoint/restart 300 jobs. 301 302config CGROUP_DEVICE 303 bool "Device controller for cgroups" 304 depends on CGROUPS && EXPERIMENTAL 305 help 306 Provides a cgroup implementing whitelists for devices which 307 a process in the cgroup can mknod or open. 308 309config CPUSETS 310 bool "Cpuset support" 311 depends on SMP && CGROUPS 312 help 313 This option will let you create and manage CPUSETs which 314 allow dynamically partitioning a system into sets of CPUs and 315 Memory Nodes and assigning tasks to run only within those sets. 316 This is primarily useful on large SMP or NUMA systems. 317 318 Say N if unsure. 319 320# 321# Architectures with an unreliable sched_clock() should select this: 322# 323config HAVE_UNSTABLE_SCHED_CLOCK 324 bool 325 326config GROUP_SCHED 327 bool "Group CPU scheduler" 328 depends on EXPERIMENTAL 329 default n 330 help 331 This feature lets CPU scheduler recognize task groups and control CPU 332 bandwidth allocation to such task groups. 333 334config FAIR_GROUP_SCHED 335 bool "Group scheduling for SCHED_OTHER" 336 depends on GROUP_SCHED 337 default GROUP_SCHED 338 339config RT_GROUP_SCHED 340 bool "Group scheduling for SCHED_RR/FIFO" 341 depends on EXPERIMENTAL 342 depends on GROUP_SCHED 343 default n 344 help 345 This feature lets you explicitly allocate real CPU bandwidth 346 to users or control groups (depending on the "Basis for grouping tasks" 347 setting below. If enabled, it will also make it impossible to 348 schedule realtime tasks for non-root users until you allocate 349 realtime bandwidth for them. 350 See Documentation/sched-rt-group.txt for more information. 351 352choice 353 depends on GROUP_SCHED 354 prompt "Basis for grouping tasks" 355 default USER_SCHED 356 357config USER_SCHED 358 bool "user id" 359 help 360 This option will choose userid as the basis for grouping 361 tasks, thus providing equal CPU bandwidth to each user. 362 363config CGROUP_SCHED 364 bool "Control groups" 365 depends on CGROUPS 366 help 367 This option allows you to create arbitrary task groups 368 using the "cgroup" pseudo filesystem and control 369 the cpu bandwidth allocated to each such task group. 370 Refer to Documentation/cgroups.txt for more information 371 on "cgroup" pseudo filesystem. 372 373endchoice 374 375config CGROUP_CPUACCT 376 bool "Simple CPU accounting cgroup subsystem" 377 depends on CGROUPS 378 help 379 Provides a simple Resource Controller for monitoring the 380 total CPU consumed by the tasks in a cgroup 381 382config RESOURCE_COUNTERS 383 bool "Resource counters" 384 help 385 This option enables controller independent resource accounting 386 infrastructure that works with cgroups 387 depends on CGROUPS 388 389config MM_OWNER 390 bool 391 392config CGROUP_MEM_RES_CTLR 393 bool "Memory Resource Controller for Control Groups" 394 depends on CGROUPS && RESOURCE_COUNTERS 395 select MM_OWNER 396 help 397 Provides a memory resource controller that manages both page cache and 398 RSS memory. 399 400 Note that setting this option increases fixed memory overhead 401 associated with each page of memory in the system by 4/8 bytes 402 and also increases cache misses because struct page on many 64bit 403 systems will not fit into a single cache line anymore. 404 405 Only enable when you're ok with these trade offs and really 406 sure you need the memory resource controller. 407 408 This config option also selects MM_OWNER config option, which 409 could in turn add some fork/exit overhead. 410 411config SYSFS_DEPRECATED 412 bool 413 414config SYSFS_DEPRECATED_V2 415 bool "Create deprecated sysfs files" 416 depends on SYSFS 417 default y 418 select SYSFS_DEPRECATED 419 help 420 This option creates deprecated symlinks such as the 421 "device"-link, the <subsystem>:<name>-link, and the 422 "bus"-link. It may also add deprecated key in the 423 uevent environment. 424 None of these features or values should be used today, as 425 they export driver core implementation details to userspace 426 or export properties which can't be kept stable across kernel 427 releases. 428 429 If enabled, this option will also move any device structures 430 that belong to a class, back into the /sys/class hierarchy, in 431 order to support older versions of udev and some userspace 432 programs. 433 434 If you are using a distro with the most recent userspace 435 packages, it should be safe to say N here. 436 437config PROC_PID_CPUSET 438 bool "Include legacy /proc/<pid>/cpuset file" 439 depends on CPUSETS 440 default y 441 442config RELAY 443 bool "Kernel->user space relay support (formerly relayfs)" 444 help 445 This option enables support for relay interface support in 446 certain file systems (such as debugfs). 447 It is designed to provide an efficient mechanism for tools and 448 facilities to relay large amounts of data from kernel space to 449 user space. 450 451 If unsure, say N. 452 453config NAMESPACES 454 bool "Namespaces support" if EMBEDDED 455 default !EMBEDDED 456 help 457 Provides the way to make tasks work with different objects using 458 the same id. For example same IPC id may refer to different objects 459 or same user id or pid may refer to different tasks when used in 460 different namespaces. 461 462config UTS_NS 463 bool "UTS namespace" 464 depends on NAMESPACES 465 help 466 In this namespace tasks see different info provided with the 467 uname() system call 468 469config IPC_NS 470 bool "IPC namespace" 471 depends on NAMESPACES && SYSVIPC 472 help 473 In this namespace tasks work with IPC ids which correspond to 474 different IPC objects in different namespaces 475 476config USER_NS 477 bool "User namespace (EXPERIMENTAL)" 478 depends on NAMESPACES && EXPERIMENTAL 479 help 480 This allows containers, i.e. vservers, to use user namespaces 481 to provide different user info for different servers. 482 If unsure, say N. 483 484config PID_NS 485 bool "PID Namespaces (EXPERIMENTAL)" 486 default n 487 depends on NAMESPACES && EXPERIMENTAL 488 help 489 Support process id namespaces. This allows having multiple 490 process with the same pid as long as they are in different 491 pid namespaces. This is a building block of containers. 492 493 Unless you want to work with an experimental feature 494 say N here. 495 496config BLK_DEV_INITRD 497 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" 498 depends on BROKEN || !FRV 499 help 500 The initial RAM filesystem is a ramfs which is loaded by the 501 boot loader (loadlin or lilo) and that is mounted as root 502 before the normal boot procedure. It is typically used to 503 load modules needed to mount the "real" root file system, 504 etc. See <file:Documentation/initrd.txt> for details. 505 506 If RAM disk support (BLK_DEV_RAM) is also included, this 507 also enables initial RAM disk (initrd) support and adds 508 15 Kbytes (more on some other architectures) to the kernel size. 509 510 If unsure say Y. 511 512if BLK_DEV_INITRD 513 514source "usr/Kconfig" 515 516endif 517 518config CC_OPTIMIZE_FOR_SIZE 519 bool "Optimize for size" 520 default y 521 help 522 Enabling this option will pass "-Os" instead of "-O2" to gcc 523 resulting in a smaller kernel. 524 525 If unsure, say Y. 526 527config SYSCTL 528 bool 529 530menuconfig EMBEDDED 531 bool "Configure standard kernel features (for small systems)" 532 help 533 This option allows certain base kernel options and settings 534 to be disabled or tweaked. This is for specialized 535 environments which can tolerate a "non-standard" kernel. 536 Only use this if you really know what you are doing. 537 538config UID16 539 bool "Enable 16-bit UID system calls" if EMBEDDED 540 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION) 541 default y 542 help 543 This enables the legacy 16-bit UID syscall wrappers. 544 545config SYSCTL_SYSCALL 546 bool "Sysctl syscall support" if EMBEDDED 547 default y 548 select SYSCTL 549 ---help--- 550 sys_sysctl uses binary paths that have been found challenging 551 to properly maintain and use. The interface in /proc/sys 552 using paths with ascii names is now the primary path to this 553 information. 554 555 Almost nothing using the binary sysctl interface so if you are 556 trying to save some space it is probably safe to disable this, 557 making your kernel marginally smaller. 558 559 If unsure say Y here. 560 561config KALLSYMS 562 bool "Load all symbols for debugging/ksymoops" if EMBEDDED 563 default y 564 help 565 Say Y here to let the kernel print out symbolic crash information and 566 symbolic stack backtraces. This increases the size of the kernel 567 somewhat, as all symbols have to be loaded into the kernel image. 568 569config KALLSYMS_ALL 570 bool "Include all symbols in kallsyms" 571 depends on DEBUG_KERNEL && KALLSYMS 572 help 573 Normally kallsyms only contains the symbols of functions, for nicer 574 OOPS messages. Some debuggers can use kallsyms for other 575 symbols too: say Y here to include all symbols, if you need them 576 and you don't care about adding 300k to the size of your kernel. 577 578 Say N. 579 580config KALLSYMS_EXTRA_PASS 581 bool "Do an extra kallsyms pass" 582 depends on KALLSYMS 583 help 584 If kallsyms is not working correctly, the build will fail with 585 inconsistent kallsyms data. If that occurs, log a bug report and 586 turn on KALLSYMS_EXTRA_PASS which should result in a stable build. 587 Always say N here unless you find a bug in kallsyms, which must be 588 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while 589 you wait for kallsyms to be fixed. 590 591 592config HOTPLUG 593 bool "Support for hot-pluggable devices" if EMBEDDED 594 default y 595 help 596 This option is provided for the case where no hotplug or uevent 597 capabilities is wanted by the kernel. You should only consider 598 disabling this option for embedded systems that do not use modules, a 599 dynamic /dev tree, or dynamic device discovery. Just say Y. 600 601config PRINTK 602 default y 603 bool "Enable support for printk" if EMBEDDED 604 help 605 This option enables normal printk support. Removing it 606 eliminates most of the message strings from the kernel image 607 and makes the kernel more or less silent. As this makes it 608 very difficult to diagnose system problems, saying N here is 609 strongly discouraged. 610 611config BUG 612 bool "BUG() support" if EMBEDDED 613 default y 614 help 615 Disabling this option eliminates support for BUG and WARN, reducing 616 the size of your kernel image and potentially quietly ignoring 617 numerous fatal conditions. You should only consider disabling this 618 option for embedded systems with no facilities for reporting errors. 619 Just say Y. 620 621config ELF_CORE 622 default y 623 bool "Enable ELF core dumps" if EMBEDDED 624 help 625 Enable support for generating core dumps. Disabling saves about 4k. 626 627config PCSPKR_PLATFORM 628 bool "Enable PC-Speaker support" if EMBEDDED 629 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES 630 default y 631 help 632 This option allows to disable the internal PC-Speaker 633 support, saving some memory. 634 635config COMPAT_BRK 636 bool "Disable heap randomization" 637 default y 638 help 639 Randomizing heap placement makes heap exploits harder, but it 640 also breaks ancient binaries (including anything libc5 based). 641 This option changes the bootup default to heap randomization 642 disabled, and can be overriden runtime by setting 643 /proc/sys/kernel/randomize_va_space to 2. 644 645 On non-ancient distros (post-2000 ones) N is usually a safe choice. 646 647config BASE_FULL 648 default y 649 bool "Enable full-sized data structures for core" if EMBEDDED 650 help 651 Disabling this option reduces the size of miscellaneous core 652 kernel data structures. This saves memory on small machines, 653 but may reduce performance. 654 655config FUTEX 656 bool "Enable futex support" if EMBEDDED 657 default y 658 select RT_MUTEXES 659 help 660 Disabling this option will cause the kernel to be built without 661 support for "fast userspace mutexes". The resulting kernel may not 662 run glibc-based applications correctly. 663 664config ANON_INODES 665 bool 666 667config EPOLL 668 bool "Enable eventpoll support" if EMBEDDED 669 default y 670 select ANON_INODES 671 help 672 Disabling this option will cause the kernel to be built without 673 support for epoll family of system calls. 674 675config SIGNALFD 676 bool "Enable signalfd() system call" if EMBEDDED 677 select ANON_INODES 678 default y 679 help 680 Enable the signalfd() system call that allows to receive signals 681 on a file descriptor. 682 683 If unsure, say Y. 684 685config TIMERFD 686 bool "Enable timerfd() system call" if EMBEDDED 687 select ANON_INODES 688 default y 689 help 690 Enable the timerfd() system call that allows to receive timer 691 events on a file descriptor. 692 693 If unsure, say Y. 694 695config EVENTFD 696 bool "Enable eventfd() system call" if EMBEDDED 697 select ANON_INODES 698 default y 699 help 700 Enable the eventfd() system call that allows to receive both 701 kernel notification (ie. KAIO) or userspace notifications. 702 703 If unsure, say Y. 704 705config SHMEM 706 bool "Use full shmem filesystem" if EMBEDDED 707 default y 708 depends on MMU 709 help 710 The shmem is an internal filesystem used to manage shared memory. 711 It is backed by swap and manages resource limits. It is also exported 712 to userspace as tmpfs if TMPFS is enabled. Disabling this 713 option replaces shmem and tmpfs with the much simpler ramfs code, 714 which may be appropriate on small systems without swap. 715 716config VM_EVENT_COUNTERS 717 default y 718 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED 719 help 720 VM event counters are needed for event counts to be shown. 721 This option allows the disabling of the VM event counters 722 on EMBEDDED systems. /proc/vmstat will only show page counts 723 if VM event counters are disabled. 724 725config SLUB_DEBUG 726 default y 727 bool "Enable SLUB debugging support" if EMBEDDED 728 depends on SLUB && SYSFS 729 help 730 SLUB has extensive debug support features. Disabling these can 731 result in significant savings in code size. This also disables 732 SLUB sysfs support. /sys/slab will not exist and there will be 733 no support for cache validation etc. 734 735choice 736 prompt "Choose SLAB allocator" 737 default SLUB 738 help 739 This option allows to select a slab allocator. 740 741config SLAB 742 bool "SLAB" 743 help 744 The regular slab allocator that is established and known to work 745 well in all environments. It organizes cache hot objects in 746 per cpu and per node queues. SLAB is the default choice for 747 a slab allocator. 748 749config SLUB 750 bool "SLUB (Unqueued Allocator)" 751 help 752 SLUB is a slab allocator that minimizes cache line usage 753 instead of managing queues of cached objects (SLAB approach). 754 Per cpu caching is realized using slabs of objects instead 755 of queues of objects. SLUB can use memory efficiently 756 and has enhanced diagnostics. 757 758config SLOB 759 depends on EMBEDDED 760 bool "SLOB (Simple Allocator)" 761 help 762 SLOB replaces the stock allocator with a drastically simpler 763 allocator. SLOB is generally more space efficient but 764 does not perform as well on large systems. 765 766endchoice 767 768config PROFILING 769 bool "Profiling support (EXPERIMENTAL)" 770 help 771 Say Y here to enable the extended profiling support mechanisms used 772 by profilers such as OProfile. 773 774config MARKERS 775 bool "Activate markers" 776 help 777 Place an empty function call at each marker site. Can be 778 dynamically changed for a probe function. 779 780source "arch/Kconfig" 781 782config PROC_PAGE_MONITOR 783 default y 784 depends on PROC_FS && MMU 785 bool "Enable /proc page monitoring" if EMBEDDED 786 help 787 Various /proc files exist to monitor process memory utilization: 788 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap, 789 /proc/kpagecount, and /proc/kpageflags. Disabling these 790 interfaces will reduce the size of the kernel by approximately 4kb. 791 792endmenu # General setup 793 794config HAVE_GENERIC_DMA_COHERENT 795 bool 796 default n 797 798config SLABINFO 799 bool 800 depends on PROC_FS 801 depends on SLAB || SLUB_DEBUG 802 default y 803 804config RT_MUTEXES 805 boolean 806 select PLIST 807 808config TINY_SHMEM 809 default !SHMEM 810 bool 811 812config BASE_SMALL 813 int 814 default 0 if BASE_FULL 815 default 1 if !BASE_FULL 816 817menuconfig MODULES 818 bool "Enable loadable module support" 819 help 820 Kernel modules are small pieces of compiled code which can 821 be inserted in the running kernel, rather than being 822 permanently built into the kernel. You use the "modprobe" 823 tool to add (and sometimes remove) them. If you say Y here, 824 many parts of the kernel can be built as modules (by 825 answering M instead of Y where indicated): this is most 826 useful for infrequently used options which are not required 827 for booting. For more information, see the man pages for 828 modprobe, lsmod, modinfo, insmod and rmmod. 829 830 If you say Y here, you will need to run "make 831 modules_install" to put the modules under /lib/modules/ 832 where modprobe can find them (you may need to be root to do 833 this). 834 835 If unsure, say Y. 836 837if MODULES 838 839config MODULE_FORCE_LOAD 840 bool "Forced module loading" 841 default n 842 help 843 Allow loading of modules without version information (ie. modprobe 844 --force). Forced module loading sets the 'F' (forced) taint flag and 845 is usually a really bad idea. 846 847config MODULE_UNLOAD 848 bool "Module unloading" 849 help 850 Without this option you will not be able to unload any 851 modules (note that some modules may not be unloadable 852 anyway), which makes your kernel smaller, faster 853 and simpler. If unsure, say Y. 854 855config MODULE_FORCE_UNLOAD 856 bool "Forced module unloading" 857 depends on MODULE_UNLOAD && EXPERIMENTAL 858 help 859 This option allows you to force a module to unload, even if the 860 kernel believes it is unsafe: the kernel will remove the module 861 without waiting for anyone to stop using it (using the -f option to 862 rmmod). This is mainly for kernel developers and desperate users. 863 If unsure, say N. 864 865config MODVERSIONS 866 bool "Module versioning support" 867 help 868 Usually, you have to use modules compiled with your kernel. 869 Saying Y here makes it sometimes possible to use modules 870 compiled for different kernels, by adding enough information 871 to the modules to (hopefully) spot any changes which would 872 make them incompatible with the kernel you are running. If 873 unsure, say N. 874 875config MODULE_SRCVERSION_ALL 876 bool "Source checksum for all modules" 877 help 878 Modules which contain a MODULE_VERSION get an extra "srcversion" 879 field inserted into their modinfo section, which contains a 880 sum of the source files which made it. This helps maintainers 881 see exactly which source was used to build a module (since 882 others sometimes change the module source without updating 883 the version). With this option, such a "srcversion" field 884 will be created for all modules. If unsure, say N. 885 886config KMOD 887 def_bool y 888 help 889 This is being removed soon. These days, CONFIG_MODULES 890 implies CONFIG_KMOD, so use that instead. 891 892endif # MODULES 893 894config STOP_MACHINE 895 bool 896 default y 897 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU 898 help 899 Need stop_machine() primitive. 900 901source "block/Kconfig" 902 903config PREEMPT_NOTIFIERS 904 bool 905 906config CLASSIC_RCU 907 def_bool !PREEMPT_RCU 908 help 909 This option selects the classic RCU implementation that is 910 designed for best read-side performance on non-realtime 911 systems. Classic RCU is the default. Note that the 912 PREEMPT_RCU symbol is used to select/deselect this option. 913