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/$ARCH/defconfig" 17 18menu "General setup" 19 20config 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 These are 41 drivers that have been replaced by something else, and/or are 42 scheduled to be removed in a future kernel release. 43 44 Unless you intend to help test and develop a feature or driver that 45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 51config BROKEN 52 bool 53 54config BROKEN_ON_SMP 55 bool 56 depends on BROKEN || !SMP 57 default y 58 59config LOCK_KERNEL 60 bool 61 depends on SMP || PREEMPT 62 default y 63 64config 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 73config 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 83config 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 103config 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 113config 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 128config SYSVIPC_SYSCTL 129 bool 130 depends on SYSVIPC 131 depends on SYSCTL 132 default y 133 134config 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 150config 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 163config 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 175config 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 188config 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 199config 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 208config 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 217config 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 226config 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 236config AUDIT_TREE 237 def_bool y 238 depends on AUDITSYSCALL && INOTIFY 239 240config 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 252config 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 259config LOG_BUF_SHIFT 260 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" 261 range 12 21 262 default 17 if S390 || LOCKDEP 263 default 16 if X86_NUMAQ || IA64 264 default 15 if SMP 265 default 14 266 help 267 Select kernel log buffer size as a power of 2. 268 Defaults and Examples: 269 17 => 128 KB for S/390 270 16 => 64 KB for x86 NUMAQ or IA-64 271 15 => 32 KB for SMP 272 14 => 16 KB for uniprocessor 273 13 => 8 KB 274 12 => 4 KB 275 276config CGROUPS 277 bool "Control Group support" 278 help 279 This option will let you use process cgroup subsystems 280 such as Cpusets 281 282 Say N if unsure. 283 284config CGROUP_DEBUG 285 bool "Example debug cgroup subsystem" 286 depends on CGROUPS 287 help 288 This option enables a simple cgroup subsystem that 289 exports useful debugging information about the cgroups 290 framework 291 292 Say N if unsure 293 294config CGROUP_NS 295 bool "Namespace cgroup subsystem" 296 depends on CGROUPS 297 help 298 Provides a simple namespace cgroup subsystem to 299 provide hierarchical naming of sets of namespaces, 300 for instance virtual servers and checkpoint/restart 301 jobs. 302 303config CPUSETS 304 bool "Cpuset support" 305 depends on SMP && CGROUPS 306 help 307 This option will let you create and manage CPUSETs which 308 allow dynamically partitioning a system into sets of CPUs and 309 Memory Nodes and assigning tasks to run only within those sets. 310 This is primarily useful on large SMP or NUMA systems. 311 312 Say N if unsure. 313 314config GROUP_SCHED 315 bool "Group CPU scheduler" 316 default y 317 help 318 This feature lets CPU scheduler recognize task groups and control CPU 319 bandwidth allocation to such task groups. 320 321config FAIR_GROUP_SCHED 322 bool "Group scheduling for SCHED_OTHER" 323 depends on GROUP_SCHED 324 default y 325 326config RT_GROUP_SCHED 327 bool "Group scheduling for SCHED_RR/FIFO" 328 depends on EXPERIMENTAL 329 depends on GROUP_SCHED 330 default n 331 332choice 333 depends on GROUP_SCHED 334 prompt "Basis for grouping tasks" 335 default USER_SCHED 336 337config USER_SCHED 338 bool "user id" 339 help 340 This option will choose userid as the basis for grouping 341 tasks, thus providing equal CPU bandwidth to each user. 342 343config CGROUP_SCHED 344 bool "Control groups" 345 depends on CGROUPS 346 help 347 This option allows you to create arbitrary task groups 348 using the "cgroup" pseudo filesystem and control 349 the cpu bandwidth allocated to each such task group. 350 Refer to Documentation/cgroups.txt for more information 351 on "cgroup" pseudo filesystem. 352 353endchoice 354 355config CGROUP_CPUACCT 356 bool "Simple CPU accounting cgroup subsystem" 357 depends on CGROUPS 358 help 359 Provides a simple Resource Controller for monitoring the 360 total CPU consumed by the tasks in a cgroup 361 362config RESOURCE_COUNTERS 363 bool "Resource counters" 364 help 365 This option enables controller independent resource accounting 366 infrastructure that works with cgroups 367 depends on CGROUPS 368 369config CGROUP_MEM_RES_CTLR 370 bool "Memory Resource Controller for Control Groups" 371 depends on CGROUPS && RESOURCE_COUNTERS 372 help 373 Provides a memory resource controller that manages both page cache and 374 RSS memory. 375 376 Note that setting this option increases fixed memory overhead 377 associated with each page of memory in the system by 4/8 bytes 378 and also increases cache misses because struct page on many 64bit 379 systems will not fit into a single cache line anymore. 380 381 Only enable when you're ok with these trade offs and really 382 sure you need the memory resource controller. 383 384config SYSFS_DEPRECATED 385 bool 386 387config SYSFS_DEPRECATED_V2 388 bool "Create deprecated sysfs files" 389 depends on SYSFS 390 default y 391 select SYSFS_DEPRECATED 392 help 393 This option creates deprecated symlinks such as the 394 "device"-link, the <subsystem>:<name>-link, and the 395 "bus"-link. It may also add deprecated key in the 396 uevent environment. 397 None of these features or values should be used today, as 398 they export driver core implementation details to userspace 399 or export properties which can't be kept stable across kernel 400 releases. 401 402 If enabled, this option will also move any device structures 403 that belong to a class, back into the /sys/class hierarchy, in 404 order to support older versions of udev and some userspace 405 programs. 406 407 If you are using a distro with the most recent userspace 408 packages, it should be safe to say N here. 409 410config PROC_PID_CPUSET 411 bool "Include legacy /proc/<pid>/cpuset file" 412 depends on CPUSETS 413 default y 414 415config RELAY 416 bool "Kernel->user space relay support (formerly relayfs)" 417 help 418 This option enables support for relay interface support in 419 certain file systems (such as debugfs). 420 It is designed to provide an efficient mechanism for tools and 421 facilities to relay large amounts of data from kernel space to 422 user space. 423 424 If unsure, say N. 425 426config NAMESPACES 427 bool "Namespaces support" if EMBEDDED 428 default !EMBEDDED 429 help 430 Provides the way to make tasks work with different objects using 431 the same id. For example same IPC id may refer to different objects 432 or same user id or pid may refer to different tasks when used in 433 different namespaces. 434 435config UTS_NS 436 bool "UTS namespace" 437 depends on NAMESPACES 438 help 439 In this namespace tasks see different info provided with the 440 uname() system call 441 442config IPC_NS 443 bool "IPC namespace" 444 depends on NAMESPACES && SYSVIPC 445 help 446 In this namespace tasks work with IPC ids which correspond to 447 different IPC objects in different namespaces 448 449config USER_NS 450 bool "User namespace (EXPERIMENTAL)" 451 depends on NAMESPACES && EXPERIMENTAL 452 help 453 This allows containers, i.e. vservers, to use user namespaces 454 to provide different user info for different servers. 455 If unsure, say N. 456 457config PID_NS 458 bool "PID Namespaces (EXPERIMENTAL)" 459 default n 460 depends on NAMESPACES && EXPERIMENTAL 461 help 462 Suport process id namespaces. This allows having multiple 463 process with the same pid as long as they are in different 464 pid namespaces. This is a building block of containers. 465 466 Unless you want to work with an experimental feature 467 say N here. 468 469config BLK_DEV_INITRD 470 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" 471 depends on BROKEN || !FRV 472 help 473 The initial RAM filesystem is a ramfs which is loaded by the 474 boot loader (loadlin or lilo) and that is mounted as root 475 before the normal boot procedure. It is typically used to 476 load modules needed to mount the "real" root file system, 477 etc. See <file:Documentation/initrd.txt> for details. 478 479 If RAM disk support (BLK_DEV_RAM) is also included, this 480 also enables initial RAM disk (initrd) support and adds 481 15 Kbytes (more on some other architectures) to the kernel size. 482 483 If unsure say Y. 484 485if BLK_DEV_INITRD 486 487source "usr/Kconfig" 488 489endif 490 491config CC_OPTIMIZE_FOR_SIZE 492 bool "Optimize for size (Look out for broken compilers!)" 493 default y 494 depends on ARM || H8300 || SUPERH || EXPERIMENTAL 495 help 496 Enabling this option will pass "-Os" instead of "-O2" to gcc 497 resulting in a smaller kernel. 498 499 WARNING: some versions of gcc may generate incorrect code with this 500 option. If problems are observed, a gcc upgrade may be needed. 501 502 If unsure, say N. 503 504config SYSCTL 505 bool 506 507menuconfig EMBEDDED 508 bool "Configure standard kernel features (for small systems)" 509 help 510 This option allows certain base kernel options and settings 511 to be disabled or tweaked. This is for specialized 512 environments which can tolerate a "non-standard" kernel. 513 Only use this if you really know what you are doing. 514 515config UID16 516 bool "Enable 16-bit UID system calls" if EMBEDDED 517 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION) 518 default y 519 help 520 This enables the legacy 16-bit UID syscall wrappers. 521 522config SYSCTL_SYSCALL 523 bool "Sysctl syscall support" if EMBEDDED 524 default y 525 select SYSCTL 526 ---help--- 527 sys_sysctl uses binary paths that have been found challenging 528 to properly maintain and use. The interface in /proc/sys 529 using paths with ascii names is now the primary path to this 530 information. 531 532 Almost nothing using the binary sysctl interface so if you are 533 trying to save some space it is probably safe to disable this, 534 making your kernel marginally smaller. 535 536 If unsure say Y here. 537 538config KALLSYMS 539 bool "Load all symbols for debugging/ksymoops" if EMBEDDED 540 default y 541 help 542 Say Y here to let the kernel print out symbolic crash information and 543 symbolic stack backtraces. This increases the size of the kernel 544 somewhat, as all symbols have to be loaded into the kernel image. 545 546config KALLSYMS_ALL 547 bool "Include all symbols in kallsyms" 548 depends on DEBUG_KERNEL && KALLSYMS 549 help 550 Normally kallsyms only contains the symbols of functions, for nicer 551 OOPS messages. Some debuggers can use kallsyms for other 552 symbols too: say Y here to include all symbols, if you need them 553 and you don't care about adding 300k to the size of your kernel. 554 555 Say N. 556 557config KALLSYMS_EXTRA_PASS 558 bool "Do an extra kallsyms pass" 559 depends on KALLSYMS 560 help 561 If kallsyms is not working correctly, the build will fail with 562 inconsistent kallsyms data. If that occurs, log a bug report and 563 turn on KALLSYMS_EXTRA_PASS which should result in a stable build. 564 Always say N here unless you find a bug in kallsyms, which must be 565 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while 566 you wait for kallsyms to be fixed. 567 568 569config HOTPLUG 570 bool "Support for hot-pluggable devices" if EMBEDDED 571 default y 572 help 573 This option is provided for the case where no hotplug or uevent 574 capabilities is wanted by the kernel. You should only consider 575 disabling this option for embedded systems that do not use modules, a 576 dynamic /dev tree, or dynamic device discovery. Just say Y. 577 578config PRINTK 579 default y 580 bool "Enable support for printk" if EMBEDDED 581 help 582 This option enables normal printk support. Removing it 583 eliminates most of the message strings from the kernel image 584 and makes the kernel more or less silent. As this makes it 585 very difficult to diagnose system problems, saying N here is 586 strongly discouraged. 587 588config BUG 589 bool "BUG() support" if EMBEDDED 590 default y 591 help 592 Disabling this option eliminates support for BUG and WARN, reducing 593 the size of your kernel image and potentially quietly ignoring 594 numerous fatal conditions. You should only consider disabling this 595 option for embedded systems with no facilities for reporting errors. 596 Just say Y. 597 598config ELF_CORE 599 default y 600 bool "Enable ELF core dumps" if EMBEDDED 601 help 602 Enable support for generating core dumps. Disabling saves about 4k. 603 604config COMPAT_BRK 605 bool "Disable heap randomization" 606 default y 607 help 608 Randomizing heap placement makes heap exploits harder, but it 609 also breaks ancient binaries (including anything libc5 based). 610 This option changes the bootup default to heap randomization 611 disabled, and can be overriden runtime by setting 612 /proc/sys/kernel/randomize_va_space to 2. 613 614 On non-ancient distros (post-2000 ones) N is usually a safe choice. 615 616config BASE_FULL 617 default y 618 bool "Enable full-sized data structures for core" if EMBEDDED 619 help 620 Disabling this option reduces the size of miscellaneous core 621 kernel data structures. This saves memory on small machines, 622 but may reduce performance. 623 624config FUTEX 625 bool "Enable futex support" if EMBEDDED 626 default y 627 select RT_MUTEXES 628 help 629 Disabling this option will cause the kernel to be built without 630 support for "fast userspace mutexes". The resulting kernel may not 631 run glibc-based applications correctly. 632 633config ANON_INODES 634 bool 635 636config EPOLL 637 bool "Enable eventpoll support" if EMBEDDED 638 default y 639 select ANON_INODES 640 help 641 Disabling this option will cause the kernel to be built without 642 support for epoll family of system calls. 643 644config SIGNALFD 645 bool "Enable signalfd() system call" if EMBEDDED 646 select ANON_INODES 647 default y 648 help 649 Enable the signalfd() system call that allows to receive signals 650 on a file descriptor. 651 652 If unsure, say Y. 653 654config TIMERFD 655 bool "Enable timerfd() system call" if EMBEDDED 656 select ANON_INODES 657 default y 658 help 659 Enable the timerfd() system call that allows to receive timer 660 events on a file descriptor. 661 662 If unsure, say Y. 663 664config EVENTFD 665 bool "Enable eventfd() system call" if EMBEDDED 666 select ANON_INODES 667 default y 668 help 669 Enable the eventfd() system call that allows to receive both 670 kernel notification (ie. KAIO) or userspace notifications. 671 672 If unsure, say Y. 673 674config SHMEM 675 bool "Use full shmem filesystem" if EMBEDDED 676 default y 677 depends on MMU 678 help 679 The shmem is an internal filesystem used to manage shared memory. 680 It is backed by swap and manages resource limits. It is also exported 681 to userspace as tmpfs if TMPFS is enabled. Disabling this 682 option replaces shmem and tmpfs with the much simpler ramfs code, 683 which may be appropriate on small systems without swap. 684 685config VM_EVENT_COUNTERS 686 default y 687 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED 688 help 689 VM event counters are needed for event counts to be shown. 690 This option allows the disabling of the VM event counters 691 on EMBEDDED systems. /proc/vmstat will only show page counts 692 if VM event counters are disabled. 693 694config SLUB_DEBUG 695 default y 696 bool "Enable SLUB debugging support" if EMBEDDED 697 depends on SLUB 698 help 699 SLUB has extensive debug support features. Disabling these can 700 result in significant savings in code size. This also disables 701 SLUB sysfs support. /sys/slab will not exist and there will be 702 no support for cache validation etc. 703 704choice 705 prompt "Choose SLAB allocator" 706 default SLUB 707 help 708 This option allows to select a slab allocator. 709 710config SLAB 711 bool "SLAB" 712 help 713 The regular slab allocator that is established and known to work 714 well in all environments. It organizes cache hot objects in 715 per cpu and per node queues. SLAB is the default choice for 716 a slab allocator. 717 718config SLUB 719 bool "SLUB (Unqueued Allocator)" 720 help 721 SLUB is a slab allocator that minimizes cache line usage 722 instead of managing queues of cached objects (SLAB approach). 723 Per cpu caching is realized using slabs of objects instead 724 of queues of objects. SLUB can use memory efficiently 725 and has enhanced diagnostics. 726 727config SLOB 728 depends on EMBEDDED 729 bool "SLOB (Simple Allocator)" 730 help 731 SLOB replaces the stock allocator with a drastically simpler 732 allocator. SLOB is generally more space efficient but 733 does not perform as well on large systems. 734 735endchoice 736 737config PROFILING 738 bool "Profiling support (EXPERIMENTAL)" 739 help 740 Say Y here to enable the extended profiling support mechanisms used 741 by profilers such as OProfile. 742 743config MARKERS 744 bool "Activate markers" 745 help 746 Place an empty function call at each marker site. Can be 747 dynamically changed for a probe function. 748 749source "arch/Kconfig" 750 751config PROC_PAGE_MONITOR 752 default y 753 depends on PROC_FS && MMU 754 bool "Enable /proc page monitoring" if EMBEDDED 755 help 756 Various /proc files exist to monitor process memory utilization: 757 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap, 758 /proc/kpagecount, and /proc/kpageflags. Disabling these 759 interfaces will reduce the size of the kernel by approximately 4kb. 760 761endmenu # General setup 762 763config SLABINFO 764 bool 765 depends on PROC_FS 766 depends on SLAB || SLUB 767 default y 768 769config RT_MUTEXES 770 boolean 771 select PLIST 772 773config TINY_SHMEM 774 default !SHMEM 775 bool 776 777config BASE_SMALL 778 int 779 default 0 if BASE_FULL 780 default 1 if !BASE_FULL 781 782menuconfig MODULES 783 bool "Enable loadable module support" 784 help 785 Kernel modules are small pieces of compiled code which can 786 be inserted in the running kernel, rather than being 787 permanently built into the kernel. You use the "modprobe" 788 tool to add (and sometimes remove) them. If you say Y here, 789 many parts of the kernel can be built as modules (by 790 answering M instead of Y where indicated): this is most 791 useful for infrequently used options which are not required 792 for booting. For more information, see the man pages for 793 modprobe, lsmod, modinfo, insmod and rmmod. 794 795 If you say Y here, you will need to run "make 796 modules_install" to put the modules under /lib/modules/ 797 where modprobe can find them (you may need to be root to do 798 this). 799 800 If unsure, say Y. 801 802config MODULE_UNLOAD 803 bool "Module unloading" 804 depends on MODULES 805 help 806 Without this option you will not be able to unload any 807 modules (note that some modules may not be unloadable 808 anyway), which makes your kernel slightly smaller and 809 simpler. If unsure, say Y. 810 811config MODULE_FORCE_UNLOAD 812 bool "Forced module unloading" 813 depends on MODULE_UNLOAD && EXPERIMENTAL 814 help 815 This option allows you to force a module to unload, even if the 816 kernel believes it is unsafe: the kernel will remove the module 817 without waiting for anyone to stop using it (using the -f option to 818 rmmod). This is mainly for kernel developers and desperate users. 819 If unsure, say N. 820 821config MODVERSIONS 822 bool "Module versioning support" 823 depends on MODULES 824 help 825 Usually, you have to use modules compiled with your kernel. 826 Saying Y here makes it sometimes possible to use modules 827 compiled for different kernels, by adding enough information 828 to the modules to (hopefully) spot any changes which would 829 make them incompatible with the kernel you are running. If 830 unsure, say N. 831 832config MODULE_SRCVERSION_ALL 833 bool "Source checksum for all modules" 834 depends on MODULES 835 help 836 Modules which contain a MODULE_VERSION get an extra "srcversion" 837 field inserted into their modinfo section, which contains a 838 sum of the source files which made it. This helps maintainers 839 see exactly which source was used to build a module (since 840 others sometimes change the module source without updating 841 the version). With this option, such a "srcversion" field 842 will be created for all modules. If unsure, say N. 843 844config KMOD 845 bool "Automatic kernel module loading" 846 depends on MODULES 847 help 848 Normally when you have selected some parts of the kernel to 849 be created as kernel modules, you must load them (using the 850 "modprobe" command) before you can use them. If you say Y 851 here, some parts of the kernel will be able to load modules 852 automatically: when a part of the kernel needs a module, it 853 runs modprobe with the appropriate arguments, thereby 854 loading the module if it is available. If unsure, say Y. 855 856config STOP_MACHINE 857 bool 858 default y 859 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU 860 help 861 Need stop_machine() primitive. 862 863source "block/Kconfig" 864 865config PREEMPT_NOTIFIERS 866 bool 867 868config CLASSIC_RCU 869 def_bool !PREEMPT_RCU 870 help 871 This option selects the classic RCU implementation that is 872 designed for best read-side performance on non-realtime 873 systems. Classic RCU is the default. Note that the 874 PREEMPT_RCU symbol is used to select/deselect this option. 875