180daa560SRoman Zippelconfig ARCH 280daa560SRoman Zippel string 380daa560SRoman Zippel option env="ARCH" 480daa560SRoman Zippel 580daa560SRoman Zippelconfig KERNELVERSION 680daa560SRoman Zippel string 780daa560SRoman Zippel option env="KERNELVERSION" 880daa560SRoman Zippel 9face4374SRoman Zippelconfig DEFCONFIG_LIST 10face4374SRoman Zippel string 11b2670eacSPaolo 'Blaisorblade' Giarrusso depends on !UML 12face4374SRoman Zippel option defconfig_list 13face4374SRoman Zippel default "/lib/modules/$UNAME_RELEASE/.config" 14face4374SRoman Zippel default "/etc/kernel-config" 15face4374SRoman Zippel default "/boot/config-$UNAME_RELEASE" 16face4374SRoman Zippel default "arch/$ARCH/defconfig" 17face4374SRoman Zippel 18ff0cfc66SAl Boldimenu "General setup" 191da177e4SLinus Torvalds 201da177e4SLinus Torvaldsconfig EXPERIMENTAL 211da177e4SLinus Torvalds bool "Prompt for development and/or incomplete code/drivers" 221da177e4SLinus Torvalds ---help--- 231da177e4SLinus Torvalds Some of the various things that Linux supports (such as network 241da177e4SLinus Torvalds drivers, file systems, network protocols, etc.) can be in a state 251da177e4SLinus Torvalds of development where the functionality, stability, or the level of 261da177e4SLinus Torvalds testing is not yet high enough for general use. This is usually 271da177e4SLinus Torvalds known as the "alpha-test" phase among developers. If a feature is 281da177e4SLinus Torvalds currently in alpha-test, then the developers usually discourage 291da177e4SLinus Torvalds uninformed widespread use of this feature by the general public to 301da177e4SLinus Torvalds avoid "Why doesn't this work?" type mail messages. However, active 311da177e4SLinus Torvalds testing and use of these systems is welcomed. Just be aware that it 321da177e4SLinus Torvalds may not meet the normal level of reliability or it may fail to work 331da177e4SLinus Torvalds in some special cases. Detailed bug reports from people familiar 341da177e4SLinus Torvalds with the kernel internals are usually welcomed by the developers 351da177e4SLinus Torvalds (before submitting bug reports, please read the documents 361da177e4SLinus Torvalds <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, 371da177e4SLinus Torvalds <file:Documentation/BUG-HUNTING>, and 381da177e4SLinus Torvalds <file:Documentation/oops-tracing.txt> in the kernel source). 391da177e4SLinus Torvalds 401da177e4SLinus Torvalds This option will also make obsoleted drivers available. These are 411da177e4SLinus Torvalds drivers that have been replaced by something else, and/or are 421da177e4SLinus Torvalds scheduled to be removed in a future kernel release. 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds Unless you intend to help test and develop a feature or driver that 451da177e4SLinus Torvalds falls into this category, or you have a situation that requires 461da177e4SLinus Torvalds using these features, you should probably say N here, which will 471da177e4SLinus Torvalds cause the configurator to present you with fewer choices. If 481da177e4SLinus Torvalds you say Y here, you will be offered the choice of using features or 491da177e4SLinus Torvalds drivers that are currently considered to be in the alpha-test phase. 501da177e4SLinus Torvalds 511da177e4SLinus Torvaldsconfig BROKEN 521da177e4SLinus Torvalds bool 531da177e4SLinus Torvalds 541da177e4SLinus Torvaldsconfig BROKEN_ON_SMP 551da177e4SLinus Torvalds bool 561da177e4SLinus Torvalds depends on BROKEN || !SMP 571da177e4SLinus Torvalds default y 581da177e4SLinus Torvalds 591da177e4SLinus Torvaldsconfig LOCK_KERNEL 601da177e4SLinus Torvalds bool 611da177e4SLinus Torvalds depends on SMP || PREEMPT 621da177e4SLinus Torvalds default y 631da177e4SLinus Torvalds 641da177e4SLinus Torvaldsconfig INIT_ENV_ARG_LIMIT 651da177e4SLinus Torvalds int 66dd673bcaSAdrian Bunk default 32 if !UML 67dd673bcaSAdrian Bunk default 128 if UML 681da177e4SLinus Torvalds help 6934ad92c2SRandy Dunlap Maximum of each of the number of arguments and environment 7034ad92c2SRandy Dunlap variables passed to init from the kernel command line. 711da177e4SLinus Torvalds 721da177e4SLinus Torvalds 731da177e4SLinus Torvaldsconfig LOCALVERSION 741da177e4SLinus Torvalds string "Local version - append to kernel release" 751da177e4SLinus Torvalds help 761da177e4SLinus Torvalds Append an extra string to the end of your kernel version. 771da177e4SLinus Torvalds This will show up when you type uname, for example. 781da177e4SLinus Torvalds The string you set here will be appended after the contents of 791da177e4SLinus Torvalds any files with a filename matching localversion* in your 801da177e4SLinus Torvalds object and source tree, in that order. Your total string can 811da177e4SLinus Torvalds be a maximum of 64 characters. 821da177e4SLinus Torvalds 83aaebf433SRyan Andersonconfig LOCALVERSION_AUTO 84aaebf433SRyan Anderson bool "Automatically append version information to the version string" 85aaebf433SRyan Anderson default y 86aaebf433SRyan Anderson help 87aaebf433SRyan Anderson This will try to automatically determine if the current tree is a 886e5a5420SRobert P. J. Day release tree by looking for git tags that belong to the current 896e5a5420SRobert P. J. Day top of tree revision. 90aaebf433SRyan Anderson 91aaebf433SRyan Anderson A string of the format -gxxxxxxxx will be added to the localversion 926e5a5420SRobert P. J. Day if a git-based tree is found. The string generated by this will be 93aaebf433SRyan Anderson appended after any matching localversion* files, and after the value 946e5a5420SRobert P. J. Day set in CONFIG_LOCALVERSION. 95aaebf433SRyan Anderson 966e5a5420SRobert P. J. Day (The actual string used here is the first eight characters produced 976e5a5420SRobert P. J. Day by running the command: 986e5a5420SRobert P. J. Day 996e5a5420SRobert P. J. Day $ git rev-parse --verify HEAD 1006e5a5420SRobert P. J. Day 1016e5a5420SRobert P. J. Day which is done within the script "scripts/setlocalversion".) 102aaebf433SRyan Anderson 1031da177e4SLinus Torvaldsconfig SWAP 1041da177e4SLinus Torvalds bool "Support for paging of anonymous memory (swap)" 1059361401eSDavid Howells depends on MMU && BLOCK 1061da177e4SLinus Torvalds default y 1071da177e4SLinus Torvalds help 1081da177e4SLinus Torvalds This option allows you to choose whether you want to have support 1091da177e4SLinus Torvalds for so called swap devices or swap files in your kernel that are 1101da177e4SLinus Torvalds used to provide more virtual memory than the actual RAM present 1111da177e4SLinus Torvalds in your computer. If unsure say Y. 1121da177e4SLinus Torvalds 1131da177e4SLinus Torvaldsconfig SYSVIPC 1141da177e4SLinus Torvalds bool "System V IPC" 1151da177e4SLinus Torvalds ---help--- 1161da177e4SLinus Torvalds Inter Process Communication is a suite of library functions and 1171da177e4SLinus Torvalds system calls which let processes (running programs) synchronize and 1181da177e4SLinus Torvalds exchange information. It is generally considered to be a good thing, 1191da177e4SLinus Torvalds and some programs won't run unless you say Y here. In particular, if 1201da177e4SLinus Torvalds you want to run the DOS emulator dosemu under Linux (read the 1211da177e4SLinus Torvalds DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), 1221da177e4SLinus Torvalds you'll need to say Y here. 1231da177e4SLinus Torvalds 1241da177e4SLinus Torvalds You can find documentation about IPC with "info ipc" and also in 1251da177e4SLinus Torvalds section 6.4 of the Linux Programmer's Guide, available from 1261da177e4SLinus Torvalds <http://www.tldp.org/guides.html>. 1271da177e4SLinus Torvalds 128a5494dcdSEric W. Biedermanconfig SYSVIPC_SYSCTL 129a5494dcdSEric W. Biederman bool 130a5494dcdSEric W. Biederman depends on SYSVIPC 131a5494dcdSEric W. Biederman depends on SYSCTL 132a5494dcdSEric W. Biederman default y 133a5494dcdSEric W. Biederman 1341da177e4SLinus Torvaldsconfig POSIX_MQUEUE 1351da177e4SLinus Torvalds bool "POSIX Message Queues" 1361da177e4SLinus Torvalds depends on NET && EXPERIMENTAL 1371da177e4SLinus Torvalds ---help--- 1381da177e4SLinus Torvalds POSIX variant of message queues is a part of IPC. In POSIX message 1391da177e4SLinus Torvalds queues every message has a priority which decides about succession 1401da177e4SLinus Torvalds of receiving it by a process. If you want to compile and run 1411da177e4SLinus Torvalds programs written e.g. for Solaris with use of its POSIX message 142b0e37650SRobert P. J. Day queues (functions mq_*) say Y here. 1431da177e4SLinus Torvalds 1441da177e4SLinus Torvalds POSIX message queues are visible as a filesystem called 'mqueue' 1451da177e4SLinus Torvalds and can be mounted somewhere if you want to do filesystem 1461da177e4SLinus Torvalds operations on message queues. 1471da177e4SLinus Torvalds 1481da177e4SLinus Torvalds If unsure, say Y. 1491da177e4SLinus Torvalds 1501da177e4SLinus Torvaldsconfig BSD_PROCESS_ACCT 1511da177e4SLinus Torvalds bool "BSD Process Accounting" 1521da177e4SLinus Torvalds help 1531da177e4SLinus Torvalds If you say Y here, a user level program will be able to instruct the 1541da177e4SLinus Torvalds kernel (via a special system call) to write process accounting 1551da177e4SLinus Torvalds information to a file: whenever a process exits, information about 1561da177e4SLinus Torvalds that process will be appended to the file by the kernel. The 1571da177e4SLinus Torvalds information includes things such as creation time, owning user, 1581da177e4SLinus Torvalds command name, memory usage, controlling terminal etc. (the complete 1591da177e4SLinus Torvalds list is in the struct acct in <file:include/linux/acct.h>). It is 1601da177e4SLinus Torvalds up to the user level program to do useful things with this 1611da177e4SLinus Torvalds information. This is generally a good idea, so say Y. 1621da177e4SLinus Torvalds 1631da177e4SLinus Torvaldsconfig BSD_PROCESS_ACCT_V3 1641da177e4SLinus Torvalds bool "BSD Process Accounting version 3 file format" 1651da177e4SLinus Torvalds depends on BSD_PROCESS_ACCT 1661da177e4SLinus Torvalds default n 1671da177e4SLinus Torvalds help 1681da177e4SLinus Torvalds If you say Y here, the process accounting information is written 1691da177e4SLinus Torvalds in a new file format that also logs the process IDs of each 1701da177e4SLinus Torvalds process and it's parent. Note that this file format is incompatible 1711da177e4SLinus Torvalds with previous v0/v1/v2 file formats, so you will need updated tools 1721da177e4SLinus Torvalds for processing it. A preliminary version of these tools is available 1731da177e4SLinus Torvalds at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>. 1741da177e4SLinus Torvalds 175c757249aSShailabh Nagarconfig TASKSTATS 176c757249aSShailabh Nagar bool "Export task/process statistics through netlink (EXPERIMENTAL)" 177c757249aSShailabh Nagar depends on NET 178c757249aSShailabh Nagar default n 179c757249aSShailabh Nagar help 180c757249aSShailabh Nagar Export selected statistics for tasks/processes through the 181c757249aSShailabh Nagar generic netlink interface. Unlike BSD process accounting, the 182c757249aSShailabh Nagar statistics are available during the lifetime of tasks/processes as 183c757249aSShailabh Nagar responses to commands. Like BSD accounting, they are sent to user 184c757249aSShailabh Nagar space on task exit. 185c757249aSShailabh Nagar 186c757249aSShailabh Nagar Say N if unsure. 187c757249aSShailabh Nagar 188ca74e92bSShailabh Nagarconfig TASK_DELAY_ACCT 189ca74e92bSShailabh Nagar bool "Enable per-task delay accounting (EXPERIMENTAL)" 1906f44993fSShailabh Nagar depends on TASKSTATS 191ca74e92bSShailabh Nagar help 192ca74e92bSShailabh Nagar Collect information on time spent by a task waiting for system 193ca74e92bSShailabh Nagar resources like cpu, synchronous block I/O completion and swapping 194ca74e92bSShailabh Nagar in pages. Such statistics can help in setting a task's priorities 195ca74e92bSShailabh Nagar relative to other tasks for cpu, io, rss limits etc. 196ca74e92bSShailabh Nagar 197ca74e92bSShailabh Nagar Say N if unsure. 198ca74e92bSShailabh Nagar 19918f705f4SAlexey Dobriyanconfig TASK_XACCT 20018f705f4SAlexey Dobriyan bool "Enable extended accounting over taskstats (EXPERIMENTAL)" 20118f705f4SAlexey Dobriyan depends on TASKSTATS 20218f705f4SAlexey Dobriyan help 20318f705f4SAlexey Dobriyan Collect extended task accounting data and send the data 20418f705f4SAlexey Dobriyan to userland for processing over the taskstats interface. 20518f705f4SAlexey Dobriyan 20618f705f4SAlexey Dobriyan Say N if unsure. 20718f705f4SAlexey Dobriyan 20818f705f4SAlexey Dobriyanconfig TASK_IO_ACCOUNTING 20918f705f4SAlexey Dobriyan bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" 21018f705f4SAlexey Dobriyan depends on TASK_XACCT 21118f705f4SAlexey Dobriyan help 21218f705f4SAlexey Dobriyan Collect information on the number of bytes of storage I/O which this 21318f705f4SAlexey Dobriyan task has caused. 21418f705f4SAlexey Dobriyan 21518f705f4SAlexey Dobriyan Say N if unsure. 21618f705f4SAlexey Dobriyan 2171da177e4SLinus Torvaldsconfig AUDIT 2181da177e4SLinus Torvalds bool "Auditing support" 219804a6a49SChris Wright depends on NET 2201da177e4SLinus Torvalds help 2211da177e4SLinus Torvalds Enable auditing infrastructure that can be used with another 2221da177e4SLinus Torvalds kernel subsystem, such as SELinux (which requires this for 2231da177e4SLinus Torvalds logging of avc messages output). Does not do system-call 2241da177e4SLinus Torvalds auditing without CONFIG_AUDITSYSCALL. 2251da177e4SLinus Torvalds 2261da177e4SLinus Torvaldsconfig AUDITSYSCALL 2271da177e4SLinus Torvalds bool "Enable system-call auditing support" 2281322b9deSYuichi Nakamura depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH) 2291da177e4SLinus Torvalds default y if SECURITY_SELINUX 2301da177e4SLinus Torvalds help 2311da177e4SLinus Torvalds Enable low-overhead system-call auditing infrastructure that 2321da177e4SLinus Torvalds can be used independently or with another kernel subsystem, 233f368c07dSAmy Griffis such as SELinux. To use audit's filesystem watch feature, please 234f368c07dSAmy Griffis ensure that INOTIFY is configured. 2351da177e4SLinus Torvalds 23674c3cbe3SAl Viroconfig AUDIT_TREE 23774c3cbe3SAl Viro def_bool y 23874c3cbe3SAl Viro depends on AUDITSYSCALL && INOTIFY 23974c3cbe3SAl Viro 2401da177e4SLinus Torvaldsconfig IKCONFIG 241f2443ab6SRoss Biro tristate "Kernel .config support" 2421da177e4SLinus Torvalds ---help--- 2431da177e4SLinus Torvalds This option enables the complete Linux kernel ".config" file 2441da177e4SLinus Torvalds contents to be saved in the kernel. It provides documentation 2451da177e4SLinus Torvalds of which kernel options are used in a running kernel or in an 2461da177e4SLinus Torvalds on-disk kernel. This information can be extracted from the kernel 2471da177e4SLinus Torvalds image file with the script scripts/extract-ikconfig and used as 2481da177e4SLinus Torvalds input to rebuild the current kernel or to build another kernel. 2491da177e4SLinus Torvalds It can also be extracted from a running kernel by reading 2501da177e4SLinus Torvalds /proc/config.gz if enabled (below). 2511da177e4SLinus Torvalds 2521da177e4SLinus Torvaldsconfig IKCONFIG_PROC 2531da177e4SLinus Torvalds bool "Enable access to .config through /proc/config.gz" 2541da177e4SLinus Torvalds depends on IKCONFIG && PROC_FS 2551da177e4SLinus Torvalds ---help--- 2561da177e4SLinus Torvalds This option enables access to the kernel configuration file 2571da177e4SLinus Torvalds through /proc/config.gz. 2581da177e4SLinus Torvalds 259794543a2SAlistair John Strachanconfig LOG_BUF_SHIFT 260794543a2SAlistair John Strachan int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" 261794543a2SAlistair John Strachan range 12 21 262f17a32e9SAdrian Bunk default 17 263794543a2SAlistair John Strachan help 264794543a2SAlistair John Strachan Select kernel log buffer size as a power of 2. 265f17a32e9SAdrian Bunk Examples: 266f17a32e9SAdrian Bunk 17 => 128 KB 267f17a32e9SAdrian Bunk 16 => 64 KB 268f17a32e9SAdrian Bunk 15 => 32 KB 269f17a32e9SAdrian Bunk 14 => 16 KB 270794543a2SAlistair John Strachan 13 => 8 KB 271794543a2SAlistair John Strachan 12 => 4 KB 272794543a2SAlistair John Strachan 273ddbcc7e8SPaul Menageconfig CGROUPS 274ddbcc7e8SPaul Menage bool "Control Group support" 275ddbcc7e8SPaul Menage help 276ddbcc7e8SPaul Menage This option will let you use process cgroup subsystems 277ddbcc7e8SPaul Menage such as Cpusets 278ddbcc7e8SPaul Menage 279ddbcc7e8SPaul Menage Say N if unsure. 280ddbcc7e8SPaul Menage 281006cb992SPaul Menageconfig CGROUP_DEBUG 282006cb992SPaul Menage bool "Example debug cgroup subsystem" 283006cb992SPaul Menage depends on CGROUPS 284418d7d87SPaul Menage default n 285006cb992SPaul Menage help 286006cb992SPaul Menage This option enables a simple cgroup subsystem that 287006cb992SPaul Menage exports useful debugging information about the cgroups 288006cb992SPaul Menage framework 289006cb992SPaul Menage 290006cb992SPaul Menage Say N if unsure 291006cb992SPaul Menage 292858d72eaSSerge E. Hallynconfig CGROUP_NS 293858d72eaSSerge E. Hallyn bool "Namespace cgroup subsystem" 294858d72eaSSerge E. Hallyn depends on CGROUPS 295858d72eaSSerge E. Hallyn help 296858d72eaSSerge E. Hallyn Provides a simple namespace cgroup subsystem to 297858d72eaSSerge E. Hallyn provide hierarchical naming of sets of namespaces, 298858d72eaSSerge E. Hallyn for instance virtual servers and checkpoint/restart 299858d72eaSSerge E. Hallyn jobs. 300858d72eaSSerge E. Hallyn 30108ce5f16SSerge E. Hallynconfig CGROUP_DEVICE 30208ce5f16SSerge E. Hallyn bool "Device controller for cgroups" 30308ce5f16SSerge E. Hallyn depends on CGROUPS && EXPERIMENTAL 30408ce5f16SSerge E. Hallyn help 30508ce5f16SSerge E. Hallyn Provides a cgroup implementing whitelists for devices which 30608ce5f16SSerge E. Hallyn a process in the cgroup can mknod or open. 30708ce5f16SSerge E. Hallyn 3081da177e4SLinus Torvaldsconfig CPUSETS 3091da177e4SLinus Torvalds bool "Cpuset support" 3108793d854SPaul Menage depends on SMP && CGROUPS 3111da177e4SLinus Torvalds help 312d9fd8a6dSRandy Dunlap This option will let you create and manage CPUSETs which 3131da177e4SLinus Torvalds allow dynamically partitioning a system into sets of CPUs and 3141da177e4SLinus Torvalds Memory Nodes and assigning tasks to run only within those sets. 3151da177e4SLinus Torvalds This is primarily useful on large SMP or NUMA systems. 3161da177e4SLinus Torvalds 3171da177e4SLinus Torvalds Say N if unsure. 3181da177e4SLinus Torvalds 319052f1dc7SPeter Zijlstraconfig GROUP_SCHED 320052f1dc7SPeter Zijlstra bool "Group CPU scheduler" 321de8d585aSIngo Molnar default y 32229f59db3SSrivatsa Vaddagiri help 323fb615581SSrivatsa Vaddagiri This feature lets CPU scheduler recognize task groups and control CPU 3249b5b7751SSrivatsa Vaddagiri bandwidth allocation to such task groups. 32529f59db3SSrivatsa Vaddagiri 326052f1dc7SPeter Zijlstraconfig FAIR_GROUP_SCHED 327052f1dc7SPeter Zijlstra bool "Group scheduling for SCHED_OTHER" 328052f1dc7SPeter Zijlstra depends on GROUP_SCHED 329052f1dc7SPeter Zijlstra default y 33024e377a8SSrivatsa Vaddagiri 331052f1dc7SPeter Zijlstraconfig RT_GROUP_SCHED 332052f1dc7SPeter Zijlstra bool "Group scheduling for SCHED_RR/FIFO" 333052f1dc7SPeter Zijlstra depends on EXPERIMENTAL 334052f1dc7SPeter Zijlstra depends on GROUP_SCHED 335052f1dc7SPeter Zijlstra default n 336b9b158feSViktor Radnai help 337b9b158feSViktor Radnai This feature lets you explicitly allocate real CPU bandwidth 338b9b158feSViktor Radnai to users or control groups (depending on the "Basis for grouping tasks" 339b9b158feSViktor Radnai setting below. If enabled, it will also make it impossible to 340b9b158feSViktor Radnai schedule realtime tasks for non-root users until you allocate 341b9b158feSViktor Radnai realtime bandwidth for them. 342b9b158feSViktor Radnai See Documentation/sched-rt-group.txt for more information. 343052f1dc7SPeter Zijlstra 344052f1dc7SPeter Zijlstrachoice 345052f1dc7SPeter Zijlstra depends on GROUP_SCHED 346052f1dc7SPeter Zijlstra prompt "Basis for grouping tasks" 347052f1dc7SPeter Zijlstra default USER_SCHED 348052f1dc7SPeter Zijlstra 349052f1dc7SPeter Zijlstraconfig USER_SCHED 35024e377a8SSrivatsa Vaddagiri bool "user id" 35124e377a8SSrivatsa Vaddagiri help 35224e377a8SSrivatsa Vaddagiri This option will choose userid as the basis for grouping 353fb615581SSrivatsa Vaddagiri tasks, thus providing equal CPU bandwidth to each user. 35424e377a8SSrivatsa Vaddagiri 355052f1dc7SPeter Zijlstraconfig CGROUP_SCHED 35668318b8eSSrivatsa Vaddagiri bool "Control groups" 35768318b8eSSrivatsa Vaddagiri depends on CGROUPS 35868318b8eSSrivatsa Vaddagiri help 35968318b8eSSrivatsa Vaddagiri This option allows you to create arbitrary task groups 36068318b8eSSrivatsa Vaddagiri using the "cgroup" pseudo filesystem and control 36168318b8eSSrivatsa Vaddagiri the cpu bandwidth allocated to each such task group. 36268318b8eSSrivatsa Vaddagiri Refer to Documentation/cgroups.txt for more information 36368318b8eSSrivatsa Vaddagiri on "cgroup" pseudo filesystem. 36468318b8eSSrivatsa Vaddagiri 36524e377a8SSrivatsa Vaddagiriendchoice 36624e377a8SSrivatsa Vaddagiri 367d842de87SSrivatsa Vaddagiriconfig CGROUP_CPUACCT 368d842de87SSrivatsa Vaddagiri bool "Simple CPU accounting cgroup subsystem" 369d842de87SSrivatsa Vaddagiri depends on CGROUPS 370d842de87SSrivatsa Vaddagiri help 371d842de87SSrivatsa Vaddagiri Provides a simple Resource Controller for monitoring the 372d842de87SSrivatsa Vaddagiri total CPU consumed by the tasks in a cgroup 373d842de87SSrivatsa Vaddagiri 374e552b661SPavel Emelianovconfig RESOURCE_COUNTERS 375e552b661SPavel Emelianov bool "Resource counters" 376e552b661SPavel Emelianov help 377e552b661SPavel Emelianov This option enables controller independent resource accounting 378e552b661SPavel Emelianov infrastructure that works with cgroups 379e552b661SPavel Emelianov depends on CGROUPS 380e552b661SPavel Emelianov 381cf475ad2SBalbir Singhconfig MM_OWNER 382cf475ad2SBalbir Singh bool 383cf475ad2SBalbir Singh 38400f0b825SBalbir Singhconfig CGROUP_MEM_RES_CTLR 38500f0b825SBalbir Singh bool "Memory Resource Controller for Control Groups" 38600f0b825SBalbir Singh depends on CGROUPS && RESOURCE_COUNTERS 387cf475ad2SBalbir Singh select MM_OWNER 38800f0b825SBalbir Singh help 38900f0b825SBalbir Singh Provides a memory resource controller that manages both page cache and 39000f0b825SBalbir Singh RSS memory. 39100f0b825SBalbir Singh 39200f0b825SBalbir Singh Note that setting this option increases fixed memory overhead 39300f0b825SBalbir Singh associated with each page of memory in the system by 4/8 bytes 39400f0b825SBalbir Singh and also increases cache misses because struct page on many 64bit 39500f0b825SBalbir Singh systems will not fit into a single cache line anymore. 39600f0b825SBalbir Singh 39700f0b825SBalbir Singh Only enable when you're ok with these trade offs and really 39800f0b825SBalbir Singh sure you need the memory resource controller. 39900f0b825SBalbir Singh 400cf475ad2SBalbir Singh This config option also selects MM_OWNER config option, which 401cf475ad2SBalbir Singh could in turn add some fork/exit overhead. 402cf475ad2SBalbir Singh 40388a22c98SKay Sieversconfig SYSFS_DEPRECATED 404d47846c5SIngo Molnar bool 405d47846c5SIngo Molnar 406d47846c5SIngo Molnarconfig SYSFS_DEPRECATED_V2 40788a22c98SKay Sievers bool "Create deprecated sysfs files" 4089148fe87SRandy Dunlap depends on SYSFS 40988a22c98SKay Sievers default y 410d47846c5SIngo Molnar select SYSFS_DEPRECATED 41188a22c98SKay Sievers help 41288a22c98SKay Sievers This option creates deprecated symlinks such as the 41388a22c98SKay Sievers "device"-link, the <subsystem>:<name>-link, and the 41488a22c98SKay Sievers "bus"-link. It may also add deprecated key in the 41588a22c98SKay Sievers uevent environment. 41688a22c98SKay Sievers None of these features or values should be used today, as 41788a22c98SKay Sievers they export driver core implementation details to userspace 41888a22c98SKay Sievers or export properties which can't be kept stable across kernel 41988a22c98SKay Sievers releases. 42088a22c98SKay Sievers 42188a22c98SKay Sievers If enabled, this option will also move any device structures 4223dde6ad8SDavid Sterba that belong to a class, back into the /sys/class hierarchy, in 423024440d2SGreg Kroah-Hartman order to support older versions of udev and some userspace 424024440d2SGreg Kroah-Hartman programs. 42588a22c98SKay Sievers 426024440d2SGreg Kroah-Hartman If you are using a distro with the most recent userspace 427024440d2SGreg Kroah-Hartman packages, it should be safe to say N here. 42888a22c98SKay Sievers 4298793d854SPaul Menageconfig PROC_PID_CPUSET 4308793d854SPaul Menage bool "Include legacy /proc/<pid>/cpuset file" 4318793d854SPaul Menage depends on CPUSETS 4328793d854SPaul Menage default y 4338793d854SPaul Menage 434b86ff981SJens Axboeconfig RELAY 435b86ff981SJens Axboe bool "Kernel->user space relay support (formerly relayfs)" 436b86ff981SJens Axboe help 437b86ff981SJens Axboe This option enables support for relay interface support in 438b86ff981SJens Axboe certain file systems (such as debugfs). 439b86ff981SJens Axboe It is designed to provide an efficient mechanism for tools and 440b86ff981SJens Axboe facilities to relay large amounts of data from kernel space to 441b86ff981SJens Axboe user space. 442b86ff981SJens Axboe 443b86ff981SJens Axboe If unsure, say N. 444b86ff981SJens Axboe 445c5289a69SPavel Emelyanovconfig NAMESPACES 446c5289a69SPavel Emelyanov bool "Namespaces support" if EMBEDDED 447c5289a69SPavel Emelyanov default !EMBEDDED 448c5289a69SPavel Emelyanov help 449c5289a69SPavel Emelyanov Provides the way to make tasks work with different objects using 450c5289a69SPavel Emelyanov the same id. For example same IPC id may refer to different objects 451c5289a69SPavel Emelyanov or same user id or pid may refer to different tasks when used in 452c5289a69SPavel Emelyanov different namespaces. 453c5289a69SPavel Emelyanov 45458bfdd6dSPavel Emelyanovconfig UTS_NS 45558bfdd6dSPavel Emelyanov bool "UTS namespace" 45658bfdd6dSPavel Emelyanov depends on NAMESPACES 45758bfdd6dSPavel Emelyanov help 45858bfdd6dSPavel Emelyanov In this namespace tasks see different info provided with the 45958bfdd6dSPavel Emelyanov uname() system call 46058bfdd6dSPavel Emelyanov 461ae5e1b22SPavel Emelyanovconfig IPC_NS 462ae5e1b22SPavel Emelyanov bool "IPC namespace" 463ae5e1b22SPavel Emelyanov depends on NAMESPACES && SYSVIPC 464ae5e1b22SPavel Emelyanov help 465ae5e1b22SPavel Emelyanov In this namespace tasks work with IPC ids which correspond to 466ae5e1b22SPavel Emelyanov different IPC objects in different namespaces 467ae5e1b22SPavel Emelyanov 468aee16ce7SPavel Emelyanovconfig USER_NS 469aee16ce7SPavel Emelyanov bool "User namespace (EXPERIMENTAL)" 470aee16ce7SPavel Emelyanov depends on NAMESPACES && EXPERIMENTAL 471aee16ce7SPavel Emelyanov help 472aee16ce7SPavel Emelyanov This allows containers, i.e. vservers, to use user namespaces 473aee16ce7SPavel Emelyanov to provide different user info for different servers. 474aee16ce7SPavel Emelyanov If unsure, say N. 475aee16ce7SPavel Emelyanov 47674bd59bbSPavel Emelyanovconfig PID_NS 47774bd59bbSPavel Emelyanov bool "PID Namespaces (EXPERIMENTAL)" 47874bd59bbSPavel Emelyanov default n 47974bd59bbSPavel Emelyanov depends on NAMESPACES && EXPERIMENTAL 48074bd59bbSPavel Emelyanov help 48174bd59bbSPavel Emelyanov Suport process id namespaces. This allows having multiple 48274bd59bbSPavel Emelyanov process with the same pid as long as they are in different 48374bd59bbSPavel Emelyanov pid namespaces. This is a building block of containers. 48474bd59bbSPavel Emelyanov 48574bd59bbSPavel Emelyanov Unless you want to work with an experimental feature 48674bd59bbSPavel Emelyanov say N here. 48774bd59bbSPavel Emelyanov 488f991633dSDimitri Gorokhovikconfig BLK_DEV_INITRD 489f991633dSDimitri Gorokhovik bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" 490f991633dSDimitri Gorokhovik depends on BROKEN || !FRV 491f991633dSDimitri Gorokhovik help 492f991633dSDimitri Gorokhovik The initial RAM filesystem is a ramfs which is loaded by the 493f991633dSDimitri Gorokhovik boot loader (loadlin or lilo) and that is mounted as root 494f991633dSDimitri Gorokhovik before the normal boot procedure. It is typically used to 495f991633dSDimitri Gorokhovik load modules needed to mount the "real" root file system, 496f991633dSDimitri Gorokhovik etc. See <file:Documentation/initrd.txt> for details. 497f991633dSDimitri Gorokhovik 498f991633dSDimitri Gorokhovik If RAM disk support (BLK_DEV_RAM) is also included, this 499f991633dSDimitri Gorokhovik also enables initial RAM disk (initrd) support and adds 500f991633dSDimitri Gorokhovik 15 Kbytes (more on some other architectures) to the kernel size. 501f991633dSDimitri Gorokhovik 502f991633dSDimitri Gorokhovik If unsure say Y. 503f991633dSDimitri Gorokhovik 504c33df4eaSJean-Paul Samanif BLK_DEV_INITRD 505c33df4eaSJean-Paul Saman 506dbec4866SSam Ravnborgsource "usr/Kconfig" 507dbec4866SSam Ravnborg 508c33df4eaSJean-Paul Samanendif 509c33df4eaSJean-Paul Saman 510c45b4f1fSLinus Torvaldsconfig CC_OPTIMIZE_FOR_SIZE 51196fffeb4SIngo Molnar bool "Optimize for size" 512c45b4f1fSLinus Torvalds default y 513c45b4f1fSLinus Torvalds help 514c45b4f1fSLinus Torvalds Enabling this option will pass "-Os" instead of "-O2" to gcc 515c45b4f1fSLinus Torvalds resulting in a smaller kernel. 516c45b4f1fSLinus Torvalds 517c45b4f1fSLinus Torvalds If unsure, say N. 518c45b4f1fSLinus Torvalds 5190847062aSRandy Dunlapconfig SYSCTL 5200847062aSRandy Dunlap bool 5210847062aSRandy Dunlap 5221da177e4SLinus Torvaldsmenuconfig EMBEDDED 5231da177e4SLinus Torvalds bool "Configure standard kernel features (for small systems)" 5241da177e4SLinus Torvalds help 5251da177e4SLinus Torvalds This option allows certain base kernel options and settings 5261da177e4SLinus Torvalds to be disabled or tweaked. This is for specialized 5271da177e4SLinus Torvalds environments which can tolerate a "non-standard" kernel. 5281da177e4SLinus Torvalds Only use this if you really know what you are doing. 5291da177e4SLinus Torvalds 530ae81f9e3SChuck Ebbertconfig UID16 531ae81f9e3SChuck Ebbert bool "Enable 16-bit UID system calls" if EMBEDDED 53209337f50SDavid S. Miller depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION) 533ae81f9e3SChuck Ebbert default y 534ae81f9e3SChuck Ebbert help 535ae81f9e3SChuck Ebbert This enables the legacy 16-bit UID syscall wrappers. 536ae81f9e3SChuck Ebbert 537b89a8171SEric W. Biedermanconfig SYSCTL_SYSCALL 5380847062aSRandy Dunlap bool "Sysctl syscall support" if EMBEDDED 53913bb7e37SEric W. Biederman default y 540b89a8171SEric W. Biederman select SYSCTL 541b89a8171SEric W. Biederman ---help--- 54213bb7e37SEric W. Biederman sys_sysctl uses binary paths that have been found challenging 54313bb7e37SEric W. Biederman to properly maintain and use. The interface in /proc/sys 54413bb7e37SEric W. Biederman using paths with ascii names is now the primary path to this 54513bb7e37SEric W. Biederman information. 546b89a8171SEric W. Biederman 54713bb7e37SEric W. Biederman Almost nothing using the binary sysctl interface so if you are 54813bb7e37SEric W. Biederman trying to save some space it is probably safe to disable this, 54913bb7e37SEric W. Biederman making your kernel marginally smaller. 550b89a8171SEric W. Biederman 55113bb7e37SEric W. Biederman If unsure say Y here. 552ae81f9e3SChuck Ebbert 553*88f458e4SHolger Schurigconfig SYSCTL_SYSCALL_CHECK 554*88f458e4SHolger Schurig bool "Sysctl checks" if EMBEDDED 555*88f458e4SHolger Schurig depends on SYSCTL_SYSCALL 556*88f458e4SHolger Schurig default y 557*88f458e4SHolger Schurig ---help--- 558*88f458e4SHolger Schurig sys_sysctl uses binary paths that have been found challenging 559*88f458e4SHolger Schurig to properly maintain and use. This enables checks that help 560*88f458e4SHolger Schurig you to keep things correct. 561*88f458e4SHolger Schurig 562*88f458e4SHolger Schurig If unsure say Y here. 563*88f458e4SHolger Schurig 5641da177e4SLinus Torvaldsconfig KALLSYMS 565979c6a1eSJesper Juhl bool "Load all symbols for debugging/ksymoops" if EMBEDDED 5661da177e4SLinus Torvalds default y 5671da177e4SLinus Torvalds help 5681da177e4SLinus Torvalds Say Y here to let the kernel print out symbolic crash information and 5691da177e4SLinus Torvalds symbolic stack backtraces. This increases the size of the kernel 5701da177e4SLinus Torvalds somewhat, as all symbols have to be loaded into the kernel image. 5711da177e4SLinus Torvalds 5721da177e4SLinus Torvaldsconfig KALLSYMS_ALL 5731da177e4SLinus Torvalds bool "Include all symbols in kallsyms" 5741da177e4SLinus Torvalds depends on DEBUG_KERNEL && KALLSYMS 5751da177e4SLinus Torvalds help 5761da177e4SLinus Torvalds Normally kallsyms only contains the symbols of functions, for nicer 5771da177e4SLinus Torvalds OOPS messages. Some debuggers can use kallsyms for other 578f9f97bc0SJesper Juhl symbols too: say Y here to include all symbols, if you need them 579f9f97bc0SJesper Juhl and you don't care about adding 300k to the size of your kernel. 5801da177e4SLinus Torvalds 5811da177e4SLinus Torvalds Say N. 5821da177e4SLinus Torvalds 5831da177e4SLinus Torvaldsconfig KALLSYMS_EXTRA_PASS 5841da177e4SLinus Torvalds bool "Do an extra kallsyms pass" 5851da177e4SLinus Torvalds depends on KALLSYMS 5861da177e4SLinus Torvalds help 5871da177e4SLinus Torvalds If kallsyms is not working correctly, the build will fail with 5881da177e4SLinus Torvalds inconsistent kallsyms data. If that occurs, log a bug report and 5891da177e4SLinus Torvalds turn on KALLSYMS_EXTRA_PASS which should result in a stable build. 5901da177e4SLinus Torvalds Always say N here unless you find a bug in kallsyms, which must be 5911da177e4SLinus Torvalds reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while 5921da177e4SLinus Torvalds you wait for kallsyms to be fixed. 5931da177e4SLinus Torvalds 594d59745ceSMatt Mackall 595712f47ceSGreg Kroah-Hartmanconfig HOTPLUG 596712f47ceSGreg Kroah-Hartman bool "Support for hot-pluggable devices" if EMBEDDED 597712f47ceSGreg Kroah-Hartman default y 598712f47ceSGreg Kroah-Hartman help 599712f47ceSGreg Kroah-Hartman This option is provided for the case where no hotplug or uevent 600712f47ceSGreg Kroah-Hartman capabilities is wanted by the kernel. You should only consider 601712f47ceSGreg Kroah-Hartman disabling this option for embedded systems that do not use modules, a 602712f47ceSGreg Kroah-Hartman dynamic /dev tree, or dynamic device discovery. Just say Y. 603712f47ceSGreg Kroah-Hartman 604d59745ceSMatt Mackallconfig PRINTK 605d59745ceSMatt Mackall default y 606d59745ceSMatt Mackall bool "Enable support for printk" if EMBEDDED 607d59745ceSMatt Mackall help 608d59745ceSMatt Mackall This option enables normal printk support. Removing it 609d59745ceSMatt Mackall eliminates most of the message strings from the kernel image 610d59745ceSMatt Mackall and makes the kernel more or less silent. As this makes it 611d59745ceSMatt Mackall very difficult to diagnose system problems, saying N here is 612d59745ceSMatt Mackall strongly discouraged. 613d59745ceSMatt Mackall 614c8538a7aSMatt Mackallconfig BUG 615c8538a7aSMatt Mackall bool "BUG() support" if EMBEDDED 616c8538a7aSMatt Mackall default y 617c8538a7aSMatt Mackall help 618c8538a7aSMatt Mackall Disabling this option eliminates support for BUG and WARN, reducing 619c8538a7aSMatt Mackall the size of your kernel image and potentially quietly ignoring 620c8538a7aSMatt Mackall numerous fatal conditions. You should only consider disabling this 621c8538a7aSMatt Mackall option for embedded systems with no facilities for reporting errors. 622c8538a7aSMatt Mackall Just say Y. 623c8538a7aSMatt Mackall 624708e9a79SMatt Mackallconfig ELF_CORE 625708e9a79SMatt Mackall default y 626708e9a79SMatt Mackall bool "Enable ELF core dumps" if EMBEDDED 627708e9a79SMatt Mackall help 628708e9a79SMatt Mackall Enable support for generating core dumps. Disabling saves about 4k. 629708e9a79SMatt Mackall 63032a93233SIngo Molnarconfig COMPAT_BRK 63132a93233SIngo Molnar bool "Disable heap randomization" 63232a93233SIngo Molnar default y 63332a93233SIngo Molnar help 63432a93233SIngo Molnar Randomizing heap placement makes heap exploits harder, but it 63532a93233SIngo Molnar also breaks ancient binaries (including anything libc5 based). 63632a93233SIngo Molnar This option changes the bootup default to heap randomization 63732a93233SIngo Molnar disabled, and can be overriden runtime by setting 63832a93233SIngo Molnar /proc/sys/kernel/randomize_va_space to 2. 63932a93233SIngo Molnar 640166124fdSIngo Molnar On non-ancient distros (post-2000 ones) N is usually a safe choice. 64132a93233SIngo Molnar 6421da177e4SLinus Torvaldsconfig BASE_FULL 6431da177e4SLinus Torvalds default y 6441da177e4SLinus Torvalds bool "Enable full-sized data structures for core" if EMBEDDED 6451da177e4SLinus Torvalds help 6461da177e4SLinus Torvalds Disabling this option reduces the size of miscellaneous core 6471da177e4SLinus Torvalds kernel data structures. This saves memory on small machines, 6481da177e4SLinus Torvalds but may reduce performance. 6491da177e4SLinus Torvalds 6501da177e4SLinus Torvaldsconfig FUTEX 6511da177e4SLinus Torvalds bool "Enable futex support" if EMBEDDED 6521da177e4SLinus Torvalds default y 65323f78d4aSIngo Molnar select RT_MUTEXES 6541da177e4SLinus Torvalds help 6551da177e4SLinus Torvalds Disabling this option will cause the kernel to be built without 6561da177e4SLinus Torvalds support for "fast userspace mutexes". The resulting kernel may not 6571da177e4SLinus Torvalds run glibc-based applications correctly. 6581da177e4SLinus Torvalds 6595dc8bf81SDavide Libenziconfig ANON_INODES 660448e3ceeSAdrian Bunk bool 6615dc8bf81SDavide Libenzi 6621da177e4SLinus Torvaldsconfig EPOLL 6631da177e4SLinus Torvalds bool "Enable eventpoll support" if EMBEDDED 6641da177e4SLinus Torvalds default y 665448e3ceeSAdrian Bunk select ANON_INODES 6661da177e4SLinus Torvalds help 6671da177e4SLinus Torvalds Disabling this option will cause the kernel to be built without 6681da177e4SLinus Torvalds support for epoll family of system calls. 6691da177e4SLinus Torvalds 670fba2afaaSDavide Libenziconfig SIGNALFD 671fba2afaaSDavide Libenzi bool "Enable signalfd() system call" if EMBEDDED 672448e3ceeSAdrian Bunk select ANON_INODES 673fba2afaaSDavide Libenzi default y 674fba2afaaSDavide Libenzi help 675fba2afaaSDavide Libenzi Enable the signalfd() system call that allows to receive signals 676fba2afaaSDavide Libenzi on a file descriptor. 677fba2afaaSDavide Libenzi 678fba2afaaSDavide Libenzi If unsure, say Y. 679fba2afaaSDavide Libenzi 680b215e283SDavide Libenziconfig TIMERFD 681b215e283SDavide Libenzi bool "Enable timerfd() system call" if EMBEDDED 682448e3ceeSAdrian Bunk select ANON_INODES 683b215e283SDavide Libenzi default y 684b215e283SDavide Libenzi help 685b215e283SDavide Libenzi Enable the timerfd() system call that allows to receive timer 686b215e283SDavide Libenzi events on a file descriptor. 687b215e283SDavide Libenzi 688b215e283SDavide Libenzi If unsure, say Y. 689b215e283SDavide Libenzi 690e1ad7468SDavide Libenziconfig EVENTFD 691e1ad7468SDavide Libenzi bool "Enable eventfd() system call" if EMBEDDED 692448e3ceeSAdrian Bunk select ANON_INODES 693e1ad7468SDavide Libenzi default y 694e1ad7468SDavide Libenzi help 695e1ad7468SDavide Libenzi Enable the eventfd() system call that allows to receive both 696e1ad7468SDavide Libenzi kernel notification (ie. KAIO) or userspace notifications. 697e1ad7468SDavide Libenzi 698e1ad7468SDavide Libenzi If unsure, say Y. 699e1ad7468SDavide Libenzi 7001da177e4SLinus Torvaldsconfig SHMEM 7011da177e4SLinus Torvalds bool "Use full shmem filesystem" if EMBEDDED 7021da177e4SLinus Torvalds default y 7031da177e4SLinus Torvalds depends on MMU 7041da177e4SLinus Torvalds help 7051da177e4SLinus Torvalds The shmem is an internal filesystem used to manage shared memory. 7061da177e4SLinus Torvalds It is backed by swap and manages resource limits. It is also exported 7071da177e4SLinus Torvalds to userspace as tmpfs if TMPFS is enabled. Disabling this 7081da177e4SLinus Torvalds option replaces shmem and tmpfs with the much simpler ramfs code, 7091da177e4SLinus Torvalds which may be appropriate on small systems without swap. 7101da177e4SLinus Torvalds 711f8891e5eSChristoph Lameterconfig VM_EVENT_COUNTERS 712f8891e5eSChristoph Lameter default y 713f8891e5eSChristoph Lameter bool "Enable VM event counters for /proc/vmstat" if EMBEDDED 714f8891e5eSChristoph Lameter help 7152aea4fb6SPaul Jackson VM event counters are needed for event counts to be shown. 7162aea4fb6SPaul Jackson This option allows the disabling of the VM event counters 7172aea4fb6SPaul Jackson on EMBEDDED systems. /proc/vmstat will only show page counts 7182aea4fb6SPaul Jackson if VM event counters are disabled. 719f8891e5eSChristoph Lameter 72041ecc55bSChristoph Lameterconfig SLUB_DEBUG 72141ecc55bSChristoph Lameter default y 72241ecc55bSChristoph Lameter bool "Enable SLUB debugging support" if EMBEDDED 723d4751a27SChristoph Lameter depends on SLUB 72441ecc55bSChristoph Lameter help 72541ecc55bSChristoph Lameter SLUB has extensive debug support features. Disabling these can 72641ecc55bSChristoph Lameter result in significant savings in code size. This also disables 72741ecc55bSChristoph Lameter SLUB sysfs support. /sys/slab will not exist and there will be 72841ecc55bSChristoph Lameter no support for cache validation etc. 72941ecc55bSChristoph Lameter 73081819f0fSChristoph Lameterchoice 73181819f0fSChristoph Lameter prompt "Choose SLAB allocator" 732a0acd820SChristoph Lameter default SLUB 73381819f0fSChristoph Lameter help 73481819f0fSChristoph Lameter This option allows to select a slab allocator. 73581819f0fSChristoph Lameter 73681819f0fSChristoph Lameterconfig SLAB 73781819f0fSChristoph Lameter bool "SLAB" 73881819f0fSChristoph Lameter help 73981819f0fSChristoph Lameter The regular slab allocator that is established and known to work 74034013886SChristoph Lameter well in all environments. It organizes cache hot objects in 74181819f0fSChristoph Lameter per cpu and per node queues. SLAB is the default choice for 74234013886SChristoph Lameter a slab allocator. 74381819f0fSChristoph Lameter 74481819f0fSChristoph Lameterconfig SLUB 74581819f0fSChristoph Lameter bool "SLUB (Unqueued Allocator)" 74681819f0fSChristoph Lameter help 74781819f0fSChristoph Lameter SLUB is a slab allocator that minimizes cache line usage 74881819f0fSChristoph Lameter instead of managing queues of cached objects (SLAB approach). 74981819f0fSChristoph Lameter Per cpu caching is realized using slabs of objects instead 75081819f0fSChristoph Lameter of queues of objects. SLUB can use memory efficiently 75134013886SChristoph Lameter and has enhanced diagnostics. 75281819f0fSChristoph Lameter 75381819f0fSChristoph Lameterconfig SLOB 75484a01c2fSPaul Mundt depends on EMBEDDED 75581819f0fSChristoph Lameter bool "SLOB (Simple Allocator)" 75681819f0fSChristoph Lameter help 75737291458SMatt Mackall SLOB replaces the stock allocator with a drastically simpler 75837291458SMatt Mackall allocator. SLOB is generally more space efficient but 75937291458SMatt Mackall does not perform as well on large systems. 76081819f0fSChristoph Lameter 76181819f0fSChristoph Lameterendchoice 76281819f0fSChristoph Lameter 763125e5645SMathieu Desnoyersconfig PROFILING 764125e5645SMathieu Desnoyers bool "Profiling support (EXPERIMENTAL)" 765125e5645SMathieu Desnoyers help 766125e5645SMathieu Desnoyers Say Y here to enable the extended profiling support mechanisms used 767125e5645SMathieu Desnoyers by profilers such as OProfile. 768125e5645SMathieu Desnoyers 769125e5645SMathieu Desnoyersconfig MARKERS 770125e5645SMathieu Desnoyers bool "Activate markers" 771125e5645SMathieu Desnoyers help 772125e5645SMathieu Desnoyers Place an empty function call at each marker site. Can be 773125e5645SMathieu Desnoyers dynamically changed for a probe function. 774125e5645SMathieu Desnoyers 775fb32e03fSMathieu Desnoyerssource "arch/Kconfig" 776fb32e03fSMathieu Desnoyers 7771e883281SMatt Mackallconfig PROC_PAGE_MONITOR 7781e883281SMatt Mackall default y 7791e883281SMatt Mackall depends on PROC_FS && MMU 7801e883281SMatt Mackall bool "Enable /proc page monitoring" if EMBEDDED 7811e883281SMatt Mackall help 7821e883281SMatt Mackall Various /proc files exist to monitor process memory utilization: 7831e883281SMatt Mackall /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap, 7841e883281SMatt Mackall /proc/kpagecount, and /proc/kpageflags. Disabling these 7851e883281SMatt Mackall interfaces will reduce the size of the kernel by approximately 4kb. 7861e883281SMatt Mackall 7871da177e4SLinus Torvaldsendmenu # General setup 7881da177e4SLinus Torvalds 789158a9624SLinus Torvaldsconfig SLABINFO 790158a9624SLinus Torvalds bool 791158a9624SLinus Torvalds depends on PROC_FS 7920f389ec6SChristoph Lameter depends on SLAB || SLUB_DEBUG 793158a9624SLinus Torvalds default y 794158a9624SLinus Torvalds 795ae81f9e3SChuck Ebbertconfig RT_MUTEXES 796ae81f9e3SChuck Ebbert boolean 797ae81f9e3SChuck Ebbert select PLIST 798ae81f9e3SChuck Ebbert 7991da177e4SLinus Torvaldsconfig TINY_SHMEM 8001da177e4SLinus Torvalds default !SHMEM 8011da177e4SLinus Torvalds bool 8021da177e4SLinus Torvalds 8031da177e4SLinus Torvaldsconfig BASE_SMALL 8041da177e4SLinus Torvalds int 8051da177e4SLinus Torvalds default 0 if BASE_FULL 8061da177e4SLinus Torvalds default 1 if !BASE_FULL 8071da177e4SLinus Torvalds 80866da5733SJan Engelhardtmenuconfig MODULES 8091da177e4SLinus Torvalds bool "Enable loadable module support" 8101da177e4SLinus Torvalds help 8111da177e4SLinus Torvalds Kernel modules are small pieces of compiled code which can 8121da177e4SLinus Torvalds be inserted in the running kernel, rather than being 8131da177e4SLinus Torvalds permanently built into the kernel. You use the "modprobe" 8141da177e4SLinus Torvalds tool to add (and sometimes remove) them. If you say Y here, 8151da177e4SLinus Torvalds many parts of the kernel can be built as modules (by 8161da177e4SLinus Torvalds answering M instead of Y where indicated): this is most 8171da177e4SLinus Torvalds useful for infrequently used options which are not required 8181da177e4SLinus Torvalds for booting. For more information, see the man pages for 8191da177e4SLinus Torvalds modprobe, lsmod, modinfo, insmod and rmmod. 8201da177e4SLinus Torvalds 8211da177e4SLinus Torvalds If you say Y here, you will need to run "make 8221da177e4SLinus Torvalds modules_install" to put the modules under /lib/modules/ 8231da177e4SLinus Torvalds where modprobe can find them (you may need to be root to do 8241da177e4SLinus Torvalds this). 8251da177e4SLinus Torvalds 8261da177e4SLinus Torvalds If unsure, say Y. 8271da177e4SLinus Torvalds 8281da177e4SLinus Torvaldsconfig MODULE_UNLOAD 8291da177e4SLinus Torvalds bool "Module unloading" 8301da177e4SLinus Torvalds depends on MODULES 8311da177e4SLinus Torvalds help 8321da177e4SLinus Torvalds Without this option you will not be able to unload any 8331da177e4SLinus Torvalds modules (note that some modules may not be unloadable 8341da177e4SLinus Torvalds anyway), which makes your kernel slightly smaller and 8351da177e4SLinus Torvalds simpler. If unsure, say Y. 8361da177e4SLinus Torvalds 8371da177e4SLinus Torvaldsconfig MODULE_FORCE_UNLOAD 8381da177e4SLinus Torvalds bool "Forced module unloading" 8391da177e4SLinus Torvalds depends on MODULE_UNLOAD && EXPERIMENTAL 8401da177e4SLinus Torvalds help 8411da177e4SLinus Torvalds This option allows you to force a module to unload, even if the 8421da177e4SLinus Torvalds kernel believes it is unsafe: the kernel will remove the module 8431da177e4SLinus Torvalds without waiting for anyone to stop using it (using the -f option to 8441da177e4SLinus Torvalds rmmod). This is mainly for kernel developers and desperate users. 8451da177e4SLinus Torvalds If unsure, say N. 8461da177e4SLinus Torvalds 8471da177e4SLinus Torvaldsconfig MODVERSIONS 8480d541643SSam Ravnborg bool "Module versioning support" 8490d541643SSam Ravnborg depends on MODULES 8501da177e4SLinus Torvalds help 8511da177e4SLinus Torvalds Usually, you have to use modules compiled with your kernel. 8521da177e4SLinus Torvalds Saying Y here makes it sometimes possible to use modules 8531da177e4SLinus Torvalds compiled for different kernels, by adding enough information 8541da177e4SLinus Torvalds to the modules to (hopefully) spot any changes which would 8551da177e4SLinus Torvalds make them incompatible with the kernel you are running. If 8561da177e4SLinus Torvalds unsure, say N. 8571da177e4SLinus Torvalds 8581da177e4SLinus Torvaldsconfig MODULE_SRCVERSION_ALL 8591da177e4SLinus Torvalds bool "Source checksum for all modules" 8601da177e4SLinus Torvalds depends on MODULES 8611da177e4SLinus Torvalds help 8621da177e4SLinus Torvalds Modules which contain a MODULE_VERSION get an extra "srcversion" 8631da177e4SLinus Torvalds field inserted into their modinfo section, which contains a 8641da177e4SLinus Torvalds sum of the source files which made it. This helps maintainers 8651da177e4SLinus Torvalds see exactly which source was used to build a module (since 8661da177e4SLinus Torvalds others sometimes change the module source without updating 8671da177e4SLinus Torvalds the version). With this option, such a "srcversion" field 8681da177e4SLinus Torvalds will be created for all modules. If unsure, say N. 8691da177e4SLinus Torvalds 8701da177e4SLinus Torvaldsconfig KMOD 8711da177e4SLinus Torvalds bool "Automatic kernel module loading" 8721da177e4SLinus Torvalds depends on MODULES 8731da177e4SLinus Torvalds help 8741da177e4SLinus Torvalds Normally when you have selected some parts of the kernel to 8751da177e4SLinus Torvalds be created as kernel modules, you must load them (using the 8761da177e4SLinus Torvalds "modprobe" command) before you can use them. If you say Y 8771da177e4SLinus Torvalds here, some parts of the kernel will be able to load modules 8781da177e4SLinus Torvalds automatically: when a part of the kernel needs a module, it 8791da177e4SLinus Torvalds runs modprobe with the appropriate arguments, thereby 8801da177e4SLinus Torvalds loading the module if it is available. If unsure, say Y. 8811da177e4SLinus Torvalds 8821da177e4SLinus Torvaldsconfig STOP_MACHINE 8831da177e4SLinus Torvalds bool 8841da177e4SLinus Torvalds default y 8851da177e4SLinus Torvalds depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU 8861da177e4SLinus Torvalds help 8871da177e4SLinus Torvalds Need stop_machine() primitive. 8883a65dfe8SJens Axboe 8893a65dfe8SJens Axboesource "block/Kconfig" 890e98c3202SAvi Kivity 891e98c3202SAvi Kivityconfig PREEMPT_NOTIFIERS 892e98c3202SAvi Kivity bool 893e260be67SPaul E. McKenney 894e260be67SPaul E. McKenneyconfig CLASSIC_RCU 89521bbb39cSPaul E. McKenney def_bool !PREEMPT_RCU 896e260be67SPaul E. McKenney help 897e260be67SPaul E. McKenney This option selects the classic RCU implementation that is 898e260be67SPaul E. McKenney designed for best read-side performance on non-realtime 89921bbb39cSPaul E. McKenney systems. Classic RCU is the default. Note that the 90021bbb39cSPaul E. McKenney PREEMPT_RCU symbol is used to select/deselect this option. 901