xref: /openbmc/linux/init/Kconfig (revision af1839eb)
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"
1673531905SSam Ravnborg	default "$ARCH_DEFCONFIG"
17face4374SRoman Zippel	default "arch/$ARCH/defconfig"
18face4374SRoman Zippel
19b99b87f7SPeter Oberparleiterconfig CONSTRUCTORS
20b99b87f7SPeter Oberparleiter	bool
21b99b87f7SPeter Oberparleiter	depends on !UML
22b99b87f7SPeter Oberparleiter
23e360adbeSPeter Zijlstraconfig HAVE_IRQ_WORK
24e360adbeSPeter Zijlstra	bool
25e360adbeSPeter Zijlstra
26e360adbeSPeter Zijlstraconfig IRQ_WORK
27e360adbeSPeter Zijlstra	bool
28e360adbeSPeter Zijlstra	depends on HAVE_IRQ_WORK
29e360adbeSPeter Zijlstra
301dbdc6f1SDavid Daneyconfig BUILDTIME_EXTABLE_SORT
311dbdc6f1SDavid Daney	bool
321dbdc6f1SDavid Daney
33ff0cfc66SAl Boldimenu "General setup"
341da177e4SLinus Torvalds
351da177e4SLinus Torvaldsconfig EXPERIMENTAL
361da177e4SLinus Torvalds	bool "Prompt for development and/or incomplete code/drivers"
371da177e4SLinus Torvalds	---help---
381da177e4SLinus Torvalds	  Some of the various things that Linux supports (such as network
391da177e4SLinus Torvalds	  drivers, file systems, network protocols, etc.) can be in a state
401da177e4SLinus Torvalds	  of development where the functionality, stability, or the level of
411da177e4SLinus Torvalds	  testing is not yet high enough for general use. This is usually
421da177e4SLinus Torvalds	  known as the "alpha-test" phase among developers. If a feature is
431da177e4SLinus Torvalds	  currently in alpha-test, then the developers usually discourage
441da177e4SLinus Torvalds	  uninformed widespread use of this feature by the general public to
451da177e4SLinus Torvalds	  avoid "Why doesn't this work?" type mail messages. However, active
461da177e4SLinus Torvalds	  testing and use of these systems is welcomed. Just be aware that it
471da177e4SLinus Torvalds	  may not meet the normal level of reliability or it may fail to work
481da177e4SLinus Torvalds	  in some special cases. Detailed bug reports from people familiar
491da177e4SLinus Torvalds	  with the kernel internals are usually welcomed by the developers
501da177e4SLinus Torvalds	  (before submitting bug reports, please read the documents
511da177e4SLinus Torvalds	  <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
521da177e4SLinus Torvalds	  <file:Documentation/BUG-HUNTING>, and
531da177e4SLinus Torvalds	  <file:Documentation/oops-tracing.txt> in the kernel source).
541da177e4SLinus Torvalds
551da177e4SLinus Torvalds	  This option will also make obsoleted drivers available. These are
561da177e4SLinus Torvalds	  drivers that have been replaced by something else, and/or are
571da177e4SLinus Torvalds	  scheduled to be removed in a future kernel release.
581da177e4SLinus Torvalds
591da177e4SLinus Torvalds	  Unless you intend to help test and develop a feature or driver that
601da177e4SLinus Torvalds	  falls into this category, or you have a situation that requires
611da177e4SLinus Torvalds	  using these features, you should probably say N here, which will
621da177e4SLinus Torvalds	  cause the configurator to present you with fewer choices. If
631da177e4SLinus Torvalds	  you say Y here, you will be offered the choice of using features or
641da177e4SLinus Torvalds	  drivers that are currently considered to be in the alpha-test phase.
651da177e4SLinus Torvalds
661da177e4SLinus Torvaldsconfig BROKEN
671da177e4SLinus Torvalds	bool
681da177e4SLinus Torvalds
691da177e4SLinus Torvaldsconfig BROKEN_ON_SMP
701da177e4SLinus Torvalds	bool
711da177e4SLinus Torvalds	depends on BROKEN || !SMP
721da177e4SLinus Torvalds	default y
731da177e4SLinus Torvalds
741da177e4SLinus Torvaldsconfig INIT_ENV_ARG_LIMIT
751da177e4SLinus Torvalds	int
76dd673bcaSAdrian Bunk	default 32 if !UML
77dd673bcaSAdrian Bunk	default 128 if UML
781da177e4SLinus Torvalds	help
7934ad92c2SRandy Dunlap	  Maximum of each of the number of arguments and environment
8034ad92c2SRandy Dunlap	  variables passed to init from the kernel command line.
811da177e4SLinus Torvalds
821da177e4SLinus Torvalds
8384336466SRoland McGrathconfig CROSS_COMPILE
8484336466SRoland McGrath	string "Cross-compiler tool prefix"
8584336466SRoland McGrath	help
8684336466SRoland McGrath	  Same as running 'make CROSS_COMPILE=prefix-' but stored for
8784336466SRoland McGrath	  default make runs in this kernel build directory.  You don't
8884336466SRoland McGrath	  need to set this unless you want the configured kernel build
8984336466SRoland McGrath	  directory to select the cross-compiler automatically.
9084336466SRoland McGrath
911da177e4SLinus Torvaldsconfig LOCALVERSION
921da177e4SLinus Torvalds	string "Local version - append to kernel release"
931da177e4SLinus Torvalds	help
941da177e4SLinus Torvalds	  Append an extra string to the end of your kernel version.
951da177e4SLinus Torvalds	  This will show up when you type uname, for example.
961da177e4SLinus Torvalds	  The string you set here will be appended after the contents of
971da177e4SLinus Torvalds	  any files with a filename matching localversion* in your
981da177e4SLinus Torvalds	  object and source tree, in that order.  Your total string can
991da177e4SLinus Torvalds	  be a maximum of 64 characters.
1001da177e4SLinus Torvalds
101aaebf433SRyan Andersonconfig LOCALVERSION_AUTO
102aaebf433SRyan Anderson	bool "Automatically append version information to the version string"
103aaebf433SRyan Anderson	default y
104aaebf433SRyan Anderson	help
105aaebf433SRyan Anderson	  This will try to automatically determine if the current tree is a
1066e5a5420SRobert P. J. Day	  release tree by looking for git tags that belong to the current
1076e5a5420SRobert P. J. Day	  top of tree revision.
108aaebf433SRyan Anderson
109aaebf433SRyan Anderson	  A string of the format -gxxxxxxxx will be added to the localversion
1106e5a5420SRobert P. J. Day	  if a git-based tree is found.  The string generated by this will be
111aaebf433SRyan Anderson	  appended after any matching localversion* files, and after the value
1126e5a5420SRobert P. J. Day	  set in CONFIG_LOCALVERSION.
113aaebf433SRyan Anderson
1146e5a5420SRobert P. J. Day	  (The actual string used here is the first eight characters produced
1156e5a5420SRobert P. J. Day	  by running the command:
1166e5a5420SRobert P. J. Day
1176e5a5420SRobert P. J. Day	    $ git rev-parse --verify HEAD
1186e5a5420SRobert P. J. Day
1196e5a5420SRobert P. J. Day	  which is done within the script "scripts/setlocalversion".)
120aaebf433SRyan Anderson
1212e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_GZIP
1222e9f3bddSH. Peter Anvin	bool
1232e9f3bddSH. Peter Anvin
1242e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_BZIP2
1252e9f3bddSH. Peter Anvin	bool
1262e9f3bddSH. Peter Anvin
1272e9f3bddSH. Peter Anvinconfig HAVE_KERNEL_LZMA
1282e9f3bddSH. Peter Anvin	bool
1292e9f3bddSH. Peter Anvin
1303ebe1243SLasse Collinconfig HAVE_KERNEL_XZ
1313ebe1243SLasse Collin	bool
1323ebe1243SLasse Collin
1337dd65febSAlbin Tonnerreconfig HAVE_KERNEL_LZO
1347dd65febSAlbin Tonnerre	bool
1357dd65febSAlbin Tonnerre
13630d65dbfSAlain Knaffchoice
13730d65dbfSAlain Knaff	prompt "Kernel compression mode"
13830d65dbfSAlain Knaff	default KERNEL_GZIP
1393ebe1243SLasse Collin	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
14030d65dbfSAlain Knaff	help
14130d65dbfSAlain Knaff	  The linux kernel is a kind of self-extracting executable.
14230d65dbfSAlain Knaff	  Several compression algorithms are available, which differ
14330d65dbfSAlain Knaff	  in efficiency, compression and decompression speed.
14430d65dbfSAlain Knaff	  Compression speed is only relevant when building a kernel.
14530d65dbfSAlain Knaff	  Decompression speed is relevant at each boot.
14630d65dbfSAlain Knaff
14730d65dbfSAlain Knaff	  If you have any problems with bzip2 or lzma compressed
14830d65dbfSAlain Knaff	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
14930d65dbfSAlain Knaff	  version of this functionality (bzip2 only), for 2.4, was
15030d65dbfSAlain Knaff	  supplied by Christian Ludwig)
15130d65dbfSAlain Knaff
15230d65dbfSAlain Knaff	  High compression options are mostly useful for users, who
15330d65dbfSAlain Knaff	  are low on disk space (embedded systems), but for whom ram
15430d65dbfSAlain Knaff	  size matters less.
15530d65dbfSAlain Knaff
15630d65dbfSAlain Knaff	  If in doubt, select 'gzip'
15730d65dbfSAlain Knaff
15830d65dbfSAlain Knaffconfig KERNEL_GZIP
15930d65dbfSAlain Knaff	bool "Gzip"
1602e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_GZIP
16130d65dbfSAlain Knaff	help
1627dd65febSAlbin Tonnerre	  The old and tried gzip compression. It provides a good balance
1637dd65febSAlbin Tonnerre	  between compression ratio and decompression speed.
16430d65dbfSAlain Knaff
16530d65dbfSAlain Knaffconfig KERNEL_BZIP2
16630d65dbfSAlain Knaff	bool "Bzip2"
1672e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_BZIP2
16830d65dbfSAlain Knaff	help
16930d65dbfSAlain Knaff	  Its compression ratio and speed is intermediate.
1700a4dd35cSRandy Dunlap	  Decompression speed is slowest among the choices.  The kernel
1712e9f3bddSH. Peter Anvin	  size is about 10% smaller with bzip2, in comparison to gzip.
1722e9f3bddSH. Peter Anvin	  Bzip2 uses a large amount of memory. For modern kernels you
1732e9f3bddSH. Peter Anvin	  will need at least 8MB RAM or more for booting.
17430d65dbfSAlain Knaff
17530d65dbfSAlain Knaffconfig KERNEL_LZMA
17630d65dbfSAlain Knaff	bool "LZMA"
1772e9f3bddSH. Peter Anvin	depends on HAVE_KERNEL_LZMA
17830d65dbfSAlain Knaff	help
1790a4dd35cSRandy Dunlap	  This compression algorithm's ratio is best.  Decompression speed
1800a4dd35cSRandy Dunlap	  is between gzip and bzip2.  Compression is slowest.
1810a4dd35cSRandy Dunlap	  The kernel size is about 33% smaller with LZMA in comparison to gzip.
18230d65dbfSAlain Knaff
1833ebe1243SLasse Collinconfig KERNEL_XZ
1843ebe1243SLasse Collin	bool "XZ"
1853ebe1243SLasse Collin	depends on HAVE_KERNEL_XZ
1863ebe1243SLasse Collin	help
1873ebe1243SLasse Collin	  XZ uses the LZMA2 algorithm and instruction set specific
1883ebe1243SLasse Collin	  BCJ filters which can improve compression ratio of executable
1893ebe1243SLasse Collin	  code. The size of the kernel is about 30% smaller with XZ in
1903ebe1243SLasse Collin	  comparison to gzip. On architectures for which there is a BCJ
1913ebe1243SLasse Collin	  filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
1923ebe1243SLasse Collin	  will create a few percent smaller kernel than plain LZMA.
1933ebe1243SLasse Collin
1943ebe1243SLasse Collin	  The speed is about the same as with LZMA: The decompression
1953ebe1243SLasse Collin	  speed of XZ is better than that of bzip2 but worse than gzip
1963ebe1243SLasse Collin	  and LZO. Compression is slow.
1973ebe1243SLasse Collin
1987dd65febSAlbin Tonnerreconfig KERNEL_LZO
1997dd65febSAlbin Tonnerre	bool "LZO"
2007dd65febSAlbin Tonnerre	depends on HAVE_KERNEL_LZO
2017dd65febSAlbin Tonnerre	help
2020a4dd35cSRandy Dunlap	  Its compression ratio is the poorest among the choices. The kernel
203681b3049SStephan Sperber	  size is about 10% bigger than gzip; however its speed
2047dd65febSAlbin Tonnerre	  (both compression and decompression) is the fastest.
2057dd65febSAlbin Tonnerre
20630d65dbfSAlain Knaffendchoice
20730d65dbfSAlain Knaff
208bd5dc17bSJosh Triplettconfig DEFAULT_HOSTNAME
209bd5dc17bSJosh Triplett	string "Default hostname"
210bd5dc17bSJosh Triplett	default "(none)"
211bd5dc17bSJosh Triplett	help
212bd5dc17bSJosh Triplett	  This option determines the default system hostname before userspace
213bd5dc17bSJosh Triplett	  calls sethostname(2). The kernel traditionally uses "(none)" here,
214bd5dc17bSJosh Triplett	  but you may wish to use a different default here to make a minimal
215bd5dc17bSJosh Triplett	  system more usable with less configuration.
216bd5dc17bSJosh Triplett
2171da177e4SLinus Torvaldsconfig SWAP
2181da177e4SLinus Torvalds	bool "Support for paging of anonymous memory (swap)"
2199361401eSDavid Howells	depends on MMU && BLOCK
2201da177e4SLinus Torvalds	default y
2211da177e4SLinus Torvalds	help
2221da177e4SLinus Torvalds	  This option allows you to choose whether you want to have support
2231da177e4SLinus Torvalds	  for so called swap devices or swap files in your kernel that are
2241da177e4SLinus Torvalds	  used to provide more virtual memory than the actual RAM present
2251da177e4SLinus Torvalds	  in your computer.  If unsure say Y.
2261da177e4SLinus Torvalds
2271da177e4SLinus Torvaldsconfig SYSVIPC
2281da177e4SLinus Torvalds	bool "System V IPC"
2291da177e4SLinus Torvalds	---help---
2301da177e4SLinus Torvalds	  Inter Process Communication is a suite of library functions and
2311da177e4SLinus Torvalds	  system calls which let processes (running programs) synchronize and
2321da177e4SLinus Torvalds	  exchange information. It is generally considered to be a good thing,
2331da177e4SLinus Torvalds	  and some programs won't run unless you say Y here. In particular, if
2341da177e4SLinus Torvalds	  you want to run the DOS emulator dosemu under Linux (read the
2351da177e4SLinus Torvalds	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
2361da177e4SLinus Torvalds	  you'll need to say Y here.
2371da177e4SLinus Torvalds
2381da177e4SLinus Torvalds	  You can find documentation about IPC with "info ipc" and also in
2391da177e4SLinus Torvalds	  section 6.4 of the Linux Programmer's Guide, available from
2401da177e4SLinus Torvalds	  <http://www.tldp.org/guides.html>.
2411da177e4SLinus Torvalds
242a5494dcdSEric W. Biedermanconfig SYSVIPC_SYSCTL
243a5494dcdSEric W. Biederman	bool
244a5494dcdSEric W. Biederman	depends on SYSVIPC
245a5494dcdSEric W. Biederman	depends on SYSCTL
246a5494dcdSEric W. Biederman	default y
247a5494dcdSEric W. Biederman
2481da177e4SLinus Torvaldsconfig POSIX_MQUEUE
2491da177e4SLinus Torvalds	bool "POSIX Message Queues"
2501da177e4SLinus Torvalds	depends on NET && EXPERIMENTAL
2511da177e4SLinus Torvalds	---help---
2521da177e4SLinus Torvalds	  POSIX variant of message queues is a part of IPC. In POSIX message
2531da177e4SLinus Torvalds	  queues every message has a priority which decides about succession
2541da177e4SLinus Torvalds	  of receiving it by a process. If you want to compile and run
2551da177e4SLinus Torvalds	  programs written e.g. for Solaris with use of its POSIX message
256b0e37650SRobert P. J. Day	  queues (functions mq_*) say Y here.
2571da177e4SLinus Torvalds
2581da177e4SLinus Torvalds	  POSIX message queues are visible as a filesystem called 'mqueue'
2591da177e4SLinus Torvalds	  and can be mounted somewhere if you want to do filesystem
2601da177e4SLinus Torvalds	  operations on message queues.
2611da177e4SLinus Torvalds
2621da177e4SLinus Torvalds	  If unsure, say Y.
2631da177e4SLinus Torvalds
264bdc8e5f8SSerge E. Hallynconfig POSIX_MQUEUE_SYSCTL
265bdc8e5f8SSerge E. Hallyn	bool
266bdc8e5f8SSerge E. Hallyn	depends on POSIX_MQUEUE
267bdc8e5f8SSerge E. Hallyn	depends on SYSCTL
268bdc8e5f8SSerge E. Hallyn	default y
269bdc8e5f8SSerge E. Hallyn
270990d6c2dSAneesh Kumar K.Vconfig FHANDLE
271990d6c2dSAneesh Kumar K.V	bool "open by fhandle syscalls"
272990d6c2dSAneesh Kumar K.V	select EXPORTFS
273990d6c2dSAneesh Kumar K.V	help
274990d6c2dSAneesh Kumar K.V	  If you say Y here, a user level program will be able to map
275990d6c2dSAneesh Kumar K.V	  file names to handle and then later use the handle for
276990d6c2dSAneesh Kumar K.V	  different file system operations. This is useful in implementing
277990d6c2dSAneesh Kumar K.V	  userspace file servers, which now track files using handles instead
278990d6c2dSAneesh Kumar K.V	  of names. The handle would remain the same even if file names
279990d6c2dSAneesh Kumar K.V	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
280990d6c2dSAneesh Kumar K.V	  syscalls.
281990d6c2dSAneesh Kumar K.V
2821da177e4SLinus Torvaldsconfig AUDIT
2831da177e4SLinus Torvalds	bool "Auditing support"
284804a6a49SChris Wright	depends on NET
2851da177e4SLinus Torvalds	help
2861da177e4SLinus Torvalds	  Enable auditing infrastructure that can be used with another
2871da177e4SLinus Torvalds	  kernel subsystem, such as SELinux (which requires this for
2881da177e4SLinus Torvalds	  logging of avc messages output).  Does not do system-call
2891da177e4SLinus Torvalds	  auditing without CONFIG_AUDITSYSCALL.
2901da177e4SLinus Torvalds
2911da177e4SLinus Torvaldsconfig AUDITSYSCALL
2921da177e4SLinus Torvalds	bool "Enable system-call auditing support"
2938f827a14SWill Deacon	depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
2941da177e4SLinus Torvalds	default y if SECURITY_SELINUX
2951da177e4SLinus Torvalds	help
2961da177e4SLinus Torvalds	  Enable low-overhead system-call auditing infrastructure that
2971da177e4SLinus Torvalds	  can be used independently or with another kernel subsystem,
29867640b60SEric Paris	  such as SELinux.
2991da177e4SLinus Torvalds
300939a67fcSEric Parisconfig AUDIT_WATCH
301939a67fcSEric Paris	def_bool y
302939a67fcSEric Paris	depends on AUDITSYSCALL
303939a67fcSEric Paris	select FSNOTIFY
3041da177e4SLinus Torvalds
30574c3cbe3SAl Viroconfig AUDIT_TREE
30674c3cbe3SAl Viro	def_bool y
30763c882a0SEric Paris	depends on AUDITSYSCALL
30828a3a7ebSEric Paris	select FSNOTIFY
30974c3cbe3SAl Viro
310633b4545SEric Parisconfig AUDIT_LOGINUID_IMMUTABLE
311633b4545SEric Paris	bool "Make audit loginuid immutable"
312633b4545SEric Paris	depends on AUDIT
313633b4545SEric Paris	help
314f429ee3bSLinus Torvalds	  The config option toggles if a task setting its loginuid requires
315633b4545SEric Paris	  CAP_SYS_AUDITCONTROL or if that task should require no special permissions
316633b4545SEric Paris	  but should instead only allow setting its loginuid if it was never
317633b4545SEric Paris	  previously set.  On systems which use systemd or a similar central
318633b4545SEric Paris	  process to restart login services this should be set to true.  On older
319633b4545SEric Paris	  systems in which an admin would typically have to directly stop and
320633b4545SEric Paris	  start processes this should be set to false.  Setting this to true allows
321633b4545SEric Paris	  one to drop potentially dangerous capabilites from the login tasks,
322633b4545SEric Paris	  but may not be backwards compatible with older init systems.
323633b4545SEric Paris
324d9817ebeSThomas Gleixnersource "kernel/irq/Kconfig"
325764e0da1SThomas Gleixnersource "kernel/time/Kconfig"
326d9817ebeSThomas Gleixner
327391dc69cSFrederic Weisbeckermenu "CPU/Task time and stats accounting"
328391dc69cSFrederic Weisbecker
329fdf9c356SFrederic Weisbeckerchoice
330fdf9c356SFrederic Weisbecker	prompt "Cputime accounting"
331fdf9c356SFrederic Weisbecker	default TICK_CPU_ACCOUNTING if !PPC64
332fdf9c356SFrederic Weisbecker	default VIRT_CPU_ACCOUNTING if PPC64
333fdf9c356SFrederic Weisbecker
334fdf9c356SFrederic Weisbecker# Kind of a stub config for the pure tick based cputime accounting
335fdf9c356SFrederic Weisbeckerconfig TICK_CPU_ACCOUNTING
336fdf9c356SFrederic Weisbecker	bool "Simple tick based cputime accounting"
337fdf9c356SFrederic Weisbecker	depends on !S390
338fdf9c356SFrederic Weisbecker	help
339fdf9c356SFrederic Weisbecker	  This is the basic tick based cputime accounting that maintains
340fdf9c356SFrederic Weisbecker	  statistics about user, system and idle time spent on per jiffies
341fdf9c356SFrederic Weisbecker	  granularity.
342fdf9c356SFrederic Weisbecker
343fdf9c356SFrederic Weisbecker	  If unsure, say Y.
344fdf9c356SFrederic Weisbecker
345391dc69cSFrederic Weisbeckerconfig VIRT_CPU_ACCOUNTING
346391dc69cSFrederic Weisbecker	bool "Deterministic task and CPU time accounting"
347391dc69cSFrederic Weisbecker	depends on HAVE_VIRT_CPU_ACCOUNTING
348391dc69cSFrederic Weisbecker	help
349391dc69cSFrederic Weisbecker	  Select this option to enable more accurate task and CPU time
350391dc69cSFrederic Weisbecker	  accounting.  This is done by reading a CPU counter on each
351391dc69cSFrederic Weisbecker	  kernel entry and exit and on transitions within the kernel
352391dc69cSFrederic Weisbecker	  between system, softirq and hardirq state, so there is a
353391dc69cSFrederic Weisbecker	  small performance impact.  In the case of s390 or IBM POWER > 5,
354391dc69cSFrederic Weisbecker	  this also enables accounting of stolen time on logically-partitioned
355391dc69cSFrederic Weisbecker	  systems.
356391dc69cSFrederic Weisbecker
357fdf9c356SFrederic Weisbeckerconfig IRQ_TIME_ACCOUNTING
358fdf9c356SFrederic Weisbecker	bool "Fine granularity task level IRQ time accounting"
359fdf9c356SFrederic Weisbecker	depends on HAVE_IRQ_TIME_ACCOUNTING
360fdf9c356SFrederic Weisbecker	help
361fdf9c356SFrederic Weisbecker	  Select this option to enable fine granularity task irq time
362fdf9c356SFrederic Weisbecker	  accounting. This is done by reading a timestamp on each
363fdf9c356SFrederic Weisbecker	  transitions between softirq and hardirq state, so there can be a
364fdf9c356SFrederic Weisbecker	  small performance impact.
365fdf9c356SFrederic Weisbecker
366fdf9c356SFrederic Weisbecker	  If in doubt, say N here.
367fdf9c356SFrederic Weisbecker
368fdf9c356SFrederic Weisbeckerendchoice
369fdf9c356SFrederic Weisbecker
370391dc69cSFrederic Weisbeckerconfig BSD_PROCESS_ACCT
371391dc69cSFrederic Weisbecker	bool "BSD Process Accounting"
372391dc69cSFrederic Weisbecker	help
373391dc69cSFrederic Weisbecker	  If you say Y here, a user level program will be able to instruct the
374391dc69cSFrederic Weisbecker	  kernel (via a special system call) to write process accounting
375391dc69cSFrederic Weisbecker	  information to a file: whenever a process exits, information about
376391dc69cSFrederic Weisbecker	  that process will be appended to the file by the kernel.  The
377391dc69cSFrederic Weisbecker	  information includes things such as creation time, owning user,
378391dc69cSFrederic Weisbecker	  command name, memory usage, controlling terminal etc. (the complete
379391dc69cSFrederic Weisbecker	  list is in the struct acct in <file:include/linux/acct.h>).  It is
380391dc69cSFrederic Weisbecker	  up to the user level program to do useful things with this
381391dc69cSFrederic Weisbecker	  information.  This is generally a good idea, so say Y.
382391dc69cSFrederic Weisbecker
383391dc69cSFrederic Weisbeckerconfig BSD_PROCESS_ACCT_V3
384391dc69cSFrederic Weisbecker	bool "BSD Process Accounting version 3 file format"
385391dc69cSFrederic Weisbecker	depends on BSD_PROCESS_ACCT
386391dc69cSFrederic Weisbecker	default n
387391dc69cSFrederic Weisbecker	help
388391dc69cSFrederic Weisbecker	  If you say Y here, the process accounting information is written
389391dc69cSFrederic Weisbecker	  in a new file format that also logs the process IDs of each
390391dc69cSFrederic Weisbecker	  process and it's parent. Note that this file format is incompatible
391391dc69cSFrederic Weisbecker	  with previous v0/v1/v2 file formats, so you will need updated tools
392391dc69cSFrederic Weisbecker	  for processing it. A preliminary version of these tools is available
393391dc69cSFrederic Weisbecker	  at <http://www.gnu.org/software/acct/>.
394391dc69cSFrederic Weisbecker
395391dc69cSFrederic Weisbeckerconfig TASKSTATS
396391dc69cSFrederic Weisbecker	bool "Export task/process statistics through netlink (EXPERIMENTAL)"
397391dc69cSFrederic Weisbecker	depends on NET
398391dc69cSFrederic Weisbecker	default n
399391dc69cSFrederic Weisbecker	help
400391dc69cSFrederic Weisbecker	  Export selected statistics for tasks/processes through the
401391dc69cSFrederic Weisbecker	  generic netlink interface. Unlike BSD process accounting, the
402391dc69cSFrederic Weisbecker	  statistics are available during the lifetime of tasks/processes as
403391dc69cSFrederic Weisbecker	  responses to commands. Like BSD accounting, they are sent to user
404391dc69cSFrederic Weisbecker	  space on task exit.
405391dc69cSFrederic Weisbecker
406391dc69cSFrederic Weisbecker	  Say N if unsure.
407391dc69cSFrederic Weisbecker
408391dc69cSFrederic Weisbeckerconfig TASK_DELAY_ACCT
409391dc69cSFrederic Weisbecker	bool "Enable per-task delay accounting (EXPERIMENTAL)"
410391dc69cSFrederic Weisbecker	depends on TASKSTATS
411391dc69cSFrederic Weisbecker	help
412391dc69cSFrederic Weisbecker	  Collect information on time spent by a task waiting for system
413391dc69cSFrederic Weisbecker	  resources like cpu, synchronous block I/O completion and swapping
414391dc69cSFrederic Weisbecker	  in pages. Such statistics can help in setting a task's priorities
415391dc69cSFrederic Weisbecker	  relative to other tasks for cpu, io, rss limits etc.
416391dc69cSFrederic Weisbecker
417391dc69cSFrederic Weisbecker	  Say N if unsure.
418391dc69cSFrederic Weisbecker
419391dc69cSFrederic Weisbeckerconfig TASK_XACCT
420391dc69cSFrederic Weisbecker	bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
421391dc69cSFrederic Weisbecker	depends on TASKSTATS
422391dc69cSFrederic Weisbecker	help
423391dc69cSFrederic Weisbecker	  Collect extended task accounting data and send the data
424391dc69cSFrederic Weisbecker	  to userland for processing over the taskstats interface.
425391dc69cSFrederic Weisbecker
426391dc69cSFrederic Weisbecker	  Say N if unsure.
427391dc69cSFrederic Weisbecker
428391dc69cSFrederic Weisbeckerconfig TASK_IO_ACCOUNTING
429391dc69cSFrederic Weisbecker	bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
430391dc69cSFrederic Weisbecker	depends on TASK_XACCT
431391dc69cSFrederic Weisbecker	help
432391dc69cSFrederic Weisbecker	  Collect information on the number of bytes of storage I/O which this
433391dc69cSFrederic Weisbecker	  task has caused.
434391dc69cSFrederic Weisbecker
435391dc69cSFrederic Weisbecker	  Say N if unsure.
436391dc69cSFrederic Weisbecker
437391dc69cSFrederic Weisbeckerendmenu # "CPU/Task time and stats accounting"
438391dc69cSFrederic Weisbecker
439c903ff83SMike Travismenu "RCU Subsystem"
440c903ff83SMike Travis
441c903ff83SMike Travischoice
442c903ff83SMike Travis	prompt "RCU Implementation"
44331c9a24eSPaul E. McKenney	default TREE_RCU
444c903ff83SMike Travis
445c903ff83SMike Travisconfig TREE_RCU
446c903ff83SMike Travis	bool "Tree-based hierarchical RCU"
447687d7a96SPaul E. McKenney	depends on !PREEMPT && SMP
448c903ff83SMike Travis	help
449c903ff83SMike Travis	  This option selects the RCU implementation that is
450c903ff83SMike Travis	  designed for very large SMP system with hundreds or
451c17ef453SPaul E. McKenney	  thousands of CPUs.  It also scales down nicely to
452c17ef453SPaul E. McKenney	  smaller systems.
453c903ff83SMike Travis
454f41d911fSPaul E. McKenneyconfig TREE_PREEMPT_RCU
455a57eb940SPaul E. McKenney	bool "Preemptible tree-based hierarchical RCU"
4568008e129SPaul E. McKenney	depends on PREEMPT && SMP
457f41d911fSPaul E. McKenney	help
458f41d911fSPaul E. McKenney	  This option selects the RCU implementation that is
459f41d911fSPaul E. McKenney	  designed for very large SMP systems with hundreds or
460f41d911fSPaul E. McKenney	  thousands of CPUs, but for which real-time response
461bbe3eae8SPaul E. McKenney	  is also required.  It also scales down nicely to
462bbe3eae8SPaul E. McKenney	  smaller systems.
463f41d911fSPaul E. McKenney
4649b1d82faSPaul E. McKenneyconfig TINY_RCU
4659b1d82faSPaul E. McKenney	bool "UP-only small-memory-footprint RCU"
4668008e129SPaul E. McKenney	depends on !PREEMPT && !SMP
4679b1d82faSPaul E. McKenney	help
4689b1d82faSPaul E. McKenney	  This option selects the RCU implementation that is
4699b1d82faSPaul E. McKenney	  designed for UP systems from which real-time response
4709b1d82faSPaul E. McKenney	  is not required.  This option greatly reduces the
4719b1d82faSPaul E. McKenney	  memory footprint of RCU.
4729b1d82faSPaul E. McKenney
473a57eb940SPaul E. McKenneyconfig TINY_PREEMPT_RCU
474a57eb940SPaul E. McKenney	bool "Preemptible UP-only small-memory-footprint RCU"
4758008e129SPaul E. McKenney	depends on PREEMPT && !SMP
476a57eb940SPaul E. McKenney	help
477a57eb940SPaul E. McKenney	  This option selects the RCU implementation that is designed
478a57eb940SPaul E. McKenney	  for real-time UP systems.  This option greatly reduces the
479a57eb940SPaul E. McKenney	  memory footprint of RCU.
480a57eb940SPaul E. McKenney
481c903ff83SMike Travisendchoice
482c903ff83SMike Travis
483a57eb940SPaul E. McKenneyconfig PREEMPT_RCU
484a57eb940SPaul E. McKenney	def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
485a57eb940SPaul E. McKenney	help
486a57eb940SPaul E. McKenney	  This option enables preemptible-RCU code that is common between
487a57eb940SPaul E. McKenney	  the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
488a57eb940SPaul E. McKenney
4892b1d5024SFrederic Weisbeckerconfig RCU_USER_QS
4902b1d5024SFrederic Weisbecker	bool "Consider userspace as in RCU extended quiescent state"
4912b1d5024SFrederic Weisbecker	depends on HAVE_RCU_USER_QS && SMP
4922b1d5024SFrederic Weisbecker	help
4932b1d5024SFrederic Weisbecker	  This option sets hooks on kernel / userspace boundaries and
4942b1d5024SFrederic Weisbecker	  puts RCU in extended quiescent state when the CPU runs in
4952b1d5024SFrederic Weisbecker	  userspace. It means that when a CPU runs in userspace, it is
4962b1d5024SFrederic Weisbecker	  excluded from the global RCU state machine and thus doesn't
4972b1d5024SFrederic Weisbecker	  to keep the timer tick on for RCU.
4982b1d5024SFrederic Weisbecker
4991fd2b442SFrederic Weisbeckerconfig RCU_USER_QS_FORCE
5001fd2b442SFrederic Weisbecker	bool "Force userspace extended QS by default"
5011fd2b442SFrederic Weisbecker	depends on RCU_USER_QS
5021fd2b442SFrederic Weisbecker	help
5031fd2b442SFrederic Weisbecker	  Set the hooks in user/kernel boundaries by default in order to
5041fd2b442SFrederic Weisbecker	  test this feature that treats userspace as an extended quiescent
5051fd2b442SFrederic Weisbecker	  state until we have a real user like a full adaptive nohz option.
5061fd2b442SFrederic Weisbecker
507c903ff83SMike Travisconfig RCU_FANOUT
508c903ff83SMike Travis	int "Tree-based hierarchical RCU fanout value"
509c903ff83SMike Travis	range 2 64 if 64BIT
510c903ff83SMike Travis	range 2 32 if !64BIT
511f41d911fSPaul E. McKenney	depends on TREE_RCU || TREE_PREEMPT_RCU
512c903ff83SMike Travis	default 64 if 64BIT
513c903ff83SMike Travis	default 32 if !64BIT
514c903ff83SMike Travis	help
515c903ff83SMike Travis	  This option controls the fanout of hierarchical implementations
516c903ff83SMike Travis	  of RCU, allowing RCU to work efficiently on machines with
5174d87ffadSPaul E. McKenney	  large numbers of CPUs.  This value must be at least the fourth
5184d87ffadSPaul E. McKenney	  root of NR_CPUS, which allows NR_CPUS to be insanely large.
5194d87ffadSPaul E. McKenney	  The default value of RCU_FANOUT should be used for production
5204d87ffadSPaul E. McKenney	  systems, but if you are stress-testing the RCU implementation
5214d87ffadSPaul E. McKenney	  itself, small RCU_FANOUT values allow you to test large-system
5224d87ffadSPaul E. McKenney	  code paths on small(er) systems.
523c903ff83SMike Travis
524c903ff83SMike Travis	  Select a specific number if testing RCU itself.
525c903ff83SMike Travis	  Take the default if unsure.
526c903ff83SMike Travis
5278932a63dSPaul E. McKenneyconfig RCU_FANOUT_LEAF
5288932a63dSPaul E. McKenney	int "Tree-based hierarchical RCU leaf-level fanout value"
5298932a63dSPaul E. McKenney	range 2 RCU_FANOUT if 64BIT
5308932a63dSPaul E. McKenney	range 2 RCU_FANOUT if !64BIT
5318932a63dSPaul E. McKenney	depends on TREE_RCU || TREE_PREEMPT_RCU
5328932a63dSPaul E. McKenney	default 16
5338932a63dSPaul E. McKenney	help
5348932a63dSPaul E. McKenney	  This option controls the leaf-level fanout of hierarchical
5358932a63dSPaul E. McKenney	  implementations of RCU, and allows trading off cache misses
5368932a63dSPaul E. McKenney	  against lock contention.  Systems that synchronize their
5378932a63dSPaul E. McKenney	  scheduling-clock interrupts for energy-efficiency reasons will
5388932a63dSPaul E. McKenney	  want the default because the smaller leaf-level fanout keeps
5398932a63dSPaul E. McKenney	  lock contention levels acceptably low.  Very large systems
5408932a63dSPaul E. McKenney	  (hundreds or thousands of CPUs) will instead want to set this
5418932a63dSPaul E. McKenney	  value to the maximum value possible in order to reduce the
5428932a63dSPaul E. McKenney	  number of cache misses incurred during RCU's grace-period
5438932a63dSPaul E. McKenney	  initialization.  These systems tend to run CPU-bound, and thus
5448932a63dSPaul E. McKenney	  are not helped by synchronized interrupts, and thus tend to
5458932a63dSPaul E. McKenney	  skew them, which reduces lock contention enough that large
5468932a63dSPaul E. McKenney	  leaf-level fanouts work well.
5478932a63dSPaul E. McKenney
5488932a63dSPaul E. McKenney	  Select a specific number if testing RCU itself.
5498932a63dSPaul E. McKenney
5508932a63dSPaul E. McKenney	  Select the maximum permissible value for large systems.
5518932a63dSPaul E. McKenney
5528932a63dSPaul E. McKenney	  Take the default if unsure.
5538932a63dSPaul E. McKenney
554c903ff83SMike Travisconfig RCU_FANOUT_EXACT
555c903ff83SMike Travis	bool "Disable tree-based hierarchical RCU auto-balancing"
556f41d911fSPaul E. McKenney	depends on TREE_RCU || TREE_PREEMPT_RCU
557c903ff83SMike Travis	default n
558c903ff83SMike Travis	help
559c903ff83SMike Travis	  This option forces use of the exact RCU_FANOUT value specified,
560c903ff83SMike Travis	  regardless of imbalances in the hierarchy.  This is useful for
561c903ff83SMike Travis	  testing RCU itself, and might one day be useful on systems with
562c903ff83SMike Travis	  strong NUMA behavior.
563c903ff83SMike Travis
564c903ff83SMike Travis	  Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
565c903ff83SMike Travis
566c903ff83SMike Travis	  Say N if unsure.
567c903ff83SMike Travis
5688bd93a2cSPaul E. McKenneyconfig RCU_FAST_NO_HZ
5698bd93a2cSPaul E. McKenney	bool "Accelerate last non-dyntick-idle CPU's grace periods"
570b807fbffSPaul E. McKenney	depends on NO_HZ && SMP
5718bd93a2cSPaul E. McKenney	default n
5728bd93a2cSPaul E. McKenney	help
5738bd93a2cSPaul E. McKenney	  This option causes RCU to attempt to accelerate grace periods
574b807fbffSPaul E. McKenney	  in order to allow CPUs to enter dynticks-idle state more
575b807fbffSPaul E. McKenney	  quickly.  On the other hand, this option increases the overhead
576b807fbffSPaul E. McKenney	  of the dynticks-idle checking, particularly on systems with
577b807fbffSPaul E. McKenney	  large numbers of CPUs.
5788bd93a2cSPaul E. McKenney
5798bd93a2cSPaul E. McKenney	  Say Y if energy efficiency is critically important, particularly
5808bd93a2cSPaul E. McKenney	  	if you have relatively few CPUs.
5818bd93a2cSPaul E. McKenney
5828bd93a2cSPaul E. McKenney	  Say N if you are unsure.
5838bd93a2cSPaul E. McKenney
584c903ff83SMike Travisconfig TREE_RCU_TRACE
585f41d911fSPaul E. McKenney	def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
586c903ff83SMike Travis	select DEBUG_FS
587c903ff83SMike Travis	help
588f41d911fSPaul E. McKenney	  This option provides tracing for the TREE_RCU and
589f41d911fSPaul E. McKenney	  TREE_PREEMPT_RCU implementations, permitting Makefile to
590f41d911fSPaul E. McKenney	  trivially select kernel/rcutree_trace.c.
591c903ff83SMike Travis
59224278d14SPaul E. McKenneyconfig RCU_BOOST
59324278d14SPaul E. McKenney	bool "Enable RCU priority boosting"
59427f4d280SPaul E. McKenney	depends on RT_MUTEXES && PREEMPT_RCU
59524278d14SPaul E. McKenney	default n
59624278d14SPaul E. McKenney	help
59724278d14SPaul E. McKenney	  This option boosts the priority of preempted RCU readers that
59824278d14SPaul E. McKenney	  block the current preemptible RCU grace period for too long.
59924278d14SPaul E. McKenney	  This option also prevents heavy loads from blocking RCU
60024278d14SPaul E. McKenney	  callback invocation for all flavors of RCU.
60124278d14SPaul E. McKenney
60224278d14SPaul E. McKenney	  Say Y here if you are working with real-time apps or heavy loads
60324278d14SPaul E. McKenney	  Say N here if you are unsure.
60424278d14SPaul E. McKenney
60524278d14SPaul E. McKenneyconfig RCU_BOOST_PRIO
60624278d14SPaul E. McKenney	int "Real-time priority to boost RCU readers to"
60724278d14SPaul E. McKenney	range 1 99
60824278d14SPaul E. McKenney	depends on RCU_BOOST
60924278d14SPaul E. McKenney	default 1
61024278d14SPaul E. McKenney	help
611c9336643SPaul E. McKenney	  This option specifies the real-time priority to which long-term
612c9336643SPaul E. McKenney	  preempted RCU readers are to be boosted.  If you are working
613c9336643SPaul E. McKenney	  with a real-time application that has one or more CPU-bound
614c9336643SPaul E. McKenney	  threads running at a real-time priority level, you should set
615c9336643SPaul E. McKenney	  RCU_BOOST_PRIO to a priority higher then the highest-priority
616c9336643SPaul E. McKenney	  real-time CPU-bound thread.  The default RCU_BOOST_PRIO value
617c9336643SPaul E. McKenney	  of 1 is appropriate in the common case, which is real-time
618c9336643SPaul E. McKenney	  applications that do not have any CPU-bound threads.
619c9336643SPaul E. McKenney
620c9336643SPaul E. McKenney	  Some real-time applications might not have a single real-time
621c9336643SPaul E. McKenney	  thread that saturates a given CPU, but instead might have
622c9336643SPaul E. McKenney	  multiple real-time threads that, taken together, fully utilize
623c9336643SPaul E. McKenney	  that CPU.  In this case, you should set RCU_BOOST_PRIO to
624c9336643SPaul E. McKenney	  a priority higher than the lowest-priority thread that is
625c9336643SPaul E. McKenney	  conspiring to prevent the CPU from running any non-real-time
626c9336643SPaul E. McKenney	  tasks.  For example, if one thread at priority 10 and another
627c9336643SPaul E. McKenney	  thread at priority 5 are between themselves fully consuming
628c9336643SPaul E. McKenney	  the CPU time on a given CPU, then RCU_BOOST_PRIO should be
629c9336643SPaul E. McKenney	  set to priority 6 or higher.
63024278d14SPaul E. McKenney
63124278d14SPaul E. McKenney	  Specify the real-time priority, or take the default if unsure.
63224278d14SPaul E. McKenney
63324278d14SPaul E. McKenneyconfig RCU_BOOST_DELAY
63424278d14SPaul E. McKenney	int "Milliseconds to delay boosting after RCU grace-period start"
63524278d14SPaul E. McKenney	range 0 3000
63624278d14SPaul E. McKenney	depends on RCU_BOOST
63724278d14SPaul E. McKenney	default 500
63824278d14SPaul E. McKenney	help
63924278d14SPaul E. McKenney	  This option specifies the time to wait after the beginning of
64024278d14SPaul E. McKenney	  a given grace period before priority-boosting preempted RCU
64124278d14SPaul E. McKenney	  readers blocking that grace period.  Note that any RCU reader
64224278d14SPaul E. McKenney	  blocking an expedited RCU grace period is boosted immediately.
64324278d14SPaul E. McKenney
64424278d14SPaul E. McKenney	  Accept the default if unsure.
64524278d14SPaul E. McKenney
646c903ff83SMike Travisendmenu # "RCU Subsystem"
647c903ff83SMike Travis
6481da177e4SLinus Torvaldsconfig IKCONFIG
649f2443ab6SRoss Biro	tristate "Kernel .config support"
6501da177e4SLinus Torvalds	---help---
6511da177e4SLinus Torvalds	  This option enables the complete Linux kernel ".config" file
6521da177e4SLinus Torvalds	  contents to be saved in the kernel. It provides documentation
6531da177e4SLinus Torvalds	  of which kernel options are used in a running kernel or in an
6541da177e4SLinus Torvalds	  on-disk kernel.  This information can be extracted from the kernel
6551da177e4SLinus Torvalds	  image file with the script scripts/extract-ikconfig and used as
6561da177e4SLinus Torvalds	  input to rebuild the current kernel or to build another kernel.
6571da177e4SLinus Torvalds	  It can also be extracted from a running kernel by reading
6581da177e4SLinus Torvalds	  /proc/config.gz if enabled (below).
6591da177e4SLinus Torvalds
6601da177e4SLinus Torvaldsconfig IKCONFIG_PROC
6611da177e4SLinus Torvalds	bool "Enable access to .config through /proc/config.gz"
6621da177e4SLinus Torvalds	depends on IKCONFIG && PROC_FS
6631da177e4SLinus Torvalds	---help---
6641da177e4SLinus Torvalds	  This option enables access to the kernel configuration file
6651da177e4SLinus Torvalds	  through /proc/config.gz.
6661da177e4SLinus Torvalds
667794543a2SAlistair John Strachanconfig LOG_BUF_SHIFT
668794543a2SAlistair John Strachan	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
669794543a2SAlistair John Strachan	range 12 21
670f17a32e9SAdrian Bunk	default 17
671794543a2SAlistair John Strachan	help
672794543a2SAlistair John Strachan	  Select kernel log buffer size as a power of 2.
673f17a32e9SAdrian Bunk	  Examples:
674f17a32e9SAdrian Bunk	  	     17 => 128 KB
675f17a32e9SAdrian Bunk		     16 => 64 KB
676f17a32e9SAdrian Bunk	             15 => 32 KB
677f17a32e9SAdrian Bunk	             14 => 16 KB
678794543a2SAlistair John Strachan		     13 =>  8 KB
679794543a2SAlistair John Strachan		     12 =>  4 KB
680794543a2SAlistair John Strachan
6815cdc38f9SKAMEZAWA Hiroyuki#
6825cdc38f9SKAMEZAWA Hiroyuki# Architectures with an unreliable sched_clock() should select this:
6835cdc38f9SKAMEZAWA Hiroyuki#
6845cdc38f9SKAMEZAWA Hiroyukiconfig HAVE_UNSTABLE_SCHED_CLOCK
6855cdc38f9SKAMEZAWA Hiroyuki	bool
6865cdc38f9SKAMEZAWA Hiroyuki
68723964d2dSLi Zefanmenuconfig CGROUPS
68823964d2dSLi Zefan	boolean "Control Group support"
6890dea1168SKirill A. Shutemov	depends on EVENTFD
690ddbcc7e8SPaul Menage	help
69123964d2dSLi Zefan	  This option adds support for grouping sets of processes together, for
6925cdc38f9SKAMEZAWA Hiroyuki	  use with process control subsystems such as Cpusets, CFS, memory
6935cdc38f9SKAMEZAWA Hiroyuki	  controls or device isolation.
6945cdc38f9SKAMEZAWA Hiroyuki	  See
6955cdc38f9SKAMEZAWA Hiroyuki		- Documentation/scheduler/sched-design-CFS.txt	(CFS)
69645ce80fbSLi Zefan		- Documentation/cgroups/ (features for grouping, isolation
69745ce80fbSLi Zefan					  and resource control)
698ddbcc7e8SPaul Menage
699ddbcc7e8SPaul Menage	  Say N if unsure.
700ddbcc7e8SPaul Menage
70123964d2dSLi Zefanif CGROUPS
70223964d2dSLi Zefan
703006cb992SPaul Menageconfig CGROUP_DEBUG
704006cb992SPaul Menage	bool "Example debug cgroup subsystem"
705418d7d87SPaul Menage	default n
706006cb992SPaul Menage	help
707006cb992SPaul Menage	  This option enables a simple cgroup subsystem that
708006cb992SPaul Menage	  exports useful debugging information about the cgroups
70923964d2dSLi Zefan	  framework.
710006cb992SPaul Menage
71123964d2dSLi Zefan	  Say N if unsure.
712006cb992SPaul Menage
713dc52ddc0SMatt Helsleyconfig CGROUP_FREEZER
71423964d2dSLi Zefan	bool "Freezer cgroup subsystem"
715dc52ddc0SMatt Helsley	help
716dc52ddc0SMatt Helsley	  Provides a way to freeze and unfreeze all tasks in a
717dc52ddc0SMatt Helsley	  cgroup.
718dc52ddc0SMatt Helsley
71908ce5f16SSerge E. Hallynconfig CGROUP_DEVICE
72008ce5f16SSerge E. Hallyn	bool "Device controller for cgroups"
72108ce5f16SSerge E. Hallyn	help
72208ce5f16SSerge E. Hallyn	  Provides a cgroup implementing whitelists for devices which
72308ce5f16SSerge E. Hallyn	  a process in the cgroup can mknod or open.
72408ce5f16SSerge E. Hallyn
7251da177e4SLinus Torvaldsconfig CPUSETS
7261da177e4SLinus Torvalds	bool "Cpuset support"
7271da177e4SLinus Torvalds	help
728d9fd8a6dSRandy Dunlap	  This option will let you create and manage CPUSETs which
7291da177e4SLinus Torvalds	  allow dynamically partitioning a system into sets of CPUs and
7301da177e4SLinus Torvalds	  Memory Nodes and assigning tasks to run only within those sets.
7311da177e4SLinus Torvalds	  This is primarily useful on large SMP or NUMA systems.
7321da177e4SLinus Torvalds
7331da177e4SLinus Torvalds	  Say N if unsure.
7341da177e4SLinus Torvalds
73523964d2dSLi Zefanconfig PROC_PID_CPUSET
73623964d2dSLi Zefan	bool "Include legacy /proc/<pid>/cpuset file"
73723964d2dSLi Zefan	depends on CPUSETS
73823964d2dSLi Zefan	default y
73923964d2dSLi Zefan
740d842de87SSrivatsa Vaddagiriconfig CGROUP_CPUACCT
741d842de87SSrivatsa Vaddagiri	bool "Simple CPU accounting cgroup subsystem"
742d842de87SSrivatsa Vaddagiri	help
743d842de87SSrivatsa Vaddagiri	  Provides a simple Resource Controller for monitoring the
74423964d2dSLi Zefan	  total CPU consumed by the tasks in a cgroup.
745d842de87SSrivatsa Vaddagiri
746e552b661SPavel Emelianovconfig RESOURCE_COUNTERS
747e552b661SPavel Emelianov	bool "Resource counters"
748e552b661SPavel Emelianov	help
749e552b661SPavel Emelianov	  This option enables controller independent resource accounting
75023964d2dSLi Zefan	  infrastructure that works with cgroups.
751e552b661SPavel Emelianov
752c255a458SAndrew Mortonconfig MEMCG
75300f0b825SBalbir Singh	bool "Memory Resource Controller for Control Groups"
75479ae9c29SDaniel Lezcano	depends on RESOURCE_COUNTERS
755cf475ad2SBalbir Singh	select MM_OWNER
75600f0b825SBalbir Singh	help
75784ad6d70SKAMEZAWA Hiroyuki	  Provides a memory resource controller that manages both anonymous
75821acb9caSThadeu Lima de Souza Cascardo	  memory and page cache. (See Documentation/cgroups/memory.txt)
75900f0b825SBalbir Singh
76000f0b825SBalbir Singh	  Note that setting this option increases fixed memory overhead
76184ad6d70SKAMEZAWA Hiroyuki	  associated with each page of memory in the system. By this,
76284ad6d70SKAMEZAWA Hiroyuki	  20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
76384ad6d70SKAMEZAWA Hiroyuki	  usage tracking struct at boot. Total amount of this is printed out
76484ad6d70SKAMEZAWA Hiroyuki	  at boot.
76500f0b825SBalbir Singh
76600f0b825SBalbir Singh	  Only enable when you're ok with these trade offs and really
76784ad6d70SKAMEZAWA Hiroyuki	  sure you need the memory resource controller. Even when you enable
76884ad6d70SKAMEZAWA Hiroyuki	  this, you can set "cgroup_disable=memory" at your boot option to
76984ad6d70SKAMEZAWA Hiroyuki	  disable memory resource controller and you can avoid overheads.
770c9d5409fSLi Zefan	  (and lose benefits of memory resource controller)
77100f0b825SBalbir Singh
772cf475ad2SBalbir Singh	  This config option also selects MM_OWNER config option, which
773cf475ad2SBalbir Singh	  could in turn add some fork/exit overhead.
774cf475ad2SBalbir Singh
775c255a458SAndrew Mortonconfig MEMCG_SWAP
77665e0e811SKAMEZAWA Hiroyuki	bool "Memory Resource Controller Swap Extension"
777c255a458SAndrew Morton	depends on MEMCG && SWAP
778c077719bSKAMEZAWA Hiroyuki	help
779c077719bSKAMEZAWA Hiroyuki	  Add swap management feature to memory resource controller. When you
780c077719bSKAMEZAWA Hiroyuki	  enable this, you can limit mem+swap usage per cgroup. In other words,
781c077719bSKAMEZAWA Hiroyuki	  when you disable this, memory resource controller has no cares to
782c077719bSKAMEZAWA Hiroyuki	  usage of swap...a process can exhaust all of the swap. This extension
783c077719bSKAMEZAWA Hiroyuki	  is useful when you want to avoid exhaustion swap but this itself
784c077719bSKAMEZAWA Hiroyuki	  adds more overheads and consumes memory for remembering information.
785c077719bSKAMEZAWA Hiroyuki	  Especially if you use 32bit system or small memory system, please
786c077719bSKAMEZAWA Hiroyuki	  be careful about enabling this. When memory resource controller
787c077719bSKAMEZAWA Hiroyuki	  is disabled by boot option, this will be automatically disabled and
788c077719bSKAMEZAWA Hiroyuki	  there will be no overhead from this. Even when you set this config=y,
78900a66d29SWANG Cong	  if boot option "swapaccount=0" is set, swap will not be accounted.
790627991a2SKAMEZAWA Hiroyuki	  Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
791627991a2SKAMEZAWA Hiroyuki	  size is 4096bytes, 512k per 1Gbytes of swap.
792c255a458SAndrew Mortonconfig MEMCG_SWAP_ENABLED
793a42c390cSMichal Hocko	bool "Memory Resource Controller Swap Extension enabled by default"
794c255a458SAndrew Morton	depends on MEMCG_SWAP
795a42c390cSMichal Hocko	default y
796a42c390cSMichal Hocko	help
797a42c390cSMichal Hocko	  Memory Resource Controller Swap Extension comes with its price in
798a42c390cSMichal Hocko	  a bigger memory consumption. General purpose distribution kernels
79943d547f9SJim Cromie	  which want to enable the feature but keep it disabled by default
800a42c390cSMichal Hocko	  and let the user enable it by swapaccount boot command line
801a42c390cSMichal Hocko	  parameter should have this option unselected.
802a42c390cSMichal Hocko	  For those who want to have the feature enabled by default should
803a42c390cSMichal Hocko	  select this option (if, for some reason, they need to disable it
80400a66d29SWANG Cong	  then swapaccount=0 does the trick).
805c255a458SAndrew Mortonconfig MEMCG_KMEM
806e5671dfaSGlauber Costa	bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
807c255a458SAndrew Morton	depends on MEMCG && EXPERIMENTAL
808e5671dfaSGlauber Costa	default n
809e5671dfaSGlauber Costa	help
810e5671dfaSGlauber Costa	  The Kernel Memory extension for Memory Resource Controller can limit
811e5671dfaSGlauber Costa	  the amount of memory used by kernel objects in the system. Those are
812e5671dfaSGlauber Costa	  fundamentally different from the entities handled by the standard
813e5671dfaSGlauber Costa	  Memory Controller, which are page-based, and can be swapped. Users of
814e5671dfaSGlauber Costa	  the kmem extension can use it to guarantee that no group of processes
815e5671dfaSGlauber Costa	  will ever exhaust kernel resources alone.
816c077719bSKAMEZAWA Hiroyuki
8172bc64a20SAneesh Kumar K.Vconfig CGROUP_HUGETLB
8182bc64a20SAneesh Kumar K.V	bool "HugeTLB Resource Controller for Control Groups"
8192bc64a20SAneesh Kumar K.V	depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL
8202bc64a20SAneesh Kumar K.V	default n
8212bc64a20SAneesh Kumar K.V	help
8222bc64a20SAneesh Kumar K.V	  Provides a cgroup Resource Controller for HugeTLB pages.
8232bc64a20SAneesh Kumar K.V	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
8242bc64a20SAneesh Kumar K.V	  The limit is enforced during page fault. Since HugeTLB doesn't
8252bc64a20SAneesh Kumar K.V	  support page reclaim, enforcing the limit at page fault time implies
8262bc64a20SAneesh Kumar K.V	  that, the application will get SIGBUS signal if it tries to access
8272bc64a20SAneesh Kumar K.V	  HugeTLB pages beyond its limit. This requires the application to know
8282bc64a20SAneesh Kumar K.V	  beforehand how much HugeTLB pages it would require for its use. The
8292bc64a20SAneesh Kumar K.V	  control group is tracked in the third page lru pointer. This means
8302bc64a20SAneesh Kumar K.V	  that we cannot use the controller with huge page less than 3 pages.
8312bc64a20SAneesh Kumar K.V
832e5d1367fSStephane Eranianconfig CGROUP_PERF
833e5d1367fSStephane Eranian	bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
834e5d1367fSStephane Eranian	depends on PERF_EVENTS && CGROUPS
835e5d1367fSStephane Eranian	help
836e5d1367fSStephane Eranian	  This option extends the per-cpu mode to restrict monitoring to
8372d0f2520SLi Zefan	  threads which belong to the cgroup specified and run on the
838e5d1367fSStephane Eranian	  designated cpu.
839e5d1367fSStephane Eranian
840e5d1367fSStephane Eranian	  Say N if unsure.
841e5d1367fSStephane Eranian
8427c941438SDhaval Gianimenuconfig CGROUP_SCHED
8437c941438SDhaval Giani	bool "Group CPU scheduler"
8447c941438SDhaval Giani	default n
8457c941438SDhaval Giani	help
8467c941438SDhaval Giani	  This feature lets CPU scheduler recognize task groups and control CPU
8477c941438SDhaval Giani	  bandwidth allocation to such task groups. It uses cgroups to group
8487c941438SDhaval Giani	  tasks.
8497c941438SDhaval Giani
8507c941438SDhaval Gianiif CGROUP_SCHED
8517c941438SDhaval Gianiconfig FAIR_GROUP_SCHED
8527c941438SDhaval Giani	bool "Group scheduling for SCHED_OTHER"
8537c941438SDhaval Giani	depends on CGROUP_SCHED
8547c941438SDhaval Giani	default CGROUP_SCHED
8557c941438SDhaval Giani
856ab84d31eSPaul Turnerconfig CFS_BANDWIDTH
857ab84d31eSPaul Turner	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
858ab84d31eSPaul Turner	depends on EXPERIMENTAL
859ab84d31eSPaul Turner	depends on FAIR_GROUP_SCHED
860ab84d31eSPaul Turner	default n
861ab84d31eSPaul Turner	help
862ab84d31eSPaul Turner	  This option allows users to define CPU bandwidth rates (limits) for
863ab84d31eSPaul Turner	  tasks running within the fair group scheduler.  Groups with no limit
864ab84d31eSPaul Turner	  set are considered to be unconstrained and will run with no
865ab84d31eSPaul Turner	  restriction.
866ab84d31eSPaul Turner	  See tip/Documentation/scheduler/sched-bwc.txt for more information.
867ab84d31eSPaul Turner
8687c941438SDhaval Gianiconfig RT_GROUP_SCHED
8697c941438SDhaval Giani	bool "Group scheduling for SCHED_RR/FIFO"
8707c941438SDhaval Giani	depends on EXPERIMENTAL
8717c941438SDhaval Giani	depends on CGROUP_SCHED
8727c941438SDhaval Giani	default n
8737c941438SDhaval Giani	help
8747c941438SDhaval Giani	  This feature lets you explicitly allocate real CPU bandwidth
87532bd7eb5SLi Zefan	  to task groups. If enabled, it will also make it impossible to
8767c941438SDhaval Giani	  schedule realtime tasks for non-root users until you allocate
8777c941438SDhaval Giani	  realtime bandwidth for them.
8787c941438SDhaval Giani	  See Documentation/scheduler/sched-rt-group.txt for more information.
8797c941438SDhaval Giani
8807c941438SDhaval Gianiendif #CGROUP_SCHED
8817c941438SDhaval Giani
882afc24d49SVivek Goyalconfig BLK_CGROUP
88332e380aeSTejun Heo	bool "Block IO controller"
88479ae9c29SDaniel Lezcano	depends on BLOCK
885afc24d49SVivek Goyal	default n
886afc24d49SVivek Goyal	---help---
887afc24d49SVivek Goyal	Generic block IO controller cgroup interface. This is the common
888afc24d49SVivek Goyal	cgroup interface which should be used by various IO controlling
889afc24d49SVivek Goyal	policies.
890afc24d49SVivek Goyal
891afc24d49SVivek Goyal	Currently, CFQ IO scheduler uses it to recognize task groups and
892afc24d49SVivek Goyal	control disk bandwidth allocation (proportional time slice allocation)
893e43473b7SVivek Goyal	to such task groups. It is also used by bio throttling logic in
894e43473b7SVivek Goyal	block layer to implement upper limit in IO rates on a device.
895afc24d49SVivek Goyal
896afc24d49SVivek Goyal	This option only enables generic Block IO controller infrastructure.
897e43473b7SVivek Goyal	One needs to also enable actual IO controlling logic/policy. For
89879e2e759SMichael Witten	enabling proportional weight division of disk bandwidth in CFQ, set
89979e2e759SMichael Witten	CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
900c5e0591aSMichael Witten	CONFIG_BLK_DEV_THROTTLING=y.
901afc24d49SVivek Goyal
902afc24d49SVivek Goyal	See Documentation/cgroups/blkio-controller.txt for more information.
903afc24d49SVivek Goyal
904afc24d49SVivek Goyalconfig DEBUG_BLK_CGROUP
905afc24d49SVivek Goyal	bool "Enable Block IO controller debugging"
906afc24d49SVivek Goyal	depends on BLK_CGROUP
907afc24d49SVivek Goyal	default n
908afc24d49SVivek Goyal	---help---
909afc24d49SVivek Goyal	Enable some debugging help. Currently it exports additional stat
910afc24d49SVivek Goyal	files in a cgroup which can be useful for debugging.
911afc24d49SVivek Goyal
91223964d2dSLi Zefanendif # CGROUPS
913c077719bSKAMEZAWA Hiroyuki
914067bce1aSCyrill Gorcunovconfig CHECKPOINT_RESTORE
915067bce1aSCyrill Gorcunov	bool "Checkpoint/restore support" if EXPERT
916067bce1aSCyrill Gorcunov	default n
917067bce1aSCyrill Gorcunov	help
918067bce1aSCyrill Gorcunov	  Enables additional kernel features in a sake of checkpoint/restore.
919067bce1aSCyrill Gorcunov	  In particular it adds auxiliary prctl codes to setup process text,
920067bce1aSCyrill Gorcunov	  data and heap segment sizes, and a few additional /proc filesystem
921067bce1aSCyrill Gorcunov	  entries.
922067bce1aSCyrill Gorcunov
923067bce1aSCyrill Gorcunov	  If unsure, say N here.
924067bce1aSCyrill Gorcunov
9258dd2a82cSDaniel Lezcanomenuconfig NAMESPACES
9266a108a14SDavid Rientjes	bool "Namespaces support" if EXPERT
9276a108a14SDavid Rientjes	default !EXPERT
928c5289a69SPavel Emelyanov	help
929c5289a69SPavel Emelyanov	  Provides the way to make tasks work with different objects using
930c5289a69SPavel Emelyanov	  the same id. For example same IPC id may refer to different objects
931c5289a69SPavel Emelyanov	  or same user id or pid may refer to different tasks when used in
932c5289a69SPavel Emelyanov	  different namespaces.
933c5289a69SPavel Emelyanov
9348dd2a82cSDaniel Lezcanoif NAMESPACES
9358dd2a82cSDaniel Lezcano
93658bfdd6dSPavel Emelyanovconfig UTS_NS
93758bfdd6dSPavel Emelyanov	bool "UTS namespace"
93817a6d441SDaniel Lezcano	default y
93958bfdd6dSPavel Emelyanov	help
94058bfdd6dSPavel Emelyanov	  In this namespace tasks see different info provided with the
94158bfdd6dSPavel Emelyanov	  uname() system call
94258bfdd6dSPavel Emelyanov
943ae5e1b22SPavel Emelyanovconfig IPC_NS
944ae5e1b22SPavel Emelyanov	bool "IPC namespace"
9458dd2a82cSDaniel Lezcano	depends on (SYSVIPC || POSIX_MQUEUE)
94617a6d441SDaniel Lezcano	default y
947ae5e1b22SPavel Emelyanov	help
948ae5e1b22SPavel Emelyanov	  In this namespace tasks work with IPC ids which correspond to
949614b84cfSSerge E. Hallyn	  different IPC objects in different namespaces.
950ae5e1b22SPavel Emelyanov
951aee16ce7SPavel Emelyanovconfig USER_NS
952aee16ce7SPavel Emelyanov	bool "User namespace (EXPERIMENTAL)"
9538dd2a82cSDaniel Lezcano	depends on EXPERIMENTAL
954e1c972b6SEric W. Biederman	depends on UIDGID_CONVERTED
9555673a94cSEric W. Biederman	select UIDGID_STRICT_TYPE_CHECKS
956e1c972b6SEric W. Biederman
9575673a94cSEric W. Biederman	default n
958aee16ce7SPavel Emelyanov	help
959aee16ce7SPavel Emelyanov	  This allows containers, i.e. vservers, to use user namespaces
960aee16ce7SPavel Emelyanov	  to provide different user info for different servers.
961aee16ce7SPavel Emelyanov	  If unsure, say N.
962aee16ce7SPavel Emelyanov
96374bd59bbSPavel Emelyanovconfig PID_NS
9649bd38c2cSDaniel Lezcano	bool "PID Namespaces"
96517a6d441SDaniel Lezcano	default y
96674bd59bbSPavel Emelyanov	help
96712d2b8f9SHeikki Orsila	  Support process id namespaces.  This allows having multiple
968692105b8SMatt LaPlante	  processes with the same pid as long as they are in different
96974bd59bbSPavel Emelyanov	  pid namespaces.  This is a building block of containers.
97074bd59bbSPavel Emelyanov
971d6eb633fSMatt Helsleyconfig NET_NS
972d6eb633fSMatt Helsley	bool "Network namespace"
9738dd2a82cSDaniel Lezcano	depends on NET
97417a6d441SDaniel Lezcano	default y
975d6eb633fSMatt Helsley	help
976d6eb633fSMatt Helsley	  Allow user space to create what appear to be multiple instances
977d6eb633fSMatt Helsley	  of the network stack.
978d6eb633fSMatt Helsley
9798dd2a82cSDaniel Lezcanoendif # NAMESPACES
9808dd2a82cSDaniel Lezcano
981e1c972b6SEric W. Biedermanconfig UIDGID_CONVERTED
982e1c972b6SEric W. Biederman	# True if all of the selected software conmponents are known
983e1c972b6SEric W. Biederman	# to have uid_t and gid_t converted to kuid_t and kgid_t
984e1c972b6SEric W. Biederman	# where appropriate and are otherwise safe to use with
985e1c972b6SEric W. Biederman	# the user namespace.
986e1c972b6SEric W. Biederman	bool
987e1c972b6SEric W. Biederman	default y
988e1c972b6SEric W. Biederman
989e1c972b6SEric W. Biederman	# Networking
990e1c972b6SEric W. Biederman	depends on NET_9P = n
991e1c972b6SEric W. Biederman
992e1c972b6SEric W. Biederman	# Filesystems
993e1c972b6SEric W. Biederman	depends on 9P_FS = n
994e1c972b6SEric W. Biederman	depends on AFS_FS = n
995e1c972b6SEric W. Biederman	depends on AUTOFS4_FS = n
996e1c972b6SEric W. Biederman	depends on CEPH_FS = n
997e1c972b6SEric W. Biederman	depends on CIFS = n
998e1c972b6SEric W. Biederman	depends on CODA_FS = n
999e1c972b6SEric W. Biederman	depends on FUSE_FS = n
1000e1c972b6SEric W. Biederman	depends on GFS2_FS = n
1001e1c972b6SEric W. Biederman	depends on NCP_FS = n
1002e1c972b6SEric W. Biederman	depends on NFSD = n
1003e1c972b6SEric W. Biederman	depends on NFS_FS = n
1004e1c972b6SEric W. Biederman	depends on OCFS2_FS = n
1005e1c972b6SEric W. Biederman	depends on XFS_FS = n
1006e1c972b6SEric W. Biederman
10075673a94cSEric W. Biedermanconfig UIDGID_STRICT_TYPE_CHECKS
10085673a94cSEric W. Biederman	bool "Require conversions between uid/gids and their internal representation"
1009e1c972b6SEric W. Biederman	depends on UIDGID_CONVERTED
10105673a94cSEric W. Biederman	default n
10115673a94cSEric W. Biederman	help
10125673a94cSEric W. Biederman	 While the nececessary conversions are being added to all subsystems this option allows
10135673a94cSEric W. Biederman	 the code to continue to build for unconverted subsystems.
10145673a94cSEric W. Biederman
10155673a94cSEric W. Biederman	 Say Y here if you want the strict type checking enabled
10165673a94cSEric W. Biederman
10175091faa4SMike Galbraithconfig SCHED_AUTOGROUP
10185091faa4SMike Galbraith	bool "Automatic process group scheduling"
10195091faa4SMike Galbraith	select EVENTFD
10205091faa4SMike Galbraith	select CGROUPS
10215091faa4SMike Galbraith	select CGROUP_SCHED
10225091faa4SMike Galbraith	select FAIR_GROUP_SCHED
10235091faa4SMike Galbraith	help
10245091faa4SMike Galbraith	  This option optimizes the scheduler for common desktop workloads by
10255091faa4SMike Galbraith	  automatically creating and populating task groups.  This separation
10265091faa4SMike Galbraith	  of workloads isolates aggressive CPU burners (like build jobs) from
10275091faa4SMike Galbraith	  desktop applications.  Task group autogeneration is currently based
10285091faa4SMike Galbraith	  upon task session.
10295091faa4SMike Galbraith
10307af37becSDaniel Lezcanoconfig MM_OWNER
10317af37becSDaniel Lezcano	bool
10327af37becSDaniel Lezcano
10337af37becSDaniel Lezcanoconfig SYSFS_DEPRECATED
10345d6a4ea5SFerenc Wagner	bool "Enable deprecated sysfs features to support old userspace tools"
10357af37becSDaniel Lezcano	depends on SYSFS
10367af37becSDaniel Lezcano	default n
10377af37becSDaniel Lezcano	help
10387af37becSDaniel Lezcano	  This option adds code that switches the layout of the "block" class
10397af37becSDaniel Lezcano	  devices, to not show up in /sys/class/block/, but only in
10407af37becSDaniel Lezcano	  /sys/block/.
10417af37becSDaniel Lezcano
10427af37becSDaniel Lezcano	  This switch is only active when the sysfs.deprecated=1 boot option is
10437af37becSDaniel Lezcano	  passed or the SYSFS_DEPRECATED_V2 option is set.
10447af37becSDaniel Lezcano
10457af37becSDaniel Lezcano	  This option allows new kernels to run on old distributions and tools,
10467af37becSDaniel Lezcano	  which might get confused by /sys/class/block/. Since 2007/2008 all
10477af37becSDaniel Lezcano	  major distributions and tools handle this just fine.
10487af37becSDaniel Lezcano
10497af37becSDaniel Lezcano	  Recent distributions and userspace tools after 2009/2010 depend on
10507af37becSDaniel Lezcano	  the existence of /sys/class/block/, and will not work with this
10517af37becSDaniel Lezcano	  option enabled.
10527af37becSDaniel Lezcano
10537af37becSDaniel Lezcano	  Only if you are using a new kernel on an old distribution, you might
10547af37becSDaniel Lezcano	  need to say Y here.
10557af37becSDaniel Lezcano
10567af37becSDaniel Lezcanoconfig SYSFS_DEPRECATED_V2
10575d6a4ea5SFerenc Wagner	bool "Enable deprecated sysfs features by default"
10587af37becSDaniel Lezcano	default n
10597af37becSDaniel Lezcano	depends on SYSFS
10607af37becSDaniel Lezcano	depends on SYSFS_DEPRECATED
10617af37becSDaniel Lezcano	help
10627af37becSDaniel Lezcano	  Enable deprecated sysfs by default.
10637af37becSDaniel Lezcano
10647af37becSDaniel Lezcano	  See the CONFIG_SYSFS_DEPRECATED option for more details about this
10657af37becSDaniel Lezcano	  option.
10667af37becSDaniel Lezcano
10677af37becSDaniel Lezcano	  Only if you are using a new kernel on an old distribution, you might
10687af37becSDaniel Lezcano	  need to say Y here. Even then, odds are you would not need it
10697af37becSDaniel Lezcano	  enabled, you can always pass the boot option if absolutely necessary.
10707af37becSDaniel Lezcano
10717af37becSDaniel Lezcanoconfig RELAY
10727af37becSDaniel Lezcano	bool "Kernel->user space relay support (formerly relayfs)"
10737af37becSDaniel Lezcano	help
10747af37becSDaniel Lezcano	  This option enables support for relay interface support in
10757af37becSDaniel Lezcano	  certain file systems (such as debugfs).
10767af37becSDaniel Lezcano	  It is designed to provide an efficient mechanism for tools and
10777af37becSDaniel Lezcano	  facilities to relay large amounts of data from kernel space to
10787af37becSDaniel Lezcano	  user space.
10797af37becSDaniel Lezcano
10807af37becSDaniel Lezcano	  If unsure, say N.
10817af37becSDaniel Lezcano
1082f991633dSDimitri Gorokhovikconfig BLK_DEV_INITRD
1083f991633dSDimitri Gorokhovik	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1084f991633dSDimitri Gorokhovik	depends on BROKEN || !FRV
1085f991633dSDimitri Gorokhovik	help
1086f991633dSDimitri Gorokhovik	  The initial RAM filesystem is a ramfs which is loaded by the
1087f991633dSDimitri Gorokhovik	  boot loader (loadlin or lilo) and that is mounted as root
1088f991633dSDimitri Gorokhovik	  before the normal boot procedure. It is typically used to
1089f991633dSDimitri Gorokhovik	  load modules needed to mount the "real" root file system,
1090f991633dSDimitri Gorokhovik	  etc. See <file:Documentation/initrd.txt> for details.
1091f991633dSDimitri Gorokhovik
1092f991633dSDimitri Gorokhovik	  If RAM disk support (BLK_DEV_RAM) is also included, this
1093f991633dSDimitri Gorokhovik	  also enables initial RAM disk (initrd) support and adds
1094f991633dSDimitri Gorokhovik	  15 Kbytes (more on some other architectures) to the kernel size.
1095f991633dSDimitri Gorokhovik
1096f991633dSDimitri Gorokhovik	  If unsure say Y.
1097f991633dSDimitri Gorokhovik
1098c33df4eaSJean-Paul Samanif BLK_DEV_INITRD
1099c33df4eaSJean-Paul Saman
1100dbec4866SSam Ravnborgsource "usr/Kconfig"
1101dbec4866SSam Ravnborg
1102c33df4eaSJean-Paul Samanendif
1103c33df4eaSJean-Paul Saman
1104c45b4f1fSLinus Torvaldsconfig CC_OPTIMIZE_FOR_SIZE
110596fffeb4SIngo Molnar	bool "Optimize for size"
1106c45b4f1fSLinus Torvalds	help
1107c45b4f1fSLinus Torvalds	  Enabling this option will pass "-Os" instead of "-O2" to gcc
1108c45b4f1fSLinus Torvalds	  resulting in a smaller kernel.
1109c45b4f1fSLinus Torvalds
1110775a7229Sjkacur	  If unsure, say Y.
1111c45b4f1fSLinus Torvalds
11120847062aSRandy Dunlapconfig SYSCTL
11130847062aSRandy Dunlap	bool
11140847062aSRandy Dunlap
1115b943c460SRandy Dunlapconfig ANON_INODES
1116b943c460SRandy Dunlap	bool
1117b943c460SRandy Dunlap
11186a108a14SDavid Rientjesmenuconfig EXPERT
11196a108a14SDavid Rientjes	bool "Configure standard kernel features (expert users)"
1120f505c553SJosh Triplett	# Unhide debug options, to make the on-by-default options visible
1121f505c553SJosh Triplett	select DEBUG_KERNEL
11221da177e4SLinus Torvalds	help
11231da177e4SLinus Torvalds	  This option allows certain base kernel options and settings
11241da177e4SLinus Torvalds          to be disabled or tweaked. This is for specialized
11251da177e4SLinus Torvalds          environments which can tolerate a "non-standard" kernel.
11261da177e4SLinus Torvalds          Only use this if you really know what you are doing.
11271da177e4SLinus Torvalds
1128*af1839ebSCatalin Marinasconfig HAVE_UID16
1129*af1839ebSCatalin Marinas	bool
1130*af1839ebSCatalin Marinas
1131ae81f9e3SChuck Ebbertconfig UID16
11326a108a14SDavid Rientjes	bool "Enable 16-bit UID system calls" if EXPERT
1133*af1839ebSCatalin Marinas	depends on HAVE_UID16
1134ae81f9e3SChuck Ebbert	default y
1135ae81f9e3SChuck Ebbert	help
1136ae81f9e3SChuck Ebbert	  This enables the legacy 16-bit UID syscall wrappers.
1137ae81f9e3SChuck Ebbert
1138b89a8171SEric W. Biedermanconfig SYSCTL_SYSCALL
11396a108a14SDavid Rientjes	bool "Sysctl syscall support" if EXPERT
114026a7034bSEric W. Biederman	depends on PROC_SYSCTL
1141c736de60SWANG Cong	default n
1142b89a8171SEric W. Biederman	select SYSCTL
1143b89a8171SEric W. Biederman	---help---
114413bb7e37SEric W. Biederman	  sys_sysctl uses binary paths that have been found challenging
114513bb7e37SEric W. Biederman	  to properly maintain and use.  The interface in /proc/sys
114613bb7e37SEric W. Biederman	  using paths with ascii names is now the primary path to this
114713bb7e37SEric W. Biederman	  information.
1148b89a8171SEric W. Biederman
114913bb7e37SEric W. Biederman	  Almost nothing using the binary sysctl interface so if you are
115013bb7e37SEric W. Biederman	  trying to save some space it is probably safe to disable this,
115113bb7e37SEric W. Biederman	  making your kernel marginally smaller.
1152b89a8171SEric W. Biederman
1153c736de60SWANG Cong	  If unsure say N here.
1154ae81f9e3SChuck Ebbert
11551da177e4SLinus Torvaldsconfig KALLSYMS
11566a108a14SDavid Rientjes	 bool "Load all symbols for debugging/ksymoops" if EXPERT
11571da177e4SLinus Torvalds	 default y
11581da177e4SLinus Torvalds	 help
11591da177e4SLinus Torvalds	   Say Y here to let the kernel print out symbolic crash information and
11601da177e4SLinus Torvalds	   symbolic stack backtraces. This increases the size of the kernel
11611da177e4SLinus Torvalds	   somewhat, as all symbols have to be loaded into the kernel image.
11621da177e4SLinus Torvalds
11631da177e4SLinus Torvaldsconfig KALLSYMS_ALL
11641da177e4SLinus Torvalds	bool "Include all symbols in kallsyms"
11651da177e4SLinus Torvalds	depends on DEBUG_KERNEL && KALLSYMS
11661da177e4SLinus Torvalds	help
116771a83ec7SArtem Bityutskiy	   Normally kallsyms only contains the symbols of functions for nicer
116871a83ec7SArtem Bityutskiy	   OOPS messages and backtraces (i.e., symbols from the text and inittext
116971a83ec7SArtem Bityutskiy	   sections). This is sufficient for most cases. And only in very rare
117071a83ec7SArtem Bityutskiy	   cases (e.g., when a debugger is used) all symbols are required (e.g.,
117171a83ec7SArtem Bityutskiy	   names of variables from the data sections, etc).
11721da177e4SLinus Torvalds
117371a83ec7SArtem Bityutskiy	   This option makes sure that all symbols are loaded into the kernel
117471a83ec7SArtem Bityutskiy	   image (i.e., symbols from all sections) in cost of increased kernel
117571a83ec7SArtem Bityutskiy	   size (depending on the kernel configuration, it may be 300KiB or
117671a83ec7SArtem Bityutskiy	   something like this).
11771da177e4SLinus Torvalds
117871a83ec7SArtem Bityutskiy	   Say N unless you really need all symbols.
1179d59745ceSMatt Mackall
1180712f47ceSGreg Kroah-Hartmanconfig HOTPLUG
118145f035abSGreg Kroah-Hartman	def_bool y
1182712f47ceSGreg Kroah-Hartman
1183d59745ceSMatt Mackallconfig PRINTK
1184d59745ceSMatt Mackall	default y
11856a108a14SDavid Rientjes	bool "Enable support for printk" if EXPERT
1186d59745ceSMatt Mackall	help
1187d59745ceSMatt Mackall	  This option enables normal printk support. Removing it
1188d59745ceSMatt Mackall	  eliminates most of the message strings from the kernel image
1189d59745ceSMatt Mackall	  and makes the kernel more or less silent. As this makes it
1190d59745ceSMatt Mackall	  very difficult to diagnose system problems, saying N here is
1191d59745ceSMatt Mackall	  strongly discouraged.
1192d59745ceSMatt Mackall
1193c8538a7aSMatt Mackallconfig BUG
11946a108a14SDavid Rientjes	bool "BUG() support" if EXPERT
1195c8538a7aSMatt Mackall	default y
1196c8538a7aSMatt Mackall	help
1197c8538a7aSMatt Mackall          Disabling this option eliminates support for BUG and WARN, reducing
1198c8538a7aSMatt Mackall          the size of your kernel image and potentially quietly ignoring
1199c8538a7aSMatt Mackall          numerous fatal conditions. You should only consider disabling this
1200c8538a7aSMatt Mackall          option for embedded systems with no facilities for reporting errors.
1201c8538a7aSMatt Mackall          Just say Y.
1202c8538a7aSMatt Mackall
1203708e9a79SMatt Mackallconfig ELF_CORE
1204046d662fSAlex Kelly	depends on COREDUMP
1205708e9a79SMatt Mackall	default y
12066a108a14SDavid Rientjes	bool "Enable ELF core dumps" if EXPERT
1207708e9a79SMatt Mackall	help
1208708e9a79SMatt Mackall	  Enable support for generating core dumps. Disabling saves about 4k.
1209708e9a79SMatt Mackall
12108761f1abSRalf Baechle
1211e5e1d3cbSStas Sergeevconfig PCSPKR_PLATFORM
12126a108a14SDavid Rientjes	bool "Enable PC-Speaker support" if EXPERT
12138761f1abSRalf Baechle	depends on HAVE_PCSPKR_PLATFORM
121415f304b6SRalf Baechle	select I8253_LOCK
1215e5e1d3cbSStas Sergeev	default y
1216e5e1d3cbSStas Sergeev	help
1217e5e1d3cbSStas Sergeev          This option allows to disable the internal PC-Speaker
1218e5e1d3cbSStas Sergeev          support, saving some memory.
1219e5e1d3cbSStas Sergeev
12208761f1abSRalf Baechleconfig HAVE_PCSPKR_PLATFORM
12218761f1abSRalf Baechle	bool
12228761f1abSRalf Baechle
12231da177e4SLinus Torvaldsconfig BASE_FULL
12241da177e4SLinus Torvalds	default y
12256a108a14SDavid Rientjes	bool "Enable full-sized data structures for core" if EXPERT
12261da177e4SLinus Torvalds	help
12271da177e4SLinus Torvalds	  Disabling this option reduces the size of miscellaneous core
12281da177e4SLinus Torvalds	  kernel data structures. This saves memory on small machines,
12291da177e4SLinus Torvalds	  but may reduce performance.
12301da177e4SLinus Torvalds
12311da177e4SLinus Torvaldsconfig FUTEX
12326a108a14SDavid Rientjes	bool "Enable futex support" if EXPERT
12331da177e4SLinus Torvalds	default y
123423f78d4aSIngo Molnar	select RT_MUTEXES
12351da177e4SLinus Torvalds	help
12361da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
12371da177e4SLinus Torvalds	  support for "fast userspace mutexes".  The resulting kernel may not
12381da177e4SLinus Torvalds	  run glibc-based applications correctly.
12391da177e4SLinus Torvalds
12401da177e4SLinus Torvaldsconfig EPOLL
12416a108a14SDavid Rientjes	bool "Enable eventpoll support" if EXPERT
12421da177e4SLinus Torvalds	default y
1243448e3ceeSAdrian Bunk	select ANON_INODES
12441da177e4SLinus Torvalds	help
12451da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
12461da177e4SLinus Torvalds	  support for epoll family of system calls.
12471da177e4SLinus Torvalds
1248fba2afaaSDavide Libenziconfig SIGNALFD
12496a108a14SDavid Rientjes	bool "Enable signalfd() system call" if EXPERT
1250448e3ceeSAdrian Bunk	select ANON_INODES
1251fba2afaaSDavide Libenzi	default y
1252fba2afaaSDavide Libenzi	help
1253fba2afaaSDavide Libenzi	  Enable the signalfd() system call that allows to receive signals
1254fba2afaaSDavide Libenzi	  on a file descriptor.
1255fba2afaaSDavide Libenzi
1256fba2afaaSDavide Libenzi	  If unsure, say Y.
1257fba2afaaSDavide Libenzi
1258b215e283SDavide Libenziconfig TIMERFD
12596a108a14SDavid Rientjes	bool "Enable timerfd() system call" if EXPERT
1260448e3ceeSAdrian Bunk	select ANON_INODES
1261b215e283SDavide Libenzi	default y
1262b215e283SDavide Libenzi	help
1263b215e283SDavide Libenzi	  Enable the timerfd() system call that allows to receive timer
1264b215e283SDavide Libenzi	  events on a file descriptor.
1265b215e283SDavide Libenzi
1266b215e283SDavide Libenzi	  If unsure, say Y.
1267b215e283SDavide Libenzi
1268e1ad7468SDavide Libenziconfig EVENTFD
12696a108a14SDavid Rientjes	bool "Enable eventfd() system call" if EXPERT
1270448e3ceeSAdrian Bunk	select ANON_INODES
1271e1ad7468SDavide Libenzi	default y
1272e1ad7468SDavide Libenzi	help
1273e1ad7468SDavide Libenzi	  Enable the eventfd() system call that allows to receive both
1274e1ad7468SDavide Libenzi	  kernel notification (ie. KAIO) or userspace notifications.
1275e1ad7468SDavide Libenzi
1276e1ad7468SDavide Libenzi	  If unsure, say Y.
1277e1ad7468SDavide Libenzi
12781da177e4SLinus Torvaldsconfig SHMEM
12796a108a14SDavid Rientjes	bool "Use full shmem filesystem" if EXPERT
12801da177e4SLinus Torvalds	default y
12811da177e4SLinus Torvalds	depends on MMU
12821da177e4SLinus Torvalds	help
12831da177e4SLinus Torvalds	  The shmem is an internal filesystem used to manage shared memory.
12841da177e4SLinus Torvalds	  It is backed by swap and manages resource limits. It is also exported
12851da177e4SLinus Torvalds	  to userspace as tmpfs if TMPFS is enabled. Disabling this
12861da177e4SLinus Torvalds	  option replaces shmem and tmpfs with the much simpler ramfs code,
12871da177e4SLinus Torvalds	  which may be appropriate on small systems without swap.
12881da177e4SLinus Torvalds
1289ebf3f09cSThomas Petazzoniconfig AIO
12906a108a14SDavid Rientjes	bool "Enable AIO support" if EXPERT
1291ebf3f09cSThomas Petazzoni	default y
1292ebf3f09cSThomas Petazzoni	help
1293ebf3f09cSThomas Petazzoni	  This option enables POSIX asynchronous I/O which may by used
1294ebf3f09cSThomas Petazzoni          by some high performance threaded applications. Disabling
1295ebf3f09cSThomas Petazzoni          this option saves about 7k.
1296ebf3f09cSThomas Petazzoni
12976befe5f6SRandy Dunlapconfig EMBEDDED
12986befe5f6SRandy Dunlap	bool "Embedded system"
12996befe5f6SRandy Dunlap	select EXPERT
13006befe5f6SRandy Dunlap	help
13016befe5f6SRandy Dunlap	  This option should be enabled if compiling the kernel for
13026befe5f6SRandy Dunlap	  an embedded system so certain expert options are available
13036befe5f6SRandy Dunlap	  for configuration.
13046befe5f6SRandy Dunlap
1305cdd6c482SIngo Molnarconfig HAVE_PERF_EVENTS
13060793a61dSThomas Gleixner	bool
1307018df72dSMike Frysinger	help
1308018df72dSMike Frysinger	  See tools/perf/design.txt for details.
13090793a61dSThomas Gleixner
1310906010b2SPeter Zijlstraconfig PERF_USE_VMALLOC
1311906010b2SPeter Zijlstra	bool
1312906010b2SPeter Zijlstra	help
1313906010b2SPeter Zijlstra	  See tools/perf/design.txt for details
1314906010b2SPeter Zijlstra
131557c0c15bSIngo Molnarmenu "Kernel Performance Events And Counters"
13160793a61dSThomas Gleixner
1317cdd6c482SIngo Molnarconfig PERF_EVENTS
131857c0c15bSIngo Molnar	bool "Kernel performance events and counters"
1319392d65a9SRobert Richter	default y if PROFILING
1320cdd6c482SIngo Molnar	depends on HAVE_PERF_EVENTS
13214c59e467SIngo Molnar	select ANON_INODES
1322e360adbeSPeter Zijlstra	select IRQ_WORK
13230793a61dSThomas Gleixner	help
132457c0c15bSIngo Molnar	  Enable kernel support for various performance events provided
132557c0c15bSIngo Molnar	  by software and hardware.
13260793a61dSThomas Gleixner
1327dd77038dSThadeu Lima de Souza Cascardo	  Software events are supported either built-in or via the
132857c0c15bSIngo Molnar	  use of generic tracepoints.
132957c0c15bSIngo Molnar
133057c0c15bSIngo Molnar	  Most modern CPUs support performance events via performance
133157c0c15bSIngo Molnar	  counter registers. These registers count the number of certain
13320793a61dSThomas Gleixner	  types of hw events: such as instructions executed, cachemisses
13330793a61dSThomas Gleixner	  suffered, or branches mis-predicted - without slowing down the
13340793a61dSThomas Gleixner	  kernel or applications. These registers can also trigger interrupts
13350793a61dSThomas Gleixner	  when a threshold number of events have passed - and can thus be
13360793a61dSThomas Gleixner	  used to profile the code that runs on that CPU.
13370793a61dSThomas Gleixner
133857c0c15bSIngo Molnar	  The Linux Performance Event subsystem provides an abstraction of
1339dd77038dSThadeu Lima de Souza Cascardo	  these software and hardware event capabilities, available via a
134057c0c15bSIngo Molnar	  system call and used by the "perf" utility in tools/perf/. It
13410793a61dSThomas Gleixner	  provides per task and per CPU counters, and it provides event
13420793a61dSThomas Gleixner	  capabilities on top of those.
13430793a61dSThomas Gleixner
13440793a61dSThomas Gleixner	  Say Y if unsure.
13450793a61dSThomas Gleixner
1346906010b2SPeter Zijlstraconfig DEBUG_PERF_USE_VMALLOC
1347906010b2SPeter Zijlstra	default n
1348906010b2SPeter Zijlstra	bool "Debug: use vmalloc to back perf mmap() buffers"
1349906010b2SPeter Zijlstra	depends on PERF_EVENTS && DEBUG_KERNEL
1350906010b2SPeter Zijlstra	select PERF_USE_VMALLOC
1351906010b2SPeter Zijlstra	help
1352906010b2SPeter Zijlstra	 Use vmalloc memory to back perf mmap() buffers.
1353906010b2SPeter Zijlstra
1354906010b2SPeter Zijlstra	 Mostly useful for debugging the vmalloc code on platforms
1355906010b2SPeter Zijlstra	 that don't require it.
1356906010b2SPeter Zijlstra
1357906010b2SPeter Zijlstra	 Say N if unsure.
1358906010b2SPeter Zijlstra
13590793a61dSThomas Gleixnerendmenu
13600793a61dSThomas Gleixner
1361f8891e5eSChristoph Lameterconfig VM_EVENT_COUNTERS
1362f8891e5eSChristoph Lameter	default y
13636a108a14SDavid Rientjes	bool "Enable VM event counters for /proc/vmstat" if EXPERT
1364f8891e5eSChristoph Lameter	help
13652aea4fb6SPaul Jackson	  VM event counters are needed for event counts to be shown.
13662aea4fb6SPaul Jackson	  This option allows the disabling of the VM event counters
13676a108a14SDavid Rientjes	  on EXPERT systems.  /proc/vmstat will only show page counts
13682aea4fb6SPaul Jackson	  if VM event counters are disabled.
1369f8891e5eSChristoph Lameter
13703d137310SThomas Petazzoniconfig PCI_QUIRKS
13713d137310SThomas Petazzoni	default y
13726a108a14SDavid Rientjes	bool "Enable PCI quirk workarounds" if EXPERT
137361cfc7e4SGeert Uytterhoeven	depends on PCI
13743d137310SThomas Petazzoni	help
13753d137310SThomas Petazzoni	  This enables workarounds for various PCI chipset
13763d137310SThomas Petazzoni          bugs/quirks. Disable this only if your target machine is
13773d137310SThomas Petazzoni          unaffected by PCI quirks.
13783d137310SThomas Petazzoni
137941ecc55bSChristoph Lameterconfig SLUB_DEBUG
138041ecc55bSChristoph Lameter	default y
13816a108a14SDavid Rientjes	bool "Enable SLUB debugging support" if EXPERT
1382f6acb635SChristoph Lameter	depends on SLUB && SYSFS
138341ecc55bSChristoph Lameter	help
138441ecc55bSChristoph Lameter	  SLUB has extensive debug support features. Disabling these can
138541ecc55bSChristoph Lameter	  result in significant savings in code size. This also disables
138641ecc55bSChristoph Lameter	  SLUB sysfs support. /sys/slab will not exist and there will be
138741ecc55bSChristoph Lameter	  no support for cache validation etc.
138841ecc55bSChristoph Lameter
1389b943c460SRandy Dunlapconfig COMPAT_BRK
1390b943c460SRandy Dunlap	bool "Disable heap randomization"
1391b943c460SRandy Dunlap	default y
1392b943c460SRandy Dunlap	help
1393b943c460SRandy Dunlap	  Randomizing heap placement makes heap exploits harder, but it
1394b943c460SRandy Dunlap	  also breaks ancient binaries (including anything libc5 based).
1395b943c460SRandy Dunlap	  This option changes the bootup default to heap randomization
1396692105b8SMatt LaPlante	  disabled, and can be overridden at runtime by setting
1397b943c460SRandy Dunlap	  /proc/sys/kernel/randomize_va_space to 2.
1398b943c460SRandy Dunlap
1399b943c460SRandy Dunlap	  On non-ancient distros (post-2000 ones) N is usually a safe choice.
1400b943c460SRandy Dunlap
140181819f0fSChristoph Lameterchoice
140281819f0fSChristoph Lameter	prompt "Choose SLAB allocator"
1403a0acd820SChristoph Lameter	default SLUB
140481819f0fSChristoph Lameter	help
140581819f0fSChristoph Lameter	   This option allows to select a slab allocator.
140681819f0fSChristoph Lameter
140781819f0fSChristoph Lameterconfig SLAB
140881819f0fSChristoph Lameter	bool "SLAB"
140981819f0fSChristoph Lameter	help
141081819f0fSChristoph Lameter	  The regular slab allocator that is established and known to work
141134013886SChristoph Lameter	  well in all environments. It organizes cache hot objects in
141202f56210SSimon Arlott	  per cpu and per node queues.
141381819f0fSChristoph Lameter
141481819f0fSChristoph Lameterconfig SLUB
141581819f0fSChristoph Lameter	bool "SLUB (Unqueued Allocator)"
141681819f0fSChristoph Lameter	help
141781819f0fSChristoph Lameter	   SLUB is a slab allocator that minimizes cache line usage
141881819f0fSChristoph Lameter	   instead of managing queues of cached objects (SLAB approach).
141981819f0fSChristoph Lameter	   Per cpu caching is realized using slabs of objects instead
142081819f0fSChristoph Lameter	   of queues of objects. SLUB can use memory efficiently
142102f56210SSimon Arlott	   and has enhanced diagnostics. SLUB is the default choice for
142202f56210SSimon Arlott	   a slab allocator.
142381819f0fSChristoph Lameter
142481819f0fSChristoph Lameterconfig SLOB
14256a108a14SDavid Rientjes	depends on EXPERT
142681819f0fSChristoph Lameter	bool "SLOB (Simple Allocator)"
142781819f0fSChristoph Lameter	help
142837291458SMatt Mackall	   SLOB replaces the stock allocator with a drastically simpler
142937291458SMatt Mackall	   allocator. SLOB is generally more space efficient but
143037291458SMatt Mackall	   does not perform as well on large systems.
143181819f0fSChristoph Lameter
143281819f0fSChristoph Lameterendchoice
143381819f0fSChristoph Lameter
1434ea637639SJie Zhangconfig MMAP_ALLOW_UNINITIALIZED
1435ea637639SJie Zhang	bool "Allow mmapped anonymous memory to be uninitialized"
14366a108a14SDavid Rientjes	depends on EXPERT && !MMU
1437ea637639SJie Zhang	default n
1438ea637639SJie Zhang	help
1439ea637639SJie Zhang	  Normally, and according to the Linux spec, anonymous memory obtained
1440ea637639SJie Zhang	  from mmap() has it's contents cleared before it is passed to
1441ea637639SJie Zhang	  userspace.  Enabling this config option allows you to request that
1442ea637639SJie Zhang	  mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1443ea637639SJie Zhang	  providing a huge performance boost.  If this option is not enabled,
1444ea637639SJie Zhang	  then the flag will be ignored.
1445ea637639SJie Zhang
1446ea637639SJie Zhang	  This is taken advantage of by uClibc's malloc(), and also by
1447ea637639SJie Zhang	  ELF-FDPIC binfmt's brk and stack allocator.
1448ea637639SJie Zhang
1449ea637639SJie Zhang	  Because of the obvious security issues, this option should only be
1450ea637639SJie Zhang	  enabled on embedded devices where you control what is run in
1451ea637639SJie Zhang	  userspace.  Since that isn't generally a problem on no-MMU systems,
1452ea637639SJie Zhang	  it is normally safe to say Y here.
1453ea637639SJie Zhang
1454ea637639SJie Zhang	  See Documentation/nommu-mmap.txt for more information.
1455ea637639SJie Zhang
1456125e5645SMathieu Desnoyersconfig PROFILING
1457b309a294SRobert Richter	bool "Profiling support"
1458125e5645SMathieu Desnoyers	help
1459125e5645SMathieu Desnoyers	  Say Y here to enable the extended profiling support mechanisms used
1460125e5645SMathieu Desnoyers	  by profilers such as OProfile.
1461125e5645SMathieu Desnoyers
14625f87f112SIngo Molnar#
14635f87f112SIngo Molnar# Place an empty function call at each tracepoint site. Can be
14645f87f112SIngo Molnar# dynamically changed for a probe function.
14655f87f112SIngo Molnar#
146697e1c18eSMathieu Desnoyersconfig TRACEPOINTS
14675f87f112SIngo Molnar	bool
146897e1c18eSMathieu Desnoyers
1469fb32e03fSMathieu Desnoyerssource "arch/Kconfig"
1470fb32e03fSMathieu Desnoyers
14711da177e4SLinus Torvaldsendmenu		# General setup
14721da177e4SLinus Torvalds
1473ee7e5516SDmitry Baryshkovconfig HAVE_GENERIC_DMA_COHERENT
1474ee7e5516SDmitry Baryshkov	bool
1475ee7e5516SDmitry Baryshkov	default n
1476ee7e5516SDmitry Baryshkov
1477158a9624SLinus Torvaldsconfig SLABINFO
1478158a9624SLinus Torvalds	bool
1479158a9624SLinus Torvalds	depends on PROC_FS
14800f389ec6SChristoph Lameter	depends on SLAB || SLUB_DEBUG
1481158a9624SLinus Torvalds	default y
1482158a9624SLinus Torvalds
1483ae81f9e3SChuck Ebbertconfig RT_MUTEXES
1484ae81f9e3SChuck Ebbert	boolean
1485ae81f9e3SChuck Ebbert
14861da177e4SLinus Torvaldsconfig BASE_SMALL
14871da177e4SLinus Torvalds	int
14881da177e4SLinus Torvalds	default 0 if BASE_FULL
14891da177e4SLinus Torvalds	default 1 if !BASE_FULL
14901da177e4SLinus Torvalds
149166da5733SJan Engelhardtmenuconfig MODULES
14921da177e4SLinus Torvalds	bool "Enable loadable module support"
14931da177e4SLinus Torvalds	help
14941da177e4SLinus Torvalds	  Kernel modules are small pieces of compiled code which can
14951da177e4SLinus Torvalds	  be inserted in the running kernel, rather than being
14961da177e4SLinus Torvalds	  permanently built into the kernel.  You use the "modprobe"
14971da177e4SLinus Torvalds	  tool to add (and sometimes remove) them.  If you say Y here,
14981da177e4SLinus Torvalds	  many parts of the kernel can be built as modules (by
14991da177e4SLinus Torvalds	  answering M instead of Y where indicated): this is most
15001da177e4SLinus Torvalds	  useful for infrequently used options which are not required
15011da177e4SLinus Torvalds	  for booting.  For more information, see the man pages for
15021da177e4SLinus Torvalds	  modprobe, lsmod, modinfo, insmod and rmmod.
15031da177e4SLinus Torvalds
15041da177e4SLinus Torvalds	  If you say Y here, you will need to run "make
15051da177e4SLinus Torvalds	  modules_install" to put the modules under /lib/modules/
15061da177e4SLinus Torvalds	  where modprobe can find them (you may need to be root to do
15071da177e4SLinus Torvalds	  this).
15081da177e4SLinus Torvalds
15091da177e4SLinus Torvalds	  If unsure, say Y.
15101da177e4SLinus Torvalds
15110b0de144SRobert P. J. Dayif MODULES
15120b0de144SRobert P. J. Day
1513826e4506SLinus Torvaldsconfig MODULE_FORCE_LOAD
1514826e4506SLinus Torvalds	bool "Forced module loading"
1515826e4506SLinus Torvalds	default n
1516826e4506SLinus Torvalds	help
151791e37a79SRusty Russell	  Allow loading of modules without version information (ie. modprobe
151891e37a79SRusty Russell	  --force).  Forced module loading sets the 'F' (forced) taint flag and
151991e37a79SRusty Russell	  is usually a really bad idea.
1520826e4506SLinus Torvalds
15211da177e4SLinus Torvaldsconfig MODULE_UNLOAD
15221da177e4SLinus Torvalds	bool "Module unloading"
15231da177e4SLinus Torvalds	help
15241da177e4SLinus Torvalds	  Without this option you will not be able to unload any
15251da177e4SLinus Torvalds	  modules (note that some modules may not be unloadable
1526f7f5b675SDenys Vlasenko	  anyway), which makes your kernel smaller, faster
1527f7f5b675SDenys Vlasenko	  and simpler.  If unsure, say Y.
15281da177e4SLinus Torvalds
15291da177e4SLinus Torvaldsconfig MODULE_FORCE_UNLOAD
15301da177e4SLinus Torvalds	bool "Forced module unloading"
15311da177e4SLinus Torvalds	depends on MODULE_UNLOAD && EXPERIMENTAL
15321da177e4SLinus Torvalds	help
15331da177e4SLinus Torvalds	  This option allows you to force a module to unload, even if the
15341da177e4SLinus Torvalds	  kernel believes it is unsafe: the kernel will remove the module
15351da177e4SLinus Torvalds	  without waiting for anyone to stop using it (using the -f option to
15361da177e4SLinus Torvalds	  rmmod).  This is mainly for kernel developers and desperate users.
15371da177e4SLinus Torvalds	  If unsure, say N.
15381da177e4SLinus Torvalds
15391da177e4SLinus Torvaldsconfig MODVERSIONS
15400d541643SSam Ravnborg	bool "Module versioning support"
15411da177e4SLinus Torvalds	help
15421da177e4SLinus Torvalds	  Usually, you have to use modules compiled with your kernel.
15431da177e4SLinus Torvalds	  Saying Y here makes it sometimes possible to use modules
15441da177e4SLinus Torvalds	  compiled for different kernels, by adding enough information
15451da177e4SLinus Torvalds	  to the modules to (hopefully) spot any changes which would
15461da177e4SLinus Torvalds	  make them incompatible with the kernel you are running.  If
15471da177e4SLinus Torvalds	  unsure, say N.
15481da177e4SLinus Torvalds
15491da177e4SLinus Torvaldsconfig MODULE_SRCVERSION_ALL
15501da177e4SLinus Torvalds	bool "Source checksum for all modules"
15511da177e4SLinus Torvalds	help
15521da177e4SLinus Torvalds	  Modules which contain a MODULE_VERSION get an extra "srcversion"
15531da177e4SLinus Torvalds	  field inserted into their modinfo section, which contains a
15541da177e4SLinus Torvalds    	  sum of the source files which made it.  This helps maintainers
15551da177e4SLinus Torvalds	  see exactly which source was used to build a module (since
15561da177e4SLinus Torvalds	  others sometimes change the module source without updating
15571da177e4SLinus Torvalds	  the version).  With this option, such a "srcversion" field
15581da177e4SLinus Torvalds	  will be created for all modules.  If unsure, say N.
15591da177e4SLinus Torvalds
15600b0de144SRobert P. J. Dayendif # MODULES
15610b0de144SRobert P. J. Day
156298a79d6aSRusty Russellconfig INIT_ALL_POSSIBLE
156398a79d6aSRusty Russell	bool
156498a79d6aSRusty Russell	help
15655f054e31SRusty Russell	  Back when each arch used to define their own cpu_online_mask and
15665f054e31SRusty Russell	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
156798a79d6aSRusty Russell	  with all 1s, and others with all 0s.  When they were centralised,
156898a79d6aSRusty Russell	  it was better to provide this option than to break all the archs
1569692105b8SMatt LaPlante	  and have several arch maintainers pursuing me down dark alleys.
157098a79d6aSRusty Russell
15711da177e4SLinus Torvaldsconfig STOP_MACHINE
15721da177e4SLinus Torvalds	bool
15731da177e4SLinus Torvalds	default y
15741da177e4SLinus Torvalds	depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
15751da177e4SLinus Torvalds	help
15761da177e4SLinus Torvalds	  Need stop_machine() primitive.
15773a65dfe8SJens Axboe
15783a65dfe8SJens Axboesource "block/Kconfig"
1579e98c3202SAvi Kivity
1580e98c3202SAvi Kivityconfig PREEMPT_NOTIFIERS
1581e98c3202SAvi Kivity	bool
1582e260be67SPaul E. McKenney
158316295becSSteffen Klassertconfig PADATA
158416295becSSteffen Klassert	depends on SMP
158516295becSSteffen Klassert	bool
158616295becSSteffen Klassert
1587754b7b63SAndi Kleen# Can be selected by architectures with broken toolchains
1588754b7b63SAndi Kleen# that get confused by correct const<->read_only section
1589754b7b63SAndi Kleen# mappings
1590754b7b63SAndi Kleenconfig BROKEN_RODATA
1591754b7b63SAndi Kleen	bool
1592754b7b63SAndi Kleen
15936beb0009SThomas Gleixnersource "kernel/Kconfig.locks"
1594