xref: /openbmc/linux/init/Kconfig (revision 1a687c2e)
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
499d677124bSFrederic Weisbecker	  Unless you want to hack and help the development of the full
500d677124bSFrederic Weisbecker	  tickless feature, you shouldn't enable this option. It adds
501d677124bSFrederic Weisbecker	  unnecessary overhead.
502d677124bSFrederic Weisbecker
503d677124bSFrederic Weisbecker	  If unsure say N
504d677124bSFrederic Weisbecker
5051fd2b442SFrederic Weisbeckerconfig RCU_USER_QS_FORCE
5061fd2b442SFrederic Weisbecker	bool "Force userspace extended QS by default"
5071fd2b442SFrederic Weisbecker	depends on RCU_USER_QS
5081fd2b442SFrederic Weisbecker	help
5091fd2b442SFrederic Weisbecker	  Set the hooks in user/kernel boundaries by default in order to
5101fd2b442SFrederic Weisbecker	  test this feature that treats userspace as an extended quiescent
5111fd2b442SFrederic Weisbecker	  state until we have a real user like a full adaptive nohz option.
5121fd2b442SFrederic Weisbecker
513d677124bSFrederic Weisbecker	  Unless you want to hack and help the development of the full
514d677124bSFrederic Weisbecker	  tickless feature, you shouldn't enable this option. It adds
515d677124bSFrederic Weisbecker	  unnecessary overhead.
516d677124bSFrederic Weisbecker
517d677124bSFrederic Weisbecker	  If unsure say N
518d677124bSFrederic Weisbecker
519c903ff83SMike Travisconfig RCU_FANOUT
520c903ff83SMike Travis	int "Tree-based hierarchical RCU fanout value"
521c903ff83SMike Travis	range 2 64 if 64BIT
522c903ff83SMike Travis	range 2 32 if !64BIT
523f41d911fSPaul E. McKenney	depends on TREE_RCU || TREE_PREEMPT_RCU
524c903ff83SMike Travis	default 64 if 64BIT
525c903ff83SMike Travis	default 32 if !64BIT
526c903ff83SMike Travis	help
527c903ff83SMike Travis	  This option controls the fanout of hierarchical implementations
528c903ff83SMike Travis	  of RCU, allowing RCU to work efficiently on machines with
5294d87ffadSPaul E. McKenney	  large numbers of CPUs.  This value must be at least the fourth
5304d87ffadSPaul E. McKenney	  root of NR_CPUS, which allows NR_CPUS to be insanely large.
5314d87ffadSPaul E. McKenney	  The default value of RCU_FANOUT should be used for production
5324d87ffadSPaul E. McKenney	  systems, but if you are stress-testing the RCU implementation
5334d87ffadSPaul E. McKenney	  itself, small RCU_FANOUT values allow you to test large-system
5344d87ffadSPaul E. McKenney	  code paths on small(er) systems.
535c903ff83SMike Travis
536c903ff83SMike Travis	  Select a specific number if testing RCU itself.
537c903ff83SMike Travis	  Take the default if unsure.
538c903ff83SMike Travis
5398932a63dSPaul E. McKenneyconfig RCU_FANOUT_LEAF
5408932a63dSPaul E. McKenney	int "Tree-based hierarchical RCU leaf-level fanout value"
5418932a63dSPaul E. McKenney	range 2 RCU_FANOUT if 64BIT
5428932a63dSPaul E. McKenney	range 2 RCU_FANOUT if !64BIT
5438932a63dSPaul E. McKenney	depends on TREE_RCU || TREE_PREEMPT_RCU
5448932a63dSPaul E. McKenney	default 16
5458932a63dSPaul E. McKenney	help
5468932a63dSPaul E. McKenney	  This option controls the leaf-level fanout of hierarchical
5478932a63dSPaul E. McKenney	  implementations of RCU, and allows trading off cache misses
5488932a63dSPaul E. McKenney	  against lock contention.  Systems that synchronize their
5498932a63dSPaul E. McKenney	  scheduling-clock interrupts for energy-efficiency reasons will
5508932a63dSPaul E. McKenney	  want the default because the smaller leaf-level fanout keeps
5518932a63dSPaul E. McKenney	  lock contention levels acceptably low.  Very large systems
5528932a63dSPaul E. McKenney	  (hundreds or thousands of CPUs) will instead want to set this
5538932a63dSPaul E. McKenney	  value to the maximum value possible in order to reduce the
5548932a63dSPaul E. McKenney	  number of cache misses incurred during RCU's grace-period
5558932a63dSPaul E. McKenney	  initialization.  These systems tend to run CPU-bound, and thus
5568932a63dSPaul E. McKenney	  are not helped by synchronized interrupts, and thus tend to
5578932a63dSPaul E. McKenney	  skew them, which reduces lock contention enough that large
5588932a63dSPaul E. McKenney	  leaf-level fanouts work well.
5598932a63dSPaul E. McKenney
5608932a63dSPaul E. McKenney	  Select a specific number if testing RCU itself.
5618932a63dSPaul E. McKenney
5628932a63dSPaul E. McKenney	  Select the maximum permissible value for large systems.
5638932a63dSPaul E. McKenney
5648932a63dSPaul E. McKenney	  Take the default if unsure.
5658932a63dSPaul E. McKenney
566c903ff83SMike Travisconfig RCU_FANOUT_EXACT
567c903ff83SMike Travis	bool "Disable tree-based hierarchical RCU auto-balancing"
568f41d911fSPaul E. McKenney	depends on TREE_RCU || TREE_PREEMPT_RCU
569c903ff83SMike Travis	default n
570c903ff83SMike Travis	help
571c903ff83SMike Travis	  This option forces use of the exact RCU_FANOUT value specified,
572c903ff83SMike Travis	  regardless of imbalances in the hierarchy.  This is useful for
573c903ff83SMike Travis	  testing RCU itself, and might one day be useful on systems with
574c903ff83SMike Travis	  strong NUMA behavior.
575c903ff83SMike Travis
576c903ff83SMike Travis	  Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
577c903ff83SMike Travis
578c903ff83SMike Travis	  Say N if unsure.
579c903ff83SMike Travis
5808bd93a2cSPaul E. McKenneyconfig RCU_FAST_NO_HZ
5818bd93a2cSPaul E. McKenney	bool "Accelerate last non-dyntick-idle CPU's grace periods"
582b807fbffSPaul E. McKenney	depends on NO_HZ && SMP
5838bd93a2cSPaul E. McKenney	default n
5848bd93a2cSPaul E. McKenney	help
5858bd93a2cSPaul E. McKenney	  This option causes RCU to attempt to accelerate grace periods
586b807fbffSPaul E. McKenney	  in order to allow CPUs to enter dynticks-idle state more
587b807fbffSPaul E. McKenney	  quickly.  On the other hand, this option increases the overhead
588b807fbffSPaul E. McKenney	  of the dynticks-idle checking, particularly on systems with
589b807fbffSPaul E. McKenney	  large numbers of CPUs.
5908bd93a2cSPaul E. McKenney
5918bd93a2cSPaul E. McKenney	  Say Y if energy efficiency is critically important, particularly
5928bd93a2cSPaul E. McKenney	  	if you have relatively few CPUs.
5938bd93a2cSPaul E. McKenney
5948bd93a2cSPaul E. McKenney	  Say N if you are unsure.
5958bd93a2cSPaul E. McKenney
596c903ff83SMike Travisconfig TREE_RCU_TRACE
597f41d911fSPaul E. McKenney	def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
598c903ff83SMike Travis	select DEBUG_FS
599c903ff83SMike Travis	help
600f41d911fSPaul E. McKenney	  This option provides tracing for the TREE_RCU and
601f41d911fSPaul E. McKenney	  TREE_PREEMPT_RCU implementations, permitting Makefile to
602f41d911fSPaul E. McKenney	  trivially select kernel/rcutree_trace.c.
603c903ff83SMike Travis
60424278d14SPaul E. McKenneyconfig RCU_BOOST
60524278d14SPaul E. McKenney	bool "Enable RCU priority boosting"
60627f4d280SPaul E. McKenney	depends on RT_MUTEXES && PREEMPT_RCU
60724278d14SPaul E. McKenney	default n
60824278d14SPaul E. McKenney	help
60924278d14SPaul E. McKenney	  This option boosts the priority of preempted RCU readers that
61024278d14SPaul E. McKenney	  block the current preemptible RCU grace period for too long.
61124278d14SPaul E. McKenney	  This option also prevents heavy loads from blocking RCU
61224278d14SPaul E. McKenney	  callback invocation for all flavors of RCU.
61324278d14SPaul E. McKenney
61424278d14SPaul E. McKenney	  Say Y here if you are working with real-time apps or heavy loads
61524278d14SPaul E. McKenney	  Say N here if you are unsure.
61624278d14SPaul E. McKenney
61724278d14SPaul E. McKenneyconfig RCU_BOOST_PRIO
61824278d14SPaul E. McKenney	int "Real-time priority to boost RCU readers to"
61924278d14SPaul E. McKenney	range 1 99
62024278d14SPaul E. McKenney	depends on RCU_BOOST
62124278d14SPaul E. McKenney	default 1
62224278d14SPaul E. McKenney	help
623c9336643SPaul E. McKenney	  This option specifies the real-time priority to which long-term
624c9336643SPaul E. McKenney	  preempted RCU readers are to be boosted.  If you are working
625c9336643SPaul E. McKenney	  with a real-time application that has one or more CPU-bound
626c9336643SPaul E. McKenney	  threads running at a real-time priority level, you should set
627c9336643SPaul E. McKenney	  RCU_BOOST_PRIO to a priority higher then the highest-priority
628c9336643SPaul E. McKenney	  real-time CPU-bound thread.  The default RCU_BOOST_PRIO value
629c9336643SPaul E. McKenney	  of 1 is appropriate in the common case, which is real-time
630c9336643SPaul E. McKenney	  applications that do not have any CPU-bound threads.
631c9336643SPaul E. McKenney
632c9336643SPaul E. McKenney	  Some real-time applications might not have a single real-time
633c9336643SPaul E. McKenney	  thread that saturates a given CPU, but instead might have
634c9336643SPaul E. McKenney	  multiple real-time threads that, taken together, fully utilize
635c9336643SPaul E. McKenney	  that CPU.  In this case, you should set RCU_BOOST_PRIO to
636c9336643SPaul E. McKenney	  a priority higher than the lowest-priority thread that is
637c9336643SPaul E. McKenney	  conspiring to prevent the CPU from running any non-real-time
638c9336643SPaul E. McKenney	  tasks.  For example, if one thread at priority 10 and another
639c9336643SPaul E. McKenney	  thread at priority 5 are between themselves fully consuming
640c9336643SPaul E. McKenney	  the CPU time on a given CPU, then RCU_BOOST_PRIO should be
641c9336643SPaul E. McKenney	  set to priority 6 or higher.
64224278d14SPaul E. McKenney
64324278d14SPaul E. McKenney	  Specify the real-time priority, or take the default if unsure.
64424278d14SPaul E. McKenney
64524278d14SPaul E. McKenneyconfig RCU_BOOST_DELAY
64624278d14SPaul E. McKenney	int "Milliseconds to delay boosting after RCU grace-period start"
64724278d14SPaul E. McKenney	range 0 3000
64824278d14SPaul E. McKenney	depends on RCU_BOOST
64924278d14SPaul E. McKenney	default 500
65024278d14SPaul E. McKenney	help
65124278d14SPaul E. McKenney	  This option specifies the time to wait after the beginning of
65224278d14SPaul E. McKenney	  a given grace period before priority-boosting preempted RCU
65324278d14SPaul E. McKenney	  readers blocking that grace period.  Note that any RCU reader
65424278d14SPaul E. McKenney	  blocking an expedited RCU grace period is boosted immediately.
65524278d14SPaul E. McKenney
65624278d14SPaul E. McKenney	  Accept the default if unsure.
65724278d14SPaul E. McKenney
658c903ff83SMike Travisendmenu # "RCU Subsystem"
659c903ff83SMike Travis
6601da177e4SLinus Torvaldsconfig IKCONFIG
661f2443ab6SRoss Biro	tristate "Kernel .config support"
6621da177e4SLinus Torvalds	---help---
6631da177e4SLinus Torvalds	  This option enables the complete Linux kernel ".config" file
6641da177e4SLinus Torvalds	  contents to be saved in the kernel. It provides documentation
6651da177e4SLinus Torvalds	  of which kernel options are used in a running kernel or in an
6661da177e4SLinus Torvalds	  on-disk kernel.  This information can be extracted from the kernel
6671da177e4SLinus Torvalds	  image file with the script scripts/extract-ikconfig and used as
6681da177e4SLinus Torvalds	  input to rebuild the current kernel or to build another kernel.
6691da177e4SLinus Torvalds	  It can also be extracted from a running kernel by reading
6701da177e4SLinus Torvalds	  /proc/config.gz if enabled (below).
6711da177e4SLinus Torvalds
6721da177e4SLinus Torvaldsconfig IKCONFIG_PROC
6731da177e4SLinus Torvalds	bool "Enable access to .config through /proc/config.gz"
6741da177e4SLinus Torvalds	depends on IKCONFIG && PROC_FS
6751da177e4SLinus Torvalds	---help---
6761da177e4SLinus Torvalds	  This option enables access to the kernel configuration file
6771da177e4SLinus Torvalds	  through /proc/config.gz.
6781da177e4SLinus Torvalds
679794543a2SAlistair John Strachanconfig LOG_BUF_SHIFT
680794543a2SAlistair John Strachan	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
681794543a2SAlistair John Strachan	range 12 21
682f17a32e9SAdrian Bunk	default 17
683794543a2SAlistair John Strachan	help
684794543a2SAlistair John Strachan	  Select kernel log buffer size as a power of 2.
685f17a32e9SAdrian Bunk	  Examples:
686f17a32e9SAdrian Bunk	  	     17 => 128 KB
687f17a32e9SAdrian Bunk		     16 => 64 KB
688f17a32e9SAdrian Bunk	             15 => 32 KB
689f17a32e9SAdrian Bunk	             14 => 16 KB
690794543a2SAlistair John Strachan		     13 =>  8 KB
691794543a2SAlistair John Strachan		     12 =>  4 KB
692794543a2SAlistair John Strachan
6935cdc38f9SKAMEZAWA Hiroyuki#
6945cdc38f9SKAMEZAWA Hiroyuki# Architectures with an unreliable sched_clock() should select this:
6955cdc38f9SKAMEZAWA Hiroyuki#
6965cdc38f9SKAMEZAWA Hiroyukiconfig HAVE_UNSTABLE_SCHED_CLOCK
6975cdc38f9SKAMEZAWA Hiroyuki	bool
6985cdc38f9SKAMEZAWA Hiroyuki
699be3a7284SAndrea Arcangeli#
700be3a7284SAndrea Arcangeli# For architectures that want to enable the support for NUMA-affine scheduler
701be3a7284SAndrea Arcangeli# balancing logic:
702be3a7284SAndrea Arcangeli#
703be3a7284SAndrea Arcangeliconfig ARCH_SUPPORTS_NUMA_BALANCING
704be3a7284SAndrea Arcangeli	bool
705be3a7284SAndrea Arcangeli
706be3a7284SAndrea Arcangeli# For architectures that (ab)use NUMA to represent different memory regions
707be3a7284SAndrea Arcangeli# all cpu-local but of different latencies, such as SuperH.
708be3a7284SAndrea Arcangeli#
709be3a7284SAndrea Arcangeliconfig ARCH_WANT_NUMA_VARIABLE_LOCALITY
710be3a7284SAndrea Arcangeli	bool
711be3a7284SAndrea Arcangeli
712be3a7284SAndrea Arcangeli#
713be3a7284SAndrea Arcangeli# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
714be3a7284SAndrea Arcangeliconfig ARCH_WANTS_PROT_NUMA_PROT_NONE
715be3a7284SAndrea Arcangeli	bool
716be3a7284SAndrea Arcangeli
717be3a7284SAndrea Arcangeliconfig ARCH_USES_NUMA_PROT_NONE
718be3a7284SAndrea Arcangeli	bool
719be3a7284SAndrea Arcangeli	default y
720be3a7284SAndrea Arcangeli	depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
721be3a7284SAndrea Arcangeli	depends on NUMA_BALANCING
722be3a7284SAndrea Arcangeli
723*1a687c2eSMel Gormanconfig NUMA_BALANCING_DEFAULT_ENABLED
724*1a687c2eSMel Gorman	bool "Automatically enable NUMA aware memory/task placement"
725*1a687c2eSMel Gorman	default y
726*1a687c2eSMel Gorman	depends on NUMA_BALANCING
727*1a687c2eSMel Gorman	help
728*1a687c2eSMel Gorman	  If set, autonumic NUMA balancing will be enabled if running on a NUMA
729*1a687c2eSMel Gorman	  machine.
730*1a687c2eSMel Gorman
731be3a7284SAndrea Arcangeliconfig NUMA_BALANCING
732be3a7284SAndrea Arcangeli	bool "Memory placement aware NUMA scheduler"
733be3a7284SAndrea Arcangeli	default y
734be3a7284SAndrea Arcangeli	depends on ARCH_SUPPORTS_NUMA_BALANCING
735be3a7284SAndrea Arcangeli	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
736be3a7284SAndrea Arcangeli	depends on SMP && NUMA && MIGRATION
737be3a7284SAndrea Arcangeli	help
738be3a7284SAndrea Arcangeli	  This option adds support for automatic NUMA aware memory/task placement.
739be3a7284SAndrea Arcangeli	  The mechanism is quite primitive and is based on migrating memory when
740be3a7284SAndrea Arcangeli	  it is references to the node the task is running on.
741be3a7284SAndrea Arcangeli
742be3a7284SAndrea Arcangeli	  This system will be inactive on UMA systems.
743be3a7284SAndrea Arcangeli
74423964d2dSLi Zefanmenuconfig CGROUPS
74523964d2dSLi Zefan	boolean "Control Group support"
7460dea1168SKirill A. Shutemov	depends on EVENTFD
747ddbcc7e8SPaul Menage	help
74823964d2dSLi Zefan	  This option adds support for grouping sets of processes together, for
7495cdc38f9SKAMEZAWA Hiroyuki	  use with process control subsystems such as Cpusets, CFS, memory
7505cdc38f9SKAMEZAWA Hiroyuki	  controls or device isolation.
7515cdc38f9SKAMEZAWA Hiroyuki	  See
7525cdc38f9SKAMEZAWA Hiroyuki		- Documentation/scheduler/sched-design-CFS.txt	(CFS)
75345ce80fbSLi Zefan		- Documentation/cgroups/ (features for grouping, isolation
75445ce80fbSLi Zefan					  and resource control)
755ddbcc7e8SPaul Menage
756ddbcc7e8SPaul Menage	  Say N if unsure.
757ddbcc7e8SPaul Menage
75823964d2dSLi Zefanif CGROUPS
75923964d2dSLi Zefan
760006cb992SPaul Menageconfig CGROUP_DEBUG
761006cb992SPaul Menage	bool "Example debug cgroup subsystem"
762418d7d87SPaul Menage	default n
763006cb992SPaul Menage	help
764006cb992SPaul Menage	  This option enables a simple cgroup subsystem that
765006cb992SPaul Menage	  exports useful debugging information about the cgroups
76623964d2dSLi Zefan	  framework.
767006cb992SPaul Menage
76823964d2dSLi Zefan	  Say N if unsure.
769006cb992SPaul Menage
770dc52ddc0SMatt Helsleyconfig CGROUP_FREEZER
77123964d2dSLi Zefan	bool "Freezer cgroup subsystem"
772dc52ddc0SMatt Helsley	help
773dc52ddc0SMatt Helsley	  Provides a way to freeze and unfreeze all tasks in a
774dc52ddc0SMatt Helsley	  cgroup.
775dc52ddc0SMatt Helsley
77608ce5f16SSerge E. Hallynconfig CGROUP_DEVICE
77708ce5f16SSerge E. Hallyn	bool "Device controller for cgroups"
77808ce5f16SSerge E. Hallyn	help
77908ce5f16SSerge E. Hallyn	  Provides a cgroup implementing whitelists for devices which
78008ce5f16SSerge E. Hallyn	  a process in the cgroup can mknod or open.
78108ce5f16SSerge E. Hallyn
7821da177e4SLinus Torvaldsconfig CPUSETS
7831da177e4SLinus Torvalds	bool "Cpuset support"
7841da177e4SLinus Torvalds	help
785d9fd8a6dSRandy Dunlap	  This option will let you create and manage CPUSETs which
7861da177e4SLinus Torvalds	  allow dynamically partitioning a system into sets of CPUs and
7871da177e4SLinus Torvalds	  Memory Nodes and assigning tasks to run only within those sets.
7881da177e4SLinus Torvalds	  This is primarily useful on large SMP or NUMA systems.
7891da177e4SLinus Torvalds
7901da177e4SLinus Torvalds	  Say N if unsure.
7911da177e4SLinus Torvalds
79223964d2dSLi Zefanconfig PROC_PID_CPUSET
79323964d2dSLi Zefan	bool "Include legacy /proc/<pid>/cpuset file"
79423964d2dSLi Zefan	depends on CPUSETS
79523964d2dSLi Zefan	default y
79623964d2dSLi Zefan
797d842de87SSrivatsa Vaddagiriconfig CGROUP_CPUACCT
798d842de87SSrivatsa Vaddagiri	bool "Simple CPU accounting cgroup subsystem"
799d842de87SSrivatsa Vaddagiri	help
800d842de87SSrivatsa Vaddagiri	  Provides a simple Resource Controller for monitoring the
80123964d2dSLi Zefan	  total CPU consumed by the tasks in a cgroup.
802d842de87SSrivatsa Vaddagiri
803e552b661SPavel Emelianovconfig RESOURCE_COUNTERS
804e552b661SPavel Emelianov	bool "Resource counters"
805e552b661SPavel Emelianov	help
806e552b661SPavel Emelianov	  This option enables controller independent resource accounting
80723964d2dSLi Zefan	  infrastructure that works with cgroups.
808e552b661SPavel Emelianov
809c255a458SAndrew Mortonconfig MEMCG
81000f0b825SBalbir Singh	bool "Memory Resource Controller for Control Groups"
81179ae9c29SDaniel Lezcano	depends on RESOURCE_COUNTERS
812cf475ad2SBalbir Singh	select MM_OWNER
81300f0b825SBalbir Singh	help
81484ad6d70SKAMEZAWA Hiroyuki	  Provides a memory resource controller that manages both anonymous
81521acb9caSThadeu Lima de Souza Cascardo	  memory and page cache. (See Documentation/cgroups/memory.txt)
81600f0b825SBalbir Singh
81700f0b825SBalbir Singh	  Note that setting this option increases fixed memory overhead
81884ad6d70SKAMEZAWA Hiroyuki	  associated with each page of memory in the system. By this,
81984ad6d70SKAMEZAWA Hiroyuki	  20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
82084ad6d70SKAMEZAWA Hiroyuki	  usage tracking struct at boot. Total amount of this is printed out
82184ad6d70SKAMEZAWA Hiroyuki	  at boot.
82200f0b825SBalbir Singh
82300f0b825SBalbir Singh	  Only enable when you're ok with these trade offs and really
82484ad6d70SKAMEZAWA Hiroyuki	  sure you need the memory resource controller. Even when you enable
82584ad6d70SKAMEZAWA Hiroyuki	  this, you can set "cgroup_disable=memory" at your boot option to
82684ad6d70SKAMEZAWA Hiroyuki	  disable memory resource controller and you can avoid overheads.
827c9d5409fSLi Zefan	  (and lose benefits of memory resource controller)
82800f0b825SBalbir Singh
829cf475ad2SBalbir Singh	  This config option also selects MM_OWNER config option, which
830cf475ad2SBalbir Singh	  could in turn add some fork/exit overhead.
831cf475ad2SBalbir Singh
832c255a458SAndrew Mortonconfig MEMCG_SWAP
83365e0e811SKAMEZAWA Hiroyuki	bool "Memory Resource Controller Swap Extension"
834c255a458SAndrew Morton	depends on MEMCG && SWAP
835c077719bSKAMEZAWA Hiroyuki	help
836c077719bSKAMEZAWA Hiroyuki	  Add swap management feature to memory resource controller. When you
837c077719bSKAMEZAWA Hiroyuki	  enable this, you can limit mem+swap usage per cgroup. In other words,
838c077719bSKAMEZAWA Hiroyuki	  when you disable this, memory resource controller has no cares to
839c077719bSKAMEZAWA Hiroyuki	  usage of swap...a process can exhaust all of the swap. This extension
840c077719bSKAMEZAWA Hiroyuki	  is useful when you want to avoid exhaustion swap but this itself
841c077719bSKAMEZAWA Hiroyuki	  adds more overheads and consumes memory for remembering information.
842c077719bSKAMEZAWA Hiroyuki	  Especially if you use 32bit system or small memory system, please
843c077719bSKAMEZAWA Hiroyuki	  be careful about enabling this. When memory resource controller
844c077719bSKAMEZAWA Hiroyuki	  is disabled by boot option, this will be automatically disabled and
845c077719bSKAMEZAWA Hiroyuki	  there will be no overhead from this. Even when you set this config=y,
84600a66d29SWANG Cong	  if boot option "swapaccount=0" is set, swap will not be accounted.
847627991a2SKAMEZAWA Hiroyuki	  Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
848627991a2SKAMEZAWA Hiroyuki	  size is 4096bytes, 512k per 1Gbytes of swap.
849c255a458SAndrew Mortonconfig MEMCG_SWAP_ENABLED
850a42c390cSMichal Hocko	bool "Memory Resource Controller Swap Extension enabled by default"
851c255a458SAndrew Morton	depends on MEMCG_SWAP
852a42c390cSMichal Hocko	default y
853a42c390cSMichal Hocko	help
854a42c390cSMichal Hocko	  Memory Resource Controller Swap Extension comes with its price in
855a42c390cSMichal Hocko	  a bigger memory consumption. General purpose distribution kernels
85643d547f9SJim Cromie	  which want to enable the feature but keep it disabled by default
857a42c390cSMichal Hocko	  and let the user enable it by swapaccount boot command line
858a42c390cSMichal Hocko	  parameter should have this option unselected.
859a42c390cSMichal Hocko	  For those who want to have the feature enabled by default should
860a42c390cSMichal Hocko	  select this option (if, for some reason, they need to disable it
86100a66d29SWANG Cong	  then swapaccount=0 does the trick).
862c255a458SAndrew Mortonconfig MEMCG_KMEM
863e5671dfaSGlauber Costa	bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
864c255a458SAndrew Morton	depends on MEMCG && EXPERIMENTAL
865e5671dfaSGlauber Costa	default n
866e5671dfaSGlauber Costa	help
867e5671dfaSGlauber Costa	  The Kernel Memory extension for Memory Resource Controller can limit
868e5671dfaSGlauber Costa	  the amount of memory used by kernel objects in the system. Those are
869e5671dfaSGlauber Costa	  fundamentally different from the entities handled by the standard
870e5671dfaSGlauber Costa	  Memory Controller, which are page-based, and can be swapped. Users of
871e5671dfaSGlauber Costa	  the kmem extension can use it to guarantee that no group of processes
872e5671dfaSGlauber Costa	  will ever exhaust kernel resources alone.
873c077719bSKAMEZAWA Hiroyuki
8742bc64a20SAneesh Kumar K.Vconfig CGROUP_HUGETLB
8752bc64a20SAneesh Kumar K.V	bool "HugeTLB Resource Controller for Control Groups"
8762bc64a20SAneesh Kumar K.V	depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL
8772bc64a20SAneesh Kumar K.V	default n
8782bc64a20SAneesh Kumar K.V	help
8792bc64a20SAneesh Kumar K.V	  Provides a cgroup Resource Controller for HugeTLB pages.
8802bc64a20SAneesh Kumar K.V	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
8812bc64a20SAneesh Kumar K.V	  The limit is enforced during page fault. Since HugeTLB doesn't
8822bc64a20SAneesh Kumar K.V	  support page reclaim, enforcing the limit at page fault time implies
8832bc64a20SAneesh Kumar K.V	  that, the application will get SIGBUS signal if it tries to access
8842bc64a20SAneesh Kumar K.V	  HugeTLB pages beyond its limit. This requires the application to know
8852bc64a20SAneesh Kumar K.V	  beforehand how much HugeTLB pages it would require for its use. The
8862bc64a20SAneesh Kumar K.V	  control group is tracked in the third page lru pointer. This means
8872bc64a20SAneesh Kumar K.V	  that we cannot use the controller with huge page less than 3 pages.
8882bc64a20SAneesh Kumar K.V
889e5d1367fSStephane Eranianconfig CGROUP_PERF
890e5d1367fSStephane Eranian	bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
891e5d1367fSStephane Eranian	depends on PERF_EVENTS && CGROUPS
892e5d1367fSStephane Eranian	help
893e5d1367fSStephane Eranian	  This option extends the per-cpu mode to restrict monitoring to
8942d0f2520SLi Zefan	  threads which belong to the cgroup specified and run on the
895e5d1367fSStephane Eranian	  designated cpu.
896e5d1367fSStephane Eranian
897e5d1367fSStephane Eranian	  Say N if unsure.
898e5d1367fSStephane Eranian
8997c941438SDhaval Gianimenuconfig CGROUP_SCHED
9007c941438SDhaval Giani	bool "Group CPU scheduler"
9017c941438SDhaval Giani	default n
9027c941438SDhaval Giani	help
9037c941438SDhaval Giani	  This feature lets CPU scheduler recognize task groups and control CPU
9047c941438SDhaval Giani	  bandwidth allocation to such task groups. It uses cgroups to group
9057c941438SDhaval Giani	  tasks.
9067c941438SDhaval Giani
9077c941438SDhaval Gianiif CGROUP_SCHED
9087c941438SDhaval Gianiconfig FAIR_GROUP_SCHED
9097c941438SDhaval Giani	bool "Group scheduling for SCHED_OTHER"
9107c941438SDhaval Giani	depends on CGROUP_SCHED
9117c941438SDhaval Giani	default CGROUP_SCHED
9127c941438SDhaval Giani
913ab84d31eSPaul Turnerconfig CFS_BANDWIDTH
914ab84d31eSPaul Turner	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
915ab84d31eSPaul Turner	depends on EXPERIMENTAL
916ab84d31eSPaul Turner	depends on FAIR_GROUP_SCHED
917ab84d31eSPaul Turner	default n
918ab84d31eSPaul Turner	help
919ab84d31eSPaul Turner	  This option allows users to define CPU bandwidth rates (limits) for
920ab84d31eSPaul Turner	  tasks running within the fair group scheduler.  Groups with no limit
921ab84d31eSPaul Turner	  set are considered to be unconstrained and will run with no
922ab84d31eSPaul Turner	  restriction.
923ab84d31eSPaul Turner	  See tip/Documentation/scheduler/sched-bwc.txt for more information.
924ab84d31eSPaul Turner
9257c941438SDhaval Gianiconfig RT_GROUP_SCHED
9267c941438SDhaval Giani	bool "Group scheduling for SCHED_RR/FIFO"
9277c941438SDhaval Giani	depends on EXPERIMENTAL
9287c941438SDhaval Giani	depends on CGROUP_SCHED
9297c941438SDhaval Giani	default n
9307c941438SDhaval Giani	help
9317c941438SDhaval Giani	  This feature lets you explicitly allocate real CPU bandwidth
93232bd7eb5SLi Zefan	  to task groups. If enabled, it will also make it impossible to
9337c941438SDhaval Giani	  schedule realtime tasks for non-root users until you allocate
9347c941438SDhaval Giani	  realtime bandwidth for them.
9357c941438SDhaval Giani	  See Documentation/scheduler/sched-rt-group.txt for more information.
9367c941438SDhaval Giani
9377c941438SDhaval Gianiendif #CGROUP_SCHED
9387c941438SDhaval Giani
939afc24d49SVivek Goyalconfig BLK_CGROUP
94032e380aeSTejun Heo	bool "Block IO controller"
94179ae9c29SDaniel Lezcano	depends on BLOCK
942afc24d49SVivek Goyal	default n
943afc24d49SVivek Goyal	---help---
944afc24d49SVivek Goyal	Generic block IO controller cgroup interface. This is the common
945afc24d49SVivek Goyal	cgroup interface which should be used by various IO controlling
946afc24d49SVivek Goyal	policies.
947afc24d49SVivek Goyal
948afc24d49SVivek Goyal	Currently, CFQ IO scheduler uses it to recognize task groups and
949afc24d49SVivek Goyal	control disk bandwidth allocation (proportional time slice allocation)
950e43473b7SVivek Goyal	to such task groups. It is also used by bio throttling logic in
951e43473b7SVivek Goyal	block layer to implement upper limit in IO rates on a device.
952afc24d49SVivek Goyal
953afc24d49SVivek Goyal	This option only enables generic Block IO controller infrastructure.
954e43473b7SVivek Goyal	One needs to also enable actual IO controlling logic/policy. For
95579e2e759SMichael Witten	enabling proportional weight division of disk bandwidth in CFQ, set
95679e2e759SMichael Witten	CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
957c5e0591aSMichael Witten	CONFIG_BLK_DEV_THROTTLING=y.
958afc24d49SVivek Goyal
959afc24d49SVivek Goyal	See Documentation/cgroups/blkio-controller.txt for more information.
960afc24d49SVivek Goyal
961afc24d49SVivek Goyalconfig DEBUG_BLK_CGROUP
962afc24d49SVivek Goyal	bool "Enable Block IO controller debugging"
963afc24d49SVivek Goyal	depends on BLK_CGROUP
964afc24d49SVivek Goyal	default n
965afc24d49SVivek Goyal	---help---
966afc24d49SVivek Goyal	Enable some debugging help. Currently it exports additional stat
967afc24d49SVivek Goyal	files in a cgroup which can be useful for debugging.
968afc24d49SVivek Goyal
96923964d2dSLi Zefanendif # CGROUPS
970c077719bSKAMEZAWA Hiroyuki
971067bce1aSCyrill Gorcunovconfig CHECKPOINT_RESTORE
972067bce1aSCyrill Gorcunov	bool "Checkpoint/restore support" if EXPERT
973067bce1aSCyrill Gorcunov	default n
974067bce1aSCyrill Gorcunov	help
975067bce1aSCyrill Gorcunov	  Enables additional kernel features in a sake of checkpoint/restore.
976067bce1aSCyrill Gorcunov	  In particular it adds auxiliary prctl codes to setup process text,
977067bce1aSCyrill Gorcunov	  data and heap segment sizes, and a few additional /proc filesystem
978067bce1aSCyrill Gorcunov	  entries.
979067bce1aSCyrill Gorcunov
980067bce1aSCyrill Gorcunov	  If unsure, say N here.
981067bce1aSCyrill Gorcunov
9828dd2a82cSDaniel Lezcanomenuconfig NAMESPACES
9836a108a14SDavid Rientjes	bool "Namespaces support" if EXPERT
9846a108a14SDavid Rientjes	default !EXPERT
985c5289a69SPavel Emelyanov	help
986c5289a69SPavel Emelyanov	  Provides the way to make tasks work with different objects using
987c5289a69SPavel Emelyanov	  the same id. For example same IPC id may refer to different objects
988c5289a69SPavel Emelyanov	  or same user id or pid may refer to different tasks when used in
989c5289a69SPavel Emelyanov	  different namespaces.
990c5289a69SPavel Emelyanov
9918dd2a82cSDaniel Lezcanoif NAMESPACES
9928dd2a82cSDaniel Lezcano
99358bfdd6dSPavel Emelyanovconfig UTS_NS
99458bfdd6dSPavel Emelyanov	bool "UTS namespace"
99517a6d441SDaniel Lezcano	default y
99658bfdd6dSPavel Emelyanov	help
99758bfdd6dSPavel Emelyanov	  In this namespace tasks see different info provided with the
99858bfdd6dSPavel Emelyanov	  uname() system call
99958bfdd6dSPavel Emelyanov
1000ae5e1b22SPavel Emelyanovconfig IPC_NS
1001ae5e1b22SPavel Emelyanov	bool "IPC namespace"
10028dd2a82cSDaniel Lezcano	depends on (SYSVIPC || POSIX_MQUEUE)
100317a6d441SDaniel Lezcano	default y
1004ae5e1b22SPavel Emelyanov	help
1005ae5e1b22SPavel Emelyanov	  In this namespace tasks work with IPC ids which correspond to
1006614b84cfSSerge E. Hallyn	  different IPC objects in different namespaces.
1007ae5e1b22SPavel Emelyanov
1008aee16ce7SPavel Emelyanovconfig USER_NS
1009aee16ce7SPavel Emelyanov	bool "User namespace (EXPERIMENTAL)"
10108dd2a82cSDaniel Lezcano	depends on EXPERIMENTAL
1011e1c972b6SEric W. Biederman	depends on UIDGID_CONVERTED
10125673a94cSEric W. Biederman	select UIDGID_STRICT_TYPE_CHECKS
1013e1c972b6SEric W. Biederman
10145673a94cSEric W. Biederman	default n
1015aee16ce7SPavel Emelyanov	help
1016aee16ce7SPavel Emelyanov	  This allows containers, i.e. vservers, to use user namespaces
1017aee16ce7SPavel Emelyanov	  to provide different user info for different servers.
1018aee16ce7SPavel Emelyanov	  If unsure, say N.
1019aee16ce7SPavel Emelyanov
102074bd59bbSPavel Emelyanovconfig PID_NS
10219bd38c2cSDaniel Lezcano	bool "PID Namespaces"
102217a6d441SDaniel Lezcano	default y
102374bd59bbSPavel Emelyanov	help
102412d2b8f9SHeikki Orsila	  Support process id namespaces.  This allows having multiple
1025692105b8SMatt LaPlante	  processes with the same pid as long as they are in different
102674bd59bbSPavel Emelyanov	  pid namespaces.  This is a building block of containers.
102774bd59bbSPavel Emelyanov
1028d6eb633fSMatt Helsleyconfig NET_NS
1029d6eb633fSMatt Helsley	bool "Network namespace"
10308dd2a82cSDaniel Lezcano	depends on NET
103117a6d441SDaniel Lezcano	default y
1032d6eb633fSMatt Helsley	help
1033d6eb633fSMatt Helsley	  Allow user space to create what appear to be multiple instances
1034d6eb633fSMatt Helsley	  of the network stack.
1035d6eb633fSMatt Helsley
10368dd2a82cSDaniel Lezcanoendif # NAMESPACES
10378dd2a82cSDaniel Lezcano
1038e1c972b6SEric W. Biedermanconfig UIDGID_CONVERTED
1039e1c972b6SEric W. Biederman	# True if all of the selected software conmponents are known
1040e1c972b6SEric W. Biederman	# to have uid_t and gid_t converted to kuid_t and kgid_t
1041e1c972b6SEric W. Biederman	# where appropriate and are otherwise safe to use with
1042e1c972b6SEric W. Biederman	# the user namespace.
1043e1c972b6SEric W. Biederman	bool
1044e1c972b6SEric W. Biederman	default y
1045e1c972b6SEric W. Biederman
1046e1c972b6SEric W. Biederman	# Networking
1047e1c972b6SEric W. Biederman	depends on NET_9P = n
1048e1c972b6SEric W. Biederman
1049e1c972b6SEric W. Biederman	# Filesystems
1050e1c972b6SEric W. Biederman	depends on 9P_FS = n
1051e1c972b6SEric W. Biederman	depends on AFS_FS = n
1052e1c972b6SEric W. Biederman	depends on AUTOFS4_FS = n
1053e1c972b6SEric W. Biederman	depends on CEPH_FS = n
1054e1c972b6SEric W. Biederman	depends on CIFS = n
1055e1c972b6SEric W. Biederman	depends on CODA_FS = n
1056e1c972b6SEric W. Biederman	depends on FUSE_FS = n
1057e1c972b6SEric W. Biederman	depends on GFS2_FS = n
1058e1c972b6SEric W. Biederman	depends on NCP_FS = n
1059e1c972b6SEric W. Biederman	depends on NFSD = n
1060e1c972b6SEric W. Biederman	depends on NFS_FS = n
1061e1c972b6SEric W. Biederman	depends on OCFS2_FS = n
1062e1c972b6SEric W. Biederman	depends on XFS_FS = n
1063e1c972b6SEric W. Biederman
10645673a94cSEric W. Biedermanconfig UIDGID_STRICT_TYPE_CHECKS
10655673a94cSEric W. Biederman	bool "Require conversions between uid/gids and their internal representation"
1066e1c972b6SEric W. Biederman	depends on UIDGID_CONVERTED
10675673a94cSEric W. Biederman	default n
10685673a94cSEric W. Biederman	help
10695673a94cSEric W. Biederman	 While the nececessary conversions are being added to all subsystems this option allows
10705673a94cSEric W. Biederman	 the code to continue to build for unconverted subsystems.
10715673a94cSEric W. Biederman
10725673a94cSEric W. Biederman	 Say Y here if you want the strict type checking enabled
10735673a94cSEric W. Biederman
10745091faa4SMike Galbraithconfig SCHED_AUTOGROUP
10755091faa4SMike Galbraith	bool "Automatic process group scheduling"
10765091faa4SMike Galbraith	select EVENTFD
10775091faa4SMike Galbraith	select CGROUPS
10785091faa4SMike Galbraith	select CGROUP_SCHED
10795091faa4SMike Galbraith	select FAIR_GROUP_SCHED
10805091faa4SMike Galbraith	help
10815091faa4SMike Galbraith	  This option optimizes the scheduler for common desktop workloads by
10825091faa4SMike Galbraith	  automatically creating and populating task groups.  This separation
10835091faa4SMike Galbraith	  of workloads isolates aggressive CPU burners (like build jobs) from
10845091faa4SMike Galbraith	  desktop applications.  Task group autogeneration is currently based
10855091faa4SMike Galbraith	  upon task session.
10865091faa4SMike Galbraith
10877af37becSDaniel Lezcanoconfig MM_OWNER
10887af37becSDaniel Lezcano	bool
10897af37becSDaniel Lezcano
10907af37becSDaniel Lezcanoconfig SYSFS_DEPRECATED
10915d6a4ea5SFerenc Wagner	bool "Enable deprecated sysfs features to support old userspace tools"
10927af37becSDaniel Lezcano	depends on SYSFS
10937af37becSDaniel Lezcano	default n
10947af37becSDaniel Lezcano	help
10957af37becSDaniel Lezcano	  This option adds code that switches the layout of the "block" class
10967af37becSDaniel Lezcano	  devices, to not show up in /sys/class/block/, but only in
10977af37becSDaniel Lezcano	  /sys/block/.
10987af37becSDaniel Lezcano
10997af37becSDaniel Lezcano	  This switch is only active when the sysfs.deprecated=1 boot option is
11007af37becSDaniel Lezcano	  passed or the SYSFS_DEPRECATED_V2 option is set.
11017af37becSDaniel Lezcano
11027af37becSDaniel Lezcano	  This option allows new kernels to run on old distributions and tools,
11037af37becSDaniel Lezcano	  which might get confused by /sys/class/block/. Since 2007/2008 all
11047af37becSDaniel Lezcano	  major distributions and tools handle this just fine.
11057af37becSDaniel Lezcano
11067af37becSDaniel Lezcano	  Recent distributions and userspace tools after 2009/2010 depend on
11077af37becSDaniel Lezcano	  the existence of /sys/class/block/, and will not work with this
11087af37becSDaniel Lezcano	  option enabled.
11097af37becSDaniel Lezcano
11107af37becSDaniel Lezcano	  Only if you are using a new kernel on an old distribution, you might
11117af37becSDaniel Lezcano	  need to say Y here.
11127af37becSDaniel Lezcano
11137af37becSDaniel Lezcanoconfig SYSFS_DEPRECATED_V2
11145d6a4ea5SFerenc Wagner	bool "Enable deprecated sysfs features by default"
11157af37becSDaniel Lezcano	default n
11167af37becSDaniel Lezcano	depends on SYSFS
11177af37becSDaniel Lezcano	depends on SYSFS_DEPRECATED
11187af37becSDaniel Lezcano	help
11197af37becSDaniel Lezcano	  Enable deprecated sysfs by default.
11207af37becSDaniel Lezcano
11217af37becSDaniel Lezcano	  See the CONFIG_SYSFS_DEPRECATED option for more details about this
11227af37becSDaniel Lezcano	  option.
11237af37becSDaniel Lezcano
11247af37becSDaniel Lezcano	  Only if you are using a new kernel on an old distribution, you might
11257af37becSDaniel Lezcano	  need to say Y here. Even then, odds are you would not need it
11267af37becSDaniel Lezcano	  enabled, you can always pass the boot option if absolutely necessary.
11277af37becSDaniel Lezcano
11287af37becSDaniel Lezcanoconfig RELAY
11297af37becSDaniel Lezcano	bool "Kernel->user space relay support (formerly relayfs)"
11307af37becSDaniel Lezcano	help
11317af37becSDaniel Lezcano	  This option enables support for relay interface support in
11327af37becSDaniel Lezcano	  certain file systems (such as debugfs).
11337af37becSDaniel Lezcano	  It is designed to provide an efficient mechanism for tools and
11347af37becSDaniel Lezcano	  facilities to relay large amounts of data from kernel space to
11357af37becSDaniel Lezcano	  user space.
11367af37becSDaniel Lezcano
11377af37becSDaniel Lezcano	  If unsure, say N.
11387af37becSDaniel Lezcano
1139f991633dSDimitri Gorokhovikconfig BLK_DEV_INITRD
1140f991633dSDimitri Gorokhovik	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1141f991633dSDimitri Gorokhovik	depends on BROKEN || !FRV
1142f991633dSDimitri Gorokhovik	help
1143f991633dSDimitri Gorokhovik	  The initial RAM filesystem is a ramfs which is loaded by the
1144f991633dSDimitri Gorokhovik	  boot loader (loadlin or lilo) and that is mounted as root
1145f991633dSDimitri Gorokhovik	  before the normal boot procedure. It is typically used to
1146f991633dSDimitri Gorokhovik	  load modules needed to mount the "real" root file system,
1147f991633dSDimitri Gorokhovik	  etc. See <file:Documentation/initrd.txt> for details.
1148f991633dSDimitri Gorokhovik
1149f991633dSDimitri Gorokhovik	  If RAM disk support (BLK_DEV_RAM) is also included, this
1150f991633dSDimitri Gorokhovik	  also enables initial RAM disk (initrd) support and adds
1151f991633dSDimitri Gorokhovik	  15 Kbytes (more on some other architectures) to the kernel size.
1152f991633dSDimitri Gorokhovik
1153f991633dSDimitri Gorokhovik	  If unsure say Y.
1154f991633dSDimitri Gorokhovik
1155c33df4eaSJean-Paul Samanif BLK_DEV_INITRD
1156c33df4eaSJean-Paul Saman
1157dbec4866SSam Ravnborgsource "usr/Kconfig"
1158dbec4866SSam Ravnborg
1159c33df4eaSJean-Paul Samanendif
1160c33df4eaSJean-Paul Saman
1161c45b4f1fSLinus Torvaldsconfig CC_OPTIMIZE_FOR_SIZE
116296fffeb4SIngo Molnar	bool "Optimize for size"
1163c45b4f1fSLinus Torvalds	help
1164c45b4f1fSLinus Torvalds	  Enabling this option will pass "-Os" instead of "-O2" to gcc
1165c45b4f1fSLinus Torvalds	  resulting in a smaller kernel.
1166c45b4f1fSLinus Torvalds
1167775a7229Sjkacur	  If unsure, say Y.
1168c45b4f1fSLinus Torvalds
11690847062aSRandy Dunlapconfig SYSCTL
11700847062aSRandy Dunlap	bool
11710847062aSRandy Dunlap
1172b943c460SRandy Dunlapconfig ANON_INODES
1173b943c460SRandy Dunlap	bool
1174b943c460SRandy Dunlap
11756a108a14SDavid Rientjesmenuconfig EXPERT
11766a108a14SDavid Rientjes	bool "Configure standard kernel features (expert users)"
1177f505c553SJosh Triplett	# Unhide debug options, to make the on-by-default options visible
1178f505c553SJosh Triplett	select DEBUG_KERNEL
11791da177e4SLinus Torvalds	help
11801da177e4SLinus Torvalds	  This option allows certain base kernel options and settings
11811da177e4SLinus Torvalds          to be disabled or tweaked. This is for specialized
11821da177e4SLinus Torvalds          environments which can tolerate a "non-standard" kernel.
11831da177e4SLinus Torvalds          Only use this if you really know what you are doing.
11841da177e4SLinus Torvalds
1185af1839ebSCatalin Marinasconfig HAVE_UID16
1186af1839ebSCatalin Marinas	bool
1187af1839ebSCatalin Marinas
1188ae81f9e3SChuck Ebbertconfig UID16
11896a108a14SDavid Rientjes	bool "Enable 16-bit UID system calls" if EXPERT
1190af1839ebSCatalin Marinas	depends on HAVE_UID16
1191ae81f9e3SChuck Ebbert	default y
1192ae81f9e3SChuck Ebbert	help
1193ae81f9e3SChuck Ebbert	  This enables the legacy 16-bit UID syscall wrappers.
1194ae81f9e3SChuck Ebbert
1195b89a8171SEric W. Biedermanconfig SYSCTL_SYSCALL
11966a108a14SDavid Rientjes	bool "Sysctl syscall support" if EXPERT
119726a7034bSEric W. Biederman	depends on PROC_SYSCTL
1198c736de60SWANG Cong	default n
1199b89a8171SEric W. Biederman	select SYSCTL
1200b89a8171SEric W. Biederman	---help---
120113bb7e37SEric W. Biederman	  sys_sysctl uses binary paths that have been found challenging
120213bb7e37SEric W. Biederman	  to properly maintain and use.  The interface in /proc/sys
120313bb7e37SEric W. Biederman	  using paths with ascii names is now the primary path to this
120413bb7e37SEric W. Biederman	  information.
1205b89a8171SEric W. Biederman
120613bb7e37SEric W. Biederman	  Almost nothing using the binary sysctl interface so if you are
120713bb7e37SEric W. Biederman	  trying to save some space it is probably safe to disable this,
120813bb7e37SEric W. Biederman	  making your kernel marginally smaller.
1209b89a8171SEric W. Biederman
1210c736de60SWANG Cong	  If unsure say N here.
1211ae81f9e3SChuck Ebbert
12127ac57a89SCatalin Marinasconfig SYSCTL_EXCEPTION_TRACE
12137ac57a89SCatalin Marinas	bool
12147ac57a89SCatalin Marinas	help
12157ac57a89SCatalin Marinas	  Enable support for /proc/sys/debug/exception-trace.
12167ac57a89SCatalin Marinas
12171da177e4SLinus Torvaldsconfig KALLSYMS
12186a108a14SDavid Rientjes	 bool "Load all symbols for debugging/ksymoops" if EXPERT
12191da177e4SLinus Torvalds	 default y
12201da177e4SLinus Torvalds	 help
12211da177e4SLinus Torvalds	   Say Y here to let the kernel print out symbolic crash information and
12221da177e4SLinus Torvalds	   symbolic stack backtraces. This increases the size of the kernel
12231da177e4SLinus Torvalds	   somewhat, as all symbols have to be loaded into the kernel image.
12241da177e4SLinus Torvalds
12251da177e4SLinus Torvaldsconfig KALLSYMS_ALL
12261da177e4SLinus Torvalds	bool "Include all symbols in kallsyms"
12271da177e4SLinus Torvalds	depends on DEBUG_KERNEL && KALLSYMS
12281da177e4SLinus Torvalds	help
122971a83ec7SArtem Bityutskiy	   Normally kallsyms only contains the symbols of functions for nicer
123071a83ec7SArtem Bityutskiy	   OOPS messages and backtraces (i.e., symbols from the text and inittext
123171a83ec7SArtem Bityutskiy	   sections). This is sufficient for most cases. And only in very rare
123271a83ec7SArtem Bityutskiy	   cases (e.g., when a debugger is used) all symbols are required (e.g.,
123371a83ec7SArtem Bityutskiy	   names of variables from the data sections, etc).
12341da177e4SLinus Torvalds
123571a83ec7SArtem Bityutskiy	   This option makes sure that all symbols are loaded into the kernel
123671a83ec7SArtem Bityutskiy	   image (i.e., symbols from all sections) in cost of increased kernel
123771a83ec7SArtem Bityutskiy	   size (depending on the kernel configuration, it may be 300KiB or
123871a83ec7SArtem Bityutskiy	   something like this).
12391da177e4SLinus Torvalds
124071a83ec7SArtem Bityutskiy	   Say N unless you really need all symbols.
1241d59745ceSMatt Mackall
1242712f47ceSGreg Kroah-Hartmanconfig HOTPLUG
124345f035abSGreg Kroah-Hartman	def_bool y
1244712f47ceSGreg Kroah-Hartman
1245d59745ceSMatt Mackallconfig PRINTK
1246d59745ceSMatt Mackall	default y
12476a108a14SDavid Rientjes	bool "Enable support for printk" if EXPERT
1248d59745ceSMatt Mackall	help
1249d59745ceSMatt Mackall	  This option enables normal printk support. Removing it
1250d59745ceSMatt Mackall	  eliminates most of the message strings from the kernel image
1251d59745ceSMatt Mackall	  and makes the kernel more or less silent. As this makes it
1252d59745ceSMatt Mackall	  very difficult to diagnose system problems, saying N here is
1253d59745ceSMatt Mackall	  strongly discouraged.
1254d59745ceSMatt Mackall
1255c8538a7aSMatt Mackallconfig BUG
12566a108a14SDavid Rientjes	bool "BUG() support" if EXPERT
1257c8538a7aSMatt Mackall	default y
1258c8538a7aSMatt Mackall	help
1259c8538a7aSMatt Mackall          Disabling this option eliminates support for BUG and WARN, reducing
1260c8538a7aSMatt Mackall          the size of your kernel image and potentially quietly ignoring
1261c8538a7aSMatt Mackall          numerous fatal conditions. You should only consider disabling this
1262c8538a7aSMatt Mackall          option for embedded systems with no facilities for reporting errors.
1263c8538a7aSMatt Mackall          Just say Y.
1264c8538a7aSMatt Mackall
1265708e9a79SMatt Mackallconfig ELF_CORE
1266046d662fSAlex Kelly	depends on COREDUMP
1267708e9a79SMatt Mackall	default y
12686a108a14SDavid Rientjes	bool "Enable ELF core dumps" if EXPERT
1269708e9a79SMatt Mackall	help
1270708e9a79SMatt Mackall	  Enable support for generating core dumps. Disabling saves about 4k.
1271708e9a79SMatt Mackall
12728761f1abSRalf Baechle
1273e5e1d3cbSStas Sergeevconfig PCSPKR_PLATFORM
12746a108a14SDavid Rientjes	bool "Enable PC-Speaker support" if EXPERT
12758761f1abSRalf Baechle	depends on HAVE_PCSPKR_PLATFORM
127615f304b6SRalf Baechle	select I8253_LOCK
1277e5e1d3cbSStas Sergeev	default y
1278e5e1d3cbSStas Sergeev	help
1279e5e1d3cbSStas Sergeev          This option allows to disable the internal PC-Speaker
1280e5e1d3cbSStas Sergeev          support, saving some memory.
1281e5e1d3cbSStas Sergeev
12828761f1abSRalf Baechleconfig HAVE_PCSPKR_PLATFORM
12838761f1abSRalf Baechle	bool
12848761f1abSRalf Baechle
12851da177e4SLinus Torvaldsconfig BASE_FULL
12861da177e4SLinus Torvalds	default y
12876a108a14SDavid Rientjes	bool "Enable full-sized data structures for core" if EXPERT
12881da177e4SLinus Torvalds	help
12891da177e4SLinus Torvalds	  Disabling this option reduces the size of miscellaneous core
12901da177e4SLinus Torvalds	  kernel data structures. This saves memory on small machines,
12911da177e4SLinus Torvalds	  but may reduce performance.
12921da177e4SLinus Torvalds
12931da177e4SLinus Torvaldsconfig FUTEX
12946a108a14SDavid Rientjes	bool "Enable futex support" if EXPERT
12951da177e4SLinus Torvalds	default y
129623f78d4aSIngo Molnar	select RT_MUTEXES
12971da177e4SLinus Torvalds	help
12981da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
12991da177e4SLinus Torvalds	  support for "fast userspace mutexes".  The resulting kernel may not
13001da177e4SLinus Torvalds	  run glibc-based applications correctly.
13011da177e4SLinus Torvalds
13021da177e4SLinus Torvaldsconfig EPOLL
13036a108a14SDavid Rientjes	bool "Enable eventpoll support" if EXPERT
13041da177e4SLinus Torvalds	default y
1305448e3ceeSAdrian Bunk	select ANON_INODES
13061da177e4SLinus Torvalds	help
13071da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
13081da177e4SLinus Torvalds	  support for epoll family of system calls.
13091da177e4SLinus Torvalds
1310fba2afaaSDavide Libenziconfig SIGNALFD
13116a108a14SDavid Rientjes	bool "Enable signalfd() system call" if EXPERT
1312448e3ceeSAdrian Bunk	select ANON_INODES
1313fba2afaaSDavide Libenzi	default y
1314fba2afaaSDavide Libenzi	help
1315fba2afaaSDavide Libenzi	  Enable the signalfd() system call that allows to receive signals
1316fba2afaaSDavide Libenzi	  on a file descriptor.
1317fba2afaaSDavide Libenzi
1318fba2afaaSDavide Libenzi	  If unsure, say Y.
1319fba2afaaSDavide Libenzi
1320b215e283SDavide Libenziconfig TIMERFD
13216a108a14SDavid Rientjes	bool "Enable timerfd() system call" if EXPERT
1322448e3ceeSAdrian Bunk	select ANON_INODES
1323b215e283SDavide Libenzi	default y
1324b215e283SDavide Libenzi	help
1325b215e283SDavide Libenzi	  Enable the timerfd() system call that allows to receive timer
1326b215e283SDavide Libenzi	  events on a file descriptor.
1327b215e283SDavide Libenzi
1328b215e283SDavide Libenzi	  If unsure, say Y.
1329b215e283SDavide Libenzi
1330e1ad7468SDavide Libenziconfig EVENTFD
13316a108a14SDavid Rientjes	bool "Enable eventfd() system call" if EXPERT
1332448e3ceeSAdrian Bunk	select ANON_INODES
1333e1ad7468SDavide Libenzi	default y
1334e1ad7468SDavide Libenzi	help
1335e1ad7468SDavide Libenzi	  Enable the eventfd() system call that allows to receive both
1336e1ad7468SDavide Libenzi	  kernel notification (ie. KAIO) or userspace notifications.
1337e1ad7468SDavide Libenzi
1338e1ad7468SDavide Libenzi	  If unsure, say Y.
1339e1ad7468SDavide Libenzi
13401da177e4SLinus Torvaldsconfig SHMEM
13416a108a14SDavid Rientjes	bool "Use full shmem filesystem" if EXPERT
13421da177e4SLinus Torvalds	default y
13431da177e4SLinus Torvalds	depends on MMU
13441da177e4SLinus Torvalds	help
13451da177e4SLinus Torvalds	  The shmem is an internal filesystem used to manage shared memory.
13461da177e4SLinus Torvalds	  It is backed by swap and manages resource limits. It is also exported
13471da177e4SLinus Torvalds	  to userspace as tmpfs if TMPFS is enabled. Disabling this
13481da177e4SLinus Torvalds	  option replaces shmem and tmpfs with the much simpler ramfs code,
13491da177e4SLinus Torvalds	  which may be appropriate on small systems without swap.
13501da177e4SLinus Torvalds
1351ebf3f09cSThomas Petazzoniconfig AIO
13526a108a14SDavid Rientjes	bool "Enable AIO support" if EXPERT
1353ebf3f09cSThomas Petazzoni	default y
1354ebf3f09cSThomas Petazzoni	help
1355ebf3f09cSThomas Petazzoni	  This option enables POSIX asynchronous I/O which may by used
1356ebf3f09cSThomas Petazzoni          by some high performance threaded applications. Disabling
1357ebf3f09cSThomas Petazzoni          this option saves about 7k.
1358ebf3f09cSThomas Petazzoni
13596befe5f6SRandy Dunlapconfig EMBEDDED
13606befe5f6SRandy Dunlap	bool "Embedded system"
13616befe5f6SRandy Dunlap	select EXPERT
13626befe5f6SRandy Dunlap	help
13636befe5f6SRandy Dunlap	  This option should be enabled if compiling the kernel for
13646befe5f6SRandy Dunlap	  an embedded system so certain expert options are available
13656befe5f6SRandy Dunlap	  for configuration.
13666befe5f6SRandy Dunlap
1367cdd6c482SIngo Molnarconfig HAVE_PERF_EVENTS
13680793a61dSThomas Gleixner	bool
1369018df72dSMike Frysinger	help
1370018df72dSMike Frysinger	  See tools/perf/design.txt for details.
13710793a61dSThomas Gleixner
1372906010b2SPeter Zijlstraconfig PERF_USE_VMALLOC
1373906010b2SPeter Zijlstra	bool
1374906010b2SPeter Zijlstra	help
1375906010b2SPeter Zijlstra	  See tools/perf/design.txt for details
1376906010b2SPeter Zijlstra
137757c0c15bSIngo Molnarmenu "Kernel Performance Events And Counters"
13780793a61dSThomas Gleixner
1379cdd6c482SIngo Molnarconfig PERF_EVENTS
138057c0c15bSIngo Molnar	bool "Kernel performance events and counters"
1381392d65a9SRobert Richter	default y if PROFILING
1382cdd6c482SIngo Molnar	depends on HAVE_PERF_EVENTS
13834c59e467SIngo Molnar	select ANON_INODES
1384e360adbeSPeter Zijlstra	select IRQ_WORK
13850793a61dSThomas Gleixner	help
138657c0c15bSIngo Molnar	  Enable kernel support for various performance events provided
138757c0c15bSIngo Molnar	  by software and hardware.
13880793a61dSThomas Gleixner
1389dd77038dSThadeu Lima de Souza Cascardo	  Software events are supported either built-in or via the
139057c0c15bSIngo Molnar	  use of generic tracepoints.
139157c0c15bSIngo Molnar
139257c0c15bSIngo Molnar	  Most modern CPUs support performance events via performance
139357c0c15bSIngo Molnar	  counter registers. These registers count the number of certain
13940793a61dSThomas Gleixner	  types of hw events: such as instructions executed, cachemisses
13950793a61dSThomas Gleixner	  suffered, or branches mis-predicted - without slowing down the
13960793a61dSThomas Gleixner	  kernel or applications. These registers can also trigger interrupts
13970793a61dSThomas Gleixner	  when a threshold number of events have passed - and can thus be
13980793a61dSThomas Gleixner	  used to profile the code that runs on that CPU.
13990793a61dSThomas Gleixner
140057c0c15bSIngo Molnar	  The Linux Performance Event subsystem provides an abstraction of
1401dd77038dSThadeu Lima de Souza Cascardo	  these software and hardware event capabilities, available via a
140257c0c15bSIngo Molnar	  system call and used by the "perf" utility in tools/perf/. It
14030793a61dSThomas Gleixner	  provides per task and per CPU counters, and it provides event
14040793a61dSThomas Gleixner	  capabilities on top of those.
14050793a61dSThomas Gleixner
14060793a61dSThomas Gleixner	  Say Y if unsure.
14070793a61dSThomas Gleixner
1408906010b2SPeter Zijlstraconfig DEBUG_PERF_USE_VMALLOC
1409906010b2SPeter Zijlstra	default n
1410906010b2SPeter Zijlstra	bool "Debug: use vmalloc to back perf mmap() buffers"
1411906010b2SPeter Zijlstra	depends on PERF_EVENTS && DEBUG_KERNEL
1412906010b2SPeter Zijlstra	select PERF_USE_VMALLOC
1413906010b2SPeter Zijlstra	help
1414906010b2SPeter Zijlstra	 Use vmalloc memory to back perf mmap() buffers.
1415906010b2SPeter Zijlstra
1416906010b2SPeter Zijlstra	 Mostly useful for debugging the vmalloc code on platforms
1417906010b2SPeter Zijlstra	 that don't require it.
1418906010b2SPeter Zijlstra
1419906010b2SPeter Zijlstra	 Say N if unsure.
1420906010b2SPeter Zijlstra
14210793a61dSThomas Gleixnerendmenu
14220793a61dSThomas Gleixner
1423f8891e5eSChristoph Lameterconfig VM_EVENT_COUNTERS
1424f8891e5eSChristoph Lameter	default y
14256a108a14SDavid Rientjes	bool "Enable VM event counters for /proc/vmstat" if EXPERT
1426f8891e5eSChristoph Lameter	help
14272aea4fb6SPaul Jackson	  VM event counters are needed for event counts to be shown.
14282aea4fb6SPaul Jackson	  This option allows the disabling of the VM event counters
14296a108a14SDavid Rientjes	  on EXPERT systems.  /proc/vmstat will only show page counts
14302aea4fb6SPaul Jackson	  if VM event counters are disabled.
1431f8891e5eSChristoph Lameter
14323d137310SThomas Petazzoniconfig PCI_QUIRKS
14333d137310SThomas Petazzoni	default y
14346a108a14SDavid Rientjes	bool "Enable PCI quirk workarounds" if EXPERT
143561cfc7e4SGeert Uytterhoeven	depends on PCI
14363d137310SThomas Petazzoni	help
14373d137310SThomas Petazzoni	  This enables workarounds for various PCI chipset
14383d137310SThomas Petazzoni          bugs/quirks. Disable this only if your target machine is
14393d137310SThomas Petazzoni          unaffected by PCI quirks.
14403d137310SThomas Petazzoni
144141ecc55bSChristoph Lameterconfig SLUB_DEBUG
144241ecc55bSChristoph Lameter	default y
14436a108a14SDavid Rientjes	bool "Enable SLUB debugging support" if EXPERT
1444f6acb635SChristoph Lameter	depends on SLUB && SYSFS
144541ecc55bSChristoph Lameter	help
144641ecc55bSChristoph Lameter	  SLUB has extensive debug support features. Disabling these can
144741ecc55bSChristoph Lameter	  result in significant savings in code size. This also disables
144841ecc55bSChristoph Lameter	  SLUB sysfs support. /sys/slab will not exist and there will be
144941ecc55bSChristoph Lameter	  no support for cache validation etc.
145041ecc55bSChristoph Lameter
1451b943c460SRandy Dunlapconfig COMPAT_BRK
1452b943c460SRandy Dunlap	bool "Disable heap randomization"
1453b943c460SRandy Dunlap	default y
1454b943c460SRandy Dunlap	help
1455b943c460SRandy Dunlap	  Randomizing heap placement makes heap exploits harder, but it
1456b943c460SRandy Dunlap	  also breaks ancient binaries (including anything libc5 based).
1457b943c460SRandy Dunlap	  This option changes the bootup default to heap randomization
1458692105b8SMatt LaPlante	  disabled, and can be overridden at runtime by setting
1459b943c460SRandy Dunlap	  /proc/sys/kernel/randomize_va_space to 2.
1460b943c460SRandy Dunlap
1461b943c460SRandy Dunlap	  On non-ancient distros (post-2000 ones) N is usually a safe choice.
1462b943c460SRandy Dunlap
146381819f0fSChristoph Lameterchoice
146481819f0fSChristoph Lameter	prompt "Choose SLAB allocator"
1465a0acd820SChristoph Lameter	default SLUB
146681819f0fSChristoph Lameter	help
146781819f0fSChristoph Lameter	   This option allows to select a slab allocator.
146881819f0fSChristoph Lameter
146981819f0fSChristoph Lameterconfig SLAB
147081819f0fSChristoph Lameter	bool "SLAB"
147181819f0fSChristoph Lameter	help
147281819f0fSChristoph Lameter	  The regular slab allocator that is established and known to work
147334013886SChristoph Lameter	  well in all environments. It organizes cache hot objects in
147402f56210SSimon Arlott	  per cpu and per node queues.
147581819f0fSChristoph Lameter
147681819f0fSChristoph Lameterconfig SLUB
147781819f0fSChristoph Lameter	bool "SLUB (Unqueued Allocator)"
147881819f0fSChristoph Lameter	help
147981819f0fSChristoph Lameter	   SLUB is a slab allocator that minimizes cache line usage
148081819f0fSChristoph Lameter	   instead of managing queues of cached objects (SLAB approach).
148181819f0fSChristoph Lameter	   Per cpu caching is realized using slabs of objects instead
148281819f0fSChristoph Lameter	   of queues of objects. SLUB can use memory efficiently
148302f56210SSimon Arlott	   and has enhanced diagnostics. SLUB is the default choice for
148402f56210SSimon Arlott	   a slab allocator.
148581819f0fSChristoph Lameter
148681819f0fSChristoph Lameterconfig SLOB
14876a108a14SDavid Rientjes	depends on EXPERT
148881819f0fSChristoph Lameter	bool "SLOB (Simple Allocator)"
148981819f0fSChristoph Lameter	help
149037291458SMatt Mackall	   SLOB replaces the stock allocator with a drastically simpler
149137291458SMatt Mackall	   allocator. SLOB is generally more space efficient but
149237291458SMatt Mackall	   does not perform as well on large systems.
149381819f0fSChristoph Lameter
149481819f0fSChristoph Lameterendchoice
149581819f0fSChristoph Lameter
1496ea637639SJie Zhangconfig MMAP_ALLOW_UNINITIALIZED
1497ea637639SJie Zhang	bool "Allow mmapped anonymous memory to be uninitialized"
14986a108a14SDavid Rientjes	depends on EXPERT && !MMU
1499ea637639SJie Zhang	default n
1500ea637639SJie Zhang	help
1501ea637639SJie Zhang	  Normally, and according to the Linux spec, anonymous memory obtained
1502ea637639SJie Zhang	  from mmap() has it's contents cleared before it is passed to
1503ea637639SJie Zhang	  userspace.  Enabling this config option allows you to request that
1504ea637639SJie Zhang	  mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1505ea637639SJie Zhang	  providing a huge performance boost.  If this option is not enabled,
1506ea637639SJie Zhang	  then the flag will be ignored.
1507ea637639SJie Zhang
1508ea637639SJie Zhang	  This is taken advantage of by uClibc's malloc(), and also by
1509ea637639SJie Zhang	  ELF-FDPIC binfmt's brk and stack allocator.
1510ea637639SJie Zhang
1511ea637639SJie Zhang	  Because of the obvious security issues, this option should only be
1512ea637639SJie Zhang	  enabled on embedded devices where you control what is run in
1513ea637639SJie Zhang	  userspace.  Since that isn't generally a problem on no-MMU systems,
1514ea637639SJie Zhang	  it is normally safe to say Y here.
1515ea637639SJie Zhang
1516ea637639SJie Zhang	  See Documentation/nommu-mmap.txt for more information.
1517ea637639SJie Zhang
1518125e5645SMathieu Desnoyersconfig PROFILING
1519b309a294SRobert Richter	bool "Profiling support"
1520125e5645SMathieu Desnoyers	help
1521125e5645SMathieu Desnoyers	  Say Y here to enable the extended profiling support mechanisms used
1522125e5645SMathieu Desnoyers	  by profilers such as OProfile.
1523125e5645SMathieu Desnoyers
15245f87f112SIngo Molnar#
15255f87f112SIngo Molnar# Place an empty function call at each tracepoint site. Can be
15265f87f112SIngo Molnar# dynamically changed for a probe function.
15275f87f112SIngo Molnar#
152897e1c18eSMathieu Desnoyersconfig TRACEPOINTS
15295f87f112SIngo Molnar	bool
153097e1c18eSMathieu Desnoyers
1531fb32e03fSMathieu Desnoyerssource "arch/Kconfig"
1532fb32e03fSMathieu Desnoyers
15331da177e4SLinus Torvaldsendmenu		# General setup
15341da177e4SLinus Torvalds
1535ee7e5516SDmitry Baryshkovconfig HAVE_GENERIC_DMA_COHERENT
1536ee7e5516SDmitry Baryshkov	bool
1537ee7e5516SDmitry Baryshkov	default n
1538ee7e5516SDmitry Baryshkov
1539158a9624SLinus Torvaldsconfig SLABINFO
1540158a9624SLinus Torvalds	bool
1541158a9624SLinus Torvalds	depends on PROC_FS
15420f389ec6SChristoph Lameter	depends on SLAB || SLUB_DEBUG
1543158a9624SLinus Torvalds	default y
1544158a9624SLinus Torvalds
1545ae81f9e3SChuck Ebbertconfig RT_MUTEXES
1546ae81f9e3SChuck Ebbert	boolean
1547ae81f9e3SChuck Ebbert
15481da177e4SLinus Torvaldsconfig BASE_SMALL
15491da177e4SLinus Torvalds	int
15501da177e4SLinus Torvalds	default 0 if BASE_FULL
15511da177e4SLinus Torvalds	default 1 if !BASE_FULL
15521da177e4SLinus Torvalds
155366da5733SJan Engelhardtmenuconfig MODULES
15541da177e4SLinus Torvalds	bool "Enable loadable module support"
15551da177e4SLinus Torvalds	help
15561da177e4SLinus Torvalds	  Kernel modules are small pieces of compiled code which can
15571da177e4SLinus Torvalds	  be inserted in the running kernel, rather than being
15581da177e4SLinus Torvalds	  permanently built into the kernel.  You use the "modprobe"
15591da177e4SLinus Torvalds	  tool to add (and sometimes remove) them.  If you say Y here,
15601da177e4SLinus Torvalds	  many parts of the kernel can be built as modules (by
15611da177e4SLinus Torvalds	  answering M instead of Y where indicated): this is most
15621da177e4SLinus Torvalds	  useful for infrequently used options which are not required
15631da177e4SLinus Torvalds	  for booting.  For more information, see the man pages for
15641da177e4SLinus Torvalds	  modprobe, lsmod, modinfo, insmod and rmmod.
15651da177e4SLinus Torvalds
15661da177e4SLinus Torvalds	  If you say Y here, you will need to run "make
15671da177e4SLinus Torvalds	  modules_install" to put the modules under /lib/modules/
15681da177e4SLinus Torvalds	  where modprobe can find them (you may need to be root to do
15691da177e4SLinus Torvalds	  this).
15701da177e4SLinus Torvalds
15711da177e4SLinus Torvalds	  If unsure, say Y.
15721da177e4SLinus Torvalds
15730b0de144SRobert P. J. Dayif MODULES
15740b0de144SRobert P. J. Day
1575826e4506SLinus Torvaldsconfig MODULE_FORCE_LOAD
1576826e4506SLinus Torvalds	bool "Forced module loading"
1577826e4506SLinus Torvalds	default n
1578826e4506SLinus Torvalds	help
157991e37a79SRusty Russell	  Allow loading of modules without version information (ie. modprobe
158091e37a79SRusty Russell	  --force).  Forced module loading sets the 'F' (forced) taint flag and
158191e37a79SRusty Russell	  is usually a really bad idea.
1582826e4506SLinus Torvalds
15831da177e4SLinus Torvaldsconfig MODULE_UNLOAD
15841da177e4SLinus Torvalds	bool "Module unloading"
15851da177e4SLinus Torvalds	help
15861da177e4SLinus Torvalds	  Without this option you will not be able to unload any
15871da177e4SLinus Torvalds	  modules (note that some modules may not be unloadable
1588f7f5b675SDenys Vlasenko	  anyway), which makes your kernel smaller, faster
1589f7f5b675SDenys Vlasenko	  and simpler.  If unsure, say Y.
15901da177e4SLinus Torvalds
15911da177e4SLinus Torvaldsconfig MODULE_FORCE_UNLOAD
15921da177e4SLinus Torvalds	bool "Forced module unloading"
15931da177e4SLinus Torvalds	depends on MODULE_UNLOAD && EXPERIMENTAL
15941da177e4SLinus Torvalds	help
15951da177e4SLinus Torvalds	  This option allows you to force a module to unload, even if the
15961da177e4SLinus Torvalds	  kernel believes it is unsafe: the kernel will remove the module
15971da177e4SLinus Torvalds	  without waiting for anyone to stop using it (using the -f option to
15981da177e4SLinus Torvalds	  rmmod).  This is mainly for kernel developers and desperate users.
15991da177e4SLinus Torvalds	  If unsure, say N.
16001da177e4SLinus Torvalds
16011da177e4SLinus Torvaldsconfig MODVERSIONS
16020d541643SSam Ravnborg	bool "Module versioning support"
16031da177e4SLinus Torvalds	help
16041da177e4SLinus Torvalds	  Usually, you have to use modules compiled with your kernel.
16051da177e4SLinus Torvalds	  Saying Y here makes it sometimes possible to use modules
16061da177e4SLinus Torvalds	  compiled for different kernels, by adding enough information
16071da177e4SLinus Torvalds	  to the modules to (hopefully) spot any changes which would
16081da177e4SLinus Torvalds	  make them incompatible with the kernel you are running.  If
16091da177e4SLinus Torvalds	  unsure, say N.
16101da177e4SLinus Torvalds
16111da177e4SLinus Torvaldsconfig MODULE_SRCVERSION_ALL
16121da177e4SLinus Torvalds	bool "Source checksum for all modules"
16131da177e4SLinus Torvalds	help
16141da177e4SLinus Torvalds	  Modules which contain a MODULE_VERSION get an extra "srcversion"
16151da177e4SLinus Torvalds	  field inserted into their modinfo section, which contains a
16161da177e4SLinus Torvalds    	  sum of the source files which made it.  This helps maintainers
16171da177e4SLinus Torvalds	  see exactly which source was used to build a module (since
16181da177e4SLinus Torvalds	  others sometimes change the module source without updating
16191da177e4SLinus Torvalds	  the version).  With this option, such a "srcversion" field
16201da177e4SLinus Torvalds	  will be created for all modules.  If unsure, say N.
16211da177e4SLinus Torvalds
1622106a4ee2SRusty Russellconfig MODULE_SIG
1623106a4ee2SRusty Russell	bool "Module signature verification"
1624106a4ee2SRusty Russell	depends on MODULES
162548ba2462SDavid Howells	select KEYS
162648ba2462SDavid Howells	select CRYPTO
162748ba2462SDavid Howells	select ASYMMETRIC_KEY_TYPE
162848ba2462SDavid Howells	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
162948ba2462SDavid Howells	select PUBLIC_KEY_ALGO_RSA
163048ba2462SDavid Howells	select ASN1
163148ba2462SDavid Howells	select OID_REGISTRY
163248ba2462SDavid Howells	select X509_CERTIFICATE_PARSER
1633106a4ee2SRusty Russell	help
1634106a4ee2SRusty Russell	  Check modules for valid signatures upon load: the signature
1635106a4ee2SRusty Russell	  is simply appended to the module. For more information see
1636106a4ee2SRusty Russell	  Documentation/module-signing.txt.
1637106a4ee2SRusty Russell
1638ea0b6dcfSDavid Howells	  !!!WARNING!!!  If you enable this option, you MUST make sure that the
1639ea0b6dcfSDavid Howells	  module DOES NOT get stripped after being signed.  This includes the
1640ea0b6dcfSDavid Howells	  debuginfo strip done by some packagers (such as rpmbuild) and
1641ea0b6dcfSDavid Howells	  inclusion into an initramfs that wants the module size reduced.
1642ea0b6dcfSDavid Howells
1643106a4ee2SRusty Russellconfig MODULE_SIG_FORCE
1644106a4ee2SRusty Russell	bool "Require modules to be validly signed"
1645106a4ee2SRusty Russell	depends on MODULE_SIG
1646106a4ee2SRusty Russell	help
1647106a4ee2SRusty Russell	  Reject unsigned modules or signed modules for which we don't have a
1648106a4ee2SRusty Russell	  key.  Without this, such modules will simply taint the kernel.
1649ea0b6dcfSDavid Howells
1650ea0b6dcfSDavid Howellschoice
1651ea0b6dcfSDavid Howells	prompt "Which hash algorithm should modules be signed with?"
1652ea0b6dcfSDavid Howells	depends on MODULE_SIG
1653ea0b6dcfSDavid Howells	help
1654ea0b6dcfSDavid Howells	  This determines which sort of hashing algorithm will be used during
1655ea0b6dcfSDavid Howells	  signature generation.  This algorithm _must_ be built into the kernel
1656ea0b6dcfSDavid Howells	  directly so that signature verification can take place.  It is not
1657ea0b6dcfSDavid Howells	  possible to load a signed module containing the algorithm to check
1658ea0b6dcfSDavid Howells	  the signature on that module.
1659ea0b6dcfSDavid Howells
1660ea0b6dcfSDavid Howellsconfig MODULE_SIG_SHA1
1661ea0b6dcfSDavid Howells	bool "Sign modules with SHA-1"
1662ea0b6dcfSDavid Howells	select CRYPTO_SHA1
1663ea0b6dcfSDavid Howells
1664ea0b6dcfSDavid Howellsconfig MODULE_SIG_SHA224
1665ea0b6dcfSDavid Howells	bool "Sign modules with SHA-224"
1666ea0b6dcfSDavid Howells	select CRYPTO_SHA256
1667ea0b6dcfSDavid Howells
1668ea0b6dcfSDavid Howellsconfig MODULE_SIG_SHA256
1669ea0b6dcfSDavid Howells	bool "Sign modules with SHA-256"
1670ea0b6dcfSDavid Howells	select CRYPTO_SHA256
1671ea0b6dcfSDavid Howells
1672ea0b6dcfSDavid Howellsconfig MODULE_SIG_SHA384
1673ea0b6dcfSDavid Howells	bool "Sign modules with SHA-384"
1674ea0b6dcfSDavid Howells	select CRYPTO_SHA512
1675ea0b6dcfSDavid Howells
1676ea0b6dcfSDavid Howellsconfig MODULE_SIG_SHA512
1677ea0b6dcfSDavid Howells	bool "Sign modules with SHA-512"
1678ea0b6dcfSDavid Howells	select CRYPTO_SHA512
1679ea0b6dcfSDavid Howells
1680ea0b6dcfSDavid Howellsendchoice
1681ea0b6dcfSDavid Howells
16820b0de144SRobert P. J. Dayendif # MODULES
16830b0de144SRobert P. J. Day
168498a79d6aSRusty Russellconfig INIT_ALL_POSSIBLE
168598a79d6aSRusty Russell	bool
168698a79d6aSRusty Russell	help
16875f054e31SRusty Russell	  Back when each arch used to define their own cpu_online_mask and
16885f054e31SRusty Russell	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
168998a79d6aSRusty Russell	  with all 1s, and others with all 0s.  When they were centralised,
169098a79d6aSRusty Russell	  it was better to provide this option than to break all the archs
1691692105b8SMatt LaPlante	  and have several arch maintainers pursuing me down dark alleys.
169298a79d6aSRusty Russell
16931da177e4SLinus Torvaldsconfig STOP_MACHINE
16941da177e4SLinus Torvalds	bool
16951da177e4SLinus Torvalds	default y
16961da177e4SLinus Torvalds	depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
16971da177e4SLinus Torvalds	help
16981da177e4SLinus Torvalds	  Need stop_machine() primitive.
16993a65dfe8SJens Axboe
17003a65dfe8SJens Axboesource "block/Kconfig"
1701e98c3202SAvi Kivity
1702e98c3202SAvi Kivityconfig PREEMPT_NOTIFIERS
1703e98c3202SAvi Kivity	bool
1704e260be67SPaul E. McKenney
170516295becSSteffen Klassertconfig PADATA
170616295becSSteffen Klassert	depends on SMP
170716295becSSteffen Klassert	bool
170816295becSSteffen Klassert
1709754b7b63SAndi Kleen# Can be selected by architectures with broken toolchains
1710754b7b63SAndi Kleen# that get confused by correct const<->read_only section
1711754b7b63SAndi Kleen# mappings
1712754b7b63SAndi Kleenconfig BROKEN_RODATA
1713754b7b63SAndi Kleen	bool
1714754b7b63SAndi Kleen
17154520c6a4SDavid Howellsconfig ASN1
17164520c6a4SDavid Howells	tristate
17174520c6a4SDavid Howells	help
17184520c6a4SDavid Howells	  Build a simple ASN.1 grammar compiler that produces a bytecode output
17194520c6a4SDavid Howells	  that can be interpreted by the ASN.1 stream decoder and used to
17204520c6a4SDavid Howells	  inform it as to what tags are to be expected in a stream and what
17214520c6a4SDavid Howells	  functions to call on what tags.
17224520c6a4SDavid Howells
17236beb0009SThomas Gleixnersource "kernel/Kconfig.locks"
1724