xref: /openbmc/linux/init/Kconfig (revision af71befa)
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
497*af71befaSPaul Gortmaker	  try to keep the timer tick on for RCU.
4982b1d5024SFrederic Weisbecker
499d677124bSFrederic Weisbecker	  Unless you want to hack and help the development of the full
500*af71befaSPaul Gortmaker	  tickless feature, you shouldn't enable this option.  It also
501*af71befaSPaul Gortmaker	  adds 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
585ba49df47SPaul E. McKenney	  This option causes RCU to attempt to accelerate grace periods in
586ba49df47SPaul E. McKenney	  order to allow CPUs to enter dynticks-idle state more quickly.
587ba49df47SPaul E. McKenney	  On the other hand, this option increases the overhead of the
588ba49df47SPaul E. McKenney	  dynticks-idle checking, thus degrading scheduling latency.
5898bd93a2cSPaul E. McKenney
590ba49df47SPaul E. McKenney	  Say Y if energy efficiency is critically important, and you don't
591ba49df47SPaul E. McKenney	  	care about real-time response.
5928bd93a2cSPaul E. McKenney
5938bd93a2cSPaul E. McKenney	  Say N if you are unsure.
5948bd93a2cSPaul E. McKenney
595c903ff83SMike Travisconfig TREE_RCU_TRACE
596f41d911fSPaul E. McKenney	def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
597c903ff83SMike Travis	select DEBUG_FS
598c903ff83SMike Travis	help
599f41d911fSPaul E. McKenney	  This option provides tracing for the TREE_RCU and
600f41d911fSPaul E. McKenney	  TREE_PREEMPT_RCU implementations, permitting Makefile to
601f41d911fSPaul E. McKenney	  trivially select kernel/rcutree_trace.c.
602c903ff83SMike Travis
60324278d14SPaul E. McKenneyconfig RCU_BOOST
60424278d14SPaul E. McKenney	bool "Enable RCU priority boosting"
60527f4d280SPaul E. McKenney	depends on RT_MUTEXES && PREEMPT_RCU
60624278d14SPaul E. McKenney	default n
60724278d14SPaul E. McKenney	help
60824278d14SPaul E. McKenney	  This option boosts the priority of preempted RCU readers that
60924278d14SPaul E. McKenney	  block the current preemptible RCU grace period for too long.
61024278d14SPaul E. McKenney	  This option also prevents heavy loads from blocking RCU
61124278d14SPaul E. McKenney	  callback invocation for all flavors of RCU.
61224278d14SPaul E. McKenney
61324278d14SPaul E. McKenney	  Say Y here if you are working with real-time apps or heavy loads
61424278d14SPaul E. McKenney	  Say N here if you are unsure.
61524278d14SPaul E. McKenney
61624278d14SPaul E. McKenneyconfig RCU_BOOST_PRIO
61724278d14SPaul E. McKenney	int "Real-time priority to boost RCU readers to"
61824278d14SPaul E. McKenney	range 1 99
61924278d14SPaul E. McKenney	depends on RCU_BOOST
62024278d14SPaul E. McKenney	default 1
62124278d14SPaul E. McKenney	help
622c9336643SPaul E. McKenney	  This option specifies the real-time priority to which long-term
623c9336643SPaul E. McKenney	  preempted RCU readers are to be boosted.  If you are working
624c9336643SPaul E. McKenney	  with a real-time application that has one or more CPU-bound
625c9336643SPaul E. McKenney	  threads running at a real-time priority level, you should set
626c9336643SPaul E. McKenney	  RCU_BOOST_PRIO to a priority higher then the highest-priority
627c9336643SPaul E. McKenney	  real-time CPU-bound thread.  The default RCU_BOOST_PRIO value
628c9336643SPaul E. McKenney	  of 1 is appropriate in the common case, which is real-time
629c9336643SPaul E. McKenney	  applications that do not have any CPU-bound threads.
630c9336643SPaul E. McKenney
631c9336643SPaul E. McKenney	  Some real-time applications might not have a single real-time
632c9336643SPaul E. McKenney	  thread that saturates a given CPU, but instead might have
633c9336643SPaul E. McKenney	  multiple real-time threads that, taken together, fully utilize
634c9336643SPaul E. McKenney	  that CPU.  In this case, you should set RCU_BOOST_PRIO to
635c9336643SPaul E. McKenney	  a priority higher than the lowest-priority thread that is
636c9336643SPaul E. McKenney	  conspiring to prevent the CPU from running any non-real-time
637c9336643SPaul E. McKenney	  tasks.  For example, if one thread at priority 10 and another
638c9336643SPaul E. McKenney	  thread at priority 5 are between themselves fully consuming
639c9336643SPaul E. McKenney	  the CPU time on a given CPU, then RCU_BOOST_PRIO should be
640c9336643SPaul E. McKenney	  set to priority 6 or higher.
64124278d14SPaul E. McKenney
64224278d14SPaul E. McKenney	  Specify the real-time priority, or take the default if unsure.
64324278d14SPaul E. McKenney
64424278d14SPaul E. McKenneyconfig RCU_BOOST_DELAY
64524278d14SPaul E. McKenney	int "Milliseconds to delay boosting after RCU grace-period start"
64624278d14SPaul E. McKenney	range 0 3000
64724278d14SPaul E. McKenney	depends on RCU_BOOST
64824278d14SPaul E. McKenney	default 500
64924278d14SPaul E. McKenney	help
65024278d14SPaul E. McKenney	  This option specifies the time to wait after the beginning of
65124278d14SPaul E. McKenney	  a given grace period before priority-boosting preempted RCU
65224278d14SPaul E. McKenney	  readers blocking that grace period.  Note that any RCU reader
65324278d14SPaul E. McKenney	  blocking an expedited RCU grace period is boosted immediately.
65424278d14SPaul E. McKenney
65524278d14SPaul E. McKenney	  Accept the default if unsure.
65624278d14SPaul E. McKenney
657c903ff83SMike Travisendmenu # "RCU Subsystem"
658c903ff83SMike Travis
6591da177e4SLinus Torvaldsconfig IKCONFIG
660f2443ab6SRoss Biro	tristate "Kernel .config support"
6611da177e4SLinus Torvalds	---help---
6621da177e4SLinus Torvalds	  This option enables the complete Linux kernel ".config" file
6631da177e4SLinus Torvalds	  contents to be saved in the kernel. It provides documentation
6641da177e4SLinus Torvalds	  of which kernel options are used in a running kernel or in an
6651da177e4SLinus Torvalds	  on-disk kernel.  This information can be extracted from the kernel
6661da177e4SLinus Torvalds	  image file with the script scripts/extract-ikconfig and used as
6671da177e4SLinus Torvalds	  input to rebuild the current kernel or to build another kernel.
6681da177e4SLinus Torvalds	  It can also be extracted from a running kernel by reading
6691da177e4SLinus Torvalds	  /proc/config.gz if enabled (below).
6701da177e4SLinus Torvalds
6711da177e4SLinus Torvaldsconfig IKCONFIG_PROC
6721da177e4SLinus Torvalds	bool "Enable access to .config through /proc/config.gz"
6731da177e4SLinus Torvalds	depends on IKCONFIG && PROC_FS
6741da177e4SLinus Torvalds	---help---
6751da177e4SLinus Torvalds	  This option enables access to the kernel configuration file
6761da177e4SLinus Torvalds	  through /proc/config.gz.
6771da177e4SLinus Torvalds
678794543a2SAlistair John Strachanconfig LOG_BUF_SHIFT
679794543a2SAlistair John Strachan	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
680794543a2SAlistair John Strachan	range 12 21
681f17a32e9SAdrian Bunk	default 17
682794543a2SAlistair John Strachan	help
683794543a2SAlistair John Strachan	  Select kernel log buffer size as a power of 2.
684f17a32e9SAdrian Bunk	  Examples:
685f17a32e9SAdrian Bunk	  	     17 => 128 KB
686f17a32e9SAdrian Bunk		     16 => 64 KB
687f17a32e9SAdrian Bunk	             15 => 32 KB
688f17a32e9SAdrian Bunk	             14 => 16 KB
689794543a2SAlistair John Strachan		     13 =>  8 KB
690794543a2SAlistair John Strachan		     12 =>  4 KB
691794543a2SAlistair John Strachan
6925cdc38f9SKAMEZAWA Hiroyuki#
6935cdc38f9SKAMEZAWA Hiroyuki# Architectures with an unreliable sched_clock() should select this:
6945cdc38f9SKAMEZAWA Hiroyuki#
6955cdc38f9SKAMEZAWA Hiroyukiconfig HAVE_UNSTABLE_SCHED_CLOCK
6965cdc38f9SKAMEZAWA Hiroyuki	bool
6975cdc38f9SKAMEZAWA Hiroyuki
69823964d2dSLi Zefanmenuconfig CGROUPS
69923964d2dSLi Zefan	boolean "Control Group support"
7000dea1168SKirill A. Shutemov	depends on EVENTFD
701ddbcc7e8SPaul Menage	help
70223964d2dSLi Zefan	  This option adds support for grouping sets of processes together, for
7035cdc38f9SKAMEZAWA Hiroyuki	  use with process control subsystems such as Cpusets, CFS, memory
7045cdc38f9SKAMEZAWA Hiroyuki	  controls or device isolation.
7055cdc38f9SKAMEZAWA Hiroyuki	  See
7065cdc38f9SKAMEZAWA Hiroyuki		- Documentation/scheduler/sched-design-CFS.txt	(CFS)
70745ce80fbSLi Zefan		- Documentation/cgroups/ (features for grouping, isolation
70845ce80fbSLi Zefan					  and resource control)
709ddbcc7e8SPaul Menage
710ddbcc7e8SPaul Menage	  Say N if unsure.
711ddbcc7e8SPaul Menage
71223964d2dSLi Zefanif CGROUPS
71323964d2dSLi Zefan
714006cb992SPaul Menageconfig CGROUP_DEBUG
715006cb992SPaul Menage	bool "Example debug cgroup subsystem"
716418d7d87SPaul Menage	default n
717006cb992SPaul Menage	help
718006cb992SPaul Menage	  This option enables a simple cgroup subsystem that
719006cb992SPaul Menage	  exports useful debugging information about the cgroups
72023964d2dSLi Zefan	  framework.
721006cb992SPaul Menage
72223964d2dSLi Zefan	  Say N if unsure.
723006cb992SPaul Menage
724dc52ddc0SMatt Helsleyconfig CGROUP_FREEZER
72523964d2dSLi Zefan	bool "Freezer cgroup subsystem"
726dc52ddc0SMatt Helsley	help
727dc52ddc0SMatt Helsley	  Provides a way to freeze and unfreeze all tasks in a
728dc52ddc0SMatt Helsley	  cgroup.
729dc52ddc0SMatt Helsley
73008ce5f16SSerge E. Hallynconfig CGROUP_DEVICE
73108ce5f16SSerge E. Hallyn	bool "Device controller for cgroups"
73208ce5f16SSerge E. Hallyn	help
73308ce5f16SSerge E. Hallyn	  Provides a cgroup implementing whitelists for devices which
73408ce5f16SSerge E. Hallyn	  a process in the cgroup can mknod or open.
73508ce5f16SSerge E. Hallyn
7361da177e4SLinus Torvaldsconfig CPUSETS
7371da177e4SLinus Torvalds	bool "Cpuset support"
7381da177e4SLinus Torvalds	help
739d9fd8a6dSRandy Dunlap	  This option will let you create and manage CPUSETs which
7401da177e4SLinus Torvalds	  allow dynamically partitioning a system into sets of CPUs and
7411da177e4SLinus Torvalds	  Memory Nodes and assigning tasks to run only within those sets.
7421da177e4SLinus Torvalds	  This is primarily useful on large SMP or NUMA systems.
7431da177e4SLinus Torvalds
7441da177e4SLinus Torvalds	  Say N if unsure.
7451da177e4SLinus Torvalds
74623964d2dSLi Zefanconfig PROC_PID_CPUSET
74723964d2dSLi Zefan	bool "Include legacy /proc/<pid>/cpuset file"
74823964d2dSLi Zefan	depends on CPUSETS
74923964d2dSLi Zefan	default y
75023964d2dSLi Zefan
751d842de87SSrivatsa Vaddagiriconfig CGROUP_CPUACCT
752d842de87SSrivatsa Vaddagiri	bool "Simple CPU accounting cgroup subsystem"
753d842de87SSrivatsa Vaddagiri	help
754d842de87SSrivatsa Vaddagiri	  Provides a simple Resource Controller for monitoring the
75523964d2dSLi Zefan	  total CPU consumed by the tasks in a cgroup.
756d842de87SSrivatsa Vaddagiri
757e552b661SPavel Emelianovconfig RESOURCE_COUNTERS
758e552b661SPavel Emelianov	bool "Resource counters"
759e552b661SPavel Emelianov	help
760e552b661SPavel Emelianov	  This option enables controller independent resource accounting
76123964d2dSLi Zefan	  infrastructure that works with cgroups.
762e552b661SPavel Emelianov
763c255a458SAndrew Mortonconfig MEMCG
76400f0b825SBalbir Singh	bool "Memory Resource Controller for Control Groups"
76579ae9c29SDaniel Lezcano	depends on RESOURCE_COUNTERS
766cf475ad2SBalbir Singh	select MM_OWNER
76700f0b825SBalbir Singh	help
76884ad6d70SKAMEZAWA Hiroyuki	  Provides a memory resource controller that manages both anonymous
76921acb9caSThadeu Lima de Souza Cascardo	  memory and page cache. (See Documentation/cgroups/memory.txt)
77000f0b825SBalbir Singh
77100f0b825SBalbir Singh	  Note that setting this option increases fixed memory overhead
77284ad6d70SKAMEZAWA Hiroyuki	  associated with each page of memory in the system. By this,
77384ad6d70SKAMEZAWA Hiroyuki	  20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
77484ad6d70SKAMEZAWA Hiroyuki	  usage tracking struct at boot. Total amount of this is printed out
77584ad6d70SKAMEZAWA Hiroyuki	  at boot.
77600f0b825SBalbir Singh
77700f0b825SBalbir Singh	  Only enable when you're ok with these trade offs and really
77884ad6d70SKAMEZAWA Hiroyuki	  sure you need the memory resource controller. Even when you enable
77984ad6d70SKAMEZAWA Hiroyuki	  this, you can set "cgroup_disable=memory" at your boot option to
78084ad6d70SKAMEZAWA Hiroyuki	  disable memory resource controller and you can avoid overheads.
781c9d5409fSLi Zefan	  (and lose benefits of memory resource controller)
78200f0b825SBalbir Singh
783cf475ad2SBalbir Singh	  This config option also selects MM_OWNER config option, which
784cf475ad2SBalbir Singh	  could in turn add some fork/exit overhead.
785cf475ad2SBalbir Singh
786c255a458SAndrew Mortonconfig MEMCG_SWAP
78765e0e811SKAMEZAWA Hiroyuki	bool "Memory Resource Controller Swap Extension"
788c255a458SAndrew Morton	depends on MEMCG && SWAP
789c077719bSKAMEZAWA Hiroyuki	help
790c077719bSKAMEZAWA Hiroyuki	  Add swap management feature to memory resource controller. When you
791c077719bSKAMEZAWA Hiroyuki	  enable this, you can limit mem+swap usage per cgroup. In other words,
792c077719bSKAMEZAWA Hiroyuki	  when you disable this, memory resource controller has no cares to
793c077719bSKAMEZAWA Hiroyuki	  usage of swap...a process can exhaust all of the swap. This extension
794c077719bSKAMEZAWA Hiroyuki	  is useful when you want to avoid exhaustion swap but this itself
795c077719bSKAMEZAWA Hiroyuki	  adds more overheads and consumes memory for remembering information.
796c077719bSKAMEZAWA Hiroyuki	  Especially if you use 32bit system or small memory system, please
797c077719bSKAMEZAWA Hiroyuki	  be careful about enabling this. When memory resource controller
798c077719bSKAMEZAWA Hiroyuki	  is disabled by boot option, this will be automatically disabled and
799c077719bSKAMEZAWA Hiroyuki	  there will be no overhead from this. Even when you set this config=y,
80000a66d29SWANG Cong	  if boot option "swapaccount=0" is set, swap will not be accounted.
801627991a2SKAMEZAWA Hiroyuki	  Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
802627991a2SKAMEZAWA Hiroyuki	  size is 4096bytes, 512k per 1Gbytes of swap.
803c255a458SAndrew Mortonconfig MEMCG_SWAP_ENABLED
804a42c390cSMichal Hocko	bool "Memory Resource Controller Swap Extension enabled by default"
805c255a458SAndrew Morton	depends on MEMCG_SWAP
806a42c390cSMichal Hocko	default y
807a42c390cSMichal Hocko	help
808a42c390cSMichal Hocko	  Memory Resource Controller Swap Extension comes with its price in
809a42c390cSMichal Hocko	  a bigger memory consumption. General purpose distribution kernels
81043d547f9SJim Cromie	  which want to enable the feature but keep it disabled by default
811a42c390cSMichal Hocko	  and let the user enable it by swapaccount boot command line
812a42c390cSMichal Hocko	  parameter should have this option unselected.
813a42c390cSMichal Hocko	  For those who want to have the feature enabled by default should
814a42c390cSMichal Hocko	  select this option (if, for some reason, they need to disable it
81500a66d29SWANG Cong	  then swapaccount=0 does the trick).
816c255a458SAndrew Mortonconfig MEMCG_KMEM
817e5671dfaSGlauber Costa	bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
818c255a458SAndrew Morton	depends on MEMCG && EXPERIMENTAL
819e5671dfaSGlauber Costa	default n
820e5671dfaSGlauber Costa	help
821e5671dfaSGlauber Costa	  The Kernel Memory extension for Memory Resource Controller can limit
822e5671dfaSGlauber Costa	  the amount of memory used by kernel objects in the system. Those are
823e5671dfaSGlauber Costa	  fundamentally different from the entities handled by the standard
824e5671dfaSGlauber Costa	  Memory Controller, which are page-based, and can be swapped. Users of
825e5671dfaSGlauber Costa	  the kmem extension can use it to guarantee that no group of processes
826e5671dfaSGlauber Costa	  will ever exhaust kernel resources alone.
827c077719bSKAMEZAWA Hiroyuki
8282bc64a20SAneesh Kumar K.Vconfig CGROUP_HUGETLB
8292bc64a20SAneesh Kumar K.V	bool "HugeTLB Resource Controller for Control Groups"
8302bc64a20SAneesh Kumar K.V	depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL
8312bc64a20SAneesh Kumar K.V	default n
8322bc64a20SAneesh Kumar K.V	help
8332bc64a20SAneesh Kumar K.V	  Provides a cgroup Resource Controller for HugeTLB pages.
8342bc64a20SAneesh Kumar K.V	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
8352bc64a20SAneesh Kumar K.V	  The limit is enforced during page fault. Since HugeTLB doesn't
8362bc64a20SAneesh Kumar K.V	  support page reclaim, enforcing the limit at page fault time implies
8372bc64a20SAneesh Kumar K.V	  that, the application will get SIGBUS signal if it tries to access
8382bc64a20SAneesh Kumar K.V	  HugeTLB pages beyond its limit. This requires the application to know
8392bc64a20SAneesh Kumar K.V	  beforehand how much HugeTLB pages it would require for its use. The
8402bc64a20SAneesh Kumar K.V	  control group is tracked in the third page lru pointer. This means
8412bc64a20SAneesh Kumar K.V	  that we cannot use the controller with huge page less than 3 pages.
8422bc64a20SAneesh Kumar K.V
843e5d1367fSStephane Eranianconfig CGROUP_PERF
844e5d1367fSStephane Eranian	bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
845e5d1367fSStephane Eranian	depends on PERF_EVENTS && CGROUPS
846e5d1367fSStephane Eranian	help
847e5d1367fSStephane Eranian	  This option extends the per-cpu mode to restrict monitoring to
8482d0f2520SLi Zefan	  threads which belong to the cgroup specified and run on the
849e5d1367fSStephane Eranian	  designated cpu.
850e5d1367fSStephane Eranian
851e5d1367fSStephane Eranian	  Say N if unsure.
852e5d1367fSStephane Eranian
8537c941438SDhaval Gianimenuconfig CGROUP_SCHED
8547c941438SDhaval Giani	bool "Group CPU scheduler"
8557c941438SDhaval Giani	default n
8567c941438SDhaval Giani	help
8577c941438SDhaval Giani	  This feature lets CPU scheduler recognize task groups and control CPU
8587c941438SDhaval Giani	  bandwidth allocation to such task groups. It uses cgroups to group
8597c941438SDhaval Giani	  tasks.
8607c941438SDhaval Giani
8617c941438SDhaval Gianiif CGROUP_SCHED
8627c941438SDhaval Gianiconfig FAIR_GROUP_SCHED
8637c941438SDhaval Giani	bool "Group scheduling for SCHED_OTHER"
8647c941438SDhaval Giani	depends on CGROUP_SCHED
8657c941438SDhaval Giani	default CGROUP_SCHED
8667c941438SDhaval Giani
867ab84d31eSPaul Turnerconfig CFS_BANDWIDTH
868ab84d31eSPaul Turner	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
869ab84d31eSPaul Turner	depends on EXPERIMENTAL
870ab84d31eSPaul Turner	depends on FAIR_GROUP_SCHED
871ab84d31eSPaul Turner	default n
872ab84d31eSPaul Turner	help
873ab84d31eSPaul Turner	  This option allows users to define CPU bandwidth rates (limits) for
874ab84d31eSPaul Turner	  tasks running within the fair group scheduler.  Groups with no limit
875ab84d31eSPaul Turner	  set are considered to be unconstrained and will run with no
876ab84d31eSPaul Turner	  restriction.
877ab84d31eSPaul Turner	  See tip/Documentation/scheduler/sched-bwc.txt for more information.
878ab84d31eSPaul Turner
8797c941438SDhaval Gianiconfig RT_GROUP_SCHED
8807c941438SDhaval Giani	bool "Group scheduling for SCHED_RR/FIFO"
8817c941438SDhaval Giani	depends on EXPERIMENTAL
8827c941438SDhaval Giani	depends on CGROUP_SCHED
8837c941438SDhaval Giani	default n
8847c941438SDhaval Giani	help
8857c941438SDhaval Giani	  This feature lets you explicitly allocate real CPU bandwidth
88632bd7eb5SLi Zefan	  to task groups. If enabled, it will also make it impossible to
8877c941438SDhaval Giani	  schedule realtime tasks for non-root users until you allocate
8887c941438SDhaval Giani	  realtime bandwidth for them.
8897c941438SDhaval Giani	  See Documentation/scheduler/sched-rt-group.txt for more information.
8907c941438SDhaval Giani
8917c941438SDhaval Gianiendif #CGROUP_SCHED
8927c941438SDhaval Giani
893afc24d49SVivek Goyalconfig BLK_CGROUP
89432e380aeSTejun Heo	bool "Block IO controller"
89579ae9c29SDaniel Lezcano	depends on BLOCK
896afc24d49SVivek Goyal	default n
897afc24d49SVivek Goyal	---help---
898afc24d49SVivek Goyal	Generic block IO controller cgroup interface. This is the common
899afc24d49SVivek Goyal	cgroup interface which should be used by various IO controlling
900afc24d49SVivek Goyal	policies.
901afc24d49SVivek Goyal
902afc24d49SVivek Goyal	Currently, CFQ IO scheduler uses it to recognize task groups and
903afc24d49SVivek Goyal	control disk bandwidth allocation (proportional time slice allocation)
904e43473b7SVivek Goyal	to such task groups. It is also used by bio throttling logic in
905e43473b7SVivek Goyal	block layer to implement upper limit in IO rates on a device.
906afc24d49SVivek Goyal
907afc24d49SVivek Goyal	This option only enables generic Block IO controller infrastructure.
908e43473b7SVivek Goyal	One needs to also enable actual IO controlling logic/policy. For
90979e2e759SMichael Witten	enabling proportional weight division of disk bandwidth in CFQ, set
91079e2e759SMichael Witten	CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
911c5e0591aSMichael Witten	CONFIG_BLK_DEV_THROTTLING=y.
912afc24d49SVivek Goyal
913afc24d49SVivek Goyal	See Documentation/cgroups/blkio-controller.txt for more information.
914afc24d49SVivek Goyal
915afc24d49SVivek Goyalconfig DEBUG_BLK_CGROUP
916afc24d49SVivek Goyal	bool "Enable Block IO controller debugging"
917afc24d49SVivek Goyal	depends on BLK_CGROUP
918afc24d49SVivek Goyal	default n
919afc24d49SVivek Goyal	---help---
920afc24d49SVivek Goyal	Enable some debugging help. Currently it exports additional stat
921afc24d49SVivek Goyal	files in a cgroup which can be useful for debugging.
922afc24d49SVivek Goyal
92323964d2dSLi Zefanendif # CGROUPS
924c077719bSKAMEZAWA Hiroyuki
925067bce1aSCyrill Gorcunovconfig CHECKPOINT_RESTORE
926067bce1aSCyrill Gorcunov	bool "Checkpoint/restore support" if EXPERT
927067bce1aSCyrill Gorcunov	default n
928067bce1aSCyrill Gorcunov	help
929067bce1aSCyrill Gorcunov	  Enables additional kernel features in a sake of checkpoint/restore.
930067bce1aSCyrill Gorcunov	  In particular it adds auxiliary prctl codes to setup process text,
931067bce1aSCyrill Gorcunov	  data and heap segment sizes, and a few additional /proc filesystem
932067bce1aSCyrill Gorcunov	  entries.
933067bce1aSCyrill Gorcunov
934067bce1aSCyrill Gorcunov	  If unsure, say N here.
935067bce1aSCyrill Gorcunov
9368dd2a82cSDaniel Lezcanomenuconfig NAMESPACES
9376a108a14SDavid Rientjes	bool "Namespaces support" if EXPERT
9386a108a14SDavid Rientjes	default !EXPERT
939c5289a69SPavel Emelyanov	help
940c5289a69SPavel Emelyanov	  Provides the way to make tasks work with different objects using
941c5289a69SPavel Emelyanov	  the same id. For example same IPC id may refer to different objects
942c5289a69SPavel Emelyanov	  or same user id or pid may refer to different tasks when used in
943c5289a69SPavel Emelyanov	  different namespaces.
944c5289a69SPavel Emelyanov
9458dd2a82cSDaniel Lezcanoif NAMESPACES
9468dd2a82cSDaniel Lezcano
94758bfdd6dSPavel Emelyanovconfig UTS_NS
94858bfdd6dSPavel Emelyanov	bool "UTS namespace"
94917a6d441SDaniel Lezcano	default y
95058bfdd6dSPavel Emelyanov	help
95158bfdd6dSPavel Emelyanov	  In this namespace tasks see different info provided with the
95258bfdd6dSPavel Emelyanov	  uname() system call
95358bfdd6dSPavel Emelyanov
954ae5e1b22SPavel Emelyanovconfig IPC_NS
955ae5e1b22SPavel Emelyanov	bool "IPC namespace"
9568dd2a82cSDaniel Lezcano	depends on (SYSVIPC || POSIX_MQUEUE)
95717a6d441SDaniel Lezcano	default y
958ae5e1b22SPavel Emelyanov	help
959ae5e1b22SPavel Emelyanov	  In this namespace tasks work with IPC ids which correspond to
960614b84cfSSerge E. Hallyn	  different IPC objects in different namespaces.
961ae5e1b22SPavel Emelyanov
962aee16ce7SPavel Emelyanovconfig USER_NS
963aee16ce7SPavel Emelyanov	bool "User namespace (EXPERIMENTAL)"
9648dd2a82cSDaniel Lezcano	depends on EXPERIMENTAL
965e1c972b6SEric W. Biederman	depends on UIDGID_CONVERTED
9665673a94cSEric W. Biederman	select UIDGID_STRICT_TYPE_CHECKS
967e1c972b6SEric W. Biederman
9685673a94cSEric W. Biederman	default n
969aee16ce7SPavel Emelyanov	help
970aee16ce7SPavel Emelyanov	  This allows containers, i.e. vservers, to use user namespaces
971aee16ce7SPavel Emelyanov	  to provide different user info for different servers.
972aee16ce7SPavel Emelyanov	  If unsure, say N.
973aee16ce7SPavel Emelyanov
97474bd59bbSPavel Emelyanovconfig PID_NS
9759bd38c2cSDaniel Lezcano	bool "PID Namespaces"
97617a6d441SDaniel Lezcano	default y
97774bd59bbSPavel Emelyanov	help
97812d2b8f9SHeikki Orsila	  Support process id namespaces.  This allows having multiple
979692105b8SMatt LaPlante	  processes with the same pid as long as they are in different
98074bd59bbSPavel Emelyanov	  pid namespaces.  This is a building block of containers.
98174bd59bbSPavel Emelyanov
982d6eb633fSMatt Helsleyconfig NET_NS
983d6eb633fSMatt Helsley	bool "Network namespace"
9848dd2a82cSDaniel Lezcano	depends on NET
98517a6d441SDaniel Lezcano	default y
986d6eb633fSMatt Helsley	help
987d6eb633fSMatt Helsley	  Allow user space to create what appear to be multiple instances
988d6eb633fSMatt Helsley	  of the network stack.
989d6eb633fSMatt Helsley
9908dd2a82cSDaniel Lezcanoendif # NAMESPACES
9918dd2a82cSDaniel Lezcano
992e1c972b6SEric W. Biedermanconfig UIDGID_CONVERTED
993e1c972b6SEric W. Biederman	# True if all of the selected software conmponents are known
994e1c972b6SEric W. Biederman	# to have uid_t and gid_t converted to kuid_t and kgid_t
995e1c972b6SEric W. Biederman	# where appropriate and are otherwise safe to use with
996e1c972b6SEric W. Biederman	# the user namespace.
997e1c972b6SEric W. Biederman	bool
998e1c972b6SEric W. Biederman	default y
999e1c972b6SEric W. Biederman
1000e1c972b6SEric W. Biederman	# Networking
1001e1c972b6SEric W. Biederman	depends on NET_9P = n
1002e1c972b6SEric W. Biederman
1003e1c972b6SEric W. Biederman	# Filesystems
1004e1c972b6SEric W. Biederman	depends on 9P_FS = n
1005e1c972b6SEric W. Biederman	depends on AFS_FS = n
1006e1c972b6SEric W. Biederman	depends on AUTOFS4_FS = n
1007e1c972b6SEric W. Biederman	depends on CEPH_FS = n
1008e1c972b6SEric W. Biederman	depends on CIFS = n
1009e1c972b6SEric W. Biederman	depends on CODA_FS = n
1010e1c972b6SEric W. Biederman	depends on FUSE_FS = n
1011e1c972b6SEric W. Biederman	depends on GFS2_FS = n
1012e1c972b6SEric W. Biederman	depends on NCP_FS = n
1013e1c972b6SEric W. Biederman	depends on NFSD = n
1014e1c972b6SEric W. Biederman	depends on NFS_FS = n
1015e1c972b6SEric W. Biederman	depends on OCFS2_FS = n
1016e1c972b6SEric W. Biederman	depends on XFS_FS = n
1017e1c972b6SEric W. Biederman
10185673a94cSEric W. Biedermanconfig UIDGID_STRICT_TYPE_CHECKS
10195673a94cSEric W. Biederman	bool "Require conversions between uid/gids and their internal representation"
1020e1c972b6SEric W. Biederman	depends on UIDGID_CONVERTED
10215673a94cSEric W. Biederman	default n
10225673a94cSEric W. Biederman	help
10235673a94cSEric W. Biederman	 While the nececessary conversions are being added to all subsystems this option allows
10245673a94cSEric W. Biederman	 the code to continue to build for unconverted subsystems.
10255673a94cSEric W. Biederman
10265673a94cSEric W. Biederman	 Say Y here if you want the strict type checking enabled
10275673a94cSEric W. Biederman
10285091faa4SMike Galbraithconfig SCHED_AUTOGROUP
10295091faa4SMike Galbraith	bool "Automatic process group scheduling"
10305091faa4SMike Galbraith	select EVENTFD
10315091faa4SMike Galbraith	select CGROUPS
10325091faa4SMike Galbraith	select CGROUP_SCHED
10335091faa4SMike Galbraith	select FAIR_GROUP_SCHED
10345091faa4SMike Galbraith	help
10355091faa4SMike Galbraith	  This option optimizes the scheduler for common desktop workloads by
10365091faa4SMike Galbraith	  automatically creating and populating task groups.  This separation
10375091faa4SMike Galbraith	  of workloads isolates aggressive CPU burners (like build jobs) from
10385091faa4SMike Galbraith	  desktop applications.  Task group autogeneration is currently based
10395091faa4SMike Galbraith	  upon task session.
10405091faa4SMike Galbraith
10417af37becSDaniel Lezcanoconfig MM_OWNER
10427af37becSDaniel Lezcano	bool
10437af37becSDaniel Lezcano
10447af37becSDaniel Lezcanoconfig SYSFS_DEPRECATED
10455d6a4ea5SFerenc Wagner	bool "Enable deprecated sysfs features to support old userspace tools"
10467af37becSDaniel Lezcano	depends on SYSFS
10477af37becSDaniel Lezcano	default n
10487af37becSDaniel Lezcano	help
10497af37becSDaniel Lezcano	  This option adds code that switches the layout of the "block" class
10507af37becSDaniel Lezcano	  devices, to not show up in /sys/class/block/, but only in
10517af37becSDaniel Lezcano	  /sys/block/.
10527af37becSDaniel Lezcano
10537af37becSDaniel Lezcano	  This switch is only active when the sysfs.deprecated=1 boot option is
10547af37becSDaniel Lezcano	  passed or the SYSFS_DEPRECATED_V2 option is set.
10557af37becSDaniel Lezcano
10567af37becSDaniel Lezcano	  This option allows new kernels to run on old distributions and tools,
10577af37becSDaniel Lezcano	  which might get confused by /sys/class/block/. Since 2007/2008 all
10587af37becSDaniel Lezcano	  major distributions and tools handle this just fine.
10597af37becSDaniel Lezcano
10607af37becSDaniel Lezcano	  Recent distributions and userspace tools after 2009/2010 depend on
10617af37becSDaniel Lezcano	  the existence of /sys/class/block/, and will not work with this
10627af37becSDaniel Lezcano	  option enabled.
10637af37becSDaniel Lezcano
10647af37becSDaniel Lezcano	  Only if you are using a new kernel on an old distribution, you might
10657af37becSDaniel Lezcano	  need to say Y here.
10667af37becSDaniel Lezcano
10677af37becSDaniel Lezcanoconfig SYSFS_DEPRECATED_V2
10685d6a4ea5SFerenc Wagner	bool "Enable deprecated sysfs features by default"
10697af37becSDaniel Lezcano	default n
10707af37becSDaniel Lezcano	depends on SYSFS
10717af37becSDaniel Lezcano	depends on SYSFS_DEPRECATED
10727af37becSDaniel Lezcano	help
10737af37becSDaniel Lezcano	  Enable deprecated sysfs by default.
10747af37becSDaniel Lezcano
10757af37becSDaniel Lezcano	  See the CONFIG_SYSFS_DEPRECATED option for more details about this
10767af37becSDaniel Lezcano	  option.
10777af37becSDaniel Lezcano
10787af37becSDaniel Lezcano	  Only if you are using a new kernel on an old distribution, you might
10797af37becSDaniel Lezcano	  need to say Y here. Even then, odds are you would not need it
10807af37becSDaniel Lezcano	  enabled, you can always pass the boot option if absolutely necessary.
10817af37becSDaniel Lezcano
10827af37becSDaniel Lezcanoconfig RELAY
10837af37becSDaniel Lezcano	bool "Kernel->user space relay support (formerly relayfs)"
10847af37becSDaniel Lezcano	help
10857af37becSDaniel Lezcano	  This option enables support for relay interface support in
10867af37becSDaniel Lezcano	  certain file systems (such as debugfs).
10877af37becSDaniel Lezcano	  It is designed to provide an efficient mechanism for tools and
10887af37becSDaniel Lezcano	  facilities to relay large amounts of data from kernel space to
10897af37becSDaniel Lezcano	  user space.
10907af37becSDaniel Lezcano
10917af37becSDaniel Lezcano	  If unsure, say N.
10927af37becSDaniel Lezcano
1093f991633dSDimitri Gorokhovikconfig BLK_DEV_INITRD
1094f991633dSDimitri Gorokhovik	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1095f991633dSDimitri Gorokhovik	depends on BROKEN || !FRV
1096f991633dSDimitri Gorokhovik	help
1097f991633dSDimitri Gorokhovik	  The initial RAM filesystem is a ramfs which is loaded by the
1098f991633dSDimitri Gorokhovik	  boot loader (loadlin or lilo) and that is mounted as root
1099f991633dSDimitri Gorokhovik	  before the normal boot procedure. It is typically used to
1100f991633dSDimitri Gorokhovik	  load modules needed to mount the "real" root file system,
1101f991633dSDimitri Gorokhovik	  etc. See <file:Documentation/initrd.txt> for details.
1102f991633dSDimitri Gorokhovik
1103f991633dSDimitri Gorokhovik	  If RAM disk support (BLK_DEV_RAM) is also included, this
1104f991633dSDimitri Gorokhovik	  also enables initial RAM disk (initrd) support and adds
1105f991633dSDimitri Gorokhovik	  15 Kbytes (more on some other architectures) to the kernel size.
1106f991633dSDimitri Gorokhovik
1107f991633dSDimitri Gorokhovik	  If unsure say Y.
1108f991633dSDimitri Gorokhovik
1109c33df4eaSJean-Paul Samanif BLK_DEV_INITRD
1110c33df4eaSJean-Paul Saman
1111dbec4866SSam Ravnborgsource "usr/Kconfig"
1112dbec4866SSam Ravnborg
1113c33df4eaSJean-Paul Samanendif
1114c33df4eaSJean-Paul Saman
1115c45b4f1fSLinus Torvaldsconfig CC_OPTIMIZE_FOR_SIZE
111696fffeb4SIngo Molnar	bool "Optimize for size"
1117c45b4f1fSLinus Torvalds	help
1118c45b4f1fSLinus Torvalds	  Enabling this option will pass "-Os" instead of "-O2" to gcc
1119c45b4f1fSLinus Torvalds	  resulting in a smaller kernel.
1120c45b4f1fSLinus Torvalds
1121775a7229Sjkacur	  If unsure, say Y.
1122c45b4f1fSLinus Torvalds
11230847062aSRandy Dunlapconfig SYSCTL
11240847062aSRandy Dunlap	bool
11250847062aSRandy Dunlap
1126b943c460SRandy Dunlapconfig ANON_INODES
1127b943c460SRandy Dunlap	bool
1128b943c460SRandy Dunlap
11296a108a14SDavid Rientjesmenuconfig EXPERT
11306a108a14SDavid Rientjes	bool "Configure standard kernel features (expert users)"
1131f505c553SJosh Triplett	# Unhide debug options, to make the on-by-default options visible
1132f505c553SJosh Triplett	select DEBUG_KERNEL
11331da177e4SLinus Torvalds	help
11341da177e4SLinus Torvalds	  This option allows certain base kernel options and settings
11351da177e4SLinus Torvalds          to be disabled or tweaked. This is for specialized
11361da177e4SLinus Torvalds          environments which can tolerate a "non-standard" kernel.
11371da177e4SLinus Torvalds          Only use this if you really know what you are doing.
11381da177e4SLinus Torvalds
1139af1839ebSCatalin Marinasconfig HAVE_UID16
1140af1839ebSCatalin Marinas	bool
1141af1839ebSCatalin Marinas
1142ae81f9e3SChuck Ebbertconfig UID16
11436a108a14SDavid Rientjes	bool "Enable 16-bit UID system calls" if EXPERT
1144af1839ebSCatalin Marinas	depends on HAVE_UID16
1145ae81f9e3SChuck Ebbert	default y
1146ae81f9e3SChuck Ebbert	help
1147ae81f9e3SChuck Ebbert	  This enables the legacy 16-bit UID syscall wrappers.
1148ae81f9e3SChuck Ebbert
1149b89a8171SEric W. Biedermanconfig SYSCTL_SYSCALL
11506a108a14SDavid Rientjes	bool "Sysctl syscall support" if EXPERT
115126a7034bSEric W. Biederman	depends on PROC_SYSCTL
1152c736de60SWANG Cong	default n
1153b89a8171SEric W. Biederman	select SYSCTL
1154b89a8171SEric W. Biederman	---help---
115513bb7e37SEric W. Biederman	  sys_sysctl uses binary paths that have been found challenging
115613bb7e37SEric W. Biederman	  to properly maintain and use.  The interface in /proc/sys
115713bb7e37SEric W. Biederman	  using paths with ascii names is now the primary path to this
115813bb7e37SEric W. Biederman	  information.
1159b89a8171SEric W. Biederman
116013bb7e37SEric W. Biederman	  Almost nothing using the binary sysctl interface so if you are
116113bb7e37SEric W. Biederman	  trying to save some space it is probably safe to disable this,
116213bb7e37SEric W. Biederman	  making your kernel marginally smaller.
1163b89a8171SEric W. Biederman
1164c736de60SWANG Cong	  If unsure say N here.
1165ae81f9e3SChuck Ebbert
11667ac57a89SCatalin Marinasconfig SYSCTL_EXCEPTION_TRACE
11677ac57a89SCatalin Marinas	bool
11687ac57a89SCatalin Marinas	help
11697ac57a89SCatalin Marinas	  Enable support for /proc/sys/debug/exception-trace.
11707ac57a89SCatalin Marinas
11711da177e4SLinus Torvaldsconfig KALLSYMS
11726a108a14SDavid Rientjes	 bool "Load all symbols for debugging/ksymoops" if EXPERT
11731da177e4SLinus Torvalds	 default y
11741da177e4SLinus Torvalds	 help
11751da177e4SLinus Torvalds	   Say Y here to let the kernel print out symbolic crash information and
11761da177e4SLinus Torvalds	   symbolic stack backtraces. This increases the size of the kernel
11771da177e4SLinus Torvalds	   somewhat, as all symbols have to be loaded into the kernel image.
11781da177e4SLinus Torvalds
11791da177e4SLinus Torvaldsconfig KALLSYMS_ALL
11801da177e4SLinus Torvalds	bool "Include all symbols in kallsyms"
11811da177e4SLinus Torvalds	depends on DEBUG_KERNEL && KALLSYMS
11821da177e4SLinus Torvalds	help
118371a83ec7SArtem Bityutskiy	   Normally kallsyms only contains the symbols of functions for nicer
118471a83ec7SArtem Bityutskiy	   OOPS messages and backtraces (i.e., symbols from the text and inittext
118571a83ec7SArtem Bityutskiy	   sections). This is sufficient for most cases. And only in very rare
118671a83ec7SArtem Bityutskiy	   cases (e.g., when a debugger is used) all symbols are required (e.g.,
118771a83ec7SArtem Bityutskiy	   names of variables from the data sections, etc).
11881da177e4SLinus Torvalds
118971a83ec7SArtem Bityutskiy	   This option makes sure that all symbols are loaded into the kernel
119071a83ec7SArtem Bityutskiy	   image (i.e., symbols from all sections) in cost of increased kernel
119171a83ec7SArtem Bityutskiy	   size (depending on the kernel configuration, it may be 300KiB or
119271a83ec7SArtem Bityutskiy	   something like this).
11931da177e4SLinus Torvalds
119471a83ec7SArtem Bityutskiy	   Say N unless you really need all symbols.
1195d59745ceSMatt Mackall
1196712f47ceSGreg Kroah-Hartmanconfig HOTPLUG
119745f035abSGreg Kroah-Hartman	def_bool y
1198712f47ceSGreg Kroah-Hartman
1199d59745ceSMatt Mackallconfig PRINTK
1200d59745ceSMatt Mackall	default y
12016a108a14SDavid Rientjes	bool "Enable support for printk" if EXPERT
1202d59745ceSMatt Mackall	help
1203d59745ceSMatt Mackall	  This option enables normal printk support. Removing it
1204d59745ceSMatt Mackall	  eliminates most of the message strings from the kernel image
1205d59745ceSMatt Mackall	  and makes the kernel more or less silent. As this makes it
1206d59745ceSMatt Mackall	  very difficult to diagnose system problems, saying N here is
1207d59745ceSMatt Mackall	  strongly discouraged.
1208d59745ceSMatt Mackall
1209c8538a7aSMatt Mackallconfig BUG
12106a108a14SDavid Rientjes	bool "BUG() support" if EXPERT
1211c8538a7aSMatt Mackall	default y
1212c8538a7aSMatt Mackall	help
1213c8538a7aSMatt Mackall          Disabling this option eliminates support for BUG and WARN, reducing
1214c8538a7aSMatt Mackall          the size of your kernel image and potentially quietly ignoring
1215c8538a7aSMatt Mackall          numerous fatal conditions. You should only consider disabling this
1216c8538a7aSMatt Mackall          option for embedded systems with no facilities for reporting errors.
1217c8538a7aSMatt Mackall          Just say Y.
1218c8538a7aSMatt Mackall
1219708e9a79SMatt Mackallconfig ELF_CORE
1220046d662fSAlex Kelly	depends on COREDUMP
1221708e9a79SMatt Mackall	default y
12226a108a14SDavid Rientjes	bool "Enable ELF core dumps" if EXPERT
1223708e9a79SMatt Mackall	help
1224708e9a79SMatt Mackall	  Enable support for generating core dumps. Disabling saves about 4k.
1225708e9a79SMatt Mackall
12268761f1abSRalf Baechle
1227e5e1d3cbSStas Sergeevconfig PCSPKR_PLATFORM
12286a108a14SDavid Rientjes	bool "Enable PC-Speaker support" if EXPERT
12298761f1abSRalf Baechle	depends on HAVE_PCSPKR_PLATFORM
123015f304b6SRalf Baechle	select I8253_LOCK
1231e5e1d3cbSStas Sergeev	default y
1232e5e1d3cbSStas Sergeev	help
1233e5e1d3cbSStas Sergeev          This option allows to disable the internal PC-Speaker
1234e5e1d3cbSStas Sergeev          support, saving some memory.
1235e5e1d3cbSStas Sergeev
12368761f1abSRalf Baechleconfig HAVE_PCSPKR_PLATFORM
12378761f1abSRalf Baechle	bool
12388761f1abSRalf Baechle
12391da177e4SLinus Torvaldsconfig BASE_FULL
12401da177e4SLinus Torvalds	default y
12416a108a14SDavid Rientjes	bool "Enable full-sized data structures for core" if EXPERT
12421da177e4SLinus Torvalds	help
12431da177e4SLinus Torvalds	  Disabling this option reduces the size of miscellaneous core
12441da177e4SLinus Torvalds	  kernel data structures. This saves memory on small machines,
12451da177e4SLinus Torvalds	  but may reduce performance.
12461da177e4SLinus Torvalds
12471da177e4SLinus Torvaldsconfig FUTEX
12486a108a14SDavid Rientjes	bool "Enable futex support" if EXPERT
12491da177e4SLinus Torvalds	default y
125023f78d4aSIngo Molnar	select RT_MUTEXES
12511da177e4SLinus Torvalds	help
12521da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
12531da177e4SLinus Torvalds	  support for "fast userspace mutexes".  The resulting kernel may not
12541da177e4SLinus Torvalds	  run glibc-based applications correctly.
12551da177e4SLinus Torvalds
12561da177e4SLinus Torvaldsconfig EPOLL
12576a108a14SDavid Rientjes	bool "Enable eventpoll support" if EXPERT
12581da177e4SLinus Torvalds	default y
1259448e3ceeSAdrian Bunk	select ANON_INODES
12601da177e4SLinus Torvalds	help
12611da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
12621da177e4SLinus Torvalds	  support for epoll family of system calls.
12631da177e4SLinus Torvalds
1264fba2afaaSDavide Libenziconfig SIGNALFD
12656a108a14SDavid Rientjes	bool "Enable signalfd() system call" if EXPERT
1266448e3ceeSAdrian Bunk	select ANON_INODES
1267fba2afaaSDavide Libenzi	default y
1268fba2afaaSDavide Libenzi	help
1269fba2afaaSDavide Libenzi	  Enable the signalfd() system call that allows to receive signals
1270fba2afaaSDavide Libenzi	  on a file descriptor.
1271fba2afaaSDavide Libenzi
1272fba2afaaSDavide Libenzi	  If unsure, say Y.
1273fba2afaaSDavide Libenzi
1274b215e283SDavide Libenziconfig TIMERFD
12756a108a14SDavid Rientjes	bool "Enable timerfd() system call" if EXPERT
1276448e3ceeSAdrian Bunk	select ANON_INODES
1277b215e283SDavide Libenzi	default y
1278b215e283SDavide Libenzi	help
1279b215e283SDavide Libenzi	  Enable the timerfd() system call that allows to receive timer
1280b215e283SDavide Libenzi	  events on a file descriptor.
1281b215e283SDavide Libenzi
1282b215e283SDavide Libenzi	  If unsure, say Y.
1283b215e283SDavide Libenzi
1284e1ad7468SDavide Libenziconfig EVENTFD
12856a108a14SDavid Rientjes	bool "Enable eventfd() system call" if EXPERT
1286448e3ceeSAdrian Bunk	select ANON_INODES
1287e1ad7468SDavide Libenzi	default y
1288e1ad7468SDavide Libenzi	help
1289e1ad7468SDavide Libenzi	  Enable the eventfd() system call that allows to receive both
1290e1ad7468SDavide Libenzi	  kernel notification (ie. KAIO) or userspace notifications.
1291e1ad7468SDavide Libenzi
1292e1ad7468SDavide Libenzi	  If unsure, say Y.
1293e1ad7468SDavide Libenzi
12941da177e4SLinus Torvaldsconfig SHMEM
12956a108a14SDavid Rientjes	bool "Use full shmem filesystem" if EXPERT
12961da177e4SLinus Torvalds	default y
12971da177e4SLinus Torvalds	depends on MMU
12981da177e4SLinus Torvalds	help
12991da177e4SLinus Torvalds	  The shmem is an internal filesystem used to manage shared memory.
13001da177e4SLinus Torvalds	  It is backed by swap and manages resource limits. It is also exported
13011da177e4SLinus Torvalds	  to userspace as tmpfs if TMPFS is enabled. Disabling this
13021da177e4SLinus Torvalds	  option replaces shmem and tmpfs with the much simpler ramfs code,
13031da177e4SLinus Torvalds	  which may be appropriate on small systems without swap.
13041da177e4SLinus Torvalds
1305ebf3f09cSThomas Petazzoniconfig AIO
13066a108a14SDavid Rientjes	bool "Enable AIO support" if EXPERT
1307ebf3f09cSThomas Petazzoni	default y
1308ebf3f09cSThomas Petazzoni	help
1309ebf3f09cSThomas Petazzoni	  This option enables POSIX asynchronous I/O which may by used
1310ebf3f09cSThomas Petazzoni          by some high performance threaded applications. Disabling
1311ebf3f09cSThomas Petazzoni          this option saves about 7k.
1312ebf3f09cSThomas Petazzoni
13136befe5f6SRandy Dunlapconfig EMBEDDED
13146befe5f6SRandy Dunlap	bool "Embedded system"
13156befe5f6SRandy Dunlap	select EXPERT
13166befe5f6SRandy Dunlap	help
13176befe5f6SRandy Dunlap	  This option should be enabled if compiling the kernel for
13186befe5f6SRandy Dunlap	  an embedded system so certain expert options are available
13196befe5f6SRandy Dunlap	  for configuration.
13206befe5f6SRandy Dunlap
1321cdd6c482SIngo Molnarconfig HAVE_PERF_EVENTS
13220793a61dSThomas Gleixner	bool
1323018df72dSMike Frysinger	help
1324018df72dSMike Frysinger	  See tools/perf/design.txt for details.
13250793a61dSThomas Gleixner
1326906010b2SPeter Zijlstraconfig PERF_USE_VMALLOC
1327906010b2SPeter Zijlstra	bool
1328906010b2SPeter Zijlstra	help
1329906010b2SPeter Zijlstra	  See tools/perf/design.txt for details
1330906010b2SPeter Zijlstra
133157c0c15bSIngo Molnarmenu "Kernel Performance Events And Counters"
13320793a61dSThomas Gleixner
1333cdd6c482SIngo Molnarconfig PERF_EVENTS
133457c0c15bSIngo Molnar	bool "Kernel performance events and counters"
1335392d65a9SRobert Richter	default y if PROFILING
1336cdd6c482SIngo Molnar	depends on HAVE_PERF_EVENTS
13374c59e467SIngo Molnar	select ANON_INODES
1338e360adbeSPeter Zijlstra	select IRQ_WORK
13390793a61dSThomas Gleixner	help
134057c0c15bSIngo Molnar	  Enable kernel support for various performance events provided
134157c0c15bSIngo Molnar	  by software and hardware.
13420793a61dSThomas Gleixner
1343dd77038dSThadeu Lima de Souza Cascardo	  Software events are supported either built-in or via the
134457c0c15bSIngo Molnar	  use of generic tracepoints.
134557c0c15bSIngo Molnar
134657c0c15bSIngo Molnar	  Most modern CPUs support performance events via performance
134757c0c15bSIngo Molnar	  counter registers. These registers count the number of certain
13480793a61dSThomas Gleixner	  types of hw events: such as instructions executed, cachemisses
13490793a61dSThomas Gleixner	  suffered, or branches mis-predicted - without slowing down the
13500793a61dSThomas Gleixner	  kernel or applications. These registers can also trigger interrupts
13510793a61dSThomas Gleixner	  when a threshold number of events have passed - and can thus be
13520793a61dSThomas Gleixner	  used to profile the code that runs on that CPU.
13530793a61dSThomas Gleixner
135457c0c15bSIngo Molnar	  The Linux Performance Event subsystem provides an abstraction of
1355dd77038dSThadeu Lima de Souza Cascardo	  these software and hardware event capabilities, available via a
135657c0c15bSIngo Molnar	  system call and used by the "perf" utility in tools/perf/. It
13570793a61dSThomas Gleixner	  provides per task and per CPU counters, and it provides event
13580793a61dSThomas Gleixner	  capabilities on top of those.
13590793a61dSThomas Gleixner
13600793a61dSThomas Gleixner	  Say Y if unsure.
13610793a61dSThomas Gleixner
1362906010b2SPeter Zijlstraconfig DEBUG_PERF_USE_VMALLOC
1363906010b2SPeter Zijlstra	default n
1364906010b2SPeter Zijlstra	bool "Debug: use vmalloc to back perf mmap() buffers"
1365906010b2SPeter Zijlstra	depends on PERF_EVENTS && DEBUG_KERNEL
1366906010b2SPeter Zijlstra	select PERF_USE_VMALLOC
1367906010b2SPeter Zijlstra	help
1368906010b2SPeter Zijlstra	 Use vmalloc memory to back perf mmap() buffers.
1369906010b2SPeter Zijlstra
1370906010b2SPeter Zijlstra	 Mostly useful for debugging the vmalloc code on platforms
1371906010b2SPeter Zijlstra	 that don't require it.
1372906010b2SPeter Zijlstra
1373906010b2SPeter Zijlstra	 Say N if unsure.
1374906010b2SPeter Zijlstra
13750793a61dSThomas Gleixnerendmenu
13760793a61dSThomas Gleixner
1377f8891e5eSChristoph Lameterconfig VM_EVENT_COUNTERS
1378f8891e5eSChristoph Lameter	default y
13796a108a14SDavid Rientjes	bool "Enable VM event counters for /proc/vmstat" if EXPERT
1380f8891e5eSChristoph Lameter	help
13812aea4fb6SPaul Jackson	  VM event counters are needed for event counts to be shown.
13822aea4fb6SPaul Jackson	  This option allows the disabling of the VM event counters
13836a108a14SDavid Rientjes	  on EXPERT systems.  /proc/vmstat will only show page counts
13842aea4fb6SPaul Jackson	  if VM event counters are disabled.
1385f8891e5eSChristoph Lameter
13863d137310SThomas Petazzoniconfig PCI_QUIRKS
13873d137310SThomas Petazzoni	default y
13886a108a14SDavid Rientjes	bool "Enable PCI quirk workarounds" if EXPERT
138961cfc7e4SGeert Uytterhoeven	depends on PCI
13903d137310SThomas Petazzoni	help
13913d137310SThomas Petazzoni	  This enables workarounds for various PCI chipset
13923d137310SThomas Petazzoni          bugs/quirks. Disable this only if your target machine is
13933d137310SThomas Petazzoni          unaffected by PCI quirks.
13943d137310SThomas Petazzoni
139541ecc55bSChristoph Lameterconfig SLUB_DEBUG
139641ecc55bSChristoph Lameter	default y
13976a108a14SDavid Rientjes	bool "Enable SLUB debugging support" if EXPERT
1398f6acb635SChristoph Lameter	depends on SLUB && SYSFS
139941ecc55bSChristoph Lameter	help
140041ecc55bSChristoph Lameter	  SLUB has extensive debug support features. Disabling these can
140141ecc55bSChristoph Lameter	  result in significant savings in code size. This also disables
140241ecc55bSChristoph Lameter	  SLUB sysfs support. /sys/slab will not exist and there will be
140341ecc55bSChristoph Lameter	  no support for cache validation etc.
140441ecc55bSChristoph Lameter
1405b943c460SRandy Dunlapconfig COMPAT_BRK
1406b943c460SRandy Dunlap	bool "Disable heap randomization"
1407b943c460SRandy Dunlap	default y
1408b943c460SRandy Dunlap	help
1409b943c460SRandy Dunlap	  Randomizing heap placement makes heap exploits harder, but it
1410b943c460SRandy Dunlap	  also breaks ancient binaries (including anything libc5 based).
1411b943c460SRandy Dunlap	  This option changes the bootup default to heap randomization
1412692105b8SMatt LaPlante	  disabled, and can be overridden at runtime by setting
1413b943c460SRandy Dunlap	  /proc/sys/kernel/randomize_va_space to 2.
1414b943c460SRandy Dunlap
1415b943c460SRandy Dunlap	  On non-ancient distros (post-2000 ones) N is usually a safe choice.
1416b943c460SRandy Dunlap
141781819f0fSChristoph Lameterchoice
141881819f0fSChristoph Lameter	prompt "Choose SLAB allocator"
1419a0acd820SChristoph Lameter	default SLUB
142081819f0fSChristoph Lameter	help
142181819f0fSChristoph Lameter	   This option allows to select a slab allocator.
142281819f0fSChristoph Lameter
142381819f0fSChristoph Lameterconfig SLAB
142481819f0fSChristoph Lameter	bool "SLAB"
142581819f0fSChristoph Lameter	help
142681819f0fSChristoph Lameter	  The regular slab allocator that is established and known to work
142734013886SChristoph Lameter	  well in all environments. It organizes cache hot objects in
142802f56210SSimon Arlott	  per cpu and per node queues.
142981819f0fSChristoph Lameter
143081819f0fSChristoph Lameterconfig SLUB
143181819f0fSChristoph Lameter	bool "SLUB (Unqueued Allocator)"
143281819f0fSChristoph Lameter	help
143381819f0fSChristoph Lameter	   SLUB is a slab allocator that minimizes cache line usage
143481819f0fSChristoph Lameter	   instead of managing queues of cached objects (SLAB approach).
143581819f0fSChristoph Lameter	   Per cpu caching is realized using slabs of objects instead
143681819f0fSChristoph Lameter	   of queues of objects. SLUB can use memory efficiently
143702f56210SSimon Arlott	   and has enhanced diagnostics. SLUB is the default choice for
143802f56210SSimon Arlott	   a slab allocator.
143981819f0fSChristoph Lameter
144081819f0fSChristoph Lameterconfig SLOB
14416a108a14SDavid Rientjes	depends on EXPERT
144281819f0fSChristoph Lameter	bool "SLOB (Simple Allocator)"
144381819f0fSChristoph Lameter	help
144437291458SMatt Mackall	   SLOB replaces the stock allocator with a drastically simpler
144537291458SMatt Mackall	   allocator. SLOB is generally more space efficient but
144637291458SMatt Mackall	   does not perform as well on large systems.
144781819f0fSChristoph Lameter
144881819f0fSChristoph Lameterendchoice
144981819f0fSChristoph Lameter
1450ea637639SJie Zhangconfig MMAP_ALLOW_UNINITIALIZED
1451ea637639SJie Zhang	bool "Allow mmapped anonymous memory to be uninitialized"
14526a108a14SDavid Rientjes	depends on EXPERT && !MMU
1453ea637639SJie Zhang	default n
1454ea637639SJie Zhang	help
1455ea637639SJie Zhang	  Normally, and according to the Linux spec, anonymous memory obtained
1456ea637639SJie Zhang	  from mmap() has it's contents cleared before it is passed to
1457ea637639SJie Zhang	  userspace.  Enabling this config option allows you to request that
1458ea637639SJie Zhang	  mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1459ea637639SJie Zhang	  providing a huge performance boost.  If this option is not enabled,
1460ea637639SJie Zhang	  then the flag will be ignored.
1461ea637639SJie Zhang
1462ea637639SJie Zhang	  This is taken advantage of by uClibc's malloc(), and also by
1463ea637639SJie Zhang	  ELF-FDPIC binfmt's brk and stack allocator.
1464ea637639SJie Zhang
1465ea637639SJie Zhang	  Because of the obvious security issues, this option should only be
1466ea637639SJie Zhang	  enabled on embedded devices where you control what is run in
1467ea637639SJie Zhang	  userspace.  Since that isn't generally a problem on no-MMU systems,
1468ea637639SJie Zhang	  it is normally safe to say Y here.
1469ea637639SJie Zhang
1470ea637639SJie Zhang	  See Documentation/nommu-mmap.txt for more information.
1471ea637639SJie Zhang
1472125e5645SMathieu Desnoyersconfig PROFILING
1473b309a294SRobert Richter	bool "Profiling support"
1474125e5645SMathieu Desnoyers	help
1475125e5645SMathieu Desnoyers	  Say Y here to enable the extended profiling support mechanisms used
1476125e5645SMathieu Desnoyers	  by profilers such as OProfile.
1477125e5645SMathieu Desnoyers
14785f87f112SIngo Molnar#
14795f87f112SIngo Molnar# Place an empty function call at each tracepoint site. Can be
14805f87f112SIngo Molnar# dynamically changed for a probe function.
14815f87f112SIngo Molnar#
148297e1c18eSMathieu Desnoyersconfig TRACEPOINTS
14835f87f112SIngo Molnar	bool
148497e1c18eSMathieu Desnoyers
1485fb32e03fSMathieu Desnoyerssource "arch/Kconfig"
1486fb32e03fSMathieu Desnoyers
14871da177e4SLinus Torvaldsendmenu		# General setup
14881da177e4SLinus Torvalds
1489ee7e5516SDmitry Baryshkovconfig HAVE_GENERIC_DMA_COHERENT
1490ee7e5516SDmitry Baryshkov	bool
1491ee7e5516SDmitry Baryshkov	default n
1492ee7e5516SDmitry Baryshkov
1493158a9624SLinus Torvaldsconfig SLABINFO
1494158a9624SLinus Torvalds	bool
1495158a9624SLinus Torvalds	depends on PROC_FS
14960f389ec6SChristoph Lameter	depends on SLAB || SLUB_DEBUG
1497158a9624SLinus Torvalds	default y
1498158a9624SLinus Torvalds
1499ae81f9e3SChuck Ebbertconfig RT_MUTEXES
1500ae81f9e3SChuck Ebbert	boolean
1501ae81f9e3SChuck Ebbert
15021da177e4SLinus Torvaldsconfig BASE_SMALL
15031da177e4SLinus Torvalds	int
15041da177e4SLinus Torvalds	default 0 if BASE_FULL
15051da177e4SLinus Torvalds	default 1 if !BASE_FULL
15061da177e4SLinus Torvalds
150766da5733SJan Engelhardtmenuconfig MODULES
15081da177e4SLinus Torvalds	bool "Enable loadable module support"
15091da177e4SLinus Torvalds	help
15101da177e4SLinus Torvalds	  Kernel modules are small pieces of compiled code which can
15111da177e4SLinus Torvalds	  be inserted in the running kernel, rather than being
15121da177e4SLinus Torvalds	  permanently built into the kernel.  You use the "modprobe"
15131da177e4SLinus Torvalds	  tool to add (and sometimes remove) them.  If you say Y here,
15141da177e4SLinus Torvalds	  many parts of the kernel can be built as modules (by
15151da177e4SLinus Torvalds	  answering M instead of Y where indicated): this is most
15161da177e4SLinus Torvalds	  useful for infrequently used options which are not required
15171da177e4SLinus Torvalds	  for booting.  For more information, see the man pages for
15181da177e4SLinus Torvalds	  modprobe, lsmod, modinfo, insmod and rmmod.
15191da177e4SLinus Torvalds
15201da177e4SLinus Torvalds	  If you say Y here, you will need to run "make
15211da177e4SLinus Torvalds	  modules_install" to put the modules under /lib/modules/
15221da177e4SLinus Torvalds	  where modprobe can find them (you may need to be root to do
15231da177e4SLinus Torvalds	  this).
15241da177e4SLinus Torvalds
15251da177e4SLinus Torvalds	  If unsure, say Y.
15261da177e4SLinus Torvalds
15270b0de144SRobert P. J. Dayif MODULES
15280b0de144SRobert P. J. Day
1529826e4506SLinus Torvaldsconfig MODULE_FORCE_LOAD
1530826e4506SLinus Torvalds	bool "Forced module loading"
1531826e4506SLinus Torvalds	default n
1532826e4506SLinus Torvalds	help
153391e37a79SRusty Russell	  Allow loading of modules without version information (ie. modprobe
153491e37a79SRusty Russell	  --force).  Forced module loading sets the 'F' (forced) taint flag and
153591e37a79SRusty Russell	  is usually a really bad idea.
1536826e4506SLinus Torvalds
15371da177e4SLinus Torvaldsconfig MODULE_UNLOAD
15381da177e4SLinus Torvalds	bool "Module unloading"
15391da177e4SLinus Torvalds	help
15401da177e4SLinus Torvalds	  Without this option you will not be able to unload any
15411da177e4SLinus Torvalds	  modules (note that some modules may not be unloadable
1542f7f5b675SDenys Vlasenko	  anyway), which makes your kernel smaller, faster
1543f7f5b675SDenys Vlasenko	  and simpler.  If unsure, say Y.
15441da177e4SLinus Torvalds
15451da177e4SLinus Torvaldsconfig MODULE_FORCE_UNLOAD
15461da177e4SLinus Torvalds	bool "Forced module unloading"
15471da177e4SLinus Torvalds	depends on MODULE_UNLOAD && EXPERIMENTAL
15481da177e4SLinus Torvalds	help
15491da177e4SLinus Torvalds	  This option allows you to force a module to unload, even if the
15501da177e4SLinus Torvalds	  kernel believes it is unsafe: the kernel will remove the module
15511da177e4SLinus Torvalds	  without waiting for anyone to stop using it (using the -f option to
15521da177e4SLinus Torvalds	  rmmod).  This is mainly for kernel developers and desperate users.
15531da177e4SLinus Torvalds	  If unsure, say N.
15541da177e4SLinus Torvalds
15551da177e4SLinus Torvaldsconfig MODVERSIONS
15560d541643SSam Ravnborg	bool "Module versioning support"
15571da177e4SLinus Torvalds	help
15581da177e4SLinus Torvalds	  Usually, you have to use modules compiled with your kernel.
15591da177e4SLinus Torvalds	  Saying Y here makes it sometimes possible to use modules
15601da177e4SLinus Torvalds	  compiled for different kernels, by adding enough information
15611da177e4SLinus Torvalds	  to the modules to (hopefully) spot any changes which would
15621da177e4SLinus Torvalds	  make them incompatible with the kernel you are running.  If
15631da177e4SLinus Torvalds	  unsure, say N.
15641da177e4SLinus Torvalds
15651da177e4SLinus Torvaldsconfig MODULE_SRCVERSION_ALL
15661da177e4SLinus Torvalds	bool "Source checksum for all modules"
15671da177e4SLinus Torvalds	help
15681da177e4SLinus Torvalds	  Modules which contain a MODULE_VERSION get an extra "srcversion"
15691da177e4SLinus Torvalds	  field inserted into their modinfo section, which contains a
15701da177e4SLinus Torvalds    	  sum of the source files which made it.  This helps maintainers
15711da177e4SLinus Torvalds	  see exactly which source was used to build a module (since
15721da177e4SLinus Torvalds	  others sometimes change the module source without updating
15731da177e4SLinus Torvalds	  the version).  With this option, such a "srcversion" field
15741da177e4SLinus Torvalds	  will be created for all modules.  If unsure, say N.
15751da177e4SLinus Torvalds
1576106a4ee2SRusty Russellconfig MODULE_SIG
1577106a4ee2SRusty Russell	bool "Module signature verification"
1578106a4ee2SRusty Russell	depends on MODULES
157948ba2462SDavid Howells	select KEYS
158048ba2462SDavid Howells	select CRYPTO
158148ba2462SDavid Howells	select ASYMMETRIC_KEY_TYPE
158248ba2462SDavid Howells	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
158348ba2462SDavid Howells	select PUBLIC_KEY_ALGO_RSA
158448ba2462SDavid Howells	select ASN1
158548ba2462SDavid Howells	select OID_REGISTRY
158648ba2462SDavid Howells	select X509_CERTIFICATE_PARSER
1587106a4ee2SRusty Russell	help
1588106a4ee2SRusty Russell	  Check modules for valid signatures upon load: the signature
1589106a4ee2SRusty Russell	  is simply appended to the module. For more information see
1590106a4ee2SRusty Russell	  Documentation/module-signing.txt.
1591106a4ee2SRusty Russell
1592ea0b6dcfSDavid Howells	  !!!WARNING!!!  If you enable this option, you MUST make sure that the
1593ea0b6dcfSDavid Howells	  module DOES NOT get stripped after being signed.  This includes the
1594ea0b6dcfSDavid Howells	  debuginfo strip done by some packagers (such as rpmbuild) and
1595ea0b6dcfSDavid Howells	  inclusion into an initramfs that wants the module size reduced.
1596ea0b6dcfSDavid Howells
1597106a4ee2SRusty Russellconfig MODULE_SIG_FORCE
1598106a4ee2SRusty Russell	bool "Require modules to be validly signed"
1599106a4ee2SRusty Russell	depends on MODULE_SIG
1600106a4ee2SRusty Russell	help
1601106a4ee2SRusty Russell	  Reject unsigned modules or signed modules for which we don't have a
1602106a4ee2SRusty Russell	  key.  Without this, such modules will simply taint the kernel.
1603ea0b6dcfSDavid Howells
1604ea0b6dcfSDavid Howellschoice
1605ea0b6dcfSDavid Howells	prompt "Which hash algorithm should modules be signed with?"
1606ea0b6dcfSDavid Howells	depends on MODULE_SIG
1607ea0b6dcfSDavid Howells	help
1608ea0b6dcfSDavid Howells	  This determines which sort of hashing algorithm will be used during
1609ea0b6dcfSDavid Howells	  signature generation.  This algorithm _must_ be built into the kernel
1610ea0b6dcfSDavid Howells	  directly so that signature verification can take place.  It is not
1611ea0b6dcfSDavid Howells	  possible to load a signed module containing the algorithm to check
1612ea0b6dcfSDavid Howells	  the signature on that module.
1613ea0b6dcfSDavid Howells
1614ea0b6dcfSDavid Howellsconfig MODULE_SIG_SHA1
1615ea0b6dcfSDavid Howells	bool "Sign modules with SHA-1"
1616ea0b6dcfSDavid Howells	select CRYPTO_SHA1
1617ea0b6dcfSDavid Howells
1618ea0b6dcfSDavid Howellsconfig MODULE_SIG_SHA224
1619ea0b6dcfSDavid Howells	bool "Sign modules with SHA-224"
1620ea0b6dcfSDavid Howells	select CRYPTO_SHA256
1621ea0b6dcfSDavid Howells
1622ea0b6dcfSDavid Howellsconfig MODULE_SIG_SHA256
1623ea0b6dcfSDavid Howells	bool "Sign modules with SHA-256"
1624ea0b6dcfSDavid Howells	select CRYPTO_SHA256
1625ea0b6dcfSDavid Howells
1626ea0b6dcfSDavid Howellsconfig MODULE_SIG_SHA384
1627ea0b6dcfSDavid Howells	bool "Sign modules with SHA-384"
1628ea0b6dcfSDavid Howells	select CRYPTO_SHA512
1629ea0b6dcfSDavid Howells
1630ea0b6dcfSDavid Howellsconfig MODULE_SIG_SHA512
1631ea0b6dcfSDavid Howells	bool "Sign modules with SHA-512"
1632ea0b6dcfSDavid Howells	select CRYPTO_SHA512
1633ea0b6dcfSDavid Howells
1634ea0b6dcfSDavid Howellsendchoice
1635ea0b6dcfSDavid Howells
16360b0de144SRobert P. J. Dayendif # MODULES
16370b0de144SRobert P. J. Day
163898a79d6aSRusty Russellconfig INIT_ALL_POSSIBLE
163998a79d6aSRusty Russell	bool
164098a79d6aSRusty Russell	help
16415f054e31SRusty Russell	  Back when each arch used to define their own cpu_online_mask and
16425f054e31SRusty Russell	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
164398a79d6aSRusty Russell	  with all 1s, and others with all 0s.  When they were centralised,
164498a79d6aSRusty Russell	  it was better to provide this option than to break all the archs
1645692105b8SMatt LaPlante	  and have several arch maintainers pursuing me down dark alleys.
164698a79d6aSRusty Russell
16471da177e4SLinus Torvaldsconfig STOP_MACHINE
16481da177e4SLinus Torvalds	bool
16491da177e4SLinus Torvalds	default y
16501da177e4SLinus Torvalds	depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
16511da177e4SLinus Torvalds	help
16521da177e4SLinus Torvalds	  Need stop_machine() primitive.
16533a65dfe8SJens Axboe
16543a65dfe8SJens Axboesource "block/Kconfig"
1655e98c3202SAvi Kivity
1656e98c3202SAvi Kivityconfig PREEMPT_NOTIFIERS
1657e98c3202SAvi Kivity	bool
1658e260be67SPaul E. McKenney
165916295becSSteffen Klassertconfig PADATA
166016295becSSteffen Klassert	depends on SMP
166116295becSSteffen Klassert	bool
166216295becSSteffen Klassert
1663754b7b63SAndi Kleen# Can be selected by architectures with broken toolchains
1664754b7b63SAndi Kleen# that get confused by correct const<->read_only section
1665754b7b63SAndi Kleen# mappings
1666754b7b63SAndi Kleenconfig BROKEN_RODATA
1667754b7b63SAndi Kleen	bool
1668754b7b63SAndi Kleen
16694520c6a4SDavid Howellsconfig ASN1
16704520c6a4SDavid Howells	tristate
16714520c6a4SDavid Howells	help
16724520c6a4SDavid Howells	  Build a simple ASN.1 grammar compiler that produces a bytecode output
16734520c6a4SDavid Howells	  that can be interpreted by the ASN.1 stream decoder and used to
16744520c6a4SDavid Howells	  inform it as to what tags are to be expected in a stream and what
16754520c6a4SDavid Howells	  functions to call on what tags.
16764520c6a4SDavid Howells
16776beb0009SThomas Gleixnersource "kernel/Kconfig.locks"
1678