1config ARCH
 
   2	string
   3	option env="ARCH"
 
 
   4
   5config KERNELVERSION
   6	string
   7	option env="KERNELVERSION"
 
   8
   9config DEFCONFIG_LIST
  10	string
  11	depends on !UML
  12	option defconfig_list
  13	default "/lib/modules/$UNAME_RELEASE/.config"
  14	default "/etc/kernel-config"
  15	default "/boot/config-$UNAME_RELEASE"
  16	default "$ARCH_DEFCONFIG"
  17	default "arch/$ARCH/defconfig"
  18
  19config CONSTRUCTORS
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  20	bool
  21	depends on !UML
 
  22
  23config HAVE_IRQ_WORK
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  24	bool
  25
  26config IRQ_WORK
  27	bool
  28	depends on HAVE_IRQ_WORK
  29
  30menu "General setup"
 
  31
  32config EXPERIMENTAL
  33	bool "Prompt for development and/or incomplete code/drivers"
  34	---help---
  35	  Some of the various things that Linux supports (such as network
  36	  drivers, file systems, network protocols, etc.) can be in a state
  37	  of development where the functionality, stability, or the level of
  38	  testing is not yet high enough for general use. This is usually
  39	  known as the "alpha-test" phase among developers. If a feature is
  40	  currently in alpha-test, then the developers usually discourage
  41	  uninformed widespread use of this feature by the general public to
  42	  avoid "Why doesn't this work?" type mail messages. However, active
  43	  testing and use of these systems is welcomed. Just be aware that it
  44	  may not meet the normal level of reliability or it may fail to work
  45	  in some special cases. Detailed bug reports from people familiar
  46	  with the kernel internals are usually welcomed by the developers
  47	  (before submitting bug reports, please read the documents
  48	  <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
  49	  <file:Documentation/BUG-HUNTING>, and
  50	  <file:Documentation/oops-tracing.txt> in the kernel source).
  51
  52	  This option will also make obsoleted drivers available. These are
  53	  drivers that have been replaced by something else, and/or are
  54	  scheduled to be removed in a future kernel release.
  55
  56	  Unless you intend to help test and develop a feature or driver that
  57	  falls into this category, or you have a situation that requires
  58	  using these features, you should probably say N here, which will
  59	  cause the configurator to present you with fewer choices. If
  60	  you say Y here, you will be offered the choice of using features or
  61	  drivers that are currently considered to be in the alpha-test phase.
  62
  63config BROKEN
  64	bool
  65
  66config BROKEN_ON_SMP
  67	bool
  68	depends on BROKEN || !SMP
  69	default y
  70
  71config INIT_ENV_ARG_LIMIT
  72	int
  73	default 32 if !UML
  74	default 128 if UML
  75	help
  76	  Maximum of each of the number of arguments and environment
  77	  variables passed to init from the kernel command line.
  78
  79
  80config CROSS_COMPILE
  81	string "Cross-compiler tool prefix"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  82	help
  83	  Same as running 'make CROSS_COMPILE=prefix-' but stored for
  84	  default make runs in this kernel build directory.  You don't
  85	  need to set this unless you want the configured kernel build
  86	  directory to select the cross-compiler automatically.
 
  87
  88config LOCALVERSION
  89	string "Local version - append to kernel release"
  90	help
  91	  Append an extra string to the end of your kernel version.
  92	  This will show up when you type uname, for example.
  93	  The string you set here will be appended after the contents of
  94	  any files with a filename matching localversion* in your
  95	  object and source tree, in that order.  Your total string can
  96	  be a maximum of 64 characters.
  97
  98config LOCALVERSION_AUTO
  99	bool "Automatically append version information to the version string"
 100	default y
 
 101	help
 102	  This will try to automatically determine if the current tree is a
 103	  release tree by looking for git tags that belong to the current
 104	  top of tree revision.
 105
 106	  A string of the format -gxxxxxxxx will be added to the localversion
 107	  if a git-based tree is found.  The string generated by this will be
 108	  appended after any matching localversion* files, and after the value
 109	  set in CONFIG_LOCALVERSION.
 110
 111	  (The actual string used here is the first eight characters produced
 112	  by running the command:
 113
 114	    $ git rev-parse --verify HEAD
 115
 116	  which is done within the script "scripts/setlocalversion".)
 117
 
 
 
 
 
 
 
 
 
 118config HAVE_KERNEL_GZIP
 119	bool
 120
 121config HAVE_KERNEL_BZIP2
 122	bool
 123
 124config HAVE_KERNEL_LZMA
 125	bool
 126
 127config HAVE_KERNEL_XZ
 128	bool
 129
 130config HAVE_KERNEL_LZO
 131	bool
 132
 
 
 
 
 
 
 
 
 
 133choice
 134	prompt "Kernel compression mode"
 135	default KERNEL_GZIP
 136	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
 137	help
 138	  The linux kernel is a kind of self-extracting executable.
 139	  Several compression algorithms are available, which differ
 140	  in efficiency, compression and decompression speed.
 141	  Compression speed is only relevant when building a kernel.
 142	  Decompression speed is relevant at each boot.
 143
 144	  If you have any problems with bzip2 or lzma compressed
 145	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
 146	  version of this functionality (bzip2 only), for 2.4, was
 147	  supplied by Christian Ludwig)
 148
 149	  High compression options are mostly useful for users, who
 150	  are low on disk space (embedded systems), but for whom ram
 151	  size matters less.
 152
 153	  If in doubt, select 'gzip'
 154
 155config KERNEL_GZIP
 156	bool "Gzip"
 157	depends on HAVE_KERNEL_GZIP
 158	help
 159	  The old and tried gzip compression. It provides a good balance
 160	  between compression ratio and decompression speed.
 161
 162config KERNEL_BZIP2
 163	bool "Bzip2"
 164	depends on HAVE_KERNEL_BZIP2
 165	help
 166	  Its compression ratio and speed is intermediate.
 167	  Decompression speed is slowest among the three.  The kernel
 168	  size is about 10% smaller with bzip2, in comparison to gzip.
 169	  Bzip2 uses a large amount of memory. For modern kernels you
 170	  will need at least 8MB RAM or more for booting.
 171
 172config KERNEL_LZMA
 173	bool "LZMA"
 174	depends on HAVE_KERNEL_LZMA
 175	help
 176	  The most recent compression algorithm.
 177	  Its ratio is best, decompression speed is between the other
 178	  two. Compression is slowest.	The kernel size is about 33%
 179	  smaller with LZMA in comparison to gzip.
 180
 181config KERNEL_XZ
 182	bool "XZ"
 183	depends on HAVE_KERNEL_XZ
 184	help
 185	  XZ uses the LZMA2 algorithm and instruction set specific
 186	  BCJ filters which can improve compression ratio of executable
 187	  code. The size of the kernel is about 30% smaller with XZ in
 188	  comparison to gzip. On architectures for which there is a BCJ
 189	  filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
 190	  will create a few percent smaller kernel than plain LZMA.
 191
 192	  The speed is about the same as with LZMA: The decompression
 193	  speed of XZ is better than that of bzip2 but worse than gzip
 194	  and LZO. Compression is slow.
 195
 196config KERNEL_LZO
 197	bool "LZO"
 198	depends on HAVE_KERNEL_LZO
 199	help
 200	  Its compression ratio is the poorest among the 4. The kernel
 201	  size is about 10% bigger than gzip; however its speed
 202	  (both compression and decompression) is the fastest.
 203
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 204endchoice
 205
 
 
 
 
 
 
 
 
 
 
 206config DEFAULT_HOSTNAME
 207	string "Default hostname"
 208	default "(none)"
 209	help
 210	  This option determines the default system hostname before userspace
 211	  calls sethostname(2). The kernel traditionally uses "(none)" here,
 212	  but you may wish to use a different default here to make a minimal
 213	  system more usable with less configuration.
 214
 215config SWAP
 216	bool "Support for paging of anonymous memory (swap)"
 217	depends on MMU && BLOCK
 218	default y
 219	help
 220	  This option allows you to choose whether you want to have support
 221	  for so called swap devices or swap files in your kernel that are
 222	  used to provide more virtual memory than the actual RAM present
 223	  in your computer.  If unsure say Y.
 224
 225config SYSVIPC
 226	bool "System V IPC"
 227	---help---
 228	  Inter Process Communication is a suite of library functions and
 229	  system calls which let processes (running programs) synchronize and
 230	  exchange information. It is generally considered to be a good thing,
 231	  and some programs won't run unless you say Y here. In particular, if
 232	  you want to run the DOS emulator dosemu under Linux (read the
 233	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
 234	  you'll need to say Y here.
 235
 236	  You can find documentation about IPC with "info ipc" and also in
 237	  section 6.4 of the Linux Programmer's Guide, available from
 238	  <http://www.tldp.org/guides.html>.
 239
 240config SYSVIPC_SYSCTL
 241	bool
 242	depends on SYSVIPC
 243	depends on SYSCTL
 244	default y
 245
 
 
 
 
 246config POSIX_MQUEUE
 247	bool "POSIX Message Queues"
 248	depends on NET && EXPERIMENTAL
 249	---help---
 250	  POSIX variant of message queues is a part of IPC. In POSIX message
 251	  queues every message has a priority which decides about succession
 252	  of receiving it by a process. If you want to compile and run
 253	  programs written e.g. for Solaris with use of its POSIX message
 254	  queues (functions mq_*) say Y here.
 255
 256	  POSIX message queues are visible as a filesystem called 'mqueue'
 257	  and can be mounted somewhere if you want to do filesystem
 258	  operations on message queues.
 259
 260	  If unsure, say Y.
 261
 262config POSIX_MQUEUE_SYSCTL
 263	bool
 264	depends on POSIX_MQUEUE
 265	depends on SYSCTL
 266	default y
 267
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 268config BSD_PROCESS_ACCT
 269	bool "BSD Process Accounting"
 
 270	help
 271	  If you say Y here, a user level program will be able to instruct the
 272	  kernel (via a special system call) to write process accounting
 273	  information to a file: whenever a process exits, information about
 274	  that process will be appended to the file by the kernel.  The
 275	  information includes things such as creation time, owning user,
 276	  command name, memory usage, controlling terminal etc. (the complete
 277	  list is in the struct acct in <file:include/linux/acct.h>).  It is
 278	  up to the user level program to do useful things with this
 279	  information.  This is generally a good idea, so say Y.
 280
 281config BSD_PROCESS_ACCT_V3
 282	bool "BSD Process Accounting version 3 file format"
 283	depends on BSD_PROCESS_ACCT
 284	default n
 285	help
 286	  If you say Y here, the process accounting information is written
 287	  in a new file format that also logs the process IDs of each
 288	  process and it's parent. Note that this file format is incompatible
 289	  with previous v0/v1/v2 file formats, so you will need updated tools
 290	  for processing it. A preliminary version of these tools is available
 291	  at <http://www.gnu.org/software/acct/>.
 292
 293config FHANDLE
 294	bool "open by fhandle syscalls"
 295	select EXPORTFS
 296	help
 297	  If you say Y here, a user level program will be able to map
 298	  file names to handle and then later use the handle for
 299	  different file system operations. This is useful in implementing
 300	  userspace file servers, which now track files using handles instead
 301	  of names. The handle would remain the same even if file names
 302	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
 303	  syscalls.
 304
 305config TASKSTATS
 306	bool "Export task/process statistics through netlink (EXPERIMENTAL)"
 307	depends on NET
 
 308	default n
 309	help
 310	  Export selected statistics for tasks/processes through the
 311	  generic netlink interface. Unlike BSD process accounting, the
 312	  statistics are available during the lifetime of tasks/processes as
 313	  responses to commands. Like BSD accounting, they are sent to user
 314	  space on task exit.
 315
 316	  Say N if unsure.
 317
 318config TASK_DELAY_ACCT
 319	bool "Enable per-task delay accounting (EXPERIMENTAL)"
 320	depends on TASKSTATS
 
 321	help
 322	  Collect information on time spent by a task waiting for system
 323	  resources like cpu, synchronous block I/O completion and swapping
 324	  in pages. Such statistics can help in setting a task's priorities
 325	  relative to other tasks for cpu, io, rss limits etc.
 326
 327	  Say N if unsure.
 328
 329config TASK_XACCT
 330	bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
 331	depends on TASKSTATS
 332	help
 333	  Collect extended task accounting data and send the data
 334	  to userland for processing over the taskstats interface.
 335
 336	  Say N if unsure.
 337
 338config TASK_IO_ACCOUNTING
 339	bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
 340	depends on TASK_XACCT
 341	help
 342	  Collect information on the number of bytes of storage I/O which this
 343	  task has caused.
 344
 345	  Say N if unsure.
 346
 347config AUDIT
 348	bool "Auditing support"
 349	depends on NET
 350	help
 351	  Enable auditing infrastructure that can be used with another
 352	  kernel subsystem, such as SELinux (which requires this for
 353	  logging of avc messages output).  Does not do system-call
 354	  auditing without CONFIG_AUDITSYSCALL.
 
 
 
 
 
 
 
 355
 356config AUDITSYSCALL
 357	bool "Enable system-call auditing support"
 358	depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
 359	default y if SECURITY_SELINUX
 360	help
 361	  Enable low-overhead system-call auditing infrastructure that
 362	  can be used independently or with another kernel subsystem,
 363	  such as SELinux.
 364
 365config AUDIT_WATCH
 366	def_bool y
 367	depends on AUDITSYSCALL
 368	select FSNOTIFY
 369
 370config AUDIT_TREE
 371	def_bool y
 372	depends on AUDITSYSCALL
 373	select FSNOTIFY
 374
 375source "kernel/irq/Kconfig"
 376
 377menu "RCU Subsystem"
 378
 379choice
 380	prompt "RCU Implementation"
 381	default TREE_RCU
 382
 383config TREE_RCU
 384	bool "Tree-based hierarchical RCU"
 385	depends on !PREEMPT && SMP
 386	help
 387	  This option selects the RCU implementation that is
 388	  designed for very large SMP system with hundreds or
 389	  thousands of CPUs.  It also scales down nicely to
 390	  smaller systems.
 391
 392config TREE_PREEMPT_RCU
 393	bool "Preemptible tree-based hierarchical RCU"
 394	depends on PREEMPT
 395	help
 396	  This option selects the RCU implementation that is
 397	  designed for very large SMP systems with hundreds or
 398	  thousands of CPUs, but for which real-time response
 399	  is also required.  It also scales down nicely to
 400	  smaller systems.
 401
 402config TINY_RCU
 403	bool "UP-only small-memory-footprint RCU"
 404	depends on !SMP
 405	help
 406	  This option selects the RCU implementation that is
 407	  designed for UP systems from which real-time response
 408	  is not required.  This option greatly reduces the
 409	  memory footprint of RCU.
 410
 411config TINY_PREEMPT_RCU
 412	bool "Preemptible UP-only small-memory-footprint RCU"
 413	depends on !SMP && PREEMPT
 414	help
 415	  This option selects the RCU implementation that is designed
 416	  for real-time UP systems.  This option greatly reduces the
 417	  memory footprint of RCU.
 418
 419endchoice
 420
 421config PREEMPT_RCU
 422	def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
 423	help
 424	  This option enables preemptible-RCU code that is common between
 425	  the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
 426
 427config RCU_TRACE
 428	bool "Enable tracing for RCU"
 429	help
 430	  This option provides tracing in RCU which presents stats
 431	  in debugfs for debugging RCU implementation.
 432
 433	  Say Y here if you want to enable RCU tracing
 434	  Say N if you are unsure.
 435
 436config RCU_FANOUT
 437	int "Tree-based hierarchical RCU fanout value"
 438	range 2 64 if 64BIT
 439	range 2 32 if !64BIT
 440	depends on TREE_RCU || TREE_PREEMPT_RCU
 441	default 64 if 64BIT
 442	default 32 if !64BIT
 443	help
 444	  This option controls the fanout of hierarchical implementations
 445	  of RCU, allowing RCU to work efficiently on machines with
 446	  large numbers of CPUs.  This value must be at least the fourth
 447	  root of NR_CPUS, which allows NR_CPUS to be insanely large.
 448	  The default value of RCU_FANOUT should be used for production
 449	  systems, but if you are stress-testing the RCU implementation
 450	  itself, small RCU_FANOUT values allow you to test large-system
 451	  code paths on small(er) systems.
 452
 453	  Select a specific number if testing RCU itself.
 454	  Take the default if unsure.
 455
 456config RCU_FANOUT_EXACT
 457	bool "Disable tree-based hierarchical RCU auto-balancing"
 458	depends on TREE_RCU || TREE_PREEMPT_RCU
 459	default n
 
 460	help
 461	  This option forces use of the exact RCU_FANOUT value specified,
 462	  regardless of imbalances in the hierarchy.  This is useful for
 463	  testing RCU itself, and might one day be useful on systems with
 464	  strong NUMA behavior.
 
 
 
 
 
 465
 466	  Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
 
 467
 468	  Say N if unsure.
 469
 470config RCU_FAST_NO_HZ
 471	bool "Accelerate last non-dyntick-idle CPU's grace periods"
 472	depends on TREE_RCU && NO_HZ && SMP
 473	default n
 474	help
 475	  This option causes RCU to attempt to accelerate grace periods
 476	  in order to allow the final CPU to enter dynticks-idle state
 477	  more quickly.  On the other hand, this option increases the
 478	  overhead of the dynticks-idle checking, particularly on systems
 479	  with large numbers of CPUs.
 480
 481	  Say Y if energy efficiency is critically important, particularly
 482	  	if you have relatively few CPUs.
 483
 484	  Say N if you are unsure.
 485
 486config TREE_RCU_TRACE
 487	def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
 488	select DEBUG_FS
 489	help
 490	  This option provides tracing for the TREE_RCU and
 491	  TREE_PREEMPT_RCU implementations, permitting Makefile to
 492	  trivially select kernel/rcutree_trace.c.
 493
 494config RCU_BOOST
 495	bool "Enable RCU priority boosting"
 496	depends on RT_MUTEXES && PREEMPT_RCU
 497	default n
 498	help
 499	  This option boosts the priority of preempted RCU readers that
 500	  block the current preemptible RCU grace period for too long.
 501	  This option also prevents heavy loads from blocking RCU
 502	  callback invocation for all flavors of RCU.
 503
 504	  Say Y here if you are working with real-time apps or heavy loads
 505	  Say N here if you are unsure.
 506
 507config RCU_BOOST_PRIO
 508	int "Real-time priority to boost RCU readers to"
 509	range 1 99
 510	depends on RCU_BOOST
 511	default 1
 512	help
 513	  This option specifies the real-time priority to which preempted
 514	  RCU readers are to be boosted.  If you are working with CPU-bound
 515	  real-time applications, you should specify a priority higher then
 516	  the highest-priority CPU-bound application.
 517
 518	  Specify the real-time priority, or take the default if unsure.
 519
 520config RCU_BOOST_DELAY
 521	int "Milliseconds to delay boosting after RCU grace-period start"
 522	range 0 3000
 523	depends on RCU_BOOST
 524	default 500
 525	help
 526	  This option specifies the time to wait after the beginning of
 527	  a given grace period before priority-boosting preempted RCU
 528	  readers blocking that grace period.  Note that any RCU reader
 529	  blocking an expedited RCU grace period is boosted immediately.
 530
 531	  Accept the default if unsure.
 532
 533endmenu # "RCU Subsystem"
 534
 535config IKCONFIG
 536	tristate "Kernel .config support"
 537	---help---
 538	  This option enables the complete Linux kernel ".config" file
 539	  contents to be saved in the kernel. It provides documentation
 540	  of which kernel options are used in a running kernel or in an
 541	  on-disk kernel.  This information can be extracted from the kernel
 542	  image file with the script scripts/extract-ikconfig and used as
 543	  input to rebuild the current kernel or to build another kernel.
 544	  It can also be extracted from a running kernel by reading
 545	  /proc/config.gz if enabled (below).
 546
 547config IKCONFIG_PROC
 548	bool "Enable access to .config through /proc/config.gz"
 549	depends on IKCONFIG && PROC_FS
 550	---help---
 551	  This option enables access to the kernel configuration file
 552	  through /proc/config.gz.
 553
 
 
 
 
 
 
 
 
 
 554config LOG_BUF_SHIFT
 555	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
 556	range 12 21
 557	default 17
 
 558	help
 559	  Select kernel log buffer size as a power of 2.
 
 
 
 
 560	  Examples:
 561	  	     17 => 128 KB
 562		     16 => 64 KB
 563	             15 => 32 KB
 564	             14 => 16 KB
 565		     13 =>  8 KB
 566		     12 =>  4 KB
 567
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 568#
 569# Architectures with an unreliable sched_clock() should select this:
 570#
 571config HAVE_UNSTABLE_SCHED_CLOCK
 572	bool
 573
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 574menuconfig CGROUPS
 575	boolean "Control Group support"
 576	depends on EVENTFD
 577	help
 578	  This option adds support for grouping sets of processes together, for
 579	  use with process control subsystems such as Cpusets, CFS, memory
 580	  controls or device isolation.
 581	  See
 582		- Documentation/scheduler/sched-design-CFS.txt	(CFS)
 583		- Documentation/cgroups/ (features for grouping, isolation
 584					  and resource control)
 585
 586	  Say N if unsure.
 587
 588if CGROUPS
 589
 590config CGROUP_DEBUG
 591	bool "Example debug cgroup subsystem"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 592	default n
 593	help
 594	  This option enables a simple cgroup subsystem that
 595	  exports useful debugging information about the cgroups
 596	  framework.
 597
 598	  Say N if unsure.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 599
 600config CGROUP_FREEZER
 601	bool "Freezer cgroup subsystem"
 602	help
 603	  Provides a way to freeze and unfreeze all tasks in a
 604	  cgroup.
 605
 606config CGROUP_DEVICE
 607	bool "Device controller for cgroups"
 
 
 
 
 
 
 
 
 608	help
 609	  Provides a cgroup implementing whitelists for devices which
 610	  a process in the cgroup can mknod or open.
 
 
 
 
 
 
 
 611
 612config CPUSETS
 613	bool "Cpuset support"
 
 614	help
 615	  This option will let you create and manage CPUSETs which
 616	  allow dynamically partitioning a system into sets of CPUs and
 617	  Memory Nodes and assigning tasks to run only within those sets.
 618	  This is primarily useful on large SMP or NUMA systems.
 619
 620	  Say N if unsure.
 621
 622config PROC_PID_CPUSET
 623	bool "Include legacy /proc/<pid>/cpuset file"
 624	depends on CPUSETS
 625	default y
 626
 627config CGROUP_CPUACCT
 628	bool "Simple CPU accounting cgroup subsystem"
 629	help
 630	  Provides a simple Resource Controller for monitoring the
 631	  total CPU consumed by the tasks in a cgroup.
 632
 633config RESOURCE_COUNTERS
 634	bool "Resource counters"
 635	help
 636	  This option enables controller independent resource accounting
 637	  infrastructure that works with cgroups.
 638
 639config CGROUP_MEM_RES_CTLR
 640	bool "Memory Resource Controller for Control Groups"
 641	depends on RESOURCE_COUNTERS
 642	select MM_OWNER
 643	help
 644	  Provides a memory resource controller that manages both anonymous
 645	  memory and page cache. (See Documentation/cgroups/memory.txt)
 646
 647	  Note that setting this option increases fixed memory overhead
 648	  associated with each page of memory in the system. By this,
 649	  20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
 650	  usage tracking struct at boot. Total amount of this is printed out
 651	  at boot.
 652
 653	  Only enable when you're ok with these trade offs and really
 654	  sure you need the memory resource controller. Even when you enable
 655	  this, you can set "cgroup_disable=memory" at your boot option to
 656	  disable memory resource controller and you can avoid overheads.
 657	  (and lose benefits of memory resource controller)
 658
 659	  This config option also selects MM_OWNER config option, which
 660	  could in turn add some fork/exit overhead.
 661
 662config CGROUP_MEM_RES_CTLR_SWAP
 663	bool "Memory Resource Controller Swap Extension"
 664	depends on CGROUP_MEM_RES_CTLR && SWAP
 665	help
 666	  Add swap management feature to memory resource controller. When you
 667	  enable this, you can limit mem+swap usage per cgroup. In other words,
 668	  when you disable this, memory resource controller has no cares to
 669	  usage of swap...a process can exhaust all of the swap. This extension
 670	  is useful when you want to avoid exhaustion swap but this itself
 671	  adds more overheads and consumes memory for remembering information.
 672	  Especially if you use 32bit system or small memory system, please
 673	  be careful about enabling this. When memory resource controller
 674	  is disabled by boot option, this will be automatically disabled and
 675	  there will be no overhead from this. Even when you set this config=y,
 676	  if boot option "swapaccount=0" is set, swap will not be accounted.
 677	  Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
 678	  size is 4096bytes, 512k per 1Gbytes of swap.
 679config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
 680	bool "Memory Resource Controller Swap Extension enabled by default"
 681	depends on CGROUP_MEM_RES_CTLR_SWAP
 682	default y
 683	help
 684	  Memory Resource Controller Swap Extension comes with its price in
 685	  a bigger memory consumption. General purpose distribution kernels
 686	  which want to enable the feature but keep it disabled by default
 687	  and let the user enable it by swapaccount boot command line
 688	  parameter should have this option unselected.
 689	  For those who want to have the feature enabled by default should
 690	  select this option (if, for some reason, they need to disable it
 691	  then swapaccount=0 does the trick).
 692
 693config CGROUP_PERF
 694	bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
 695	depends on PERF_EVENTS && CGROUPS
 696	help
 697	  This option extends the per-cpu mode to restrict monitoring to
 698	  threads which belong to the cgroup specified and run on the
 699	  designated cpu.
 
 700
 701	  Say N if unsure.
 702
 703menuconfig CGROUP_SCHED
 704	bool "Group CPU scheduler"
 705	depends on EXPERIMENTAL
 706	default n
 707	help
 708	  This feature lets CPU scheduler recognize task groups and control CPU
 709	  bandwidth allocation to such task groups. It uses cgroups to group
 710	  tasks.
 
 
 
 
 711
 712if CGROUP_SCHED
 713config FAIR_GROUP_SCHED
 714	bool "Group scheduling for SCHED_OTHER"
 715	depends on CGROUP_SCHED
 716	default CGROUP_SCHED
 717
 718config RT_GROUP_SCHED
 719	bool "Group scheduling for SCHED_RR/FIFO"
 720	depends on EXPERIMENTAL
 721	depends on CGROUP_SCHED
 722	default n
 723	help
 724	  This feature lets you explicitly allocate real CPU bandwidth
 725	  to task groups. If enabled, it will also make it impossible to
 726	  schedule realtime tasks for non-root users until you allocate
 727	  realtime bandwidth for them.
 728	  See Documentation/scheduler/sched-rt-group.txt for more information.
 729
 730endif #CGROUP_SCHED
 
 
 
 731
 732config BLK_CGROUP
 733	tristate "Block IO controller"
 734	depends on BLOCK
 735	default n
 736	---help---
 737	Generic block IO controller cgroup interface. This is the common
 738	cgroup interface which should be used by various IO controlling
 739	policies.
 740
 741	Currently, CFQ IO scheduler uses it to recognize task groups and
 742	control disk bandwidth allocation (proportional time slice allocation)
 743	to such task groups. It is also used by bio throttling logic in
 744	block layer to implement upper limit in IO rates on a device.
 745
 746	This option only enables generic Block IO controller infrastructure.
 747	One needs to also enable actual IO controlling logic/policy. For
 748	enabling proportional weight division of disk bandwidth in CFQ, set
 749	CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
 750	CONFIG_BLK_DEV_THROTTLING=y.
 
 
 
 
 751
 752	See Documentation/cgroups/blkio-controller.txt for more information.
 753
 754config DEBUG_BLK_CGROUP
 755	bool "Enable Block IO controller debugging"
 756	depends on BLK_CGROUP
 757	default n
 758	---help---
 759	Enable some debugging help. Currently it exports additional stat
 760	files in a cgroup which can be useful for debugging.
 761
 762endif # CGROUPS
 763
 764menuconfig NAMESPACES
 765	bool "Namespaces support" if EXPERT
 
 766	default !EXPERT
 767	help
 768	  Provides the way to make tasks work with different objects using
 769	  the same id. For example same IPC id may refer to different objects
 770	  or same user id or pid may refer to different tasks when used in
 771	  different namespaces.
 772
 773if NAMESPACES
 774
 775config UTS_NS
 776	bool "UTS namespace"
 777	default y
 778	help
 779	  In this namespace tasks see different info provided with the
 780	  uname() system call
 781
 
 
 
 
 
 
 
 
 782config IPC_NS
 783	bool "IPC namespace"
 784	depends on (SYSVIPC || POSIX_MQUEUE)
 785	default y
 786	help
 787	  In this namespace tasks work with IPC ids which correspond to
 788	  different IPC objects in different namespaces.
 789
 790config USER_NS
 791	bool "User namespace (EXPERIMENTAL)"
 792	depends on EXPERIMENTAL
 793	default y
 794	help
 795	  This allows containers, i.e. vservers, to use user namespaces
 796	  to provide different user info for different servers.
 
 
 
 
 
 
 797	  If unsure, say N.
 798
 799config PID_NS
 800	bool "PID Namespaces"
 801	default y
 802	help
 803	  Support process id namespaces.  This allows having multiple
 804	  processes with the same pid as long as they are in different
 805	  pid namespaces.  This is a building block of containers.
 806
 807config NET_NS
 808	bool "Network namespace"
 809	depends on NET
 810	default y
 811	help
 812	  Allow user space to create what appear to be multiple instances
 813	  of the network stack.
 814
 815endif # NAMESPACES
 816
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 817config SCHED_AUTOGROUP
 818	bool "Automatic process group scheduling"
 819	select EVENTFD
 820	select CGROUPS
 821	select CGROUP_SCHED
 822	select FAIR_GROUP_SCHED
 823	help
 824	  This option optimizes the scheduler for common desktop workloads by
 825	  automatically creating and populating task groups.  This separation
 826	  of workloads isolates aggressive CPU burners (like build jobs) from
 827	  desktop applications.  Task group autogeneration is currently based
 828	  upon task session.
 829
 830config MM_OWNER
 831	bool
 832
 833config SYSFS_DEPRECATED
 834	bool "Enable deprecated sysfs features to support old userspace tools"
 835	depends on SYSFS
 836	default n
 837	help
 838	  This option adds code that switches the layout of the "block" class
 839	  devices, to not show up in /sys/class/block/, but only in
 840	  /sys/block/.
 841
 842	  This switch is only active when the sysfs.deprecated=1 boot option is
 843	  passed or the SYSFS_DEPRECATED_V2 option is set.
 844
 845	  This option allows new kernels to run on old distributions and tools,
 846	  which might get confused by /sys/class/block/. Since 2007/2008 all
 847	  major distributions and tools handle this just fine.
 848
 849	  Recent distributions and userspace tools after 2009/2010 depend on
 850	  the existence of /sys/class/block/, and will not work with this
 851	  option enabled.
 852
 853	  Only if you are using a new kernel on an old distribution, you might
 854	  need to say Y here.
 855
 856config SYSFS_DEPRECATED_V2
 857	bool "Enable deprecated sysfs features by default"
 858	default n
 859	depends on SYSFS
 860	depends on SYSFS_DEPRECATED
 861	help
 862	  Enable deprecated sysfs by default.
 863
 864	  See the CONFIG_SYSFS_DEPRECATED option for more details about this
 865	  option.
 866
 867	  Only if you are using a new kernel on an old distribution, you might
 868	  need to say Y here. Even then, odds are you would not need it
 869	  enabled, you can always pass the boot option if absolutely necessary.
 870
 871config RELAY
 872	bool "Kernel->user space relay support (formerly relayfs)"
 
 873	help
 874	  This option enables support for relay interface support in
 875	  certain file systems (such as debugfs).
 876	  It is designed to provide an efficient mechanism for tools and
 877	  facilities to relay large amounts of data from kernel space to
 878	  user space.
 879
 880	  If unsure, say N.
 881
 882config BLK_DEV_INITRD
 883	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
 884	depends on BROKEN || !FRV
 885	help
 886	  The initial RAM filesystem is a ramfs which is loaded by the
 887	  boot loader (loadlin or lilo) and that is mounted as root
 888	  before the normal boot procedure. It is typically used to
 889	  load modules needed to mount the "real" root file system,
 890	  etc. See <file:Documentation/initrd.txt> for details.
 891
 892	  If RAM disk support (BLK_DEV_RAM) is also included, this
 893	  also enables initial RAM disk (initrd) support and adds
 894	  15 Kbytes (more on some other architectures) to the kernel size.
 895
 896	  If unsure say Y.
 897
 898if BLK_DEV_INITRD
 899
 900source "usr/Kconfig"
 901
 902endif
 903
 904config CC_OPTIMIZE_FOR_SIZE
 905	bool "Optimize for size"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 906	help
 907	  Enabling this option will pass "-Os" instead of "-O2" to gcc
 908	  resulting in a smaller kernel.
 
 909
 910	  If unsure, say Y.
 911
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 912config SYSCTL
 913	bool
 914
 915config ANON_INODES
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 916	bool
 
 917
 918menuconfig EXPERT
 919	bool "Configure standard kernel features (expert users)"
 920	# Unhide debug options, to make the on-by-default options visible
 921	select DEBUG_KERNEL
 922	help
 923	  This option allows certain base kernel options and settings
 924          to be disabled or tweaked. This is for specialized
 925          environments which can tolerate a "non-standard" kernel.
 926          Only use this if you really know what you are doing.
 927
 928config UID16
 929	bool "Enable 16-bit UID system calls" if EXPERT
 930	depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
 931	default y
 932	help
 933	  This enables the legacy 16-bit UID syscall wrappers.
 934
 935config SYSCTL_SYSCALL
 936	bool "Sysctl syscall support" if EXPERT
 937	depends on PROC_SYSCTL
 938	default y
 939	select SYSCTL
 940	---help---
 941	  sys_sysctl uses binary paths that have been found challenging
 942	  to properly maintain and use.  The interface in /proc/sys
 943	  using paths with ascii names is now the primary path to this
 944	  information.
 945
 946	  Almost nothing using the binary sysctl interface so if you are
 947	  trying to save some space it is probably safe to disable this,
 948	  making your kernel marginally smaller.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 949
 950	  If unsure say Y here.
 951
 952config KALLSYMS
 953	 bool "Load all symbols for debugging/ksymoops" if EXPERT
 954	 default y
 955	 help
 956	   Say Y here to let the kernel print out symbolic crash information and
 957	   symbolic stack backtraces. This increases the size of the kernel
 958	   somewhat, as all symbols have to be loaded into the kernel image.
 
 
 
 
 
 959
 960config KALLSYMS_ALL
 961	bool "Include all symbols in kallsyms"
 962	depends on DEBUG_KERNEL && KALLSYMS
 963	help
 964	   Normally kallsyms only contains the symbols of functions for nicer
 965	   OOPS messages and backtraces (i.e., symbols from the text and inittext
 966	   sections). This is sufficient for most cases. And only in very rare
 967	   cases (e.g., when a debugger is used) all symbols are required (e.g.,
 968	   names of variables from the data sections, etc).
 969
 970	   This option makes sure that all symbols are loaded into the kernel
 971	   image (i.e., symbols from all sections) in cost of increased kernel
 972	   size (depending on the kernel configuration, it may be 300KiB or
 973	   something like this).
 974
 975	   Say N unless you really need all symbols.
 976
 977config HOTPLUG
 978	bool "Support for hot-pluggable devices" if EXPERT
 979	default y
 980	help
 981	  This option is provided for the case where no hotplug or uevent
 982	  capabilities is wanted by the kernel.  You should only consider
 983	  disabling this option for embedded systems that do not use modules, a
 984	  dynamic /dev tree, or dynamic device discovery.  Just say Y.
 985
 986config PRINTK
 987	default y
 988	bool "Enable support for printk" if EXPERT
 
 989	help
 990	  This option enables normal printk support. Removing it
 991	  eliminates most of the message strings from the kernel image
 992	  and makes the kernel more or less silent. As this makes it
 993	  very difficult to diagnose system problems, saying N here is
 994	  strongly discouraged.
 995
 996config BUG
 997	bool "BUG() support" if EXPERT
 998	default y
 999	help
1000          Disabling this option eliminates support for BUG and WARN, reducing
1001          the size of your kernel image and potentially quietly ignoring
1002          numerous fatal conditions. You should only consider disabling this
1003          option for embedded systems with no facilities for reporting errors.
1004          Just say Y.
1005
1006config ELF_CORE
 
1007	default y
1008	bool "Enable ELF core dumps" if EXPERT
1009	help
1010	  Enable support for generating core dumps. Disabling saves about 4k.
1011
1012
1013config PCSPKR_PLATFORM
1014	bool "Enable PC-Speaker support" if EXPERT
1015	depends on HAVE_PCSPKR_PLATFORM
1016	select I8253_LOCK
1017	default y
1018	help
1019          This option allows to disable the internal PC-Speaker
1020          support, saving some memory.
1021
1022config HAVE_PCSPKR_PLATFORM
1023	bool
1024
1025config BASE_FULL
1026	default y
1027	bool "Enable full-sized data structures for core" if EXPERT
1028	help
1029	  Disabling this option reduces the size of miscellaneous core
1030	  kernel data structures. This saves memory on small machines,
1031	  but may reduce performance.
1032
1033config FUTEX
1034	bool "Enable futex support" if EXPERT
 
1035	default y
1036	select RT_MUTEXES
1037	help
1038	  Disabling this option will cause the kernel to be built without
1039	  support for "fast userspace mutexes".  The resulting kernel may not
1040	  run glibc-based applications correctly.
1041
 
 
 
 
 
1042config EPOLL
1043	bool "Enable eventpoll support" if EXPERT
1044	default y
1045	select ANON_INODES
1046	help
1047	  Disabling this option will cause the kernel to be built without
1048	  support for epoll family of system calls.
1049
1050config SIGNALFD
1051	bool "Enable signalfd() system call" if EXPERT
1052	select ANON_INODES
1053	default y
1054	help
1055	  Enable the signalfd() system call that allows to receive signals
1056	  on a file descriptor.
1057
1058	  If unsure, say Y.
1059
1060config TIMERFD
1061	bool "Enable timerfd() system call" if EXPERT
1062	select ANON_INODES
1063	default y
1064	help
1065	  Enable the timerfd() system call that allows to receive timer
1066	  events on a file descriptor.
1067
1068	  If unsure, say Y.
1069
1070config EVENTFD
1071	bool "Enable eventfd() system call" if EXPERT
1072	select ANON_INODES
1073	default y
1074	help
1075	  Enable the eventfd() system call that allows to receive both
1076	  kernel notification (ie. KAIO) or userspace notifications.
1077
1078	  If unsure, say Y.
1079
1080config SHMEM
1081	bool "Use full shmem filesystem" if EXPERT
1082	default y
1083	depends on MMU
1084	help
1085	  The shmem is an internal filesystem used to manage shared memory.
1086	  It is backed by swap and manages resource limits. It is also exported
1087	  to userspace as tmpfs if TMPFS is enabled. Disabling this
1088	  option replaces shmem and tmpfs with the much simpler ramfs code,
1089	  which may be appropriate on small systems without swap.
1090
1091config AIO
1092	bool "Enable AIO support" if EXPERT
1093	default y
1094	help
1095	  This option enables POSIX asynchronous I/O which may by used
1096          by some high performance threaded applications. Disabling
1097          this option saves about 7k.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1098
1099config EMBEDDED
1100	bool "Embedded system"
1101	select EXPERT
1102	help
1103	  This option should be enabled if compiling the kernel for
1104	  an embedded system so certain expert options are available
1105	  for configuration.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1106
1107config HAVE_PERF_EVENTS
1108	bool
1109	help
1110	  See tools/perf/design.txt for details.
1111
 
 
 
 
1112config PERF_USE_VMALLOC
1113	bool
1114	help
1115	  See tools/perf/design.txt for details
1116
1117menu "Kernel Performance Events And Counters"
1118
1119config PERF_EVENTS
1120	bool "Kernel performance events and counters"
1121	default y if (PROFILING || PERF_COUNTERS)
1122	depends on HAVE_PERF_EVENTS
1123	select ANON_INODES
1124	select IRQ_WORK
1125	help
1126	  Enable kernel support for various performance events provided
1127	  by software and hardware.
1128
1129	  Software events are supported either built-in or via the
1130	  use of generic tracepoints.
1131
1132	  Most modern CPUs support performance events via performance
1133	  counter registers. These registers count the number of certain
1134	  types of hw events: such as instructions executed, cachemisses
1135	  suffered, or branches mis-predicted - without slowing down the
1136	  kernel or applications. These registers can also trigger interrupts
1137	  when a threshold number of events have passed - and can thus be
1138	  used to profile the code that runs on that CPU.
1139
1140	  The Linux Performance Event subsystem provides an abstraction of
1141	  these software and hardware event capabilities, available via a
1142	  system call and used by the "perf" utility in tools/perf/. It
1143	  provides per task and per CPU counters, and it provides event
1144	  capabilities on top of those.
1145
1146	  Say Y if unsure.
1147
1148config PERF_COUNTERS
1149	bool "Kernel performance counters (old config option)"
1150	depends on HAVE_PERF_EVENTS
1151	help
1152	  This config has been obsoleted by the PERF_EVENTS
1153	  config option - please see that one for details.
1154
1155	  It has no effect on the kernel whether you enable
1156	  it or not, it is a compatibility placeholder.
1157
1158	  Say N if unsure.
1159
1160config DEBUG_PERF_USE_VMALLOC
1161	default n
1162	bool "Debug: use vmalloc to back perf mmap() buffers"
1163	depends on PERF_EVENTS && DEBUG_KERNEL
1164	select PERF_USE_VMALLOC
1165	help
1166	 Use vmalloc memory to back perf mmap() buffers.
1167
1168	 Mostly useful for debugging the vmalloc code on platforms
1169	 that don't require it.
1170
1171	 Say N if unsure.
1172
1173endmenu
1174
1175config VM_EVENT_COUNTERS
1176	default y
1177	bool "Enable VM event counters for /proc/vmstat" if EXPERT
1178	help
1179	  VM event counters are needed for event counts to be shown.
1180	  This option allows the disabling of the VM event counters
1181	  on EXPERT systems.  /proc/vmstat will only show page counts
1182	  if VM event counters are disabled.
1183
1184config PCI_QUIRKS
1185	default y
1186	bool "Enable PCI quirk workarounds" if EXPERT
1187	depends on PCI
1188	help
1189	  This enables workarounds for various PCI chipset
1190          bugs/quirks. Disable this only if your target machine is
1191          unaffected by PCI quirks.
1192
1193config SLUB_DEBUG
1194	default y
1195	bool "Enable SLUB debugging support" if EXPERT
1196	depends on SLUB && SYSFS
1197	help
1198	  SLUB has extensive debug support features. Disabling these can
1199	  result in significant savings in code size. This also disables
1200	  SLUB sysfs support. /sys/slab will not exist and there will be
1201	  no support for cache validation etc.
1202
1203config COMPAT_BRK
1204	bool "Disable heap randomization"
1205	default y
1206	help
1207	  Randomizing heap placement makes heap exploits harder, but it
1208	  also breaks ancient binaries (including anything libc5 based).
1209	  This option changes the bootup default to heap randomization
1210	  disabled, and can be overridden at runtime by setting
1211	  /proc/sys/kernel/randomize_va_space to 2.
1212
1213	  On non-ancient distros (post-2000 ones) N is usually a safe choice.
1214
1215choice
1216	prompt "Choose SLAB allocator"
1217	default SLUB
1218	help
1219	   This option allows to select a slab allocator.
 
1220
1221config SLAB
1222	bool "SLAB"
1223	help
1224	  The regular slab allocator that is established and known to work
1225	  well in all environments. It organizes cache hot objects in
1226	  per cpu and per node queues.
 
 
 
 
 
1227
1228config SLUB
1229	bool "SLUB (Unqueued Allocator)"
1230	help
1231	   SLUB is a slab allocator that minimizes cache line usage
1232	   instead of managing queues of cached objects (SLAB approach).
1233	   Per cpu caching is realized using slabs of objects instead
1234	   of queues of objects. SLUB can use memory efficiently
1235	   and has enhanced diagnostics. SLUB is the default choice for
1236	   a slab allocator.
1237
1238config SLOB
1239	depends on EXPERT
1240	bool "SLOB (Simple Allocator)"
1241	help
1242	   SLOB replaces the stock allocator with a drastically simpler
1243	   allocator. SLOB is generally more space efficient but
1244	   does not perform as well on large systems.
1245
1246endchoice
1247
1248config MMAP_ALLOW_UNINITIALIZED
1249	bool "Allow mmapped anonymous memory to be uninitialized"
1250	depends on EXPERT && !MMU
1251	default n
1252	help
1253	  Normally, and according to the Linux spec, anonymous memory obtained
1254	  from mmap() has it's contents cleared before it is passed to
1255	  userspace.  Enabling this config option allows you to request that
1256	  mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1257	  providing a huge performance boost.  If this option is not enabled,
1258	  then the flag will be ignored.
1259
1260	  This is taken advantage of by uClibc's malloc(), and also by
1261	  ELF-FDPIC binfmt's brk and stack allocator.
1262
1263	  Because of the obvious security issues, this option should only be
1264	  enabled on embedded devices where you control what is run in
1265	  userspace.  Since that isn't generally a problem on no-MMU systems,
1266	  it is normally safe to say Y here.
1267
1268	  See Documentation/nommu-mmap.txt for more information.
 
 
 
1269
1270config PROFILING
1271	bool "Profiling support"
1272	help
1273	  Say Y here to enable the extended profiling support mechanisms used
1274	  by profilers such as OProfile.
1275
1276#
1277# Place an empty function call at each tracepoint site. Can be
1278# dynamically changed for a probe function.
1279#
1280config TRACEPOINTS
1281	bool
1282
1283source "arch/Kconfig"
1284
1285endmenu		# General setup
1286
1287config HAVE_GENERIC_DMA_COHERENT
1288	bool
1289	default n
1290
1291config SLABINFO
1292	bool
1293	depends on PROC_FS
1294	depends on SLAB || SLUB_DEBUG
1295	default y
1296
1297config RT_MUTEXES
1298	boolean
 
1299
1300config BASE_SMALL
1301	int
1302	default 0 if BASE_FULL
1303	default 1 if !BASE_FULL
1304
1305menuconfig MODULES
1306	bool "Enable loadable module support"
1307	help
1308	  Kernel modules are small pieces of compiled code which can
1309	  be inserted in the running kernel, rather than being
1310	  permanently built into the kernel.  You use the "modprobe"
1311	  tool to add (and sometimes remove) them.  If you say Y here,
1312	  many parts of the kernel can be built as modules (by
1313	  answering M instead of Y where indicated): this is most
1314	  useful for infrequently used options which are not required
1315	  for booting.  For more information, see the man pages for
1316	  modprobe, lsmod, modinfo, insmod and rmmod.
1317
1318	  If you say Y here, you will need to run "make
1319	  modules_install" to put the modules under /lib/modules/
1320	  where modprobe can find them (you may need to be root to do
1321	  this).
1322
1323	  If unsure, say Y.
1324
1325if MODULES
1326
1327config MODULE_FORCE_LOAD
1328	bool "Forced module loading"
1329	default n
1330	help
1331	  Allow loading of modules without version information (ie. modprobe
1332	  --force).  Forced module loading sets the 'F' (forced) taint flag and
1333	  is usually a really bad idea.
1334
1335config MODULE_UNLOAD
1336	bool "Module unloading"
1337	help
1338	  Without this option you will not be able to unload any
1339	  modules (note that some modules may not be unloadable
1340	  anyway), which makes your kernel smaller, faster
1341	  and simpler.  If unsure, say Y.
1342
1343config MODULE_FORCE_UNLOAD
1344	bool "Forced module unloading"
1345	depends on MODULE_UNLOAD && EXPERIMENTAL
1346	help
1347	  This option allows you to force a module to unload, even if the
1348	  kernel believes it is unsafe: the kernel will remove the module
1349	  without waiting for anyone to stop using it (using the -f option to
1350	  rmmod).  This is mainly for kernel developers and desperate users.
1351	  If unsure, say N.
1352
1353config MODVERSIONS
1354	bool "Module versioning support"
1355	help
1356	  Usually, you have to use modules compiled with your kernel.
1357	  Saying Y here makes it sometimes possible to use modules
1358	  compiled for different kernels, by adding enough information
1359	  to the modules to (hopefully) spot any changes which would
1360	  make them incompatible with the kernel you are running.  If
1361	  unsure, say N.
1362
1363config MODULE_SRCVERSION_ALL
1364	bool "Source checksum for all modules"
1365	help
1366	  Modules which contain a MODULE_VERSION get an extra "srcversion"
1367	  field inserted into their modinfo section, which contains a
1368    	  sum of the source files which made it.  This helps maintainers
1369	  see exactly which source was used to build a module (since
1370	  others sometimes change the module source without updating
1371	  the version).  With this option, such a "srcversion" field
1372	  will be created for all modules.  If unsure, say N.
1373
1374endif # MODULES
1375
1376config INIT_ALL_POSSIBLE
1377	bool
1378	help
1379	  Back when each arch used to define their own cpu_online_map and
1380	  cpu_possible_map, some of them chose to initialize cpu_possible_map
1381	  with all 1s, and others with all 0s.  When they were centralised,
1382	  it was better to provide this option than to break all the archs
1383	  and have several arch maintainers pursuing me down dark alleys.
1384
1385config STOP_MACHINE
1386	bool
1387	default y
1388	depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1389	help
1390	  Need stop_machine() primitive.
1391
1392source "block/Kconfig"
1393
1394config PREEMPT_NOTIFIERS
1395	bool
1396
1397config PADATA
1398	depends on SMP
1399	bool
1400
 
 
 
 
 
 
 
 
1401source "kernel/Kconfig.locks"