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 IRQ_WORK
  24	bool
  25
  26config BUILDTIME_EXTABLE_SORT
 
 
 
  27	bool
 
 
 
 
 
 
 
  28
  29menu "General setup"
  30
  31config BROKEN
  32	bool
  33
  34config BROKEN_ON_SMP
  35	bool
  36	depends on BROKEN || !SMP
  37	default y
  38
  39config INIT_ENV_ARG_LIMIT
  40	int
  41	default 32 if !UML
  42	default 128 if UML
  43	help
  44	  Maximum of each of the number of arguments and environment
  45	  variables passed to init from the kernel command line.
  46
  47
  48config CROSS_COMPILE
  49	string "Cross-compiler tool prefix"
  50	help
  51	  Same as running 'make CROSS_COMPILE=prefix-' but stored for
  52	  default make runs in this kernel build directory.  You don't
  53	  need to set this unless you want the configured kernel build
  54	  directory to select the cross-compiler automatically.
  55
  56config COMPILE_TEST
  57	bool "Compile also drivers which will not load"
  58	default n
  59	help
  60	  Some drivers can be compiled on a different platform than they are
  61	  intended to be run on. Despite they cannot be loaded there (or even
  62	  when they load they cannot be used due to missing HW support),
  63	  developers still, opposing to distributors, might want to build such
  64	  drivers to compile-test them.
  65
  66	  If you are a developer and want to build everything available, say Y
  67	  here. If you are a user/distributor, say N here to exclude useless
  68	  drivers to be distributed.
  69
 
 
 
 
 
 
 
 
 
 
  70config LOCALVERSION
  71	string "Local version - append to kernel release"
  72	help
  73	  Append an extra string to the end of your kernel version.
  74	  This will show up when you type uname, for example.
  75	  The string you set here will be appended after the contents of
  76	  any files with a filename matching localversion* in your
  77	  object and source tree, in that order.  Your total string can
  78	  be a maximum of 64 characters.
  79
  80config LOCALVERSION_AUTO
  81	bool "Automatically append version information to the version string"
  82	default y
 
  83	help
  84	  This will try to automatically determine if the current tree is a
  85	  release tree by looking for git tags that belong to the current
  86	  top of tree revision.
  87
  88	  A string of the format -gxxxxxxxx will be added to the localversion
  89	  if a git-based tree is found.  The string generated by this will be
  90	  appended after any matching localversion* files, and after the value
  91	  set in CONFIG_LOCALVERSION.
  92
  93	  (The actual string used here is the first eight characters produced
  94	  by running the command:
  95
  96	    $ git rev-parse --verify HEAD
  97
  98	  which is done within the script "scripts/setlocalversion".)
  99
 
 
 
 
 
 
 
 
 
 100config HAVE_KERNEL_GZIP
 101	bool
 102
 103config HAVE_KERNEL_BZIP2
 104	bool
 105
 106config HAVE_KERNEL_LZMA
 107	bool
 108
 109config HAVE_KERNEL_XZ
 110	bool
 111
 112config HAVE_KERNEL_LZO
 113	bool
 114
 115config HAVE_KERNEL_LZ4
 116	bool
 117
 
 
 
 
 
 
 118choice
 119	prompt "Kernel compression mode"
 120	default KERNEL_GZIP
 121	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4
 122	help
 123	  The linux kernel is a kind of self-extracting executable.
 124	  Several compression algorithms are available, which differ
 125	  in efficiency, compression and decompression speed.
 126	  Compression speed is only relevant when building a kernel.
 127	  Decompression speed is relevant at each boot.
 128
 129	  If you have any problems with bzip2 or lzma compressed
 130	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
 131	  version of this functionality (bzip2 only), for 2.4, was
 132	  supplied by Christian Ludwig)
 133
 134	  High compression options are mostly useful for users, who
 135	  are low on disk space (embedded systems), but for whom ram
 136	  size matters less.
 137
 138	  If in doubt, select 'gzip'
 139
 140config KERNEL_GZIP
 141	bool "Gzip"
 142	depends on HAVE_KERNEL_GZIP
 143	help
 144	  The old and tried gzip compression. It provides a good balance
 145	  between compression ratio and decompression speed.
 146
 147config KERNEL_BZIP2
 148	bool "Bzip2"
 149	depends on HAVE_KERNEL_BZIP2
 150	help
 151	  Its compression ratio and speed is intermediate.
 152	  Decompression speed is slowest among the choices.  The kernel
 153	  size is about 10% smaller with bzip2, in comparison to gzip.
 154	  Bzip2 uses a large amount of memory. For modern kernels you
 155	  will need at least 8MB RAM or more for booting.
 156
 157config KERNEL_LZMA
 158	bool "LZMA"
 159	depends on HAVE_KERNEL_LZMA
 160	help
 161	  This compression algorithm's ratio is best.  Decompression speed
 162	  is between gzip and bzip2.  Compression is slowest.
 163	  The kernel size is about 33% smaller with LZMA in comparison to gzip.
 164
 165config KERNEL_XZ
 166	bool "XZ"
 167	depends on HAVE_KERNEL_XZ
 168	help
 169	  XZ uses the LZMA2 algorithm and instruction set specific
 170	  BCJ filters which can improve compression ratio of executable
 171	  code. The size of the kernel is about 30% smaller with XZ in
 172	  comparison to gzip. On architectures for which there is a BCJ
 173	  filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
 174	  will create a few percent smaller kernel than plain LZMA.
 175
 176	  The speed is about the same as with LZMA: The decompression
 177	  speed of XZ is better than that of bzip2 but worse than gzip
 178	  and LZO. Compression is slow.
 179
 180config KERNEL_LZO
 181	bool "LZO"
 182	depends on HAVE_KERNEL_LZO
 183	help
 184	  Its compression ratio is the poorest among the choices. The kernel
 185	  size is about 10% bigger than gzip; however its speed
 186	  (both compression and decompression) is the fastest.
 187
 188config KERNEL_LZ4
 189	bool "LZ4"
 190	depends on HAVE_KERNEL_LZ4
 191	help
 192	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
 193	  A preliminary version of LZ4 de/compression tool is available at
 194	  <https://code.google.com/p/lz4/>.
 195
 196	  Its compression ratio is worse than LZO. The size of the kernel
 197	  is about 8% bigger than LZO. But the decompression speed is
 198	  faster than LZO.
 199
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 200endchoice
 201
 
 
 
 
 
 
 
 
 
 
 202config DEFAULT_HOSTNAME
 203	string "Default hostname"
 204	default "(none)"
 205	help
 206	  This option determines the default system hostname before userspace
 207	  calls sethostname(2). The kernel traditionally uses "(none)" here,
 208	  but you may wish to use a different default here to make a minimal
 209	  system more usable with less configuration.
 210
 
 
 
 
 
 
 
 211config SWAP
 212	bool "Support for paging of anonymous memory (swap)"
 213	depends on MMU && BLOCK
 214	default y
 215	help
 216	  This option allows you to choose whether you want to have support
 217	  for so called swap devices or swap files in your kernel that are
 218	  used to provide more virtual memory than the actual RAM present
 219	  in your computer.  If unsure say Y.
 220
 221config SYSVIPC
 222	bool "System V IPC"
 223	---help---
 224	  Inter Process Communication is a suite of library functions and
 225	  system calls which let processes (running programs) synchronize and
 226	  exchange information. It is generally considered to be a good thing,
 227	  and some programs won't run unless you say Y here. In particular, if
 228	  you want to run the DOS emulator dosemu under Linux (read the
 229	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
 230	  you'll need to say Y here.
 231
 232	  You can find documentation about IPC with "info ipc" and also in
 233	  section 6.4 of the Linux Programmer's Guide, available from
 234	  <http://www.tldp.org/guides.html>.
 235
 236config SYSVIPC_SYSCTL
 237	bool
 238	depends on SYSVIPC
 239	depends on SYSCTL
 240	default y
 241
 242config POSIX_MQUEUE
 243	bool "POSIX Message Queues"
 244	depends on NET
 245	---help---
 246	  POSIX variant of message queues is a part of IPC. In POSIX message
 247	  queues every message has a priority which decides about succession
 248	  of receiving it by a process. If you want to compile and run
 249	  programs written e.g. for Solaris with use of its POSIX message
 250	  queues (functions mq_*) say Y here.
 251
 252	  POSIX message queues are visible as a filesystem called 'mqueue'
 253	  and can be mounted somewhere if you want to do filesystem
 254	  operations on message queues.
 255
 256	  If unsure, say Y.
 257
 258config POSIX_MQUEUE_SYSCTL
 259	bool
 260	depends on POSIX_MQUEUE
 261	depends on SYSCTL
 262	default y
 263
 
 
 
 
 
 
 
 
 
 
 
 
 264config CROSS_MEMORY_ATTACH
 265	bool "Enable process_vm_readv/writev syscalls"
 266	depends on MMU
 267	default y
 268	help
 269	  Enabling this option adds the system calls process_vm_readv and
 270	  process_vm_writev which allow a process with the correct privileges
 271	  to directly read from or write to another process' address space.
 272	  See the man page for more details.
 273
 274config FHANDLE
 275	bool "open by fhandle syscalls" if EXPERT
 276	select EXPORTFS
 277	default y
 278	help
 279	  If you say Y here, a user level program will be able to map
 280	  file names to handle and then later use the handle for
 281	  different file system operations. This is useful in implementing
 282	  userspace file servers, which now track files using handles instead
 283	  of names. The handle would remain the same even if file names
 284	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
 285	  syscalls.
 286
 287config USELIB
 288	bool "uselib syscall"
 289	def_bool ALPHA || M68K || SPARC || X86_32 || IA32_EMULATION
 290	help
 291	  This option enables the uselib syscall, a system call used in the
 292	  dynamic linker from libc5 and earlier.  glibc does not use this
 293	  system call.  If you intend to run programs built on libc5 or
 294	  earlier, you may need to enable this syscall.  Current systems
 295	  running glibc can safely disable this.
 296
 297config AUDIT
 298	bool "Auditing support"
 299	depends on NET
 300	help
 301	  Enable auditing infrastructure that can be used with another
 302	  kernel subsystem, such as SELinux (which requires this for
 303	  logging of avc messages output).  System call auditing is included
 304	  on architectures which support it.
 305
 306config HAVE_ARCH_AUDITSYSCALL
 307	bool
 308
 309config AUDITSYSCALL
 310	def_bool y
 311	depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
 312
 313config AUDIT_WATCH
 314	def_bool y
 315	depends on AUDITSYSCALL
 316	select FSNOTIFY
 317
 318config AUDIT_TREE
 319	def_bool y
 320	depends on AUDITSYSCALL
 321	select FSNOTIFY
 322
 323source "kernel/irq/Kconfig"
 324source "kernel/time/Kconfig"
 
 
 325
 326menu "CPU/Task time and stats accounting"
 327
 328config VIRT_CPU_ACCOUNTING
 329	bool
 330
 331choice
 332	prompt "Cputime accounting"
 333	default TICK_CPU_ACCOUNTING if !PPC64
 334	default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
 335
 336# Kind of a stub config for the pure tick based cputime accounting
 337config TICK_CPU_ACCOUNTING
 338	bool "Simple tick based cputime accounting"
 339	depends on !S390 && !NO_HZ_FULL
 340	help
 341	  This is the basic tick based cputime accounting that maintains
 342	  statistics about user, system and idle time spent on per jiffies
 343	  granularity.
 344
 345	  If unsure, say Y.
 346
 347config VIRT_CPU_ACCOUNTING_NATIVE
 348	bool "Deterministic task and CPU time accounting"
 349	depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
 350	select VIRT_CPU_ACCOUNTING
 351	help
 352	  Select this option to enable more accurate task and CPU time
 353	  accounting.  This is done by reading a CPU counter on each
 354	  kernel entry and exit and on transitions within the kernel
 355	  between system, softirq and hardirq state, so there is a
 356	  small performance impact.  In the case of s390 or IBM POWER > 5,
 357	  this also enables accounting of stolen time on logically-partitioned
 358	  systems.
 359
 360config VIRT_CPU_ACCOUNTING_GEN
 361	bool "Full dynticks CPU time accounting"
 362	depends on HAVE_CONTEXT_TRACKING
 363	depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
 
 364	select VIRT_CPU_ACCOUNTING
 365	select CONTEXT_TRACKING
 366	help
 367	  Select this option to enable task and CPU time accounting on full
 368	  dynticks systems. This accounting is implemented by watching every
 369	  kernel-user boundaries using the context tracking subsystem.
 370	  The accounting is thus performed at the expense of some significant
 371	  overhead.
 372
 373	  For now this is only useful if you are working on the full
 374	  dynticks subsystem development.
 375
 376	  If unsure, say N.
 377
 
 
 378config IRQ_TIME_ACCOUNTING
 379	bool "Fine granularity task level IRQ time accounting"
 380	depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
 381	help
 382	  Select this option to enable fine granularity task irq time
 383	  accounting. This is done by reading a timestamp on each
 384	  transitions between softirq and hardirq state, so there can be a
 385	  small performance impact.
 386
 387	  If in doubt, say N here.
 388
 389endchoice
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 390
 391config BSD_PROCESS_ACCT
 392	bool "BSD Process Accounting"
 393	depends on MULTIUSER
 394	help
 395	  If you say Y here, a user level program will be able to instruct the
 396	  kernel (via a special system call) to write process accounting
 397	  information to a file: whenever a process exits, information about
 398	  that process will be appended to the file by the kernel.  The
 399	  information includes things such as creation time, owning user,
 400	  command name, memory usage, controlling terminal etc. (the complete
 401	  list is in the struct acct in <file:include/linux/acct.h>).  It is
 402	  up to the user level program to do useful things with this
 403	  information.  This is generally a good idea, so say Y.
 404
 405config BSD_PROCESS_ACCT_V3
 406	bool "BSD Process Accounting version 3 file format"
 407	depends on BSD_PROCESS_ACCT
 408	default n
 409	help
 410	  If you say Y here, the process accounting information is written
 411	  in a new file format that also logs the process IDs of each
 412	  process and it's parent. Note that this file format is incompatible
 413	  with previous v0/v1/v2 file formats, so you will need updated tools
 414	  for processing it. A preliminary version of these tools is available
 415	  at <http://www.gnu.org/software/acct/>.
 416
 417config TASKSTATS
 418	bool "Export task/process statistics through netlink"
 419	depends on NET
 420	depends on MULTIUSER
 421	default n
 422	help
 423	  Export selected statistics for tasks/processes through the
 424	  generic netlink interface. Unlike BSD process accounting, the
 425	  statistics are available during the lifetime of tasks/processes as
 426	  responses to commands. Like BSD accounting, they are sent to user
 427	  space on task exit.
 428
 429	  Say N if unsure.
 430
 431config TASK_DELAY_ACCT
 432	bool "Enable per-task delay accounting"
 433	depends on TASKSTATS
 434	select SCHED_INFO
 435	help
 436	  Collect information on time spent by a task waiting for system
 437	  resources like cpu, synchronous block I/O completion and swapping
 438	  in pages. Such statistics can help in setting a task's priorities
 439	  relative to other tasks for cpu, io, rss limits etc.
 440
 441	  Say N if unsure.
 442
 443config TASK_XACCT
 444	bool "Enable extended accounting over taskstats"
 445	depends on TASKSTATS
 446	help
 447	  Collect extended task accounting data and send the data
 448	  to userland for processing over the taskstats interface.
 449
 450	  Say N if unsure.
 451
 452config TASK_IO_ACCOUNTING
 453	bool "Enable per-task storage I/O accounting"
 454	depends on TASK_XACCT
 455	help
 456	  Collect information on the number of bytes of storage I/O which this
 457	  task has caused.
 458
 459	  Say N if unsure.
 460
 461endmenu # "CPU/Task time and stats accounting"
 462
 463menu "RCU Subsystem"
 464
 465config TREE_RCU
 466	bool
 467	default y if !PREEMPT && SMP
 468	help
 469	  This option selects the RCU implementation that is
 470	  designed for very large SMP system with hundreds or
 471	  thousands of CPUs.  It also scales down nicely to
 472	  smaller systems.
 473
 474config PREEMPT_RCU
 475	bool
 476	default y if PREEMPT
 477	help
 478	  This option selects the RCU implementation that is
 479	  designed for very large SMP systems with hundreds or
 480	  thousands of CPUs, but for which real-time response
 481	  is also required.  It also scales down nicely to
 482	  smaller systems.
 483
 484	  Select this option if you are unsure.
 485
 486config TINY_RCU
 487	bool
 488	default y if !PREEMPT && !SMP
 489	help
 490	  This option selects the RCU implementation that is
 491	  designed for UP systems from which real-time response
 492	  is not required.  This option greatly reduces the
 493	  memory footprint of RCU.
 494
 495config RCU_EXPERT
 496	bool "Make expert-level adjustments to RCU configuration"
 497	default n
 498	help
 499	  This option needs to be enabled if you wish to make
 500	  expert-level adjustments to RCU configuration.  By default,
 501	  no such adjustments can be made, which has the often-beneficial
 502	  side-effect of preventing "make oldconfig" from asking you all
 503	  sorts of detailed questions about how you would like numerous
 504	  obscure RCU options to be set up.
 505
 506	  Say Y if you need to make expert-level adjustments to RCU.
 
 
 
 
 
 
 
 507
 508	  Say N if you are unsure.
 509
 510config SRCU
 511	bool
 512	help
 513	  This option selects the sleepable version of RCU. This version
 514	  permits arbitrary sleeping or blocking within RCU read-side critical
 515	  sections.
 516
 517config TASKS_RCU
 518	bool
 519	default n
 520	select SRCU
 521	help
 522	  This option enables a task-based RCU implementation that uses
 523	  only voluntary context switch (not preemption!), idle, and
 524	  user-mode execution as quiescent states.
 525
 526config RCU_STALL_COMMON
 527	def_bool ( TREE_RCU || PREEMPT_RCU || RCU_TRACE )
 528	help
 529	  This option enables RCU CPU stall code that is common between
 530	  the TINY and TREE variants of RCU.  The purpose is to allow
 531	  the tiny variants to disable RCU CPU stall warnings, while
 532	  making these warnings mandatory for the tree variants.
 533
 534config CONTEXT_TRACKING
 535       bool
 536
 537config CONTEXT_TRACKING_FORCE
 538	bool "Force context tracking"
 539	depends on CONTEXT_TRACKING
 540	default y if !NO_HZ_FULL
 541	help
 542	  The major pre-requirement for full dynticks to work is to
 543	  support the context tracking subsystem. But there are also
 544	  other dependencies to provide in order to make the full
 545	  dynticks working.
 546
 547	  This option stands for testing when an arch implements the
 548	  context tracking backend but doesn't yet fullfill all the
 549	  requirements to make the full dynticks feature working.
 550	  Without the full dynticks, there is no way to test the support
 551	  for context tracking and the subsystems that rely on it: RCU
 552	  userspace extended quiescent state and tickless cputime
 553	  accounting. This option copes with the absence of the full
 554	  dynticks subsystem by forcing the context tracking on all
 555	  CPUs in the system.
 556
 557	  Say Y only if you're working on the development of an
 558	  architecture backend for the context tracking.
 559
 560	  Say N otherwise, this option brings an overhead that you
 561	  don't want in production.
 562
 563
 564config RCU_FANOUT
 565	int "Tree-based hierarchical RCU fanout value"
 566	range 2 64 if 64BIT
 567	range 2 32 if !64BIT
 568	depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT
 569	default 64 if 64BIT
 570	default 32 if !64BIT
 571	help
 572	  This option controls the fanout of hierarchical implementations
 573	  of RCU, allowing RCU to work efficiently on machines with
 574	  large numbers of CPUs.  This value must be at least the fourth
 575	  root of NR_CPUS, which allows NR_CPUS to be insanely large.
 576	  The default value of RCU_FANOUT should be used for production
 577	  systems, but if you are stress-testing the RCU implementation
 578	  itself, small RCU_FANOUT values allow you to test large-system
 579	  code paths on small(er) systems.
 580
 581	  Select a specific number if testing RCU itself.
 582	  Take the default if unsure.
 583
 584config RCU_FANOUT_LEAF
 585	int "Tree-based hierarchical RCU leaf-level fanout value"
 586	range 2 64 if 64BIT
 587	range 2 32 if !64BIT
 588	depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT
 589	default 16
 590	help
 591	  This option controls the leaf-level fanout of hierarchical
 592	  implementations of RCU, and allows trading off cache misses
 593	  against lock contention.  Systems that synchronize their
 594	  scheduling-clock interrupts for energy-efficiency reasons will
 595	  want the default because the smaller leaf-level fanout keeps
 596	  lock contention levels acceptably low.  Very large systems
 597	  (hundreds or thousands of CPUs) will instead want to set this
 598	  value to the maximum value possible in order to reduce the
 599	  number of cache misses incurred during RCU's grace-period
 600	  initialization.  These systems tend to run CPU-bound, and thus
 601	  are not helped by synchronized interrupts, and thus tend to
 602	  skew them, which reduces lock contention enough that large
 603	  leaf-level fanouts work well.
 604
 605	  Select a specific number if testing RCU itself.
 606
 607	  Select the maximum permissible value for large systems.
 608
 609	  Take the default if unsure.
 610
 611config RCU_FAST_NO_HZ
 612	bool "Accelerate last non-dyntick-idle CPU's grace periods"
 613	depends on NO_HZ_COMMON && SMP && RCU_EXPERT
 614	default n
 615	help
 616	  This option permits CPUs to enter dynticks-idle state even if
 617	  they have RCU callbacks queued, and prevents RCU from waking
 618	  these CPUs up more than roughly once every four jiffies (by
 619	  default, you can adjust this using the rcutree.rcu_idle_gp_delay
 620	  parameter), thus improving energy efficiency.  On the other
 621	  hand, this option increases the duration of RCU grace periods,
 622	  for example, slowing down synchronize_rcu().
 623
 624	  Say Y if energy efficiency is critically important, and you
 625	  	don't care about increased grace-period durations.
 626
 627	  Say N if you are unsure.
 628
 629config TREE_RCU_TRACE
 630	def_bool RCU_TRACE && ( TREE_RCU || PREEMPT_RCU )
 631	select DEBUG_FS
 632	help
 633	  This option provides tracing for the TREE_RCU and
 634	  PREEMPT_RCU implementations, permitting Makefile to
 635	  trivially select kernel/rcutree_trace.c.
 636
 637config RCU_BOOST
 638	bool "Enable RCU priority boosting"
 639	depends on RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT
 640	default n
 641	help
 642	  This option boosts the priority of preempted RCU readers that
 643	  block the current preemptible RCU grace period for too long.
 644	  This option also prevents heavy loads from blocking RCU
 645	  callback invocation for all flavors of RCU.
 646
 647	  Say Y here if you are working with real-time apps or heavy loads
 648	  Say N here if you are unsure.
 649
 650config RCU_KTHREAD_PRIO
 651	int "Real-time priority to use for RCU worker threads"
 652	range 1 99 if RCU_BOOST
 653	range 0 99 if !RCU_BOOST
 654	default 1 if RCU_BOOST
 655	default 0 if !RCU_BOOST
 656	depends on RCU_EXPERT
 657	help
 658	  This option specifies the SCHED_FIFO priority value that will be
 659	  assigned to the rcuc/n and rcub/n threads and is also the value
 660	  used for RCU_BOOST (if enabled). If you are working with a
 661	  real-time application that has one or more CPU-bound threads
 662	  running at a real-time priority level, you should set
 663	  RCU_KTHREAD_PRIO to a priority higher than the highest-priority
 664	  real-time CPU-bound application thread.  The default RCU_KTHREAD_PRIO
 665	  value of 1 is appropriate in the common case, which is real-time
 666	  applications that do not have any CPU-bound threads.
 667
 668	  Some real-time applications might not have a single real-time
 669	  thread that saturates a given CPU, but instead might have
 670	  multiple real-time threads that, taken together, fully utilize
 671	  that CPU.  In this case, you should set RCU_KTHREAD_PRIO to
 672	  a priority higher than the lowest-priority thread that is
 673	  conspiring to prevent the CPU from running any non-real-time
 674	  tasks.  For example, if one thread at priority 10 and another
 675	  thread at priority 5 are between themselves fully consuming
 676	  the CPU time on a given CPU, then RCU_KTHREAD_PRIO should be
 677	  set to priority 6 or higher.
 678
 679	  Specify the real-time priority, or take the default if unsure.
 680
 681config RCU_BOOST_DELAY
 682	int "Milliseconds to delay boosting after RCU grace-period start"
 683	range 0 3000
 684	depends on RCU_BOOST
 685	default 500
 686	help
 687	  This option specifies the time to wait after the beginning of
 688	  a given grace period before priority-boosting preempted RCU
 689	  readers blocking that grace period.  Note that any RCU reader
 690	  blocking an expedited RCU grace period is boosted immediately.
 691
 692	  Accept the default if unsure.
 693
 694config RCU_NOCB_CPU
 695	bool "Offload RCU callback processing from boot-selected CPUs"
 696	depends on TREE_RCU || PREEMPT_RCU
 697	depends on RCU_EXPERT || NO_HZ_FULL
 698	default n
 699	help
 700	  Use this option to reduce OS jitter for aggressive HPC or
 701	  real-time workloads.	It can also be used to offload RCU
 702	  callback invocation to energy-efficient CPUs in battery-powered
 703	  asymmetric multiprocessors.
 704
 705	  This option offloads callback invocation from the set of
 706	  CPUs specified at boot time by the rcu_nocbs parameter.
 707	  For each such CPU, a kthread ("rcuox/N") will be created to
 708	  invoke callbacks, where the "N" is the CPU being offloaded,
 709	  and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
 710	  "s" for RCU-sched.  Nothing prevents this kthread from running
 711	  on the specified CPUs, but (1) the kthreads may be preempted
 712	  between each callback, and (2) affinity or cgroups can be used
 713	  to force the kthreads to run on whatever set of CPUs is desired.
 714
 715	  Say Y here if you want to help to debug reduced OS jitter.
 716	  Say N here if you are unsure.
 717
 718choice
 719	prompt "Build-forced no-CBs CPUs"
 720	default RCU_NOCB_CPU_NONE
 721	depends on RCU_NOCB_CPU
 722	help
 723	  This option allows no-CBs CPUs (whose RCU callbacks are invoked
 724	  from kthreads rather than from softirq context) to be specified
 725	  at build time.  Additional no-CBs CPUs may be specified by
 726	  the rcu_nocbs= boot parameter.
 727
 728config RCU_NOCB_CPU_NONE
 729	bool "No build_forced no-CBs CPUs"
 730	help
 731	  This option does not force any of the CPUs to be no-CBs CPUs.
 732	  Only CPUs designated by the rcu_nocbs= boot parameter will be
 733	  no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU
 734	  kthreads whose names begin with "rcuo".  All other CPUs will
 735	  invoke their own RCU callbacks in softirq context.
 736
 737	  Select this option if you want to choose no-CBs CPUs at
 738	  boot time, for example, to allow testing of different no-CBs
 739	  configurations without having to rebuild the kernel each time.
 740
 741config RCU_NOCB_CPU_ZERO
 742	bool "CPU 0 is a build_forced no-CBs CPU"
 743	help
 744	  This option forces CPU 0 to be a no-CBs CPU, so that its RCU
 745	  callbacks are invoked by a per-CPU kthread whose name begins
 746	  with "rcuo".	Additional CPUs may be designated as no-CBs
 747	  CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs.
 748	  All other CPUs will invoke their own RCU callbacks in softirq
 749	  context.
 750
 751	  Select this if CPU 0 needs to be a no-CBs CPU for real-time
 752	  or energy-efficiency reasons, but the real reason it exists
 753	  is to ensure that randconfig testing covers mixed systems.
 754
 755config RCU_NOCB_CPU_ALL
 756	bool "All CPUs are build_forced no-CBs CPUs"
 757	help
 758	  This option forces all CPUs to be no-CBs CPUs.  The rcu_nocbs=
 759	  boot parameter will be ignored.  All CPUs' RCU callbacks will
 760	  be executed in the context of per-CPU rcuo kthreads created for
 761	  this purpose.  Assuming that the kthreads whose names start with
 762	  "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter
 763	  on the remaining CPUs, but might decrease memory locality during
 764	  RCU-callback invocation, thus potentially degrading throughput.
 765
 766	  Select this if all CPUs need to be no-CBs CPUs for real-time
 767	  or energy-efficiency reasons.
 768
 769endchoice
 770
 771config RCU_EXPEDITE_BOOT
 772	bool
 773	default n
 
 774	help
 775	  This option enables expedited grace periods at boot time,
 776	  as if rcu_expedite_gp() had been invoked early in boot.
 777	  The corresponding rcu_unexpedite_gp() is invoked from
 778	  rcu_end_inkernel_boot(), which is intended to be invoked
 779	  at the end of the kernel-only boot sequence, just before
 780	  init is exec'ed.
 781
 782	  Accept the default if unsure.
 783
 784endmenu # "RCU Subsystem"
 785
 786config BUILD_BIN2C
 787	bool
 788	default n
 789
 790config IKCONFIG
 791	tristate "Kernel .config support"
 792	select BUILD_BIN2C
 793	---help---
 794	  This option enables the complete Linux kernel ".config" file
 795	  contents to be saved in the kernel. It provides documentation
 796	  of which kernel options are used in a running kernel or in an
 797	  on-disk kernel.  This information can be extracted from the kernel
 798	  image file with the script scripts/extract-ikconfig and used as
 799	  input to rebuild the current kernel or to build another kernel.
 800	  It can also be extracted from a running kernel by reading
 801	  /proc/config.gz if enabled (below).
 802
 803config IKCONFIG_PROC
 804	bool "Enable access to .config through /proc/config.gz"
 805	depends on IKCONFIG && PROC_FS
 806	---help---
 807	  This option enables access to the kernel configuration file
 808	  through /proc/config.gz.
 809
 
 
 
 
 
 
 
 
 
 810config LOG_BUF_SHIFT
 811	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
 812	range 12 25
 
 813	default 17
 814	depends on PRINTK
 815	help
 816	  Select the minimal kernel log buffer size as a power of 2.
 817	  The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
 818	  parameter, see below. Any higher size also might be forced
 819	  by "log_buf_len" boot parameter.
 820
 821	  Examples:
 822		     17 => 128 KB
 823		     16 => 64 KB
 824		     15 => 32 KB
 825		     14 => 16 KB
 826		     13 =>  8 KB
 827		     12 =>  4 KB
 828
 829config LOG_CPU_MAX_BUF_SHIFT
 830	int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
 831	depends on SMP
 832	range 0 21
 833	default 12 if !BASE_SMALL
 834	default 0 if BASE_SMALL
 835	depends on PRINTK
 836	help
 837	  This option allows to increase the default ring buffer size
 838	  according to the number of CPUs. The value defines the contribution
 839	  of each CPU as a power of 2. The used space is typically only few
 840	  lines however it might be much more when problems are reported,
 841	  e.g. backtraces.
 842
 843	  The increased size means that a new buffer has to be allocated and
 844	  the original static one is unused. It makes sense only on systems
 845	  with more CPUs. Therefore this value is used only when the sum of
 846	  contributions is greater than the half of the default kernel ring
 847	  buffer as defined by LOG_BUF_SHIFT. The default values are set
 848	  so that more than 64 CPUs are needed to trigger the allocation.
 849
 850	  Also this option is ignored when "log_buf_len" kernel parameter is
 851	  used as it forces an exact (power of two) size of the ring buffer.
 852
 853	  The number of possible CPUs is used for this computation ignoring
 854	  hotplugging making the compuation optimal for the the worst case
 855	  scenerio while allowing a simple algorithm to be used from bootup.
 856
 857	  Examples shift values and their meaning:
 858		     17 => 128 KB for each CPU
 859		     16 =>  64 KB for each CPU
 860		     15 =>  32 KB for each CPU
 861		     14 =>  16 KB for each CPU
 862		     13 =>   8 KB for each CPU
 863		     12 =>   4 KB for each CPU
 864
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 865#
 866# Architectures with an unreliable sched_clock() should select this:
 867#
 868config HAVE_UNSTABLE_SCHED_CLOCK
 869	bool
 870
 871config GENERIC_SCHED_CLOCK
 872	bool
 873
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 874#
 875# For architectures that want to enable the support for NUMA-affine scheduler
 876# balancing logic:
 877#
 878config ARCH_SUPPORTS_NUMA_BALANCING
 879	bool
 880
 881#
 882# For architectures that prefer to flush all TLBs after a number of pages
 883# are unmapped instead of sending one IPI per page to flush. The architecture
 884# must provide guarantees on what happens if a clean TLB cache entry is
 885# written after the unmap. Details are in mm/rmap.c near the check for
 886# should_defer_flush. The architecture should also consider if the full flush
 887# and the refill costs are offset by the savings of sending fewer IPIs.
 888config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
 889	bool
 890
 
 
 
 891#
 892# For architectures that know their GCC __int128 support is sound
 893#
 894config ARCH_SUPPORTS_INT128
 895	bool
 896
 897# For architectures that (ab)use NUMA to represent different memory regions
 898# all cpu-local but of different latencies, such as SuperH.
 899#
 900config ARCH_WANT_NUMA_VARIABLE_LOCALITY
 901	bool
 902
 903config NUMA_BALANCING
 904	bool "Memory placement aware NUMA scheduler"
 905	depends on ARCH_SUPPORTS_NUMA_BALANCING
 906	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
 907	depends on SMP && NUMA && MIGRATION
 908	help
 909	  This option adds support for automatic NUMA aware memory/task placement.
 910	  The mechanism is quite primitive and is based on migrating memory when
 911	  it has references to the node the task is running on.
 912
 913	  This system will be inactive on UMA systems.
 914
 915config NUMA_BALANCING_DEFAULT_ENABLED
 916	bool "Automatically enable NUMA aware memory/task placement"
 917	default y
 918	depends on NUMA_BALANCING
 919	help
 920	  If set, automatic NUMA balancing will be enabled if running on a NUMA
 921	  machine.
 922
 923menuconfig CGROUPS
 924	bool "Control Group support"
 925	select KERNFS
 926	help
 927	  This option adds support for grouping sets of processes together, for
 928	  use with process control subsystems such as Cpusets, CFS, memory
 929	  controls or device isolation.
 930	  See
 931		- Documentation/scheduler/sched-design-CFS.txt	(CFS)
 932		- Documentation/cgroups/ (features for grouping, isolation
 933					  and resource control)
 934
 935	  Say N if unsure.
 936
 937if CGROUPS
 938
 939config PAGE_COUNTER
 940       bool
 941
 942config MEMCG
 943	bool "Memory controller"
 944	select PAGE_COUNTER
 945	select EVENTFD
 946	help
 947	  Provides control over the memory footprint of tasks in a cgroup.
 948
 949config MEMCG_SWAP
 950	bool "Swap controller"
 951	depends on MEMCG && SWAP
 952	help
 953	  Provides control over the swap space consumed by tasks in a cgroup.
 954
 955config MEMCG_SWAP_ENABLED
 956	bool "Swap controller enabled by default"
 957	depends on MEMCG_SWAP
 958	default y
 959	help
 960	  Memory Resource Controller Swap Extension comes with its price in
 961	  a bigger memory consumption. General purpose distribution kernels
 962	  which want to enable the feature but keep it disabled by default
 963	  and let the user enable it by swapaccount=1 boot command line
 964	  parameter should have this option unselected.
 965	  For those who want to have the feature enabled by default should
 966	  select this option (if, for some reason, they need to disable it
 967	  then swapaccount=0 does the trick).
 968
 969config BLK_CGROUP
 970	bool "IO controller"
 971	depends on BLOCK
 972	default n
 973	---help---
 974	Generic block IO controller cgroup interface. This is the common
 975	cgroup interface which should be used by various IO controlling
 976	policies.
 977
 978	Currently, CFQ IO scheduler uses it to recognize task groups and
 979	control disk bandwidth allocation (proportional time slice allocation)
 980	to such task groups. It is also used by bio throttling logic in
 981	block layer to implement upper limit in IO rates on a device.
 982
 983	This option only enables generic Block IO controller infrastructure.
 984	One needs to also enable actual IO controlling logic/policy. For
 985	enabling proportional weight division of disk bandwidth in CFQ, set
 986	CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
 987	CONFIG_BLK_DEV_THROTTLING=y.
 988
 989	See Documentation/cgroups/blkio-controller.txt for more information.
 990
 991config DEBUG_BLK_CGROUP
 992	bool "IO controller debugging"
 993	depends on BLK_CGROUP
 994	default n
 995	---help---
 996	Enable some debugging help. Currently it exports additional stat
 997	files in a cgroup which can be useful for debugging.
 998
 999config CGROUP_WRITEBACK
1000	bool
1001	depends on MEMCG && BLK_CGROUP
1002	default y
1003
1004menuconfig CGROUP_SCHED
1005	bool "CPU controller"
1006	default n
1007	help
1008	  This feature lets CPU scheduler recognize task groups and control CPU
1009	  bandwidth allocation to such task groups. It uses cgroups to group
1010	  tasks.
1011
1012if CGROUP_SCHED
1013config FAIR_GROUP_SCHED
1014	bool "Group scheduling for SCHED_OTHER"
1015	depends on CGROUP_SCHED
1016	default CGROUP_SCHED
1017
1018config CFS_BANDWIDTH
1019	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
1020	depends on FAIR_GROUP_SCHED
1021	default n
1022	help
1023	  This option allows users to define CPU bandwidth rates (limits) for
1024	  tasks running within the fair group scheduler.  Groups with no limit
1025	  set are considered to be unconstrained and will run with no
1026	  restriction.
1027	  See tip/Documentation/scheduler/sched-bwc.txt for more information.
1028
1029config RT_GROUP_SCHED
1030	bool "Group scheduling for SCHED_RR/FIFO"
1031	depends on CGROUP_SCHED
1032	default n
1033	help
1034	  This feature lets you explicitly allocate real CPU bandwidth
1035	  to task groups. If enabled, it will also make it impossible to
1036	  schedule realtime tasks for non-root users until you allocate
1037	  realtime bandwidth for them.
1038	  See Documentation/scheduler/sched-rt-group.txt for more information.
1039
1040endif #CGROUP_SCHED
1041
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1042config CGROUP_PIDS
1043	bool "PIDs controller"
1044	help
1045	  Provides enforcement of process number limits in the scope of a
1046	  cgroup. Any attempt to fork more processes than is allowed in the
1047	  cgroup will fail. PIDs are fundamentally a global resource because it
1048	  is fairly trivial to reach PID exhaustion before you reach even a
1049	  conservative kmemcg limit. As a result, it is possible to grind a
1050	  system to halt without being limited by other cgroup policies. The
1051	  PIDs controller is designed to stop this from happening.
1052
1053	  It should be noted that organisational operations (such as attaching
1054	  to a cgroup hierarchy will *not* be blocked by the PIDs controller),
1055	  since the PIDs limit only affects a process's ability to fork, not to
1056	  attach to a cgroup.
1057
 
 
 
 
 
 
 
 
 
 
1058config CGROUP_FREEZER
1059	bool "Freezer controller"
1060	help
1061	  Provides a way to freeze and unfreeze all tasks in a
1062	  cgroup.
1063
1064	  This option affects the ORIGINAL cgroup interface. The cgroup2 memory
1065	  controller includes important in-kernel memory consumers per default.
1066
1067	  If you're using cgroup2, say N.
1068
1069config CGROUP_HUGETLB
1070	bool "HugeTLB controller"
1071	depends on HUGETLB_PAGE
1072	select PAGE_COUNTER
1073	default n
1074	help
1075	  Provides a cgroup controller for HugeTLB pages.
1076	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
1077	  The limit is enforced during page fault. Since HugeTLB doesn't
1078	  support page reclaim, enforcing the limit at page fault time implies
1079	  that, the application will get SIGBUS signal if it tries to access
1080	  HugeTLB pages beyond its limit. This requires the application to know
1081	  beforehand how much HugeTLB pages it would require for its use. The
1082	  control group is tracked in the third page lru pointer. This means
1083	  that we cannot use the controller with huge page less than 3 pages.
1084
1085config CPUSETS
1086	bool "Cpuset controller"
 
1087	help
1088	  This option will let you create and manage CPUSETs which
1089	  allow dynamically partitioning a system into sets of CPUs and
1090	  Memory Nodes and assigning tasks to run only within those sets.
1091	  This is primarily useful on large SMP or NUMA systems.
1092
1093	  Say N if unsure.
1094
1095config PROC_PID_CPUSET
1096	bool "Include legacy /proc/<pid>/cpuset file"
1097	depends on CPUSETS
1098	default y
1099
1100config CGROUP_DEVICE
1101	bool "Device controller"
1102	help
1103	  Provides a cgroup controller implementing whitelists for
1104	  devices which a process in the cgroup can mknod or open.
1105
1106config CGROUP_CPUACCT
1107	bool "Simple CPU accounting controller"
1108	help
1109	  Provides a simple controller for monitoring the
1110	  total CPU consumed by the tasks in a cgroup.
1111
1112config CGROUP_PERF
1113	bool "Perf controller"
1114	depends on PERF_EVENTS
1115	help
1116	  This option extends the perf per-cpu mode to restrict monitoring
1117	  to threads which belong to the cgroup specified and run on the
1118	  designated cpu.
 
1119
1120	  Say N if unsure.
1121
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1122config CGROUP_DEBUG
1123	bool "Example controller"
1124	default n
 
1125	help
1126	  This option enables a simple controller that exports
1127	  debugging information about the cgroups framework.
 
 
1128
1129	  Say N.
1130
1131endif # CGROUPS
1132
1133config CHECKPOINT_RESTORE
1134	bool "Checkpoint/restore support" if EXPERT
1135	select PROC_CHILDREN
1136	default n
1137	help
1138	  Enables additional kernel features in a sake of checkpoint/restore.
1139	  In particular it adds auxiliary prctl codes to setup process text,
1140	  data and heap segment sizes, and a few additional /proc filesystem
1141	  entries.
1142
1143	  If unsure, say N here.
1144
1145menuconfig NAMESPACES
1146	bool "Namespaces support" if EXPERT
1147	depends on MULTIUSER
1148	default !EXPERT
1149	help
1150	  Provides the way to make tasks work with different objects using
1151	  the same id. For example same IPC id may refer to different objects
1152	  or same user id or pid may refer to different tasks when used in
1153	  different namespaces.
1154
1155if NAMESPACES
1156
1157config UTS_NS
1158	bool "UTS namespace"
1159	default y
1160	help
1161	  In this namespace tasks see different info provided with the
1162	  uname() system call
1163
 
 
 
 
 
 
 
 
1164config IPC_NS
1165	bool "IPC namespace"
1166	depends on (SYSVIPC || POSIX_MQUEUE)
1167	default y
1168	help
1169	  In this namespace tasks work with IPC ids which correspond to
1170	  different IPC objects in different namespaces.
1171
1172config USER_NS
1173	bool "User namespace"
1174	default n
1175	help
1176	  This allows containers, i.e. vservers, to use user namespaces
1177	  to provide different user info for different servers.
1178
1179	  When user namespaces are enabled in the kernel it is
1180	  recommended that the MEMCG option also be enabled and that
1181	  user-space use the memory control groups to limit the amount
1182	  of memory a memory unprivileged users can use.
1183
1184	  If unsure, say N.
1185
1186config PID_NS
1187	bool "PID Namespaces"
1188	default y
1189	help
1190	  Support process id namespaces.  This allows having multiple
1191	  processes with the same pid as long as they are in different
1192	  pid namespaces.  This is a building block of containers.
1193
1194config NET_NS
1195	bool "Network namespace"
1196	depends on NET
1197	default y
1198	help
1199	  Allow user space to create what appear to be multiple instances
1200	  of the network stack.
1201
1202endif # NAMESPACES
1203
 
 
 
 
 
 
 
 
 
 
 
 
 
1204config SCHED_AUTOGROUP
1205	bool "Automatic process group scheduling"
1206	select CGROUPS
1207	select CGROUP_SCHED
1208	select FAIR_GROUP_SCHED
1209	help
1210	  This option optimizes the scheduler for common desktop workloads by
1211	  automatically creating and populating task groups.  This separation
1212	  of workloads isolates aggressive CPU burners (like build jobs) from
1213	  desktop applications.  Task group autogeneration is currently based
1214	  upon task session.
1215
1216config SYSFS_DEPRECATED
1217	bool "Enable deprecated sysfs features to support old userspace tools"
1218	depends on SYSFS
1219	default n
1220	help
1221	  This option adds code that switches the layout of the "block" class
1222	  devices, to not show up in /sys/class/block/, but only in
1223	  /sys/block/.
1224
1225	  This switch is only active when the sysfs.deprecated=1 boot option is
1226	  passed or the SYSFS_DEPRECATED_V2 option is set.
1227
1228	  This option allows new kernels to run on old distributions and tools,
1229	  which might get confused by /sys/class/block/. Since 2007/2008 all
1230	  major distributions and tools handle this just fine.
1231
1232	  Recent distributions and userspace tools after 2009/2010 depend on
1233	  the existence of /sys/class/block/, and will not work with this
1234	  option enabled.
1235
1236	  Only if you are using a new kernel on an old distribution, you might
1237	  need to say Y here.
1238
1239config SYSFS_DEPRECATED_V2
1240	bool "Enable deprecated sysfs features by default"
1241	default n
1242	depends on SYSFS
1243	depends on SYSFS_DEPRECATED
1244	help
1245	  Enable deprecated sysfs by default.
1246
1247	  See the CONFIG_SYSFS_DEPRECATED option for more details about this
1248	  option.
1249
1250	  Only if you are using a new kernel on an old distribution, you might
1251	  need to say Y here. Even then, odds are you would not need it
1252	  enabled, you can always pass the boot option if absolutely necessary.
1253
1254config RELAY
1255	bool "Kernel->user space relay support (formerly relayfs)"
 
1256	help
1257	  This option enables support for relay interface support in
1258	  certain file systems (such as debugfs).
1259	  It is designed to provide an efficient mechanism for tools and
1260	  facilities to relay large amounts of data from kernel space to
1261	  user space.
1262
1263	  If unsure, say N.
1264
1265config BLK_DEV_INITRD
1266	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1267	depends on BROKEN || !FRV
1268	help
1269	  The initial RAM filesystem is a ramfs which is loaded by the
1270	  boot loader (loadlin or lilo) and that is mounted as root
1271	  before the normal boot procedure. It is typically used to
1272	  load modules needed to mount the "real" root file system,
1273	  etc. See <file:Documentation/initrd.txt> for details.
1274
1275	  If RAM disk support (BLK_DEV_RAM) is also included, this
1276	  also enables initial RAM disk (initrd) support and adds
1277	  15 Kbytes (more on some other architectures) to the kernel size.
1278
1279	  If unsure say Y.
1280
1281if BLK_DEV_INITRD
1282
1283source "usr/Kconfig"
1284
1285endif
1286
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1287config CC_OPTIMIZE_FOR_SIZE
1288	bool "Optimize for size"
1289	help
1290	  Enabling this option will pass "-Os" instead of "-O2" to
1291	  your compiler resulting in a smaller kernel.
1292
1293	  If unsure, say N.
1294
1295config SYSCTL
1296	bool
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1297
1298config ANON_INODES
1299	bool
1300
1301config HAVE_UID16
1302	bool
1303
1304config SYSCTL_EXCEPTION_TRACE
1305	bool
1306	help
1307	  Enable support for /proc/sys/debug/exception-trace.
1308
1309config SYSCTL_ARCH_UNALIGN_NO_WARN
1310	bool
1311	help
1312	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1313	  Allows arch to define/use @no_unaligned_warning to possibly warn
1314	  about unaligned access emulation going on under the hood.
1315
1316config SYSCTL_ARCH_UNALIGN_ALLOW
1317	bool
1318	help
1319	  Enable support for /proc/sys/kernel/unaligned-trap
1320	  Allows arches to define/use @unaligned_enabled to runtime toggle
1321	  the unaligned access emulation.
1322	  see arch/parisc/kernel/unaligned.c for reference
1323
1324config HAVE_PCSPKR_PLATFORM
1325	bool
1326
1327# interpreter that classic socket filters depend on
1328config BPF
1329	bool
1330
1331menuconfig EXPERT
1332	bool "Configure standard kernel features (expert users)"
1333	# Unhide debug options, to make the on-by-default options visible
1334	select DEBUG_KERNEL
1335	help
1336	  This option allows certain base kernel options and settings
1337          to be disabled or tweaked. This is for specialized
1338          environments which can tolerate a "non-standard" kernel.
1339          Only use this if you really know what you are doing.
1340
1341config UID16
1342	bool "Enable 16-bit UID system calls" if EXPERT
1343	depends on HAVE_UID16 && MULTIUSER
1344	default y
1345	help
1346	  This enables the legacy 16-bit UID syscall wrappers.
1347
1348config MULTIUSER
1349	bool "Multiple users, groups and capabilities support" if EXPERT
1350	default y
1351	help
1352	  This option enables support for non-root users, groups and
1353	  capabilities.
1354
1355	  If you say N here, all processes will run with UID 0, GID 0, and all
1356	  possible capabilities.  Saying N here also compiles out support for
1357	  system calls related to UIDs, GIDs, and capabilities, such as setuid,
1358	  setgid, and capset.
1359
1360	  If unsure, say Y here.
1361
1362config SGETMASK_SYSCALL
1363	bool "sgetmask/ssetmask syscalls support" if EXPERT
1364	def_bool PARISC || MN10300 || BLACKFIN || M68K || PPC || MIPS || X86 || SPARC || CRIS || MICROBLAZE || SUPERH
1365	---help---
1366	  sys_sgetmask and sys_ssetmask are obsolete system calls
1367	  no longer supported in libc but still enabled by default in some
1368	  architectures.
1369
1370	  If unsure, leave the default option here.
1371
1372config SYSFS_SYSCALL
1373	bool "Sysfs syscall support" if EXPERT
1374	default y
1375	---help---
1376	  sys_sysfs is an obsolete system call no longer supported in libc.
1377	  Note that disabling this option is more secure but might break
1378	  compatibility with some systems.
1379
1380	  If unsure say Y here.
1381
1382config SYSCTL_SYSCALL
1383	bool "Sysctl syscall support" if EXPERT
1384	depends on PROC_SYSCTL
1385	default n
1386	select SYSCTL
1387	---help---
1388	  sys_sysctl uses binary paths that have been found challenging
1389	  to properly maintain and use.  The interface in /proc/sys
1390	  using paths with ascii names is now the primary path to this
1391	  information.
1392
1393	  Almost nothing using the binary sysctl interface so if you are
1394	  trying to save some space it is probably safe to disable this,
1395	  making your kernel marginally smaller.
1396
1397	  If unsure say N here.
1398
1399config KALLSYMS
1400	 bool "Load all symbols for debugging/ksymoops" if EXPERT
1401	 default y
1402	 help
1403	   Say Y here to let the kernel print out symbolic crash information and
1404	   symbolic stack backtraces. This increases the size of the kernel
1405	   somewhat, as all symbols have to be loaded into the kernel image.
1406
1407config KALLSYMS_ALL
1408	bool "Include all symbols in kallsyms"
1409	depends on DEBUG_KERNEL && KALLSYMS
1410	help
1411	   Normally kallsyms only contains the symbols of functions for nicer
1412	   OOPS messages and backtraces (i.e., symbols from the text and inittext
1413	   sections). This is sufficient for most cases. And only in very rare
1414	   cases (e.g., when a debugger is used) all symbols are required (e.g.,
1415	   names of variables from the data sections, etc).
1416
1417	   This option makes sure that all symbols are loaded into the kernel
1418	   image (i.e., symbols from all sections) in cost of increased kernel
1419	   size (depending on the kernel configuration, it may be 300KiB or
1420	   something like this).
1421
1422	   Say N unless you really need all symbols.
1423
1424config KALLSYMS_ABSOLUTE_PERCPU
1425	bool
1426	default X86_64 && SMP
1427
1428config KALLSYMS_BASE_RELATIVE
1429	bool
1430	depends on KALLSYMS
1431	default !IA64 && !(TILE && 64BIT)
1432	help
1433	  Instead of emitting them as absolute values in the native word size,
1434	  emit the symbol references in the kallsyms table as 32-bit entries,
1435	  each containing a relative value in the range [base, base + U32_MAX]
1436	  or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either
1437	  an absolute value in the range [0, S32_MAX] or a relative value in the
1438	  range [base, base + S32_MAX], where base is the lowest relative symbol
1439	  address encountered in the image.
 
 
 
1440
1441	  On 64-bit builds, this reduces the size of the address table by 50%,
1442	  but more importantly, it results in entries whose values are build
1443	  time constants, and no relocation pass is required at runtime to fix
1444	  up the entries based on the runtime load address of the kernel.
1445
1446config PRINTK
1447	default y
1448	bool "Enable support for printk" if EXPERT
1449	select IRQ_WORK
1450	help
1451	  This option enables normal printk support. Removing it
1452	  eliminates most of the message strings from the kernel image
1453	  and makes the kernel more or less silent. As this makes it
1454	  very difficult to diagnose system problems, saying N here is
1455	  strongly discouraged.
1456
 
 
 
 
 
1457config BUG
1458	bool "BUG() support" if EXPERT
1459	default y
1460	help
1461          Disabling this option eliminates support for BUG and WARN, reducing
1462          the size of your kernel image and potentially quietly ignoring
1463          numerous fatal conditions. You should only consider disabling this
1464          option for embedded systems with no facilities for reporting errors.
1465          Just say Y.
1466
1467config ELF_CORE
1468	depends on COREDUMP
1469	default y
1470	bool "Enable ELF core dumps" if EXPERT
1471	help
1472	  Enable support for generating core dumps. Disabling saves about 4k.
1473
1474
1475config PCSPKR_PLATFORM
1476	bool "Enable PC-Speaker support" if EXPERT
1477	depends on HAVE_PCSPKR_PLATFORM
1478	select I8253_LOCK
1479	default y
1480	help
1481          This option allows to disable the internal PC-Speaker
1482          support, saving some memory.
1483
1484config BASE_FULL
1485	default y
1486	bool "Enable full-sized data structures for core" if EXPERT
1487	help
1488	  Disabling this option reduces the size of miscellaneous core
1489	  kernel data structures. This saves memory on small machines,
1490	  but may reduce performance.
1491
1492config FUTEX
1493	bool "Enable futex support" if EXPERT
1494	default y
1495	select RT_MUTEXES
1496	help
1497	  Disabling this option will cause the kernel to be built without
1498	  support for "fast userspace mutexes".  The resulting kernel may not
1499	  run glibc-based applications correctly.
1500
 
 
 
 
 
1501config HAVE_FUTEX_CMPXCHG
1502	bool
1503	depends on FUTEX
1504	help
1505	  Architectures should select this if futex_atomic_cmpxchg_inatomic()
1506	  is implemented and always working. This removes a couple of runtime
1507	  checks.
1508
1509config EPOLL
1510	bool "Enable eventpoll support" if EXPERT
1511	default y
1512	select ANON_INODES
1513	help
1514	  Disabling this option will cause the kernel to be built without
1515	  support for epoll family of system calls.
1516
1517config SIGNALFD
1518	bool "Enable signalfd() system call" if EXPERT
1519	select ANON_INODES
1520	default y
1521	help
1522	  Enable the signalfd() system call that allows to receive signals
1523	  on a file descriptor.
1524
1525	  If unsure, say Y.
1526
1527config TIMERFD
1528	bool "Enable timerfd() system call" if EXPERT
1529	select ANON_INODES
1530	default y
1531	help
1532	  Enable the timerfd() system call that allows to receive timer
1533	  events on a file descriptor.
1534
1535	  If unsure, say Y.
1536
1537config EVENTFD
1538	bool "Enable eventfd() system call" if EXPERT
1539	select ANON_INODES
1540	default y
1541	help
1542	  Enable the eventfd() system call that allows to receive both
1543	  kernel notification (ie. KAIO) or userspace notifications.
1544
1545	  If unsure, say Y.
1546
1547# syscall, maps, verifier
1548config BPF_SYSCALL
1549	bool "Enable bpf() system call"
1550	select ANON_INODES
1551	select BPF
1552	default n
1553	help
1554	  Enable the bpf() system call that allows to manipulate eBPF
1555	  programs and maps via file descriptors.
1556
1557config SHMEM
1558	bool "Use full shmem filesystem" if EXPERT
1559	default y
1560	depends on MMU
1561	help
1562	  The shmem is an internal filesystem used to manage shared memory.
1563	  It is backed by swap and manages resource limits. It is also exported
1564	  to userspace as tmpfs if TMPFS is enabled. Disabling this
1565	  option replaces shmem and tmpfs with the much simpler ramfs code,
1566	  which may be appropriate on small systems without swap.
1567
1568config AIO
1569	bool "Enable AIO support" if EXPERT
1570	default y
1571	help
1572	  This option enables POSIX asynchronous I/O which may by used
1573	  by some high performance threaded applications. Disabling
1574	  this option saves about 7k.
1575
 
 
 
 
 
 
 
 
 
1576config ADVISE_SYSCALLS
1577	bool "Enable madvise/fadvise syscalls" if EXPERT
1578	default y
1579	help
1580	  This option enables the madvise and fadvise syscalls, used by
1581	  applications to advise the kernel about their future memory or file
1582	  usage, improving performance. If building an embedded system where no
1583	  applications use these syscalls, you can disable this option to save
1584	  space.
1585
1586config USERFAULTFD
1587	bool "Enable userfaultfd() system call"
1588	select ANON_INODES
1589	depends on MMU
1590	help
1591	  Enable the userfaultfd() system call that allows to intercept and
1592	  handle page faults in userland.
1593
1594config PCI_QUIRKS
1595	default y
1596	bool "Enable PCI quirk workarounds" if EXPERT
1597	depends on PCI
1598	help
1599	  This enables workarounds for various PCI chipset
1600	  bugs/quirks. Disable this only if your target machine is
1601	  unaffected by PCI quirks.
1602
1603config MEMBARRIER
1604	bool "Enable membarrier() system call" if EXPERT
1605	default y
1606	help
1607	  Enable the membarrier() system call that allows issuing memory
1608	  barriers across all running threads, which can be used to distribute
1609	  the cost of user-space memory barriers asymmetrically by transforming
1610	  pairs of memory barriers into pairs consisting of membarrier() and a
1611	  compiler barrier.
1612
1613	  If unsure, say Y.
1614
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1615config EMBEDDED
1616	bool "Embedded system"
1617	option allnoconfig_y
1618	select EXPERT
1619	help
1620	  This option should be enabled if compiling the kernel for
1621	  an embedded system so certain expert options are available
1622	  for configuration.
1623
1624config HAVE_PERF_EVENTS
1625	bool
1626	help
1627	  See tools/perf/design.txt for details.
1628
1629config PERF_USE_VMALLOC
1630	bool
1631	help
1632	  See tools/perf/design.txt for details
1633
 
 
 
 
 
 
 
1634menu "Kernel Performance Events And Counters"
1635
1636config PERF_EVENTS
1637	bool "Kernel performance events and counters"
1638	default y if PROFILING
1639	depends on HAVE_PERF_EVENTS
1640	select ANON_INODES
1641	select IRQ_WORK
1642	select SRCU
1643	help
1644	  Enable kernel support for various performance events provided
1645	  by software and hardware.
1646
1647	  Software events are supported either built-in or via the
1648	  use of generic tracepoints.
1649
1650	  Most modern CPUs support performance events via performance
1651	  counter registers. These registers count the number of certain
1652	  types of hw events: such as instructions executed, cachemisses
1653	  suffered, or branches mis-predicted - without slowing down the
1654	  kernel or applications. These registers can also trigger interrupts
1655	  when a threshold number of events have passed - and can thus be
1656	  used to profile the code that runs on that CPU.
1657
1658	  The Linux Performance Event subsystem provides an abstraction of
1659	  these software and hardware event capabilities, available via a
1660	  system call and used by the "perf" utility in tools/perf/. It
1661	  provides per task and per CPU counters, and it provides event
1662	  capabilities on top of those.
1663
1664	  Say Y if unsure.
1665
1666config DEBUG_PERF_USE_VMALLOC
1667	default n
1668	bool "Debug: use vmalloc to back perf mmap() buffers"
1669	depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
1670	select PERF_USE_VMALLOC
1671	help
1672	 Use vmalloc memory to back perf mmap() buffers.
1673
1674	 Mostly useful for debugging the vmalloc code on platforms
1675	 that don't require it.
1676
1677	 Say N if unsure.
1678
1679endmenu
1680
1681config VM_EVENT_COUNTERS
1682	default y
1683	bool "Enable VM event counters for /proc/vmstat" if EXPERT
1684	help
1685	  VM event counters are needed for event counts to be shown.
1686	  This option allows the disabling of the VM event counters
1687	  on EXPERT systems.  /proc/vmstat will only show page counts
1688	  if VM event counters are disabled.
1689
1690config SLUB_DEBUG
1691	default y
1692	bool "Enable SLUB debugging support" if EXPERT
1693	depends on SLUB && SYSFS
1694	help
1695	  SLUB has extensive debug support features. Disabling these can
1696	  result in significant savings in code size. This also disables
1697	  SLUB sysfs support. /sys/slab will not exist and there will be
1698	  no support for cache validation etc.
1699
1700config COMPAT_BRK
1701	bool "Disable heap randomization"
1702	default y
1703	help
1704	  Randomizing heap placement makes heap exploits harder, but it
1705	  also breaks ancient binaries (including anything libc5 based).
1706	  This option changes the bootup default to heap randomization
1707	  disabled, and can be overridden at runtime by setting
1708	  /proc/sys/kernel/randomize_va_space to 2.
1709
1710	  On non-ancient distros (post-2000 ones) N is usually a safe choice.
1711
1712choice
1713	prompt "Choose SLAB allocator"
1714	default SLUB
1715	help
1716	   This option allows to select a slab allocator.
1717
1718config SLAB
1719	bool "SLAB"
 
1720	help
1721	  The regular slab allocator that is established and known to work
1722	  well in all environments. It organizes cache hot objects in
1723	  per cpu and per node queues.
1724
1725config SLUB
1726	bool "SLUB (Unqueued Allocator)"
 
1727	help
1728	   SLUB is a slab allocator that minimizes cache line usage
1729	   instead of managing queues of cached objects (SLAB approach).
1730	   Per cpu caching is realized using slabs of objects instead
1731	   of queues of objects. SLUB can use memory efficiently
1732	   and has enhanced diagnostics. SLUB is the default choice for
1733	   a slab allocator.
1734
1735config SLOB
1736	depends on EXPERT
1737	bool "SLOB (Simple Allocator)"
1738	help
1739	   SLOB replaces the stock allocator with a drastically simpler
1740	   allocator. SLOB is generally more space efficient but
1741	   does not perform as well on large systems.
1742
1743endchoice
1744
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1745config SLUB_CPU_PARTIAL
1746	default y
1747	depends on SLUB && SMP
1748	bool "SLUB per cpu partial cache"
1749	help
1750	  Per cpu partial caches accellerate objects allocation and freeing
1751	  that is local to a processor at the price of more indeterminism
1752	  in the latency of the free. On overflow these caches will be cleared
1753	  which requires the taking of locks that may cause latency spikes.
1754	  Typically one would choose no for a realtime system.
1755
1756config MMAP_ALLOW_UNINITIALIZED
1757	bool "Allow mmapped anonymous memory to be uninitialized"
1758	depends on EXPERT && !MMU
1759	default n
1760	help
1761	  Normally, and according to the Linux spec, anonymous memory obtained
1762	  from mmap() has it's contents cleared before it is passed to
1763	  userspace.  Enabling this config option allows you to request that
1764	  mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1765	  providing a huge performance boost.  If this option is not enabled,
1766	  then the flag will be ignored.
1767
1768	  This is taken advantage of by uClibc's malloc(), and also by
1769	  ELF-FDPIC binfmt's brk and stack allocator.
1770
1771	  Because of the obvious security issues, this option should only be
1772	  enabled on embedded devices where you control what is run in
1773	  userspace.  Since that isn't generally a problem on no-MMU systems,
1774	  it is normally safe to say Y here.
1775
1776	  See Documentation/nommu-mmap.txt for more information.
1777
1778config SYSTEM_DATA_VERIFICATION
1779	def_bool n
1780	select SYSTEM_TRUSTED_KEYRING
1781	select KEYS
1782	select CRYPTO
1783	select CRYPTO_RSA
1784	select ASYMMETRIC_KEY_TYPE
1785	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1786	select ASN1
1787	select OID_REGISTRY
1788	select X509_CERTIFICATE_PARSER
1789	select PKCS7_MESSAGE_PARSER
1790	help
1791	  Provide PKCS#7 message verification using the contents of the system
1792	  trusted keyring to provide public keys.  This then can be used for
1793	  module verification, kexec image verification and firmware blob
1794	  verification.
1795
1796config PROFILING
1797	bool "Profiling support"
1798	help
1799	  Say Y here to enable the extended profiling support mechanisms used
1800	  by profilers such as OProfile.
1801
1802#
1803# Place an empty function call at each tracepoint site. Can be
1804# dynamically changed for a probe function.
1805#
1806config TRACEPOINTS
1807	bool
1808
1809source "arch/Kconfig"
1810
1811endmenu		# General setup
1812
1813config HAVE_GENERIC_DMA_COHERENT
1814	bool
1815	default n
1816
1817config SLABINFO
1818	bool
1819	depends on PROC_FS
1820	depends on SLAB || SLUB_DEBUG
1821	default y
1822
1823config RT_MUTEXES
1824	bool
1825
1826config BASE_SMALL
1827	int
1828	default 0 if BASE_FULL
1829	default 1 if !BASE_FULL
1830
 
 
 
 
1831menuconfig MODULES
1832	bool "Enable loadable module support"
1833	option modules
1834	help
1835	  Kernel modules are small pieces of compiled code which can
1836	  be inserted in the running kernel, rather than being
1837	  permanently built into the kernel.  You use the "modprobe"
1838	  tool to add (and sometimes remove) them.  If you say Y here,
1839	  many parts of the kernel can be built as modules (by
1840	  answering M instead of Y where indicated): this is most
1841	  useful for infrequently used options which are not required
1842	  for booting.  For more information, see the man pages for
1843	  modprobe, lsmod, modinfo, insmod and rmmod.
1844
1845	  If you say Y here, you will need to run "make
1846	  modules_install" to put the modules under /lib/modules/
1847	  where modprobe can find them (you may need to be root to do
1848	  this).
1849
1850	  If unsure, say Y.
1851
1852if MODULES
1853
1854config MODULE_FORCE_LOAD
1855	bool "Forced module loading"
1856	default n
1857	help
1858	  Allow loading of modules without version information (ie. modprobe
1859	  --force).  Forced module loading sets the 'F' (forced) taint flag and
1860	  is usually a really bad idea.
1861
1862config MODULE_UNLOAD
1863	bool "Module unloading"
1864	help
1865	  Without this option you will not be able to unload any
1866	  modules (note that some modules may not be unloadable
1867	  anyway), which makes your kernel smaller, faster
1868	  and simpler.  If unsure, say Y.
1869
1870config MODULE_FORCE_UNLOAD
1871	bool "Forced module unloading"
1872	depends on MODULE_UNLOAD
1873	help
1874	  This option allows you to force a module to unload, even if the
1875	  kernel believes it is unsafe: the kernel will remove the module
1876	  without waiting for anyone to stop using it (using the -f option to
1877	  rmmod).  This is mainly for kernel developers and desperate users.
1878	  If unsure, say N.
1879
1880config MODVERSIONS
1881	bool "Module versioning support"
1882	help
1883	  Usually, you have to use modules compiled with your kernel.
1884	  Saying Y here makes it sometimes possible to use modules
1885	  compiled for different kernels, by adding enough information
1886	  to the modules to (hopefully) spot any changes which would
1887	  make them incompatible with the kernel you are running.  If
1888	  unsure, say N.
1889
 
 
 
 
 
 
 
 
 
 
 
 
1890config MODULE_SRCVERSION_ALL
1891	bool "Source checksum for all modules"
1892	help
1893	  Modules which contain a MODULE_VERSION get an extra "srcversion"
1894	  field inserted into their modinfo section, which contains a
1895    	  sum of the source files which made it.  This helps maintainers
1896	  see exactly which source was used to build a module (since
1897	  others sometimes change the module source without updating
1898	  the version).  With this option, such a "srcversion" field
1899	  will be created for all modules.  If unsure, say N.
1900
1901config MODULE_SIG
1902	bool "Module signature verification"
1903	depends on MODULES
1904	select SYSTEM_DATA_VERIFICATION
1905	help
1906	  Check modules for valid signatures upon load: the signature
1907	  is simply appended to the module. For more information see
1908	  Documentation/module-signing.txt.
1909
1910	  Note that this option adds the OpenSSL development packages as a
1911	  kernel build dependency so that the signing tool can use its crypto
1912	  library.
1913
 
 
 
 
 
1914	  !!!WARNING!!!  If you enable this option, you MUST make sure that the
1915	  module DOES NOT get stripped after being signed.  This includes the
1916	  debuginfo strip done by some packagers (such as rpmbuild) and
1917	  inclusion into an initramfs that wants the module size reduced.
1918
1919config MODULE_SIG_FORCE
1920	bool "Require modules to be validly signed"
1921	depends on MODULE_SIG
1922	help
1923	  Reject unsigned modules or signed modules for which we don't have a
1924	  key.  Without this, such modules will simply taint the kernel.
1925
1926config MODULE_SIG_ALL
1927	bool "Automatically sign all modules"
1928	default y
1929	depends on MODULE_SIG
1930	help
1931	  Sign all modules during make modules_install. Without this option,
1932	  modules must be signed manually, using the scripts/sign-file tool.
1933
1934comment "Do not forget to sign required modules with scripts/sign-file"
1935	depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1936
1937choice
1938	prompt "Which hash algorithm should modules be signed with?"
1939	depends on MODULE_SIG
1940	help
1941	  This determines which sort of hashing algorithm will be used during
1942	  signature generation.  This algorithm _must_ be built into the kernel
1943	  directly so that signature verification can take place.  It is not
1944	  possible to load a signed module containing the algorithm to check
1945	  the signature on that module.
1946
1947config MODULE_SIG_SHA1
1948	bool "Sign modules with SHA-1"
1949	select CRYPTO_SHA1
1950
1951config MODULE_SIG_SHA224
1952	bool "Sign modules with SHA-224"
1953	select CRYPTO_SHA256
1954
1955config MODULE_SIG_SHA256
1956	bool "Sign modules with SHA-256"
1957	select CRYPTO_SHA256
1958
1959config MODULE_SIG_SHA384
1960	bool "Sign modules with SHA-384"
1961	select CRYPTO_SHA512
1962
1963config MODULE_SIG_SHA512
1964	bool "Sign modules with SHA-512"
1965	select CRYPTO_SHA512
1966
1967endchoice
1968
1969config MODULE_SIG_HASH
1970	string
1971	depends on MODULE_SIG
1972	default "sha1" if MODULE_SIG_SHA1
1973	default "sha224" if MODULE_SIG_SHA224
1974	default "sha256" if MODULE_SIG_SHA256
1975	default "sha384" if MODULE_SIG_SHA384
1976	default "sha512" if MODULE_SIG_SHA512
1977
1978config MODULE_COMPRESS
1979	bool "Compress modules on installation"
1980	depends on MODULES
1981	help
 
 
 
1982
1983	  Compresses kernel modules when 'make modules_install' is run; gzip or
1984	  xz depending on "Compression algorithm" below.
1985
1986	  module-init-tools MAY support gzip, and kmod MAY support gzip and xz.
 
1987
1988	  Out-of-tree kernel modules installed using Kbuild will also be
1989	  compressed upon installation.
1990
1991	  Note: for modules inside an initrd or initramfs, it's more efficient
1992	  to compress the whole initrd or initramfs instead.
 
1993
1994	  Note: This is fully compatible with signed modules.
 
1995
1996	  If in doubt, say N.
1997
1998choice
1999	prompt "Compression algorithm"
2000	depends on MODULE_COMPRESS
2001	default MODULE_COMPRESS_GZIP
2002	help
2003	  This determines which sort of compression will be used during
2004	  'make modules_install'.
2005
2006	  GZIP (default) and XZ are supported.
2007
2008config MODULE_COMPRESS_GZIP
2009	bool "GZIP"
 
 
 
2010
2011config MODULE_COMPRESS_XZ
2012	bool "XZ"
 
 
 
 
 
 
 
 
 
2013
2014endchoice
2015
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2016endif # MODULES
2017
2018config MODULES_TREE_LOOKUP
2019	def_bool y
2020	depends on PERF_EVENTS || TRACING
2021
2022config INIT_ALL_POSSIBLE
2023	bool
2024	help
2025	  Back when each arch used to define their own cpu_online_mask and
2026	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
2027	  with all 1s, and others with all 0s.  When they were centralised,
2028	  it was better to provide this option than to break all the archs
2029	  and have several arch maintainers pursuing me down dark alleys.
2030
2031source "block/Kconfig"
2032
2033config PREEMPT_NOTIFIERS
2034	bool
2035
2036config PADATA
2037	depends on SMP
2038	bool
2039
2040# Can be selected by architectures with broken toolchains
2041# that get confused by correct const<->read_only section
2042# mappings
2043config BROKEN_RODATA
2044	bool
2045
2046config ASN1
2047	tristate
2048	help
2049	  Build a simple ASN.1 grammar compiler that produces a bytecode output
2050	  that can be interpreted by the ASN.1 stream decoder and used to
2051	  inform it as to what tags are to be expected in a stream and what
2052	  functions to call on what tags.
2053
2054source "kernel/Kconfig.locks"