# SPDX-License-Identifier: GPL-2.0-only

  config DEFCONFIG_LIST
  	string

  	depends on !UML

  	option defconfig_list

  	default "/lib/modules/$(shell,uname -r)/.config"

  	default "/etc/kernel-config"

  	default "/boot/config-$(shell,uname -r)"

  	default "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)"

  config CC_VERSION_TEXT
  	string
  	default "$(CC_VERSION_TEXT)"
  	help
  	  This is used in unclear ways:
  
  	  - Re-run Kconfig when the compiler is updated
  	    The 'default' property references the environment variable,
  	    CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd.
  	    When the compiler is updated, Kconfig will be invoked.
  
  	  - Ensure full rebuild when the compier is updated
  	    include/linux/kconfig.h contains this option in the comment line so
  	    fixdep adds include/config/cc/version/text.h into the auto-generated
  	    dependency. When the compiler is updated, syncconfig will touch it
  	    and then every file will be rebuilt.

  config CC_IS_GCC

  	def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q gcc)

  
  config GCC_VERSION
  	int

  	default $(shell,$(srctree)/scripts/gcc-version.sh $(CC)) if CC_IS_GCC

  	default 0

  config LD_VERSION
  	int
  	default $(shell,$(LD) --version | $(srctree)/scripts/ld-version.sh)

  config CC_IS_CLANG

  	def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q clang)

  config LD_IS_LLD
  	def_bool $(success,$(LD) -v | head -n 1 | grep -q LLD)

  config CLANG_VERSION
  	int
  	default $(shell,$(srctree)/scripts/clang-version.sh $(CC))

  config LLD_VERSION
  	int
  	default $(shell,$(srctree)/scripts/lld-version.sh $(LD))

  config CC_CAN_LINK

  	bool

  	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
  	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag))

  
  config CC_CAN_LINK_STATIC
  	bool

  	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag) -static) if 64BIT
  	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag) -static)

  config CC_HAS_ASM_GOTO
  	def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))

  config CC_HAS_ASM_GOTO_OUTPUT
  	depends on CC_HAS_ASM_GOTO
  	def_bool $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)

  config TOOLS_SUPPORT_RELR

  	def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)

  config CC_HAS_ASM_INLINE
  	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)

  config CONSTRUCTORS
  	bool

  	depends on !UML

  config IRQ_WORK
  	bool

  config BUILDTIME_TABLE_SORT

  	bool

  config THREAD_INFO_IN_TASK
  	bool
  	help
  	  Select this to move thread_info off the stack into task_struct.  To
  	  make this work, an arch will need to remove all thread_info fields
  	  except flags and fix any runtime bugs.

  	  One subtle change that will be needed is to use try_get_task_stack()
  	  and put_task_stack() in save_thread_stack_tsk() and get_wchan().

  menu "General setup"

  config BROKEN
  	bool

  
  config BROKEN_ON_SMP
  	bool
  	depends on BROKEN || !SMP
  	default y

  config INIT_ENV_ARG_LIMIT
  	int

  	default 32 if !UML
  	default 128 if UML

  	help

  	  Maximum of each of the number of arguments and environment
  	  variables passed to init from the kernel command line.

  config COMPILE_TEST
  	bool "Compile also drivers which will not load"

  	depends on !UML

  	default n
  	help
  	  Some drivers can be compiled on a different platform than they are
  	  intended to be run on. Despite they cannot be loaded there (or even
  	  when they load they cannot be used due to missing HW support),
  	  developers still, opposing to distributors, might want to build such
  	  drivers to compile-test them.
  
  	  If you are a developer and want to build everything available, say Y
  	  here. If you are a user/distributor, say N here to exclude useless
  	  drivers to be distributed.

  config UAPI_HEADER_TEST
  	bool "Compile test UAPI headers"

  	depends on HEADERS_INSTALL && CC_CAN_LINK

  	help
  	  Compile test headers exported to user-space to ensure they are
  	  self-contained, i.e. compilable as standalone units.
  
  	  If you are a developer or tester and want to ensure the exported
  	  headers are self-contained, say Y here. Otherwise, choose N.

  config LOCALVERSION
  	string "Local version - append to kernel release"
  	help
  	  Append an extra string to the end of your kernel version.
  	  This will show up when you type uname, for example.
  	  The string you set here will be appended after the contents of
  	  any files with a filename matching localversion* in your
  	  object and source tree, in that order.  Your total string can
  	  be a maximum of 64 characters.

  config LOCALVERSION_AUTO
  	bool "Automatically append version information to the version string"
  	default y

  	depends on !COMPILE_TEST

  	help
  	  This will try to automatically determine if the current tree is a

  	  release tree by looking for git tags that belong to the current
  	  top of tree revision.

  
  	  A string of the format -gxxxxxxxx will be added to the localversion

  	  if a git-based tree is found.  The string generated by this will be

  	  appended after any matching localversion* files, and after the value

  	  set in CONFIG_LOCALVERSION.

  	  (The actual string used here is the first eight characters produced
  	  by running the command:
  
  	    $ git rev-parse --verify HEAD
  
  	  which is done within the script "scripts/setlocalversion".)

  config BUILD_SALT

  	string "Build ID Salt"
  	default ""
  	help
  	  The build ID is used to link binaries and their debug info. Setting
  	  this option will use the value in the calculation of the build id.
  	  This is mostly useful for distributions which want to ensure the
  	  build is unique between builds. It's safe to leave the default.

  config HAVE_KERNEL_GZIP
  	bool
  
  config HAVE_KERNEL_BZIP2
  	bool
  
  config HAVE_KERNEL_LZMA
  	bool

  config HAVE_KERNEL_XZ
  	bool

  config HAVE_KERNEL_LZO
  	bool

  config HAVE_KERNEL_LZ4
  	bool

  config HAVE_KERNEL_ZSTD
  	bool

  config HAVE_KERNEL_UNCOMPRESSED
  	bool

  choice

  	prompt "Kernel compression mode"
  	default KERNEL_GZIP

  	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_ZSTD || HAVE_KERNEL_UNCOMPRESSED

  	help

  	  The linux kernel is a kind of self-extracting executable.
  	  Several compression algorithms are available, which differ
  	  in efficiency, compression and decompression speed.
  	  Compression speed is only relevant when building a kernel.
  	  Decompression speed is relevant at each boot.
  
  	  If you have any problems with bzip2 or lzma compressed
  	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
  	  version of this functionality (bzip2 only), for 2.4, was
  	  supplied by Christian Ludwig)
  
  	  High compression options are mostly useful for users, who
  	  are low on disk space (embedded systems), but for whom ram
  	  size matters less.
  
  	  If in doubt, select 'gzip'
  
  config KERNEL_GZIP

  	bool "Gzip"
  	depends on HAVE_KERNEL_GZIP
  	help

  	  The old and tried gzip compression. It provides a good balance
  	  between compression ratio and decompression speed.

  
  config KERNEL_BZIP2
  	bool "Bzip2"

  	depends on HAVE_KERNEL_BZIP2

  	help
  	  Its compression ratio and speed is intermediate.

  	  Decompression speed is slowest among the choices.  The kernel

  	  size is about 10% smaller with bzip2, in comparison to gzip.
  	  Bzip2 uses a large amount of memory. For modern kernels you
  	  will need at least 8MB RAM or more for booting.

  
  config KERNEL_LZMA

  	bool "LZMA"
  	depends on HAVE_KERNEL_LZMA
  	help

  	  This compression algorithm's ratio is best.  Decompression speed
  	  is between gzip and bzip2.  Compression is slowest.
  	  The kernel size is about 33% smaller with LZMA in comparison to gzip.

  config KERNEL_XZ
  	bool "XZ"
  	depends on HAVE_KERNEL_XZ
  	help
  	  XZ uses the LZMA2 algorithm and instruction set specific
  	  BCJ filters which can improve compression ratio of executable
  	  code. The size of the kernel is about 30% smaller with XZ in
  	  comparison to gzip. On architectures for which there is a BCJ
  	  filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
  	  will create a few percent smaller kernel than plain LZMA.
  
  	  The speed is about the same as with LZMA: The decompression
  	  speed of XZ is better than that of bzip2 but worse than gzip
  	  and LZO. Compression is slow.

  config KERNEL_LZO
  	bool "LZO"
  	depends on HAVE_KERNEL_LZO
  	help

  	  Its compression ratio is the poorest among the choices. The kernel

  	  size is about 10% bigger than gzip; however its speed

  	  (both compression and decompression) is the fastest.

  config KERNEL_LZ4
  	bool "LZ4"
  	depends on HAVE_KERNEL_LZ4
  	help
  	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
  	  A preliminary version of LZ4 de/compression tool is available at
  	  <https://code.google.com/p/lz4/>.
  
  	  Its compression ratio is worse than LZO. The size of the kernel
  	  is about 8% bigger than LZO. But the decompression speed is
  	  faster than LZO.

  config KERNEL_ZSTD
  	bool "ZSTD"
  	depends on HAVE_KERNEL_ZSTD
  	help
  	  ZSTD is a compression algorithm targeting intermediate compression
  	  with fast decompression speed. It will compress better than GZIP and
  	  decompress around the same speed as LZO, but slower than LZ4. You
  	  will need at least 192 KB RAM or more for booting. The zstd command
  	  line tool is required for compression.

  config KERNEL_UNCOMPRESSED
  	bool "None"
  	depends on HAVE_KERNEL_UNCOMPRESSED
  	help
  	  Produce uncompressed kernel image. This option is usually not what
  	  you want. It is useful for debugging the kernel in slow simulation
  	  environments, where decompressing and moving the kernel is awfully
  	  slow. This option allows early boot code to skip the decompressor
  	  and jump right at uncompressed kernel image.

  endchoice

  config DEFAULT_INIT
  	string "Default init path"
  	default ""
  	help
  	  This option determines the default init for the system if no init=
  	  option is passed on the kernel command line. If the requested path is
  	  not present, we will still then move on to attempting further
  	  locations (e.g. /sbin/init, etc). If this is empty, we will just use
  	  the fallback list when init= is not passed.

  config DEFAULT_HOSTNAME
  	string "Default hostname"
  	default "(none)"
  	help
  	  This option determines the default system hostname before userspace
  	  calls sethostname(2). The kernel traditionally uses "(none)" here,
  	  but you may wish to use a different default here to make a minimal
  	  system more usable with less configuration.

  #
  # For some reason microblaze and nios2 hard code SWAP=n.  Hopefully we can
  # add proper SWAP support to them, in which case this can be remove.
  #
  config ARCH_NO_SWAP
  	bool

  config SWAP
  	bool "Support for paging of anonymous memory (swap)"

  	depends on MMU && BLOCK && !ARCH_NO_SWAP

  	default y
  	help
  	  This option allows you to choose whether you want to have support

  	  for so called swap devices or swap files in your kernel that are

  	  used to provide more virtual memory than the actual RAM present
  	  in your computer.  If unsure say Y.
  
  config SYSVIPC
  	bool "System V IPC"

  	help

  	  Inter Process Communication is a suite of library functions and
  	  system calls which let processes (running programs) synchronize and
  	  exchange information. It is generally considered to be a good thing,
  	  and some programs won't run unless you say Y here. In particular, if
  	  you want to run the DOS emulator dosemu under Linux (read the
  	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
  	  you'll need to say Y here.
  
  	  You can find documentation about IPC with "info ipc" and also in
  	  section 6.4 of the Linux Programmer's Guide, available from
  	  <http://www.tldp.org/guides.html>.

  config SYSVIPC_SYSCTL
  	bool
  	depends on SYSVIPC
  	depends on SYSCTL
  	default y

  config POSIX_MQUEUE
  	bool "POSIX Message Queues"

  	depends on NET

  	help

  	  POSIX variant of message queues is a part of IPC. In POSIX message
  	  queues every message has a priority which decides about succession
  	  of receiving it by a process. If you want to compile and run
  	  programs written e.g. for Solaris with use of its POSIX message

  	  queues (functions mq_*) say Y here.

  
  	  POSIX message queues are visible as a filesystem called 'mqueue'
  	  and can be mounted somewhere if you want to do filesystem
  	  operations on message queues.
  
  	  If unsure, say Y.

  config POSIX_MQUEUE_SYSCTL
  	bool
  	depends on POSIX_MQUEUE
  	depends on SYSCTL
  	default y

  config WATCH_QUEUE
  	bool "General notification queue"
  	default n
  	help
  
  	  This is a general notification queue for the kernel to pass events to
  	  userspace by splicing them into pipes.  It can be used in conjunction
  	  with watches for key/keyring change notifications and device
  	  notifications.
  
  	  See Documentation/watch_queue.rst

  config CROSS_MEMORY_ATTACH
  	bool "Enable process_vm_readv/writev syscalls"
  	depends on MMU
  	default y
  	help
  	  Enabling this option adds the system calls process_vm_readv and
  	  process_vm_writev which allow a process with the correct privileges

  	  to directly read from or write to another process' address space.

  	  See the man page for more details.

  config USELIB
  	bool "uselib syscall"

  	def_bool ALPHA || M68K || SPARC || X86_32 || IA32_EMULATION

  	help
  	  This option enables the uselib syscall, a system call used in the
  	  dynamic linker from libc5 and earlier.  glibc does not use this
  	  system call.  If you intend to run programs built on libc5 or
  	  earlier, you may need to enable this syscall.  Current systems
  	  running glibc can safely disable this.

  config AUDIT
  	bool "Auditing support"
  	depends on NET
  	help
  	  Enable auditing infrastructure that can be used with another
  	  kernel subsystem, such as SELinux (which requires this for

  	  logging of avc messages output).  System call auditing is included
  	  on architectures which support it.

  config HAVE_ARCH_AUDITSYSCALL
  	bool

  config AUDITSYSCALL

  	def_bool y

  	depends on AUDIT && HAVE_ARCH_AUDITSYSCALL

  	select FSNOTIFY

  source "kernel/irq/Kconfig"
  source "kernel/time/Kconfig"

  source "kernel/Kconfig.preempt"

  
  menu "CPU/Task time and stats accounting"

  config VIRT_CPU_ACCOUNTING
  	bool

  choice
  	prompt "Cputime accounting"
  	default TICK_CPU_ACCOUNTING if !PPC64

  	default VIRT_CPU_ACCOUNTING_NATIVE if PPC64

  
  # Kind of a stub config for the pure tick based cputime accounting
  config TICK_CPU_ACCOUNTING
  	bool "Simple tick based cputime accounting"

  	depends on !S390 && !NO_HZ_FULL

  	help
  	  This is the basic tick based cputime accounting that maintains
  	  statistics about user, system and idle time spent on per jiffies
  	  granularity.
  
  	  If unsure, say Y.

  config VIRT_CPU_ACCOUNTING_NATIVE

  	bool "Deterministic task and CPU time accounting"

  	depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL

  	select VIRT_CPU_ACCOUNTING

  	help
  	  Select this option to enable more accurate task and CPU time
  	  accounting.  This is done by reading a CPU counter on each
  	  kernel entry and exit and on transitions within the kernel
  	  between system, softirq and hardirq state, so there is a
  	  small performance impact.  In the case of s390 or IBM POWER > 5,
  	  this also enables accounting of stolen time on logically-partitioned
  	  systems.

  config VIRT_CPU_ACCOUNTING_GEN
  	bool "Full dynticks CPU time accounting"

  	depends on HAVE_CONTEXT_TRACKING

  	depends on HAVE_VIRT_CPU_ACCOUNTING_GEN

  	depends on GENERIC_CLOCKEVENTS

  	select VIRT_CPU_ACCOUNTING
  	select CONTEXT_TRACKING
  	help
  	  Select this option to enable task and CPU time accounting on full
  	  dynticks systems. This accounting is implemented by watching every
  	  kernel-user boundaries using the context tracking subsystem.
  	  The accounting is thus performed at the expense of some significant
  	  overhead.
  
  	  For now this is only useful if you are working on the full
  	  dynticks subsystem development.
  
  	  If unsure, say N.

  endchoice

  config IRQ_TIME_ACCOUNTING
  	bool "Fine granularity task level IRQ time accounting"

  	depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE

  	help
  	  Select this option to enable fine granularity task irq time
  	  accounting. This is done by reading a timestamp on each
  	  transitions between softirq and hardirq state, so there can be a
  	  small performance impact.
  
  	  If in doubt, say N here.

  config HAVE_SCHED_AVG_IRQ
  	def_bool y
  	depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
  	depends on SMP

  config SCHED_THERMAL_PRESSURE

  	bool

  	default y if ARM && ARM_CPU_TOPOLOGY
  	default y if ARM64

  	depends on SMP

  	depends on CPU_FREQ_THERMAL
  	help
  	  Select this option to enable thermal pressure accounting in the
  	  scheduler. Thermal pressure is the value conveyed to the scheduler
  	  that reflects the reduction in CPU compute capacity resulted from
  	  thermal throttling. Thermal throttling occurs when the performance of
  	  a CPU is capped due to high operating temperatures.
  
  	  If selected, the scheduler will be able to balance tasks accordingly,
  	  i.e. put less load on throttled CPUs than on non/less throttled ones.
  
  	  This requires the architecture to implement
  	  arch_set_thermal_pressure() and arch_get_thermal_pressure().

  config BSD_PROCESS_ACCT
  	bool "BSD Process Accounting"

  	depends on MULTIUSER

  	help
  	  If you say Y here, a user level program will be able to instruct the
  	  kernel (via a special system call) to write process accounting
  	  information to a file: whenever a process exits, information about
  	  that process will be appended to the file by the kernel.  The
  	  information includes things such as creation time, owning user,
  	  command name, memory usage, controlling terminal etc. (the complete
  	  list is in the struct acct in <file:include/linux/acct.h>).  It is
  	  up to the user level program to do useful things with this
  	  information.  This is generally a good idea, so say Y.
  
  config BSD_PROCESS_ACCT_V3
  	bool "BSD Process Accounting version 3 file format"
  	depends on BSD_PROCESS_ACCT
  	default n
  	help
  	  If you say Y here, the process accounting information is written
  	  in a new file format that also logs the process IDs of each

  	  process and its parent. Note that this file format is incompatible

  	  with previous v0/v1/v2 file formats, so you will need updated tools
  	  for processing it. A preliminary version of these tools is available

  	  at <http://www.gnu.org/software/acct/>.

  config TASKSTATS

  	bool "Export task/process statistics through netlink"

  	depends on NET

  	depends on MULTIUSER

  	default n
  	help
  	  Export selected statistics for tasks/processes through the
  	  generic netlink interface. Unlike BSD process accounting, the
  	  statistics are available during the lifetime of tasks/processes as
  	  responses to commands. Like BSD accounting, they are sent to user
  	  space on task exit.
  
  	  Say N if unsure.

  config TASK_DELAY_ACCT

  	bool "Enable per-task delay accounting"

  	depends on TASKSTATS

  	select SCHED_INFO

  	help
  	  Collect information on time spent by a task waiting for system
  	  resources like cpu, synchronous block I/O completion and swapping
  	  in pages. Such statistics can help in setting a task's priorities
  	  relative to other tasks for cpu, io, rss limits etc.
  
  	  Say N if unsure.

  config TASK_XACCT

  	bool "Enable extended accounting over taskstats"

  	depends on TASKSTATS
  	help
  	  Collect extended task accounting data and send the data
  	  to userland for processing over the taskstats interface.
  
  	  Say N if unsure.
  
  config TASK_IO_ACCOUNTING

  	bool "Enable per-task storage I/O accounting"

  	depends on TASK_XACCT
  	help
  	  Collect information on the number of bytes of storage I/O which this
  	  task has caused.
  
  	  Say N if unsure.

  config PSI
  	bool "Pressure stall information tracking"
  	help
  	  Collect metrics that indicate how overcommitted the CPU, memory,
  	  and IO capacity are in the system.
  
  	  If you say Y here, the kernel will create /proc/pressure/ with the
  	  pressure statistics files cpu, memory, and io. These will indicate
  	  the share of walltime in which some or all tasks in the system are
  	  delayed due to contention of the respective resource.

  	  In kernels with cgroup support, cgroups (cgroup2 only) will
  	  have cpu.pressure, memory.pressure, and io.pressure files,
  	  which aggregate pressure stalls for the grouped tasks only.

  	  For more details see Documentation/accounting/psi.rst.

  
  	  Say N if unsure.

  config PSI_DEFAULT_DISABLED
  	bool "Require boot parameter to enable pressure stall information tracking"
  	default n
  	depends on PSI
  	help
  	  If set, pressure stall information tracking will be disabled

  	  per default but can be enabled through passing psi=1 on the
  	  kernel commandline during boot.

  	  This feature adds some code to the task wakeup and sleep
  	  paths of the scheduler. The overhead is too low to affect
  	  common scheduling-intense workloads in practice (such as
  	  webservers, memcache), but it does show up in artificial
  	  scheduler stress tests, such as hackbench.
  
  	  If you are paranoid and not sure what the kernel will be
  	  used for, say Y.
  
  	  Say N if unsure.

  endmenu # "CPU/Task time and stats accounting"

  config CPU_ISOLATION
  	bool "CPU isolation"

  	depends on SMP || COMPILE_TEST

  	default y

  	help
  	  Make sure that CPUs running critical tasks are not disturbed by
  	  any source of "noise" such as unbound workqueues, timers, kthreads...

  	  Unbound jobs get offloaded to housekeeping CPUs. This is driven by
  	  the "isolcpus=" boot parameter.
  
  	  Say Y if unsure.

  source "kernel/rcu/Kconfig"

  config BUILD_BIN2C
  	bool
  	default n

  config IKCONFIG

  	tristate "Kernel .config support"

  	help

  	  This option enables the complete Linux kernel ".config" file
  	  contents to be saved in the kernel. It provides documentation
  	  of which kernel options are used in a running kernel or in an
  	  on-disk kernel.  This information can be extracted from the kernel
  	  image file with the script scripts/extract-ikconfig and used as
  	  input to rebuild the current kernel or to build another kernel.
  	  It can also be extracted from a running kernel by reading
  	  /proc/config.gz if enabled (below).
  
  config IKCONFIG_PROC
  	bool "Enable access to .config through /proc/config.gz"
  	depends on IKCONFIG && PROC_FS

  	help

  	  This option enables access to the kernel configuration file
  	  through /proc/config.gz.

  config IKHEADERS
  	tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
  	depends on SYSFS
  	help
  	  This option enables access to the in-kernel headers that are generated during
  	  the build process. These can be used to build eBPF tracing programs,
  	  or similar programs.  If you build the headers as a module, a module called
  	  kheaders.ko is built which can be loaded on-demand to get access to headers.

  config LOG_BUF_SHIFT
  	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"

  	range 12 25 if !H8300
  	range 12 19 if H8300

  	default 17

  	depends on PRINTK

  	help

  	  Select the minimal kernel log buffer size as a power of 2.
  	  The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
  	  parameter, see below. Any higher size also might be forced
  	  by "log_buf_len" boot parameter.

  	  Examples:

  		     17 => 128 KB

  		     16 => 64 KB

  		     15 => 32 KB
  		     14 => 16 KB

  		     13 =>  8 KB
  		     12 =>  4 KB

  config LOG_CPU_MAX_BUF_SHIFT
  	int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"

  	depends on SMP

  	range 0 21
  	default 12 if !BASE_SMALL
  	default 0 if BASE_SMALL

  	depends on PRINTK

  	help
  	  This option allows to increase the default ring buffer size
  	  according to the number of CPUs. The value defines the contribution
  	  of each CPU as a power of 2. The used space is typically only few
  	  lines however it might be much more when problems are reported,
  	  e.g. backtraces.
  
  	  The increased size means that a new buffer has to be allocated and
  	  the original static one is unused. It makes sense only on systems
  	  with more CPUs. Therefore this value is used only when the sum of
  	  contributions is greater than the half of the default kernel ring
  	  buffer as defined by LOG_BUF_SHIFT. The default values are set

  	  so that more than 16 CPUs are needed to trigger the allocation.

  
  	  Also this option is ignored when "log_buf_len" kernel parameter is
  	  used as it forces an exact (power of two) size of the ring buffer.
  
  	  The number of possible CPUs is used for this computation ignoring

  	  hotplugging making the computation optimal for the worst case
  	  scenario while allowing a simple algorithm to be used from bootup.

  
  	  Examples shift values and their meaning:
  		     17 => 128 KB for each CPU
  		     16 =>  64 KB for each CPU
  		     15 =>  32 KB for each CPU
  		     14 =>  16 KB for each CPU
  		     13 =>   8 KB for each CPU
  		     12 =>   4 KB for each CPU

  config PRINTK_SAFE_LOG_BUF_SHIFT
  	int "Temporary per-CPU printk log buffer size (12 => 4KB, 13 => 8KB)"

  	range 10 21
  	default 13

  	depends on PRINTK

  	help

  	  Select the size of an alternate printk per-CPU buffer where messages
  	  printed from usafe contexts are temporary stored. One example would
  	  be NMI messages, another one - printk recursion. The messages are
  	  copied to the main log buffer in a safe context to avoid a deadlock.
  	  The value defines the size as a power of 2.

  	  Those messages are rare and limited. The largest one is when

  	  a backtrace is printed. It usually fits into 4KB. Select
  	  8KB if you want to be on the safe side.
  
  	  Examples:
  		     17 => 128 KB for each CPU
  		     16 =>  64 KB for each CPU
  		     15 =>  32 KB for each CPU
  		     14 =>  16 KB for each CPU
  		     13 =>   8 KB for each CPU
  		     12 =>   4 KB for each CPU

  #
  # Architectures with an unreliable sched_clock() should select this:
  #
  config HAVE_UNSTABLE_SCHED_CLOCK
  	bool

  config GENERIC_SCHED_CLOCK
  	bool

  menu "Scheduler features"
  
  config UCLAMP_TASK
  	bool "Enable utilization clamping for RT/FAIR tasks"
  	depends on CPU_FREQ_GOV_SCHEDUTIL
  	help
  	  This feature enables the scheduler to track the clamped utilization
  	  of each CPU based on RUNNABLE tasks scheduled on that CPU.
  
  	  With this option, the user can specify the min and max CPU
  	  utilization allowed for RUNNABLE tasks. The max utilization defines
  	  the maximum frequency a task should use while the min utilization
  	  defines the minimum frequency it should use.
  
  	  Both min and max utilization clamp values are hints to the scheduler,
  	  aiming at improving its frequency selection policy, but they do not
  	  enforce or grant any specific bandwidth for tasks.
  
  	  If in doubt, say N.
  
  config UCLAMP_BUCKETS_COUNT
  	int "Number of supported utilization clamp buckets"
  	range 5 20
  	default 5
  	depends on UCLAMP_TASK
  	help
  	  Defines the number of clamp buckets to use. The range of each bucket
  	  will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the
  	  number of clamp buckets the finer their granularity and the higher
  	  the precision of clamping aggregation and tracking at run-time.
  
  	  For example, with the minimum configuration value we will have 5
  	  clamp buckets tracking 20% utilization each. A 25% boosted tasks will
  	  be refcounted in the [20..39]% bucket and will set the bucket clamp
  	  effective value to 25%.
  	  If a second 30% boosted task should be co-scheduled on the same CPU,
  	  that task will be refcounted in the same bucket of the first task and
  	  it will boost the bucket clamp effective value to 30%.
  	  The clamp effective value of a bucket is reset to its nominal value
  	  (20% in the example above) when there are no more tasks refcounted in
  	  that bucket.
  
  	  An additional boost/capping margin can be added to some tasks. In the
  	  example above the 25% task will be boosted to 30% until it exits the
  	  CPU. If that should be considered not acceptable on certain systems,
  	  it's always possible to reduce the margin by increasing the number of
  	  clamp buckets to trade off used memory for run-time tracking
  	  precision.
  
  	  If in doubt, use the default value.
  
  endmenu

  #
  # For architectures that want to enable the support for NUMA-affine scheduler
  # balancing logic:
  #
  config ARCH_SUPPORTS_NUMA_BALANCING
  	bool

  #

  # For architectures that prefer to flush all TLBs after a number of pages
  # are unmapped instead of sending one IPI per page to flush. The architecture
  # must provide guarantees on what happens if a clean TLB cache entry is
  # written after the unmap. Details are in mm/rmap.c near the check for
  # should_defer_flush. The architecture should also consider if the full flush
  # and the refill costs are offset by the savings of sending fewer IPIs.
  config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
  	bool

  config CC_HAS_INT128

  	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT

  #

  # For architectures that know their GCC __int128 support is sound
  #
  config ARCH_SUPPORTS_INT128
  	bool

  # For architectures that (ab)use NUMA to represent different memory regions
  # all cpu-local but of different latencies, such as SuperH.
  #
  config ARCH_WANT_NUMA_VARIABLE_LOCALITY
  	bool

  config NUMA_BALANCING
  	bool "Memory placement aware NUMA scheduler"

  	depends on ARCH_SUPPORTS_NUMA_BALANCING
  	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
  	depends on SMP && NUMA && MIGRATION
  	help
  	  This option adds support for automatic NUMA aware memory/task placement.
  	  The mechanism is quite primitive and is based on migrating memory when

  	  it has references to the node the task is running on.

  
  	  This system will be inactive on UMA systems.

  config NUMA_BALANCING_DEFAULT_ENABLED
  	bool "Automatically enable NUMA aware memory/task placement"
  	default y
  	depends on NUMA_BALANCING
  	help
  	  If set, automatic NUMA balancing will be enabled if running on a NUMA
  	  machine.

  menuconfig CGROUPS

  	bool "Control Group support"

  	select KERNFS

  	help

  	  This option adds support for grouping sets of processes together, for

  	  use with process control subsystems such as Cpusets, CFS, memory
  	  controls or device isolation.
  	  See

  		- Documentation/scheduler/sched-design-CFS.rst	(CFS)

  		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation

  					  and resource control)

  
  	  Say N if unsure.

  if CGROUPS

  config PAGE_COUNTER

  	bool

  config MEMCG

  	bool "Memory controller"

  	select PAGE_COUNTER

  	select EVENTFD

  	help

  	  Provides control over the memory footprint of tasks in a cgroup.

  config MEMCG_SWAP

  	bool

  	depends on MEMCG && SWAP

  	default y

  config MEMCG_KMEM
  	bool
  	depends on MEMCG && !SLOB
  	default y

  config BLK_CGROUP
  	bool "IO controller"
  	depends on BLOCK

  	default n

  	help

  	Generic block IO controller cgroup interface. This is the common
  	cgroup interface which should be used by various IO controlling
  	policies.

  	Currently, CFQ IO scheduler uses it to recognize task groups and
  	control disk bandwidth allocation (proportional time slice allocation)
  	to such task groups. It is also used by bio throttling logic in
  	block layer to implement upper limit in IO rates on a device.

  	This option only enables generic Block IO controller infrastructure.
  	One needs to also enable actual IO controlling logic/policy. For
  	enabling proportional weight division of disk bandwidth in CFQ, set

  	CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set

  	CONFIG_BLK_DEV_THROTTLING=y.

  	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.

  config CGROUP_WRITEBACK
  	bool
  	depends on MEMCG && BLK_CGROUP
  	default y

  menuconfig CGROUP_SCHED

  	bool "CPU controller"

  	default n
  	help
  	  This feature lets CPU scheduler recognize task groups and control CPU
  	  bandwidth allocation to such task groups. It uses cgroups to group
  	  tasks.
  
  if CGROUP_SCHED
  config FAIR_GROUP_SCHED
  	bool "Group scheduling for SCHED_OTHER"
  	depends on CGROUP_SCHED
  	default CGROUP_SCHED

  config CFS_BANDWIDTH
  	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"

  	depends on FAIR_GROUP_SCHED
  	default n
  	help
  	  This option allows users to define CPU bandwidth rates (limits) for
  	  tasks running within the fair group scheduler.  Groups with no limit
  	  set are considered to be unconstrained and will run with no
  	  restriction.

  	  See Documentation/scheduler/sched-bwc.rst for more information.

  config RT_GROUP_SCHED
  	bool "Group scheduling for SCHED_RR/FIFO"

  	depends on CGROUP_SCHED
  	default n
  	help
  	  This feature lets you explicitly allocate real CPU bandwidth

  	  to task groups. If enabled, it will also make it impossible to

  	  schedule realtime tasks for non-root users until you allocate
  	  realtime bandwidth for them.

  	  See Documentation/scheduler/sched-rt-group.rst for more information.

  
  endif #CGROUP_SCHED

  config UCLAMP_TASK_GROUP
  	bool "Utilization clamping per group of tasks"
  	depends on CGROUP_SCHED
  	depends on UCLAMP_TASK
  	default n
  	help
  	  This feature enables the scheduler to track the clamped utilization
  	  of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
  
  	  When this option is enabled, the user can specify a min and max
  	  CPU bandwidth which is allowed for each single task in a group.
  	  The max bandwidth allows to clamp the maximum frequency a task
  	  can use, while the min bandwidth allows to define a minimum
  	  frequency a task will always use.
  
  	  When task group based utilization clamping is enabled, an eventually
  	  specified task-specific clamp value is constrained by the cgroup
  	  specified clamp value. Both minimum and maximum task clamping cannot
  	  be bigger than the corresponding clamping defined at task group level.
  
  	  If in doubt, say N.

  config CGROUP_PIDS
  	bool "PIDs controller"
  	help
  	  Provides enforcement of process number limits in the scope of a
  	  cgroup. Any attempt to fork more processes than is allowed in the
  	  cgroup will fail. PIDs are fundamentally a global resource because it
  	  is fairly trivial to reach PID exhaustion before you reach even a
  	  conservative kmemcg limit. As a result, it is possible to grind a
  	  system to halt without being limited by other cgroup policies. The

  	  PIDs controller is designed to stop this from happening.

  
  	  It should be noted that organisational operations (such as attaching

  	  to a cgroup hierarchy) will *not* be blocked by the PIDs controller,

  	  since the PIDs limit only affects a process's ability to fork, not to
  	  attach to a cgroup.

  config CGROUP_RDMA
  	bool "RDMA controller"
  	help
  	  Provides enforcement of RDMA resources defined by IB stack.
  	  It is fairly easy for consumers to exhaust RDMA resources, which
  	  can result into resource unavailability to other consumers.
  	  RDMA controller is designed to stop this from happening.
  	  Attaching processes with active RDMA resources to the cgroup
  	  hierarchy is allowed even if can cross the hierarchy's limit.

  config CGROUP_FREEZER
  	bool "Freezer controller"
  	help
  	  Provides a way to freeze and unfreeze all tasks in a
  	  cgroup.

  	  This option affects the ORIGINAL cgroup interface. The cgroup2 memory
  	  controller includes important in-kernel memory consumers per default.
  
  	  If you're using cgroup2, say N.

  config CGROUP_HUGETLB
  	bool "HugeTLB controller"
  	depends on HUGETLB_PAGE
  	select PAGE_COUNTER

  	default n

  	help
  	  Provides a cgroup controller for HugeTLB pages.
  	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
  	  The limit is enforced during page fault. Since HugeTLB doesn't
  	  support page reclaim, enforcing the limit at page fault time implies
  	  that, the application will get SIGBUS signal if it tries to access
  	  HugeTLB pages beyond its limit. This requires the application to know
  	  beforehand how much HugeTLB pages it would require for its use. The
  	  control group is tracked in the third page lru pointer. This means
  	  that we cannot use the controller with huge page less than 3 pages.

  config CPUSETS
  	bool "Cpuset controller"

  	depends on SMP

  	help
  	  This option will let you create and manage CPUSETs which
  	  allow dynamically partitioning a system into sets of CPUs and
  	  Memory Nodes and assigning tasks to run only within those sets.
  	  This is primarily useful on large SMP or NUMA systems.

  	  Say N if unsure.

  config PROC_PID_CPUSET
  	bool "Include legacy /proc/<pid>/cpuset file"
  	depends on CPUSETS
  	default y

  config CGROUP_DEVICE
  	bool "Device controller"
  	help
  	  Provides a cgroup controller implementing whitelists for
  	  devices which a process in the cgroup can mknod or open.
  
  config CGROUP_CPUACCT
  	bool "Simple CPU accounting controller"
  	help
  	  Provides a simple controller for monitoring the
  	  total CPU consumed by the tasks in a cgroup.
  
  config CGROUP_PERF
  	bool "Perf controller"
  	depends on PERF_EVENTS
  	help
  	  This option extends the perf per-cpu mode to restrict monitoring
  	  to threads which belong to the cgroup specified and run on the

  	  designated cpu.  Or this can be used to have cgroup ID in samples
  	  so that it can monitor performance events among cgroups.

  
  	  Say N if unsure.

  config CGROUP_BPF
  	bool "Support for eBPF programs attached to cgroups"

  	depends on BPF_SYSCALL
  	select SOCK_CGROUP_DATA

  	help
  	  Allow attaching eBPF programs to a cgroup using the bpf(2)
  	  syscall command BPF_PROG_ATTACH.
  
  	  In which context these programs are accessed depends on the type
  	  of attachment. For instance, programs that are attached using
  	  BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
  	  inet sockets.

  config CGROUP_DEBUG

  	bool "Debug controller"

  	default n

  	depends on DEBUG_KERNEL

  	help
  	  This option enables a simple controller that exports

  	  debugging information about the cgroups framework. This
  	  controller is for control cgroup debugging only. Its
  	  interfaces are not stable.

  	  Say N.

  config SOCK_CGROUP_DATA
  	bool
  	default n

  endif # CGROUPS

  menuconfig NAMESPACES

  	bool "Namespaces support" if EXPERT

  	depends on MULTIUSER

  	default !EXPERT

  	help
  	  Provides the way to make tasks work with different objects using
  	  the same id. For example same IPC id may refer to different objects
  	  or same user id or pid may refer to different tasks when used in
  	  different namespaces.

  if NAMESPACES

  config UTS_NS
  	bool "UTS namespace"

  	default y

  	help
  	  In this namespace tasks see different info provided with the
  	  uname() system call

  config TIME_NS
  	bool "TIME namespace"

  	depends on GENERIC_VDSO_TIME_NS

  	default y
  	help
  	  In this namespace boottime and monotonic clocks can be set.
  	  The time will keep going with the same pace.

  config IPC_NS
  	bool "IPC namespace"

  	depends on (SYSVIPC || POSIX_MQUEUE)

  	default y

  	help
  	  In this namespace tasks work with IPC ids which correspond to

  	  different IPC objects in different namespaces.

  config USER_NS

  	bool "User namespace"

  	default n

  	help
  	  This allows containers, i.e. vservers, to use user namespaces
  	  to provide different user info for different servers.

  
  	  When user namespaces are enabled in the kernel it is

  	  recommended that the MEMCG option also be enabled and that
  	  user-space use the memory control groups to limit the amount
  	  of memory a memory unprivileged users can use.

  	  If unsure, say N.

  config PID_NS

  	bool "PID Namespaces"

  	default y

  	help

  	  Support process id namespaces.  This allows having multiple

  	  processes with the same pid as long as they are in different

  	  pid namespaces.  This is a building block of containers.

  config NET_NS
  	bool "Network namespace"

  	depends on NET

  	default y

  	help
  	  Allow user space to create what appear to be multiple instances
  	  of the network stack.

  endif # NAMESPACES

  config CHECKPOINT_RESTORE
  	bool "Checkpoint/restore support"
  	select PROC_CHILDREN
  	default n
  	help
  	  Enables additional kernel features in a sake of checkpoint/restore.
  	  In particular it adds auxiliary prctl codes to setup process text,
  	  data and heap segment sizes, and a few additional /proc filesystem
  	  entries.
  
  	  If unsure, say N here.

  config SCHED_AUTOGROUP
  	bool "Automatic process group scheduling"

  	select CGROUPS
  	select CGROUP_SCHED
  	select FAIR_GROUP_SCHED
  	help
  	  This option optimizes the scheduler for common desktop workloads by
  	  automatically creating and populating task groups.  This separation
  	  of workloads isolates aggressive CPU burners (like build jobs) from
  	  desktop applications.  Task group autogeneration is currently based
  	  upon task session.

  config SYSFS_DEPRECATED

  	bool "Enable deprecated sysfs features to support old userspace tools"

  	depends on SYSFS
  	default n
  	help
  	  This option adds code that switches the layout of the "block" class
  	  devices, to not show up in /sys/class/block/, but only in
  	  /sys/block/.
  
  	  This switch is only active when the sysfs.deprecated=1 boot option is
  	  passed or the SYSFS_DEPRECATED_V2 option is set.
  
  	  This option allows new kernels to run on old distributions and tools,
  	  which might get confused by /sys/class/block/. Since 2007/2008 all
  	  major distributions and tools handle this just fine.
  
  	  Recent distributions and userspace tools after 2009/2010 depend on
  	  the existence of /sys/class/block/, and will not work with this
  	  option enabled.
  
  	  Only if you are using a new kernel on an old distribution, you might
  	  need to say Y here.
  
  config SYSFS_DEPRECATED_V2

  	bool "Enable deprecated sysfs features by default"

  	default n
  	depends on SYSFS
  	depends on SYSFS_DEPRECATED
  	help
  	  Enable deprecated sysfs by default.
  
  	  See the CONFIG_SYSFS_DEPRECATED option for more details about this
  	  option.
  
  	  Only if you are using a new kernel on an old distribution, you might
  	  need to say Y here. Even then, odds are you would not need it
  	  enabled, you can always pass the boot option if absolutely necessary.
  
  config RELAY
  	bool "Kernel->user space relay support (formerly relayfs)"

  	select IRQ_WORK

  	help
  	  This option enables support for relay interface support in
  	  certain file systems (such as debugfs).
  	  It is designed to provide an efficient mechanism for tools and
  	  facilities to relay large amounts of data from kernel space to
  	  user space.
  
  	  If unsure, say N.

  config BLK_DEV_INITRD
  	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"

  	help
  	  The initial RAM filesystem is a ramfs which is loaded by the
  	  boot loader (loadlin or lilo) and that is mounted as root
  	  before the normal boot procedure. It is typically used to
  	  load modules needed to mount the "real" root file system,

  	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.

  
  	  If RAM disk support (BLK_DEV_RAM) is also included, this
  	  also enables initial RAM disk (initrd) support and adds
  	  15 Kbytes (more on some other architectures) to the kernel size.
  
  	  If unsure say Y.

  if BLK_DEV_INITRD

  source "usr/Kconfig"

  endif

  config BOOT_CONFIG
  	bool "Boot config support"

  	select BLK_DEV_INITRD

  	help
  	  Extra boot config allows system admin to pass a config file as
  	  complemental extension of kernel cmdline when booting.

  	  The boot config file must be attached at the end of initramfs

  	  with checksum, size and magic word.

  	  See <file:Documentation/admin-guide/bootconfig.rst> for details.

  
  	  If unsure, say Y.

  choice
  	prompt "Compiler optimization level"

  	default CC_OPTIMIZE_FOR_PERFORMANCE

  
  config CC_OPTIMIZE_FOR_PERFORMANCE

  	bool "Optimize for performance (-O2)"

  	help
  	  This is the default optimization level for the kernel, building
  	  with the "-O2" compiler flag for best performance and most
  	  helpful compile-time warnings.

  config CC_OPTIMIZE_FOR_PERFORMANCE_O3
  	bool "Optimize more for performance (-O3)"
  	depends on ARC

  	help

  	  Choosing this option will pass "-O3" to your compiler to optimize
  	  the kernel yet more for performance.

  config CC_OPTIMIZE_FOR_SIZE

  	bool "Optimize for size (-Os)"

  	help

  	  Choosing this option will pass "-Os" to your compiler resulting
  	  in a smaller kernel.

  endchoice

  config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
  	bool
  	help
  	  This requires that the arch annotates or otherwise protects
  	  its external entry points from being discarded. Linker scripts
  	  must also merge .text.*, .data.*, and .bss.* correctly into
  	  output sections. Care must be taken not to pull in unrelated
  	  sections (e.g., '.text.init'). Typically '.' in section names
  	  is used to distinguish them from label names / C identifiers.
  
  config LD_DEAD_CODE_DATA_ELIMINATION
  	bool "Dead code and data elimination (EXPERIMENTAL)"
  	depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
  	depends on EXPERT

  	depends on $(cc-option,-ffunction-sections -fdata-sections)
  	depends on $(ld-option,--gc-sections)

  	help

  	  Enable this if you want to do dead code and data elimination with
  	  the linker by compiling with -ffunction-sections -fdata-sections,
  	  and linking with --gc-sections.

  
  	  This can reduce on disk and in-memory size of the kernel
  	  code and static data, particularly for small configs and
  	  on small systems. This has the possibility of introducing
  	  silently broken kernel if the required annotations are not
  	  present. This option is not well tested yet, so use at your
  	  own risk.

  config LD_ORPHAN_WARN
  	def_bool y
  	depends on ARCH_WANT_LD_ORPHAN_WARN

  	depends on !LD_IS_LLD || LLD_VERSION >= 110000

  	depends on $(ld-option,--orphan-handling=warn)

  config SYSCTL
  	bool

  config HAVE_UID16
  	bool
  
  config SYSCTL_EXCEPTION_TRACE
  	bool
  	help
  	  Enable support for /proc/sys/debug/exception-trace.
  
  config SYSCTL_ARCH_UNALIGN_NO_WARN
  	bool
  	help
  	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
  	  Allows arch to define/use @no_unaligned_warning to possibly warn
  	  about unaligned access emulation going on under the hood.
  
  config SYSCTL_ARCH_UNALIGN_ALLOW
  	bool
  	help
  	  Enable support for /proc/sys/kernel/unaligned-trap
  	  Allows arches to define/use @unaligned_enabled to runtime toggle
  	  the unaligned access emulation.
  	  see arch/parisc/kernel/unaligned.c for reference

  config HAVE_PCSPKR_PLATFORM
  	bool

  # interpreter that classic socket filters depend on
  config BPF
  	bool

  menuconfig EXPERT
  	bool "Configure standard kernel features (expert users)"

  	# Unhide debug options, to make the on-by-default options visible
  	select DEBUG_KERNEL

  	help
  	  This option allows certain base kernel options and settings

  	  to be disabled or tweaked. This is for specialized
  	  environments which can tolerate a "non-standard" kernel.
  	  Only use this if you really know what you are doing.

  config UID16

  	bool "Enable 16-bit UID system calls" if EXPERT

  	depends on HAVE_UID16 && MULTIUSER

  	default y
  	help
  	  This enables the legacy 16-bit UID syscall wrappers.

  config MULTIUSER
  	bool "Multiple users, groups and capabilities support" if EXPERT
  	default y
  	help
  	  This option enables support for non-root users, groups and
  	  capabilities.
  
  	  If you say N here, all processes will run with UID 0, GID 0, and all
  	  possible capabilities.  Saying N here also compiles out support for
  	  system calls related to UIDs, GIDs, and capabilities, such as setuid,
  	  setgid, and capset.
  
  	  If unsure, say Y here.

  config SGETMASK_SYSCALL
  	bool "sgetmask/ssetmask syscalls support" if EXPERT

  	def_bool PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH

  	help

  	  sys_sgetmask and sys_ssetmask are obsolete system calls
  	  no longer supported in libc but still enabled by default in some
  	  architectures.
  
  	  If unsure, leave the default option here.

  config SYSFS_SYSCALL
  	bool "Sysfs syscall support" if EXPERT
  	default y

  	help

  	  sys_sysfs is an obsolete system call no longer supported in libc.
  	  Note that disabling this option is more secure but might break
  	  compatibility with some systems.
  
  	  If unsure say Y here.

  config FHANDLE
  	bool "open by fhandle syscalls" if EXPERT
  	select EXPORTFS
  	default y
  	help
  	  If you say Y here, a user level program will be able to map
  	  file names to handle and then later use the handle for
  	  different file system operations. This is useful in implementing
  	  userspace file servers, which now track files using handles instead
  	  of names. The handle would remain the same even if file names
  	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
  	  syscalls.

  config POSIX_TIMERS
  	bool "Posix Clocks & timers" if EXPERT
  	default y
  	help
  	  This includes native support for POSIX timers to the kernel.
  	  Some embedded systems have no use for them and therefore they
  	  can be configured out to reduce the size of the kernel image.
  
  	  When this option is disabled, the following syscalls won't be
  	  available: timer_create, timer_gettime: timer_getoverrun,
  	  timer_settime, timer_delete, clock_adjtime, getitimer,
  	  setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
  	  clock_getres and clock_nanosleep syscalls will be limited to
  	  CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
  
  	  If unsure say y.

  config PRINTK
  	default y

  	bool "Enable support for printk" if EXPERT

  	select IRQ_WORK

  	help
  	  This option enables normal printk support. Removing it
  	  eliminates most of the message strings from the kernel image
  	  and makes the kernel more or less silent. As this makes it
  	  very difficult to diagnose system problems, saying N here is
  	  strongly discouraged.

  config PRINTK_NMI
  	def_bool y
  	depends on PRINTK
  	depends on HAVE_NMI

  config BUG

  	bool "BUG() support" if EXPERT

  	default y
  	help

  	  Disabling this option eliminates support for BUG and WARN, reducing
  	  the size of your kernel image and potentially quietly ignoring
  	  numerous fatal conditions. You should only consider disabling this
  	  option for embedded systems with no facilities for reporting errors.
  	  Just say Y.

  config ELF_CORE

  	depends on COREDUMP

  	default y

  	bool "Enable ELF core dumps" if EXPERT

  	help
  	  Enable support for generating core dumps. Disabling saves about 4k.

  config PCSPKR_PLATFORM

  	bool "Enable PC-Speaker support" if EXPERT

  	depends on HAVE_PCSPKR_PLATFORM

  	select I8253_LOCK

  	default y
  	help

  	  This option allows to disable the internal PC-Speaker
  	  support, saving some memory.

  config BASE_FULL
  	default y

  	bool "Enable full-sized data structures for core" if EXPERT

  	help
  	  Disabling this option reduces the size of miscellaneous core
  	  kernel data structures. This saves memory on small machines,
  	  but may reduce performance.
  
  config FUTEX

  	bool "Enable futex support" if EXPERT

  	default y

  	imply RT_MUTEXES

  	help
  	  Disabling this option will cause the kernel to be built without
  	  support for "fast userspace mutexes".  The resulting kernel may not
  	  run glibc-based applications correctly.

  config FUTEX_PI
  	bool
  	depends on FUTEX && RT_MUTEXES
  	default y

  config HAVE_FUTEX_CMPXCHG
  	bool

  	depends on FUTEX

  	help
  	  Architectures should select this if futex_atomic_cmpxchg_inatomic()
  	  is implemented and always working. This removes a couple of runtime
  	  checks.

  config EPOLL

  	bool "Enable eventpoll support" if EXPERT

  	default y
  	help
  	  Disabling this option will cause the kernel to be built without
  	  support for epoll family of system calls.

  config SIGNALFD

  	bool "Enable signalfd() system call" if EXPERT

  	default y
  	help
  	  Enable the signalfd() system call that allows to receive signals
  	  on a file descriptor.
  
  	  If unsure, say Y.

  config TIMERFD

  	bool "Enable timerfd() system call" if EXPERT

  	default y
  	help
  	  Enable the timerfd() system call that allows to receive timer
  	  events on a file descriptor.
  
  	  If unsure, say Y.

  config EVENTFD

  	bool "Enable eventfd() system call" if EXPERT

  	default y
  	help
  	  Enable the eventfd() system call that allows to receive both
  	  kernel notification (ie. KAIO) or userspace notifications.
  
  	  If unsure, say Y.

  config SHMEM

  	bool "Use full shmem filesystem" if EXPERT

  	default y
  	depends on MMU
  	help
  	  The shmem is an internal filesystem used to manage shared memory.
  	  It is backed by swap and manages resource limits. It is also exported
  	  to userspace as tmpfs if TMPFS is enabled. Disabling this
  	  option replaces shmem and tmpfs with the much simpler ramfs code,
  	  which may be appropriate on small systems without swap.

  config AIO

  	bool "Enable AIO support" if EXPERT

  	default y
  	help
  	  This option enables POSIX asynchronous I/O which may by used

  	  by some high performance threaded applications. Disabling
  	  this option saves about 7k.

  config IO_URING
  	bool "Enable IO uring support" if EXPERT

  	select IO_WQ

  	default y
  	help
  	  This option enables support for the io_uring interface, enabling
  	  applications to submit and complete IO through submission and
  	  completion rings that are shared between the kernel and application.

  config ADVISE_SYSCALLS
  	bool "Enable madvise/fadvise syscalls" if EXPERT
  	default y
  	help
  	  This option enables the madvise and fadvise syscalls, used by
  	  applications to advise the kernel about their future memory or file
  	  usage, improving performance. If building an embedded system where no
  	  applications use these syscalls, you can disable this option to save
  	  space.

  config HAVE_ARCH_USERFAULTFD_WP
  	bool
  	help
  	  Arch has userfaultfd write protection support

  config MEMBARRIER
  	bool "Enable membarrier() system call" if EXPERT
  	default y
  	help
  	  Enable the membarrier() system call that allows issuing memory
  	  barriers across all running threads, which can be used to distribute
  	  the cost of user-space memory barriers asymmetrically by transforming
  	  pairs of memory barriers into pairs consisting of membarrier() and a
  	  compiler barrier.
  
  	  If unsure, say Y.

  config KALLSYMS

  	bool "Load all symbols for debugging/ksymoops" if EXPERT
  	default y
  	help
  	  Say Y here to let the kernel print out symbolic crash information and
  	  symbolic stack backtraces. This increases the size of the kernel
  	  somewhat, as all symbols have to be loaded into the kernel image.

  
  config KALLSYMS_ALL
  	bool "Include all symbols in kallsyms"
  	depends on DEBUG_KERNEL && KALLSYMS
  	help

  	  Normally kallsyms only contains the symbols of functions for nicer
  	  OOPS messages and backtraces (i.e., symbols from the text and inittext
  	  sections). This is sufficient for most cases. And only in very rare
  	  cases (e.g., when a debugger is used) all symbols are required (e.g.,
  	  names of variables from the data sections, etc).

  	  This option makes sure that all symbols are loaded into the kernel
  	  image (i.e., symbols from all sections) in cost of increased kernel
  	  size (depending on the kernel configuration, it may be 300KiB or
  	  something like this).

  	  Say N unless you really need all symbols.

  
  config KALLSYMS_ABSOLUTE_PERCPU
  	bool
  	depends on KALLSYMS
  	default X86_64 && SMP
  
  config KALLSYMS_BASE_RELATIVE
  	bool
  	depends on KALLSYMS

  	default !IA64

  	help
  	  Instead of emitting them as absolute values in the native word size,
  	  emit the symbol references in the kallsyms table as 32-bit entries,
  	  each containing a relative value in the range [base, base + U32_MAX]
  	  or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either
  	  an absolute value in the range [0, S32_MAX] or a relative value in the
  	  range [base, base + S32_MAX], where base is the lowest relative symbol
  	  address encountered in the image.
  
  	  On 64-bit builds, this reduces the size of the address table by 50%,
  	  but more importantly, it results in entries whose values are build
  	  time constants, and no relocation pass is required at runtime to fix
  	  up the entries based on the runtime load address of the kernel.
  
  # end of the "standard kernel features (expert users)" menu
  
  # syscall, maps, verifier

  
  config BPF_LSM
  	bool "LSM Instrumentation with BPF"

  	depends on BPF_EVENTS

  	depends on BPF_SYSCALL
  	depends on SECURITY
  	depends on BPF_JIT
  	help
  	  Enables instrumentation of the security hooks with eBPF programs for
  	  implementing dynamic MAC and Audit Policies.
  
  	  If you are unsure how to answer this question, answer N.

  config BPF_SYSCALL
  	bool "Enable bpf() system call"

  	select BPF

  	select IRQ_WORK

  	select TASKS_TRACE_RCU

  	default n
  	help
  	  Enable the bpf() system call that allows to manipulate eBPF
  	  programs and maps via file descriptors.

  config ARCH_WANT_DEFAULT_BPF_JIT
  	bool

  config BPF_JIT_ALWAYS_ON
  	bool "Permanently enable BPF JIT and remove BPF interpreter"
  	depends on BPF_SYSCALL && HAVE_EBPF_JIT && BPF_JIT
  	help
  	  Enables BPF JIT and removes BPF interpreter to avoid
  	  speculative execution of BPF instructions by the interpreter

  config BPF_JIT_DEFAULT_ON
  	def_bool ARCH_WANT_DEFAULT_BPF_JIT || BPF_JIT_ALWAYS_ON
  	depends on HAVE_EBPF_JIT && BPF_JIT

  source "kernel/bpf/preload/Kconfig"

  config USERFAULTFD
  	bool "Enable userfaultfd() system call"

  	depends on MMU
  	help
  	  Enable the userfaultfd() system call that allows to intercept and
  	  handle page faults in userland.

  config ARCH_HAS_MEMBARRIER_CALLBACKS
  	bool

  config ARCH_HAS_MEMBARRIER_SYNC_CORE
  	bool

  config RSEQ
  	bool "Enable rseq() system call" if EXPERT
  	default y
  	depends on HAVE_RSEQ
  	select MEMBARRIER
  	help
  	  Enable the restartable sequences system call. It provides a
  	  user-space cache for the current CPU number value, which
  	  speeds up getting the current CPU number from user-space,
  	  as well as an ABI to speed up user-space operations on
  	  per-CPU data.
  
  	  If unsure, say Y.
  
  config DEBUG_RSEQ
  	default n
  	bool "Enabled debugging of rseq() system call" if EXPERT
  	depends on RSEQ && DEBUG_KERNEL
  	help
  	  Enable extra debugging checks for the rseq system call.
  
  	  If unsure, say N.

  config EMBEDDED
  	bool "Embedded system"

  	option allnoconfig_y

  	select EXPERT
  	help
  	  This option should be enabled if compiling the kernel for
  	  an embedded system so certain expert options are available
  	  for configuration.

  config HAVE_PERF_EVENTS

  	bool

  	help
  	  See tools/perf/design.txt for details.

  config PERF_USE_VMALLOC
  	bool
  	help
  	  See tools/perf/design.txt for details

  config PC104

  	bool "PC/104 support" if EXPERT

  	help
  	  Expose PC/104 form factor device drivers and options available for
  	  selection and configuration. Enable this option if your target
  	  machine has a PC/104 bus.

  menu "Kernel Performance Events And Counters"

  config PERF_EVENTS

  	bool "Kernel performance events and counters"

  	default y if PROFILING

  	depends on HAVE_PERF_EVENTS

  	select IRQ_WORK

  	select SRCU

  	help

  	  Enable kernel support for various performance events provided
  	  by software and hardware.

  	  Software events are supported either built-in or via the

  	  use of generic tracepoints.

  	  Most modern CPUs support performance events via performance
  	  counter registers. These registers count the number of certain

  	  types of hw events: such as instructions executed, cachemisses
  	  suffered, or branches mis-predicted - without slowing down the
  	  kernel or applications. These registers can also trigger interrupts
  	  when a threshold number of events have passed - and can thus be
  	  used to profile the code that runs on that CPU.

  	  The Linux Performance Event subsystem provides an abstraction of

  	  these software and hardware event capabilities, available via a

  	  system call and used by the "perf" utility in tools/perf/. It

  	  provides per task and per CPU counters, and it provides event
  	  capabilities on top of those.
  
  	  Say Y if unsure.

  config DEBUG_PERF_USE_VMALLOC
  	default n
  	bool "Debug: use vmalloc to back perf mmap() buffers"

  	depends on PERF_EVENTS && DEBUG_KERNEL && !PPC

  	select PERF_USE_VMALLOC
  	help

  	  Use vmalloc memory to back perf mmap() buffers.

  	  Mostly useful for debugging the vmalloc code on platforms
  	  that don't require it.

  	  Say N if unsure.

  endmenu

  config VM_EVENT_COUNTERS
  	default y

  	bool "Enable VM event counters for /proc/vmstat" if EXPERT

  	help

  	  VM event counters are needed for event counts to be shown.
  	  This option allows the disabling of the VM event counters

  	  on EXPERT systems.  /proc/vmstat will only show page counts

  	  if VM event counters are disabled.

  config SLUB_DEBUG
  	default y

  	bool "Enable SLUB debugging support" if EXPERT

  	depends on SLUB && SYSFS

  	help
  	  SLUB has extensive debug support features. Disabling these can
  	  result in significant savings in code size. This also disables
  	  SLUB sysfs support. /sys/slab will not exist and there will be
  	  no support for cache validation etc.

  config SLUB_MEMCG_SYSFS_ON
  	default n
  	bool "Enable memcg SLUB sysfs support by default" if EXPERT
  	depends on SLUB && SYSFS && MEMCG
  	help
  	  SLUB creates a directory under /sys/kernel/slab for each
  	  allocation cache to host info and debug files. If memory
  	  cgroup is enabled, each cache can have per memory cgroup
  	  caches. SLUB can create the same sysfs directories for these
  	  caches under /sys/kernel/slab/CACHE/cgroup but it can lead
  	  to a very high number of debug files being created. This is
  	  controlled by slub_memcg_sysfs boot parameter and this
  	  config option determines the parameter's default value.

  config COMPAT_BRK
  	bool "Disable heap randomization"
  	default y
  	help
  	  Randomizing heap placement makes heap exploits harder, but it
  	  also breaks ancient binaries (including anything libc5 based).
  	  This option changes the bootup default to heap randomization

  	  disabled, and can be overridden at runtime by setting

  	  /proc/sys/kernel/randomize_va_space to 2.
  
  	  On non-ancient distros (post-2000 ones) N is usually a safe choice.

  choice
  	prompt "Choose SLAB allocator"

  	default SLUB

  	help
  	   This option allows to select a slab allocator.
  
  config SLAB
  	bool "SLAB"

  	select HAVE_HARDENED_USERCOPY_ALLOCATOR

  	help
  	  The regular slab allocator that is established and known to work

  	  well in all environments. It organizes cache hot objects in

  	  per cpu and per node queues.

  
  config SLUB

  	bool "SLUB (Unqueued Allocator)"

  	select HAVE_HARDENED_USERCOPY_ALLOCATOR

  	help
  	   SLUB is a slab allocator that minimizes cache line usage
  	   instead of managing queues of cached objects (SLAB approach).
  	   Per cpu caching is realized using slabs of objects instead
  	   of queues of objects. SLUB can use memory efficiently

  	   and has enhanced diagnostics. SLUB is the default choice for
  	   a slab allocator.

  
  config SLOB

  	depends on EXPERT

  	bool "SLOB (Simple Allocator)"
  	help

  	   SLOB replaces the stock allocator with a drastically simpler
  	   allocator. SLOB is generally more space efficient but
  	   does not perform as well on large systems.

  
  endchoice

  config SLAB_MERGE_DEFAULT
  	bool "Allow slab caches to be merged"
  	default y
  	help
  	  For reduced kernel memory fragmentation, slab caches can be
  	  merged when they share the same size and other characteristics.
  	  This carries a risk of kernel heap overflows being able to
  	  overwrite objects from merged caches (and more easily control
  	  cache layout), which makes such heap attacks easier to exploit
  	  by attackers. By keeping caches unmerged, these kinds of exploits
  	  can usually only damage objects in the same cache. To disable
  	  merging at runtime, "slab_nomerge" can be passed on the kernel
  	  command line.

  config SLAB_FREELIST_RANDOM

  	bool "Randomize slab freelist"

  	depends on SLAB || SLUB

  	help

  	  Randomizes the freelist order used on creating new pages. This

  	  security feature reduces the predictability of the kernel slab
  	  allocator against heap overflows.

  config SLAB_FREELIST_HARDENED
  	bool "Harden slab freelist metadata"

  	depends on SLAB || SLUB

  	help
  	  Many kernel heap attacks try to target slab cache metadata and
  	  other infrastructure. This options makes minor performance

  	  sacrifices to harden the kernel slab allocator against common

  	  freelist exploit methods. Some slab implementations have more
  	  sanity-checking than others. This option is most effective with
  	  CONFIG_SLUB.

  config SHUFFLE_PAGE_ALLOCATOR
  	bool "Page allocator randomization"
  	default SLAB_FREELIST_RANDOM && ACPI_NUMA
  	help
  	  Randomization of the page allocator improves the average
  	  utilization of a direct-mapped memory-side-cache. See section
  	  5.2.27 Heterogeneous Memory Attribute Table (HMAT) in the ACPI
  	  6.2a specification for an example of how a platform advertises
  	  the presence of a memory-side-cache. There are also incidental
  	  security benefits as it reduces the predictability of page
  	  allocations to compliment SLAB_FREELIST_RANDOM, but the
  	  default granularity of shuffling on the "MAX_ORDER - 1" i.e,
  	  10th order of pages is selected based on cache utilization
  	  benefits on x86.
  
  	  While the randomization improves cache utilization it may
  	  negatively impact workloads on platforms without a cache. For
  	  this reason, by default, the randomization is enabled only
  	  after runtime detection of a direct-mapped memory-side-cache.
  	  Otherwise, the randomization may be force enabled with the
  	  'page_alloc.shuffle' kernel command line parameter.
  
  	  Say Y if unsure.

  config SLUB_CPU_PARTIAL
  	default y

  	depends on SLUB && SMP

  	bool "SLUB per cpu partial cache"
  	help

  	  Per cpu partial caches accelerate objects allocation and freeing

  	  that is local to a processor at the price of more indeterminism
  	  in the latency of the free. On overflow these caches will be cleared
  	  which requires the taking of locks that may cause latency spikes.
  	  Typically one would choose no for a realtime system.

  config MMAP_ALLOW_UNINITIALIZED
  	bool "Allow mmapped anonymous memory to be uninitialized"

  	depends on EXPERT && !MMU

  	default n
  	help
  	  Normally, and according to the Linux spec, anonymous memory obtained

  	  from mmap() has its contents cleared before it is passed to

  	  userspace.  Enabling this config option allows you to request that
  	  mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
  	  providing a huge performance boost.  If this option is not enabled,
  	  then the flag will be ignored.
  
  	  This is taken advantage of by uClibc's malloc(), and also by
  	  ELF-FDPIC binfmt's brk and stack allocator.
  
  	  Because of the obvious security issues, this option should only be
  	  enabled on embedded devices where you control what is run in
  	  userspace.  Since that isn't generally a problem on no-MMU systems,
  	  it is normally safe to say Y here.

  	  See Documentation/admin-guide/mm/nommu-mmap.rst for more information.

  config SYSTEM_DATA_VERIFICATION
  	def_bool n
  	select SYSTEM_TRUSTED_KEYRING
  	select KEYS
  	select CRYPTO

  	select CRYPTO_RSA

  	select ASYMMETRIC_KEY_TYPE
  	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE

  	select ASN1
  	select OID_REGISTRY
  	select X509_CERTIFICATE_PARSER
  	select PKCS7_MESSAGE_PARSER

  	help

  	  Provide PKCS#7 message verification using the contents of the system
  	  trusted keyring to provide public keys.  This then can be used for
  	  module verification, kexec image verification and firmware blob
  	  verification.

  config PROFILING

  	bool "Profiling support"

  	help
  	  Say Y here to enable the extended profiling support mechanisms used
  	  by profilers such as OProfile.

  #
  # Place an empty function call at each tracepoint site. Can be
  # dynamically changed for a probe function.
  #

  config TRACEPOINTS

  	bool

  endmenu		# General setup