Merge tag 'trace-printf-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace...

[drm/drm-misc.git] / init / Kconfig

# SPDX-License-Identifier: GPL-2.0-only
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 compiler is updated
            include/linux/compiler-version.h contains this option in the comment
            line so fixdep adds include/config/CC_VERSION_TEXT 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 $(success,test "$(cc-name)" = GCC)

config GCC_VERSION
        int
        default $(cc-version) if CC_IS_GCC
        default 0

config CC_IS_CLANG
        def_bool $(success,test "$(cc-name)" = Clang)

config CLANG_VERSION
        int
        default $(cc-version) if CC_IS_CLANG
        default 0

config AS_IS_GNU
        def_bool $(success,test "$(as-name)" = GNU)

config AS_IS_LLVM
        def_bool $(success,test "$(as-name)" = LLVM)

config AS_VERSION
        int
        # Use clang version if this is the integrated assembler
        default CLANG_VERSION if AS_IS_LLVM
        default $(as-version)

config LD_IS_BFD
        def_bool $(success,test "$(ld-name)" = BFD)

config LD_VERSION
        int
        default $(ld-version) if LD_IS_BFD
        default 0

config LD_IS_LLD
        def_bool $(success,test "$(ld-name)" = LLD)

config LLD_VERSION
        int
        default $(ld-version) if LD_IS_LLD
        default 0

config RUSTC_VERSION
        int
        default $(rustc-version)
        help
          It does not depend on `RUST` since that one may need to use the version
          in a `depends on`.

config RUST_IS_AVAILABLE
        def_bool $(success,$(srctree)/scripts/rust_is_available.sh)
        help
          This shows whether a suitable Rust toolchain is available (found).

          Please see Documentation/rust/quick-start.rst for instructions on how
          to satisfy the build requirements of Rust support.

          In particular, the Makefile target 'rustavailable' is useful to check
          why the Rust toolchain is not being detected.

config RUSTC_LLVM_VERSION
        int
        default $(rustc-llvm-version)

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

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

# Fixed in GCC 14, 13.3, 12.4 and 11.5
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921
config GCC_ASM_GOTO_OUTPUT_BROKEN
        bool
        depends on CC_IS_GCC
        default y if GCC_VERSION < 110500
        default y if GCC_VERSION >= 120000 && GCC_VERSION < 120400
        default y if GCC_VERSION >= 130000 && GCC_VERSION < 130300

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

config CC_HAS_ASM_GOTO_TIED_OUTPUT
        depends on CC_HAS_ASM_GOTO_OUTPUT
        # Detect buggy gcc and clang, fixed in gcc-11 clang-14.
        def_bool $(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*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 CC_HAS_NO_PROFILE_FN_ATTR
        def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)

config CC_HAS_COUNTED_BY
        # TODO: when gcc 15 is released remove the build test and add
        # a gcc version check
        def_bool $(success,echo 'struct flex { int count; int array[] __attribute__((__counted_by__(count))); };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror)
        # clang needs to be at least 19.1.3 to avoid __bdos miscalculations
        # https://github.com/llvm/llvm-project/pull/110497
        # https://github.com/llvm/llvm-project/pull/112636
        depends on !(CC_IS_CLANG && CLANG_VERSION < 190103)

config PAHOLE_VERSION
        int
        default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))

config CONSTRUCTORS
        bool

config IRQ_WORK
        def_bool y if SMP

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 HAS_IOMEM
        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 WERROR
        bool "Compile the kernel with warnings as errors"
        default COMPILE_TEST
        help
          A kernel build should not cause any compiler warnings, and this
          enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
          to enforce that rule by default. Certain warnings from other tools
          such as the linker may be upgraded to errors with this option as
          well.

          However, if you have a new (or very old) compiler or linker with odd
          and unusual warnings, or you have some architecture with problems,
          you may need to disable this config option in order to
          successfully build the kernel.

          If in doubt, say Y.

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 12 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, ARM64, RISC-V, big endian 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.

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 SYSVIPC_COMPAT
        def_bool y
        depends on COMPAT && SYSVIPC

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/core-api/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 (for libc5 and earlier)"
        default ALPHA || M68K || SPARC
        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/bpf/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

# 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_USER
        depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
        depends on GENERIC_CLOCKEVENTS
        select VIRT_CPU_ACCOUNTING
        select CONTEXT_TRACKING_USER
        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_HW_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 HW pressure accounting in the
          scheduler. HW pressure is the value conveyed to the scheduler
          that reflects the reduction in CPU compute capacity resulted from
          HW throttling. HW throttling occurs when the performance of
          a CPU is capped due to high operating temperatures as an example.

          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_update_hw_pressure() and arch_scale_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"
        select KERNFS
        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 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
        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 0 if BASE_SMALL
        default 12
        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_INDEX
        bool "Printk indexing debugfs interface"
        depends on PRINTK && DEBUG_FS
        help
          Add support for indexing of all printk formats known at compile time
          at <debugfs>/printk/index/<module>.

          This can be used as part of maintaining daemons which monitor
          /dev/kmsg, as it permits auditing the printk formats present in a
          kernel, allowing detection of cases where monitored printks are
          changed or no longer present.

          There is no additional runtime cost to printk with this enabled.

#
# 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

config CC_IMPLICIT_FALLTHROUGH
        string
        default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
        default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)

# Currently, disable gcc-10+ array-bounds globally.
# It's still broken in gcc-13, so no upper bound yet.
config GCC10_NO_ARRAY_BOUNDS
        def_bool y

config CC_NO_ARRAY_BOUNDS
        bool
        default y if CC_IS_GCC && GCC_VERSION >= 90000 && GCC10_NO_ARRAY_BOUNDS

# Currently, disable -Wstringop-overflow for GCC globally.
config GCC_NO_STRINGOP_OVERFLOW
        def_bool y

config CC_NO_STRINGOP_OVERFLOW
        bool
        default y if CC_IS_GCC && GCC_NO_STRINGOP_OVERFLOW

config CC_STRINGOP_OVERFLOW
        bool
        default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW

#
# 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 && !PREEMPT_RT
        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.

config SLAB_OBJ_EXT
        bool

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 CGROUP_FAVOR_DYNMODS
        bool "Favor dynamic modification latency reduction by default"
        help
          This option enables the "favordynmods" mount option by default
          which reduces the latencies of dynamic cgroup modifications such
          as task migrations and controller on/offs at the cost of making
          hot path operations such as forks and exits more expensive.

          Say N if unsure.

config MEMCG
        bool "Memory controller"
        select PAGE_COUNTER
        select EVENTFD
        select SLAB_OBJ_EXT
        help
          Provides control over the memory footprint of tasks in a cgroup.

config MEMCG_V1
        bool "Legacy cgroup v1 memory controller"
        depends on MEMCG
        default n
        help
          Legacy cgroup v1 memory controller which has been deprecated by
          cgroup v2 implementation. The v1 is there for legacy applications
          which haven't migrated to the new cgroup v2 interface yet. If you
          do not have any such application then you are completely fine leaving
          this option disabled.

          Please note that feature set of the legacy memory controller is likely
          going to shrink due to deprecation process. New deployments with v1
          controller are highly discouraged.

          Say N if unsure.

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 GROUP_SCHED_WEIGHT
        def_bool n

config FAIR_GROUP_SCHED
        bool "Group scheduling for SCHED_OTHER"
        depends on CGROUP_SCHED
        select GROUP_SCHED_WEIGHT
        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.

config EXT_GROUP_SCHED
        bool
        depends on SCHED_CLASS_EXT && CGROUP_SCHED
        select GROUP_SCHED_WEIGHT
        default y

endif #CGROUP_SCHED

config SCHED_MM_CID
        def_bool y
        depends on SMP && RSEQ

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
        select UNION_FIND
        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 CPUSETS_V1
        bool "Legacy cgroup v1 cpusets controller"
        depends on CPUSETS
        default n
        help
          Legacy cgroup v1 cpusets controller which has been deprecated by
          cgroup v2 implementation. The v1 is there for legacy applications
          which haven't migrated to the new cgroup v2 interface yet. If you
          do not have any such application then you are completely fine leaving
          this option disabled.

          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_MISC
        bool "Misc resource controller"
        default n
        help
          Provides a controller for miscellaneous resources on a host.

          Miscellaneous scalar resources are the resources on the host system
          which cannot be abstracted like the other cgroups. This controller
          tracks and limits the miscellaneous resources used by a process
          attached to a cgroup hierarchy.

          For more information, please check misc cgroup section in
          /Documentation/admin-guide/cgroup-v2.rst.

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"
        depends on PROC_FS
        select PROC_CHILDREN
        select KCMP
        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 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 if !BOOT_CONFIG_EMBED
        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.

config BOOT_CONFIG_FORCE
        bool "Force unconditional bootconfig processing"
        depends on BOOT_CONFIG
        default y if BOOT_CONFIG_EMBED
        help
          With this Kconfig option set, BOOT_CONFIG processing is carried
          out even when the "bootconfig" kernel-boot parameter is omitted.
          In fact, with this Kconfig option set, there is no way to
          make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
          parameters.

          If unsure, say N.

config BOOT_CONFIG_EMBED
        bool "Embed bootconfig file in the kernel"
        depends on BOOT_CONFIG
        help
          Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the
          kernel. Usually, the bootconfig file is loaded with the initrd
          image. But if the system doesn't support initrd, this option will
          help you by embedding a bootconfig file while building the kernel.

          If unsure, say N.

config BOOT_CONFIG_EMBED_FILE
        string "Embedded bootconfig file path"
        depends on BOOT_CONFIG_EMBED
        help
          Specify a bootconfig file which will be embedded to the kernel.
          This bootconfig will be used if there is no initrd or no other
          bootconfig in the initrd.

config INITRAMFS_PRESERVE_MTIME
        bool "Preserve cpio archive mtimes in initramfs"
        default y
        help
          Each entry in an initramfs cpio archive carries an mtime value. When
          enabled, extracted cpio items take this mtime, with directory mtime
          setting deferred until after creation of any child entries.

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

config LD_ORPHAN_WARN_LEVEL
        string
        depends on LD_ORPHAN_WARN
        default "error" if WERROR
        default "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

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
        default 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 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_SMALL
        bool "Enable smaller-sized data structures for core" if EXPERT
        help
          Enabling 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
        depends on !(SPARC32 && SMP)
        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 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 GCOV_PROFILE_URING
        bool "Enable GCOV profiling on the io_uring subsystem"
        depends on GCOV_KERNEL
        help
          Enable GCOV profiling on the io_uring subsystem, to facilitate
          code coverage testing.

          If unsure, say N.

          Note that this will have a negative impact on the performance of
          the io_uring subsystem, hence this should only be enabled for
          specific test purposes.

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 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 KCMP
        bool "Enable kcmp() system call" if EXPERT
        help
          Enable the kernel resource comparison system call. It provides
          user-space with the ability to compare two processes to see if they
          share a common resource, such as a file descriptor or even virtual
          memory space.

          If unsure, say N.

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 "Enable 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 CACHESTAT_SYSCALL
        bool "Enable cachestat() system call" if EXPERT
        default y
        help
          Enable the cachestat system call, which queries the page cache
          statistics of a file (number of cached pages, dirty pages,
          pages marked for writeback, (recently) evicted pages).

          If unsure say Y here.

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.

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_SELFTEST
        bool "Test the basic functions and performance of kallsyms"
        depends on KALLSYMS
        default n
        help
          Test the basic functions and performance of some interfaces, such as
          kallsyms_lookup_name. It also calculates the compression rate of the
          kallsyms compression algorithm for the current symbol set.

          Start self-test automatically after system startup. Suggest executing
          "dmesg | grep kallsyms_selftest" to collect test results. "finish" is
          displayed in the last line, indicating that the test is complete.

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 if you want to
          enable kernel live patching, or other less common use cases (e.g.,
          when a debugger is used) all symbols are required (i.e., 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, or kernel live patching.

config KALLSYMS_ABSOLUTE_PERCPU
        bool
        depends on KALLSYMS
        default X86_64 && SMP

# end of the "standard kernel features (expert users)" menu

config ARCH_HAS_MEMBARRIER_CALLBACKS
        bool

config ARCH_HAS_MEMBARRIER_SYNC_CORE
        bool

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

config GUEST_PERF_EVENTS
        bool
        depends on HAVE_PERF_EVENTS

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

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
        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 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.

config RUST
        bool "Rust support"
        depends on HAVE_RUST
        depends on RUST_IS_AVAILABLE
        depends on !MODVERSIONS
        depends on !GCC_PLUGIN_RANDSTRUCT
        depends on !RANDSTRUCT
        depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE
        depends on !CFI_CLANG || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
        select CFI_ICALL_NORMALIZE_INTEGERS if CFI_CLANG
        depends on !CALL_PADDING || RUSTC_VERSION >= 108100
        depends on !KASAN_SW_TAGS
        depends on !(MITIGATION_RETHUNK && KASAN) || RUSTC_VERSION >= 108300
        help
          Enables Rust support in the kernel.

          This allows other Rust-related options, like drivers written in Rust,
          to be selected.

          It is also required to be able to load external kernel modules
          written in Rust.

          See Documentation/rust/ for more information.

          If unsure, say N.

config RUSTC_VERSION_TEXT
        string
        depends on RUST
        default "$(RUSTC_VERSION_TEXT)"
        help
          See `CC_VERSION_TEXT`.

config BINDGEN_VERSION_TEXT
        string
        depends on RUST
        # The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0
        # (https://github.com/rust-lang/rust-bindgen/pull/2678). It can be removed when
        # the minimum version is upgraded past that (0.69.1 already fixed the issue).
        default "$(shell,$(BINDGEN) --version workaround-for-0.69.0 2>/dev/null)"

#
# Place an empty function call at each tracepoint site. Can be
# dynamically changed for a probe function.
#
config TRACEPOINTS
        bool
        select TASKS_TRACE_RCU

source "kernel/Kconfig.kexec"

endmenu         # General setup

source "arch/Kconfig"

config RT_MUTEXES
        bool
        default y if PREEMPT_RT

config MODULE_SIG_FORMAT
        def_bool n
        select SYSTEM_DATA_VERIFICATION

source "kernel/module/Kconfig"

config INIT_ALL_POSSIBLE
        bool
        help
          Back when each arch used to define their own cpu_online_mask and
          cpu_possible_mask, some of them chose to initialize cpu_possible_mask
          with all 1s, and others with all 0s.  When they were centralised,
          it was better to provide this option than to break all the archs
          and have several arch maintainers pursuing me down dark alleys.

source "block/Kconfig"

config PREEMPT_NOTIFIERS
        bool

config PADATA
        depends on SMP
        bool

config ASN1
        tristate
        help
          Build a simple ASN.1 grammar compiler that produces a bytecode output
          that can be interpreted by the ASN.1 stream decoder and used to
          inform it as to what tags are to be expected in a stream and what
          functions to call on what tags.

source "kernel/Kconfig.locks"

config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
        bool

config ARCH_HAS_PREPARE_SYNC_CORE_CMD
        bool

config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
        bool

# It may be useful for an architecture to override the definitions of the
# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
# different calling convention for syscalls. They can also override the
# macros for not-implemented syscalls in kernel/sys_ni.c and
# kernel/time/posix-stubs.c. All these overrides need to be available in
# <asm/syscall_wrapper.h>.
config ARCH_HAS_SYSCALL_WRAPPER
        def_bool n