linux-6.15/init/Kconfig

1 # SPDX-License-Identifier: GPL-2.0-only
3 	string
8 	  - Re-run Kconfig when the compiler is updated
13 	  - Ensure full rebuild when the compiler is updated
14 	    include/linux/compiler-version.h contains this option in the comment
16 	    auto-generated dependency. When the compiler is updated, syncconfig
20 	def_bool $(success,test "$(cc-name)" = GCC)
24 	default $(cc-version) if CC_IS_GCC
28 	def_bool $(success,test "$(cc-name)" = Clang)
32 	default $(cc-version) if CC_IS_CLANG
36 	def_bool $(success,test "$(as-name)" = GNU)
39 	def_bool $(success,test "$(as-name)" = LLVM)
45 	default $(as-version)
48 	def_bool $(success,test "$(ld-name)" = BFD)
52 	default $(ld-version) if LD_IS_BFD
56 	def_bool $(success,test "$(ld-name)" = LLD)
60 	default $(ld-version) if LD_IS_LLD
65 	default $(rustc-version)
75 	  Please see Documentation/rust/quick-start.rst for instructions on how
76 	  to satisfy the build requirements of Rust support.
83 	default $(rustc-llvm-version)
87 …default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLA…
88 …default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLA…
102 …nt x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
106 	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
107 …foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $…
110 …env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
113 	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
116 … '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
121 … __attribute__((__counted_by__(count))); };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror)
123 	# https://github.com/llvm/llvm-project/pull/110497
124 	# https://github.com/llvm/llvm-project/pull/112636
128 …[][4] __attribute__((__nonstring__)) = { };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror)
131 	# ld.lld prior to 21.0.0 did not support KEEP within an overlay description
132 	# https://github.com/llvm/llvm-project/pull/130661
143 	default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))
188 	  when they load they cannot be used due to missing HW support),
190 	  drivers to compile-test them.
201 	  enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
217 	  Compile test headers exported to user-space to ensure they are
218 	  self-contained, i.e. compilable as standalone units.
221 	  headers are self-contained, say Y here. Otherwise, choose N.
224 	string "Local version - append to kernel release"
226 	  Append an extra string to the end of your kernel version.
228 	  The string you set here will be appended after the contents of
230 	  object and source tree, in that order.  Your total string can
234 	bool "Automatically append version information to the version string"
242 	  A string of the format -gxxxxxxxx will be added to the localversion
243 	  if a git-based tree is found.  The string generated by this will be
247 	  (The actual string used here is the first 12 characters produced
250 	    $ git rev-parse --verify HEAD
255 	string "Build ID Salt"
292 	  The linux kernel is a kind of self-extracting executable.
342 	  filter (i386, x86_64, ARM, ARM64, RISC-V, big endian PowerPC,
362 	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
393 	string "Default init path"
403 	string "Default hostname"
419 	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
468 	  See Documentation/core-api/watch_queue.rst
491 	bool "Auditing support"
497 	  on architectures which support it.
542 	  this also enables accounting of stolen time on logically-partitioned
555 	  kernel-user boundaries using the context tracking subsystem.
642 	bool "Enable per-task delay accounting"
663 	bool "Enable per-task storage I/O accounting"
683 	  In kernels with cgroup support, cgroups (cgroup2 only) will
702 	  common scheduling-intense workloads in practice (such as
728 	tristate "Kernel .config support"
733 	  on-disk kernel.  This information can be extracted from the kernel
734 	  image file with the script scripts/extract-ikconfig and used as
750 	  This option enables access to the in-kernel headers that are generated during
753 	  kheaders.ko is built which can be loaded on-demand to get access to headers.
814 	  Add support for indexing of all printk formats known at compile time
862 	  the precision of clamping aggregation and tracking at run-time.
868 	  If a second 30% boosted task should be co-scheduled on the same CPU,
879 	  clamp buckets to trade off used memory for run-time tracking
887 # For architectures that want to enable the support for NUMA-affine scheduler
904 	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
907 	string
908 	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
909 	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
911 # Currently, disable gcc-10+ array-bounds globally.
912 # It's still broken in gcc-13, so no upper bound yet.
920 # Currently, disable -Wstringop-overflow for GCC globally.
933 # For architectures that know their GCC __int128 support is sound
939 # all cpu-local but of different latencies, such as SuperH.
950 	  This option adds support for automatic NUMA aware memory/task placement.
968 	bool "Control Group support"
971 	  This option adds support for grouping sets of processes together, for
975 		- Documentation/scheduler/sched-design-CFS.rst	(CFS)
976 		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
1041 	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
1075 	  See Documentation/scheduler/sched-bwc.rst for more information.
1084 	  schedule realtime tasks for non-root users until you allocate
1086 	  See Documentation/scheduler/sched-rt-group.rst for more information.
1116 	  specified task-specific clamp value is constrained by the cgroup
1165 	  controller includes important in-kernel memory consumers per default.
1178 	  support page reclaim, enforcing the limit at page fault time implies
1232 	  This option extends the perf per-cpu mode to restrict monitoring
1240 	bool "Support for eBPF programs attached to cgroups"
1264 	  /Documentation/admin-guide/cgroup-v2.rst.
1285 	bool "Namespaces support" if EXPERT
1328 	  user-space use the memory control groups to limit the amount
1337 	  Support process id namespaces.  This allows having multiple
1352 	bool "Checkpoint/restore support"
1378 	bool "Kernel->user space relay support (formerly relayfs)"
1381 	  This option enables support for relay interface support in
1390 	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1396 	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
1398 	  If RAM disk support (BLK_DEV_RAM) is also included, this
1399 	  also enables initial RAM disk (initrd) support and adds
1411 	bool "Boot config support"
1418 	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
1428 	  out even when the "bootconfig" kernel-boot parameter is omitted.
1430 	  make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
1441 	  image. But if the system doesn't support initrd, this option will
1447 	string "Embedded bootconfig file path"
1469 	  Build KUnit tests for initramfs. See Documentation/dev-tools/kunit
1476 	bool "Optimize for performance (-O2)"
1479 	  with the "-O2" compiler flag for best performance and most
1480 	  helpful compile-time warnings.
1483 	bool "Optimize for size (-Os)"
1485 	  Choosing this option will pass "-Os" to your compiler resulting
1504 	depends on $(cc-option,-ffunction-sections -fdata-sections)
1505 	depends on $(ld-option,--gc-sections)
1508 	  the linker by compiling with -ffunction-sections -fdata-sections,
1509 	  and linking with --gc-sections.
1511 	  This can reduce on disk and in-memory size of the kernel
1521 	depends on $(ld-option,--orphan-handling=warn)
1522 	depends on $(ld-option,--orphan-handling=error)
1525         string
1539 	  Enable support for /proc/sys/debug/exception-trace.
1544 	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1551 	  Enable support for /proc/sys/kernel/unaligned-trap
1557 	bool "Sysfs syscall support"
1571 	# Unhide debug options, to make the on-by-default options visible
1576 	  environments which can tolerate a "non-standard" kernel.
1580 	bool "Enable 16-bit UID system calls" if EXPERT
1584 	  This enables the legacy 16-bit UID syscall wrappers.
1587 	bool "Multiple users, groups and capabilities support" if EXPERT
1590 	  This option enables support for non-root users, groups and
1594 	  possible capabilities.  Saying N here also compiles out support for
1601 	bool "sgetmask/ssetmask syscalls support" if EXPERT
1627 	  This includes native support for POSIX timers to the kernel.
1642 	bool "Enable support for printk" if EXPERT
1645 	  This option enables normal printk support. Removing it
1652 	bool "BUG() support" if EXPERT
1655 	  Disabling this option eliminates support for BUG and WARN, reducing
1666 	  Enable support for generating core dumps. Disabling saves about 4k.
1670 	bool "Enable PC-Speaker support" if EXPERT
1675 	  This option allows to disable the internal PC-Speaker
1676 	  support, saving some memory.
1679 	bool "Enable smaller-sized data structures for core" if EXPERT
1686 	bool "Enable futex support" if EXPERT
1692 	  support for "fast userspace mutexes".  The resulting kernel may not
1693 	  run glibc-based applications correctly.
1701 	bool "Enable eventpoll support" if EXPERT
1705 	  support for epoll family of system calls.
1746 	bool "Enable AIO support" if EXPERT
1754 	bool "Enable IO uring support" if EXPERT
1758 	  This option enables support for the io_uring interface, enabling
1791 	  the cost of user-space memory barriers asymmetrically by transforming
1801 	  user-space with the ability to compare two processes to see if they
1814 	  user-space cache for the current CPU number value, which
1815 	  speeds up getting the current CPU number from user-space,
1816 	  as well as an ABI to speed up user-space operations on
1817 	  per-CPU data.
1841 	bool "PC/104 support" if EXPERT
1864 	  Start self-test automatically after system startup. Suggest executing
1899 	  A 64-bit kernel is required for the memory sealing feature.
1914 	  Documentation/userspace-api/mseal.rst
1938 	  Enable kernel support for various performance events provided
1941 	  Software events are supported either built-in or via the
1944 	  Most modern CPUs support performance events via performance
1947 	  suffered, or branches mis-predicted - without slowing down the
1949 	  when a threshold number of events have passed - and can thus be
1994 	bool "Profiling support"
1996 	  Say Y here to enable the extended profiling support mechanisms used
2000 	bool "Rust support"
2014 	  Enables Rust support in the kernel.
2016 	  This allows other Rust-related options, like drivers written in Rust,
2027 	string
2034 	string
2036 	# The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0
2037 	# (https://github.com/rust-lang/rust-bindgen/pull/2678) and 0.71.0
2038 	# (https://github.com/rust-lang/rust-bindgen/pull/3040). It can be removed
2041 	default "$(shell,$(BINDGEN) --version workaround-for-0.69.0 2>/dev/null)"
2108 # macros for not-implemented syscalls in kernel/sys_ni.c and
2109 # kernel/time/posix-stubs.c. All these overrides need to be available in