linux-6.8/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
68 	  Please see Documentation/rust/quick-start.rst for instructions on how
69 	  to satisfy the build requirements of Rust support.
76 …default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLA…
77 …default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLA…
81 …efault $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAG…
82 …efault $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAG…
85 …nt x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
89 	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
90 …foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $…
102 …env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
105 	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
108 … '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
112 	default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))
157 	  when they load they cannot be used due to missing HW support),
159 	  drivers to compile-test them.
170 	  enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
186 	  Compile test headers exported to user-space to ensure they are
187 	  self-contained, i.e. compilable as standalone units.
190 	  headers are self-contained, say Y here. Otherwise, choose N.
193 	string "Local version - append to kernel release"
195 	  Append an extra string to the end of your kernel version.
197 	  The string you set here will be appended after the contents of
199 	  object and source tree, in that order.  Your total string can
203 	bool "Automatically append version information to the version string"
211 	  A string of the format -gxxxxxxxx will be added to the localversion
212 	  if a git-based tree is found.  The string generated by this will be
216 	  (The actual string used here is the first 12 characters produced
219 	    $ git rev-parse --verify HEAD
224 	string "Build ID Salt"
261 	  The linux kernel is a kind of self-extracting executable.
311 	  filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
330 	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
361 	string "Default init path"
371 	string "Default hostname"
387 	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
436 	  See Documentation/core-api/watch_queue.rst
459 	bool "Auditing support"
465 	  on architectures which support it.
510 	  this also enables accounting of stolen time on logically-partitioned
523 	  kernel-user boundaries using the context tracking subsystem.
610 	bool "Enable per-task delay accounting"
631 	bool "Enable per-task storage I/O accounting"
651 	  In kernels with cgroup support, cgroups (cgroup2 only) will
670 	  common scheduling-intense workloads in practice (such as
696 	tristate "Kernel .config support"
701 	  on-disk kernel.  This information can be extracted from the kernel
702 	  image file with the script scripts/extract-ikconfig and used as
718 	  This option enables access to the in-kernel headers that are generated during
721 	  kheaders.ko is built which can be loaded on-demand to get access to headers.
782 	  Add support for indexing of all printk formats known at compile time
830 	  the precision of clamping aggregation and tracking at run-time.
836 	  If a second 30% boosted task should be co-scheduled on the same CPU,
847 	  clamp buckets to trade off used memory for run-time tracking
855 # For architectures that want to enable the support for NUMA-affine scheduler
872 	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
875 	string
876 	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
877 	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
879 # Currently, disable gcc-10+ array-bounds globally.
880 # It's still broken in gcc-13, so no upper bound yet.
888 # Currently, disable -Wstringop-overflow for GCC globally.
901 # For architectures that know their GCC __int128 support is sound
907 # all cpu-local but of different latencies, such as SuperH.
918 	  This option adds support for automatic NUMA aware memory/task placement.
933 	bool "Control Group support"
936 	  This option adds support for grouping sets of processes together, for
940 		- Documentation/scheduler/sched-design-CFS.rst	(CFS)
941 		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
993 	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
1023 	  See Documentation/scheduler/sched-bwc.rst for more information.
1032 	  schedule realtime tasks for non-root users until you allocate
1034 	  See Documentation/scheduler/sched-rt-group.rst for more information.
1058 	  specified task-specific clamp value is constrained by the cgroup
1097 	  controller includes important in-kernel memory consumers per default.
1110 	  support page reclaim, enforcing the limit at page fault time implies
1149 	  This option extends the perf per-cpu mode to restrict monitoring
1157 	bool "Support for eBPF programs attached to cgroups"
1181 	  /Documentation/admin-guide/cgroup-v2.rst.
1202 	bool "Namespaces support" if EXPERT
1245 	  user-space use the memory control groups to limit the amount
1254 	  Support process id namespaces.  This allows having multiple
1269 	bool "Checkpoint/restore support"
1295 	bool "Kernel->user space relay support (formerly relayfs)"
1298 	  This option enables support for relay interface support in
1307 	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1313 	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
1315 	  If RAM disk support (BLK_DEV_RAM) is also included, this
1316 	  also enables initial RAM disk (initrd) support and adds
1328 	bool "Boot config support"
1335 	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
1345 	  out even when the "bootconfig" kernel-boot parameter is omitted.
1347 	  make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
1358 	  image. But if the system doesn't support initrd, this option will
1364 	string "Embedded bootconfig file path"
1386 	bool "Optimize for performance (-O2)"
1389 	  with the "-O2" compiler flag for best performance and most
1390 	  helpful compile-time warnings.
1393 	bool "Optimize for size (-Os)"
1395 	  Choosing this option will pass "-Os" to your compiler resulting
1414 	depends on $(cc-option,-ffunction-sections -fdata-sections)
1415 	depends on $(ld-option,--gc-sections)
1418 	  the linker by compiling with -ffunction-sections -fdata-sections,
1419 	  and linking with --gc-sections.
1421 	  This can reduce on disk and in-memory size of the kernel
1431 	depends on $(ld-option,--orphan-handling=warn)
1432 	depends on $(ld-option,--orphan-handling=error)
1435         string
1449 	  Enable support for /proc/sys/debug/exception-trace.
1454 	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1461 	  Enable support for /proc/sys/kernel/unaligned-trap
1476 	# Unhide debug options, to make the on-by-default options visible
1481 	  environments which can tolerate a "non-standard" kernel.
1485 	bool "Enable 16-bit UID system calls" if EXPERT
1489 	  This enables the legacy 16-bit UID syscall wrappers.
1492 	bool "Multiple users, groups and capabilities support" if EXPERT
1495 	  This option enables support for non-root users, groups and
1499 	  possible capabilities.  Saying N here also compiles out support for
1506 	bool "sgetmask/ssetmask syscalls support" if EXPERT
1516 	bool "Sysfs syscall support" if EXPERT
1542 	  This includes native support for POSIX timers to the kernel.
1557 	bool "Enable support for printk" if EXPERT
1560 	  This option enables normal printk support. Removing it
1567 	bool "BUG() support" if EXPERT
1570 	  Disabling this option eliminates support for BUG and WARN, reducing
1581 	  Enable support for generating core dumps. Disabling saves about 4k.
1585 	bool "Enable PC-Speaker support" if EXPERT
1590 	  This option allows to disable the internal PC-Speaker
1591 	  support, saving some memory.
1595 	bool "Enable full-sized data structures for core" if EXPERT
1602 	bool "Enable futex support" if EXPERT
1608 	  support for "fast userspace mutexes".  The resulting kernel may not
1609 	  run glibc-based applications correctly.
1617 	bool "Enable eventpoll support" if EXPERT
1621 	  support for epoll family of system calls.
1662 	bool "Enable AIO support" if EXPERT
1670 	bool "Enable IO uring support" if EXPERT
1674 	  This option enables support for the io_uring interface, enabling
1694 	  the cost of user-space memory barriers asymmetrically by transforming
1704 	  user-space with the ability to compare two processes to see if they
1717 	  user-space cache for the current CPU number value, which
1718 	  speeds up getting the current CPU number from user-space,
1719 	  as well as an ABI to speed up user-space operations on
1720 	  per-CPU data.
1744 	bool "PC/104 support" if EXPERT
1767 	  Start self-test automatically after system startup. Suggest executing
1800 	  emit the symbol references in the kallsyms table as 32-bit entries,
1807 	  On 64-bit builds, this reduces the size of the address table by 50%,
1842 	  Enable kernel support for various performance events provided
1845 	  Software events are supported either built-in or via the
1848 	  Most modern CPUs support performance events via performance
1851 	  suffered, or branches mis-predicted - without slowing down the
1853 	  when a threshold number of events have passed - and can thus be
1898 	bool "Profiling support"
1900 	  Say Y here to enable the extended profiling support mechanisms used
1904 	bool "Rust support"
1913 	  Enables Rust support in the kernel.
1915 	  This allows other Rust-related options, like drivers written in Rust,
1926 	string
1928 	default $(shell,command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n)
1931 	string
1933 	default $(shell,command -v $(BINDGEN) >/dev/null 2>&1 && $(BINDGEN) --version || echo n)
2001 # macros for not-implemented syscalls in kernel/sys_ni.c and
2002 # kernel/time/posix-stubs.c. All these overrides need to be available in