linux-6.8/init/Kconfig

1 # SPDX-License-Identifier: GPL-2.0-only
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
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))
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"
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
219 	    $ git rev-parse --verify HEAD
261 	  The linux kernel is a kind of self-extracting executable.
273 	  are low on disk space (embedded systems), but for whom ram
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.
387 	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
436 	  See Documentation/core-api/watch_queue.rst
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"
670 	  common scheduling-intense workloads in practice (such as
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.
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
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.
907 # all cpu-local but of different latencies, such as SuperH.
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.
1149 	  This option extends the perf per-cpu mode to restrict monitoring
1181 	  /Documentation/admin-guide/cgroup-v2.rst.
1245 	  user-space use the memory control groups to limit the amount
1295 	bool "Kernel->user space relay support (formerly relayfs)"
1313 	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
1332 	  complemental extension of kernel cmdline when booting.
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
1364 	string "Embedded bootconfig file path"
1367 	  Specify a bootconfig file which will be embedded to the kernel.
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)
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.
1495 	  This option enables support for non-root users, groups and
1543 	  Some embedded systems have no use for them and therefore they
1573 	  option for embedded systems with no facilities for reporting errors.
1585 	bool "Enable PC-Speaker support" if EXPERT
1590 	  This option allows to disable the internal PC-Speaker
1595 	bool "Enable full-sized data structures for core" if EXPERT
1609 	  run glibc-based applications correctly.
1684 	  usage, improving performance. If building an embedded system where no
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.
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%,
1845 	  Software events are supported either built-in or via the
1851 	  suffered, or branches mis-predicted - without slowing down the
1853 	  when a threshold number of events have passed - and can thus be
1915 	  This allows other Rust-related options, like drivers written in Rust,
1928 	default $(shell,command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n)
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