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 …def_bool $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0;…
89 	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
90 …$(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*x) ::: bar); return *x; b…
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.
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>),
427 	bool "General notification queue"
431 	  This is a general notification queue for the kernel to pass events to
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.
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
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
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.
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