Lines Matching +full:default +full:- +full:on
1 # SPDX-License-Identifier: GPL-2.0-only
4 default "$(CC_VERSION_TEXT)"
8 - Re-run Kconfig when the compiler is updated
9 The 'default' property references the environment variable,
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
25 default 0
28 def_bool $(success,test "$(cc-name)" = Clang)
32 default $(cc-version) if CC_IS_CLANG
33 default 0
36 def_bool $(success,test "$(as-name)" = GNU)
39 def_bool $(success,test "$(as-name)" = LLVM)
44 default CLANG_VERSION if AS_IS_LLVM
45 default $(as-version)
48 def_bool $(success,test "$(ld-name)" = BFD)
52 default $(ld-version) if LD_IS_BFD
53 default 0
56 def_bool $(success,test "$(ld-name)" = LLD)
60 default $(ld-version) if LD_IS_LLD
61 default 0
65 default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
66 default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag))
70 …default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag) -static) if 6…
71 default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag) -static)
74 def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
77 depends on CC_HAS_ASM_GOTO
78 …nt x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
81 …env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
84 def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
87 … '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
115 depends on BROKEN || !SMP
116 default y
120 default 32 if !UML
121 default 128 if UML
128 depends on HAS_IOMEM
130 Some drivers can be compiled on a different platform than they are
131 intended to be run on. Despite they cannot be loaded there (or even
134 drivers to compile-test them.
142 default COMPILE_TEST
145 enables the '-Werror' flag to enforce that rule by default.
156 depends on HEADERS_INSTALL && CC_CAN_LINK
158 Compile test headers exported to user-space to ensure they are
159 self-contained, i.e. compilable as standalone units.
162 headers are self-contained, say Y here. Otherwise, choose N.
165 string "Local version - append to kernel release"
176 default y
177 depends on !COMPILE_TEST
183 A string of the format -gxxxxxxxx will be added to the localversion
184 if a git-based tree is found. The string generated by this will be
191 $ git rev-parse --verify HEAD
197 default ""
202 build is unique between builds. It's safe to leave the default.
230 default KERNEL_GZIP
231 …depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KER…
233 The linux kernel is a kind of self-extracting executable.
245 are low on disk space (embedded systems), but for whom ram
252 depends on HAVE_KERNEL_GZIP
259 depends on HAVE_KERNEL_BZIP2
269 depends on HAVE_KERNEL_LZMA
277 depends on HAVE_KERNEL_XZ
282 comparison to gzip. On architectures for which there is a BCJ
283 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
292 depends on HAVE_KERNEL_LZO
300 depends on HAVE_KERNEL_LZ4
302 LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
312 depends on HAVE_KERNEL_ZSTD
322 depends on HAVE_KERNEL_UNCOMPRESSED
333 string "Default init path"
334 default ""
336 This option determines the default init for the system if no init=
337 option is passed on the kernel command line. If the requested path is
338 not present, we will still then move on to attempting further
343 string "Default hostname"
344 default "(none)"
346 This option determines the default system hostname before userspace
348 but you may wish to use a different default here to make a minimal
360 depends on MMU && BLOCK && !ARCH_NO_SWAP
361 default y
376 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
385 depends on SYSVIPC
386 depends on SYSCTL
387 default y
391 depends on NET
401 operations on message queues.
407 depends on POSIX_MQUEUE
408 depends on SYSCTL
409 default y
413 default n
425 depends on MMU
426 default y
439 system call. If you intend to run programs built on libc5 or
445 depends on NET
450 on architectures which support it.
457 depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
472 default TICK_CPU_ACCOUNTING if !PPC64
473 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
478 depends on !S390 && !NO_HZ_FULL
481 statistics about user, system and idle time spent on per jiffies
488 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
492 accounting. This is done by reading a CPU counter on each
493 kernel entry and exit and on transitions within the kernel
496 this also enables accounting of stolen time on logically-partitioned
501 depends on HAVE_CONTEXT_TRACKING
502 depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
503 depends on GENERIC_CLOCKEVENTS
507 Select this option to enable task and CPU time accounting on full
509 kernel-user boundaries using the context tracking subsystem.
513 For now this is only useful if you are working on the full
522 depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
525 accounting. This is done by reading a timestamp on each
533 depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
534 depends on SMP
538 default y if ARM && ARM_CPU_TOPOLOGY
539 default y if ARM64
540 depends on SMP
541 depends on CPU_FREQ_THERMAL
550 i.e. put less load on throttled CPUs than on non/less throttled ones.
557 depends on MULTIUSER
571 depends on BSD_PROCESS_ACCT
572 default n
583 depends on NET
584 depends on MULTIUSER
585 default n
591 space on task exit.
596 bool "Enable per-task delay accounting"
597 depends on TASKSTATS
600 Collect information on time spent by a task waiting for system
609 depends on TASKSTATS
617 bool "Enable per-task storage I/O accounting"
618 depends on TASK_XACCT
620 Collect information on the number of bytes of storage I/O which this
646 default n
647 depends on PSI
650 per default but can be enabled through passing psi=1 on the
655 common scheduling-intense workloads in practice (such as
668 depends on SMP || COMPILE_TEST
669 default y
682 default n
690 on-disk kernel. This information can be extracted from the kernel
691 image file with the script scripts/extract-ikconfig and used as
698 depends on IKCONFIG && PROC_FS
705 depends on SYSFS
707 This option enables access to the in-kernel headers that are generated during
710 kheaders.ko is built which can be loaded on-demand to get access to headers.
716 default 17
717 depends on PRINTK
734 depends on SMP
736 default 12 if !BASE_SMALL
737 default 0 if BASE_SMALL
738 depends on PRINTK
740 This option allows to increase the default ring buffer size
747 the original static one is unused. It makes sense only on systems
749 contributions is greater than the half of the default kernel ring
750 buffer as defined by LOG_BUF_SHIFT. The default values are set
769 int "Temporary per-CPU printk log buffer size (12 => 4KB, 13 => 8KB)"
771 default 13
772 depends on PRINTK
774 Select the size of an alternate printk per-CPU buffer where messages
776 be NMI messages, another one - printk recursion. The messages are
782 8KB if you want to be on the safe side.
794 depends on PRINTK && DEBUG_FS
819 depends on CPU_FREQ_GOV_SCHEDUTIL
822 of each CPU based on RUNNABLE tasks scheduled on that CPU.
838 default 5
839 depends on UCLAMP_TASK
844 the precision of clamping aggregation and tracking at run-time.
850 If a second 30% boosted task should be co-scheduled on the same CPU,
859 CPU. If that should be considered not acceptable on certain systems,
861 clamp buckets to trade off used memory for run-time tracking
864 If in doubt, use the default value.
869 # For architectures that want to enable the support for NUMA-affine scheduler
878 # must provide guarantees on what happens if a clean TLB cache entry is
886 def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
895 # all cpu-local but of different latencies, such as SuperH.
902 depends on ARCH_SUPPORTS_NUMA_BALANCING
903 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
904 depends on SMP && NUMA && MIGRATION
907 The mechanism is quite primitive and is based on migrating memory when
908 it has references to the node the task is running on.
910 This system will be inactive on UMA systems.
914 default y
915 depends on NUMA_BALANCING
917 If set, automatic NUMA balancing will be enabled if running on a NUMA
928 - Documentation/scheduler/sched-design-CFS.rst (CFS)
929 - Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
948 depends on MEMCG && SWAP
949 default y
953 depends on MEMCG && !SLOB
954 default y
958 depends on BLOCK
959 default n
968 block layer to implement upper limit in IO rates on a device.
976 See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
980 depends on MEMCG && BLK_CGROUP
981 default y
985 default n
994 depends on CGROUP_SCHED
995 default CGROUP_SCHED
999 depends on FAIR_GROUP_SCHED
1000 default n
1006 See Documentation/scheduler/sched-bwc.rst for more information.
1010 depends on CGROUP_SCHED
1011 default n
1015 schedule realtime tasks for non-root users until you allocate
1017 See Documentation/scheduler/sched-rt-group.rst for more information.
1023 depends on CGROUP_SCHED
1024 depends on UCLAMP_TASK
1025 default n
1028 of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
1037 specified task-specific clamp value is constrained by the cgroup
1076 controller includes important in-kernel memory consumers per default.
1082 depends on HUGETLB_PAGE
1084 default n
1087 When you enable this, you can put a per cgroup limit on HugeTLB usage.
1098 depends on SMP
1103 This is primarily useful on large SMP or NUMA systems.
1109 depends on CPUSETS
1110 default y
1126 depends on PERF_EVENTS
1128 This option extends the perf per-cpu mode to restrict monitoring
1129 to threads which belong to the cgroup specified and run on the
1137 depends on BPF_SYSCALL
1143 In which context these programs are accessed depends on the type
1145 BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
1150 default n
1152 Provides a controller for miscellaneous resources on a host.
1154 Miscellaneous scalar resources are the resources on the host system
1160 /Documentation/admin-guide/cgroup-v2.rst.
1164 default n
1165 depends on DEBUG_KERNEL
1176 default n
1182 depends on MULTIUSER
1183 default !EXPERT
1194 default y
1201 depends on GENERIC_VDSO_TIME_NS
1202 default y
1209 depends on (SYSVIPC || POSIX_MQUEUE)
1210 default y
1217 default n
1224 user-space use the memory control groups to limit the amount
1231 default y
1239 depends on NET
1240 default y
1251 default n
1274 depends on SYSFS
1275 default n
1284 This option allows new kernels to run on old distributions and tools,
1288 Recent distributions and userspace tools after 2009/2010 depend on
1292 Only if you are using a new kernel on an old distribution, you might
1296 bool "Enable deprecated sysfs features by default"
1297 default n
1298 depends on SYSFS
1299 depends on SYSFS_DEPRECATED
1301 Enable deprecated sysfs by default.
1306 Only if you are using a new kernel on an old distribution, you might
1311 bool "Kernel->user space relay support (formerly relayfs)"
1329 etc. See <file:Documentation/admin-guide/initrd.rst> for details.
1333 15 Kbytes (more on some other architectures) to the kernel size.
1351 See <file:Documentation/admin-guide/bootconfig.rst> for details.
1357 default CC_OPTIMIZE_FOR_PERFORMANCE
1360 bool "Optimize for performance (-O2)"
1362 This is the default optimization level for the kernel, building
1363 with the "-O2" compiler flag for best performance and most
1364 helpful compile-time warnings.
1367 bool "Optimize more for performance (-O3)"
1368 depends on ARC
1370 Choosing this option will pass "-O3" to your compiler to optimize
1374 bool "Optimize for size (-Os)"
1376 Choosing this option will pass "-Os" to your compiler resulting
1393 depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
1394 depends on EXPERT
1395 depends on $(cc-option,-ffunction-sections -fdata-sections)
1396 depends on $(ld-option,--gc-sections)
1399 the linker by compiling with -ffunction-sections -fdata-sections,
1400 and linking with --gc-sections.
1402 This can reduce on disk and in-memory size of the kernel
1404 on small systems. This has the possibility of introducing
1411 depends on ARCH_WANT_LD_ORPHAN_WARN
1412 depends on !LD_IS_LLD || LLD_VERSION >= 110000
1413 depends on $(ld-option,--orphan-handling=warn)
1424 Enable support for /proc/sys/debug/exception-trace.
1429 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1431 about unaligned access emulation going on under the hood.
1436 Enable support for /proc/sys/kernel/unaligned-trap
1444 # interpreter that classic socket filters depend on
1450 # Unhide debug options, to make the on-by-default options visible
1455 environments which can tolerate a "non-standard" kernel.
1459 bool "Enable 16-bit UID system calls" if EXPERT
1460 depends on HAVE_UID16 && MULTIUSER
1461 default y
1463 This enables the legacy 16-bit UID syscall wrappers.
1467 default y
1469 This option enables support for non-root users, groups and
1484 no longer supported in libc but still enabled by default in some
1487 If unsure, leave the default option here.
1491 default y
1502 default y
1514 default y
1530 default y
1542 default y
1551 depends on COREDUMP
1552 default y
1559 bool "Enable PC-Speaker support" if EXPERT
1560 depends on HAVE_PCSPKR_PLATFORM
1562 default y
1564 This option allows to disable the internal PC-Speaker
1568 default y
1569 bool "Enable full-sized data structures for core" if EXPERT
1572 kernel data structures. This saves memory on small machines,
1577 default y
1582 run glibc-based applications correctly.
1586 depends on FUTEX && RT_MUTEXES
1587 default y
1591 depends on FUTEX
1599 default y
1606 default y
1609 on a file descriptor.
1615 default y
1618 events on a file descriptor.
1624 default y
1633 default y
1634 depends on MMU
1640 which may be appropriate on small systems without swap.
1644 default y
1653 default y
1661 default y
1681 default y
1685 the cost of user-space memory barriers asymmetrically by transforming
1693 default y
1701 depends on DEBUG_KERNEL && KALLSYMS
1711 size (depending on the kernel configuration, it may be 300KiB or
1718 depends on KALLSYMS
1719 default X86_64 && SMP
1723 depends on KALLSYMS
1724 default !IA64
1727 emit the symbol references in the kallsyms table as 32-bit entries,
1734 On 64-bit builds, this reduces the size of the address table by 50%,
1737 up the entries based on the runtime load address of the kernel.
1745 depends on MMU
1760 user-space with the ability to compare two processes to see if they
1768 default y
1769 depends on HAVE_RSEQ
1773 user-space cache for the current CPU number value, which
1774 speeds up getting the current CPU number from user-space,
1775 as well as an ABI to speed up user-space operations on
1776 per-CPU data.
1781 default n
1783 depends on RSEQ && DEBUG_KERNEL
1818 default y if PROFILING
1819 depends on HAVE_PERF_EVENTS
1826 Software events are supported either built-in or via the
1832 suffered, or branches mis-predicted - without slowing down the
1834 when a threshold number of events have passed - and can thus be
1835 used to profile the code that runs on that CPU.
1841 capabilities on top of those.
1846 default n
1848 depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
1853 Mostly useful for debugging the vmalloc code on platforms
1861 default y
1866 on EXPERT systems. /proc/vmstat will only show page counts
1870 default y
1872 depends on SLUB && SYSFS
1881 default y
1885 This option changes the bootup default to heap randomization
1889 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1893 default SLUB
1913 and has enhanced diagnostics. SLUB is the default choice for
1917 depends on EXPERT
1922 does not perform as well on large systems.
1928 default y
1937 merging at runtime, "slab_nomerge" can be passed on the kernel
1942 depends on SLAB || SLUB
1944 Randomizes the freelist order used on creating new pages. This
1950 depends on SLAB || SLUB
1956 sanity-checking than others. This option is most effective with
1961 default SLAB_FREELIST_RANDOM && ACPI_NUMA
1964 utilization of a direct-mapped memory-side-cache. See section
1967 the presence of a memory-side-cache. There are also incidental
1970 default granularity of shuffling on the "MAX_ORDER - 1" i.e,
1971 10th order of pages is selected based on cache utilization
1972 benefits on x86.
1975 negatively impact workloads on platforms without a cache. For
1976 this reason, by default, the randomization is enabled only
1977 after runtime detection of a direct-mapped memory-side-cache.
1984 default y
1985 depends on SLUB && SMP
1990 in the latency of the free. On overflow these caches will be cleared
1996 depends on EXPERT && !MMU
1997 default n
2007 ELF-FDPIC binfmt's brk and stack allocator.
2010 enabled on embedded devices where you control what is run in
2011 userspace. Since that isn't generally a problem on no-MMU systems,
2014 See Documentation/admin-guide/mm/nommu-mmap.rst for more information.
2056 default 0 if BASE_FULL
2057 default 1 if !BASE_FULL
2088 default n
2091 --force). Forced module loading sets the 'F' (forced) taint flag and
2104 depends on MODULE_UNLOAD
2108 without waiting for anyone to stop using it (using the -f option to
2124 default HAVE_ASM_MODVERSIONS && MODVERSIONS
2132 depends on MODVERSIONS
2151 <file:Documentation/admin-guide/module-signing.rst>.
2159 another LSM - otherwise unsigned modules will be loadable regardless
2169 depends on MODULE_SIG
2176 default y
2177 depends on MODULE_SIG || IMA_APPRAISE_MODSIG
2180 modules must be signed manually, using the scripts/sign-file tool.
2182 comment "Do not forget to sign required modules with scripts/sign-file"
2183 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
2187 depends on MODULE_SIG || IMA_APPRAISE_MODSIG
2193 the signature on that module.
2196 bool "Sign modules with SHA-1"
2200 bool "Sign modules with SHA-224"
2204 bool "Sign modules with SHA-256"
2208 bool "Sign modules with SHA-384"
2212 bool "Sign modules with SHA-512"
2219 depends on MODULE_SIG || IMA_APPRAISE_MODSIG
2220 default "sha1" if MODULE_SIG_SHA1
2221 default "sha224" if MODULE_SIG_SHA224
2222 default "sha256" if MODULE_SIG_SHA256
2223 default "sha384" if MODULE_SIG_SHA384
2224 default "sha512" if MODULE_SIG_SHA512
2242 corresponding algorithm. module-init-tools MAY support gzip, and kmod
2291 default "/sbin/modprobe"
2303 depends on !COMPILE_TEST
2307 on the set of modules being selected in your kernel configuration,
2315 If unsure, or if you need to build out-of-tree modules, say N.
2319 depends on TRIM_UNUSED_KSYMS
2321 By default, all unused exported symbols will be un-exported from the
2325 exported at all times, even in absence of in-tree users. The value to
2334 depends on PERF_EVENTS || TRACING || CFI_CLANG
2351 depends on SMP
2360 functions to call on what tags.
2374 # macros for not-implemented syscalls in kernel/sys_ni.c and
2375 # kernel/time/posix-stubs.c. All these overrides need to be available in