1 # SPDX-License-Identifier: GPL-2.0-only
3 # Copyright (C) 2006-2014 OpenWrt.org
5 config KERNEL_BUILD_USER
6 string "Custom Kernel Build User Name"
7 default "builder" if BUILDBOT
10 Sets the Kernel build user string, which for example will be returned
11 by 'uname -a' on running systems.
12 If not set, uses system user at build time.
14 config KERNEL_BUILD_DOMAIN
15 string "Custom Kernel Build Domain Name"
16 default "buildhost" if BUILDBOT
19 Sets the Kernel build domain string, which for example will be
20 returned by 'uname -a' on running systems.
21 If not set, uses system hostname at build time.
24 bool "Enable support for printk"
28 bool "Support for paging of anonymous memory (swap)"
29 default y if !SMALL_FLASH
31 config KERNEL_PROC_STRIPPED
32 bool "Strip non-essential /proc functionality to reduce code size"
33 default y if SMALL_FLASH
35 config KERNEL_DEBUG_FS
36 bool "Compile the kernel with debug filesystem enabled"
39 debugfs is a virtual file system that kernel developers use to put
40 debugging files into. Enable this option to be able to read and
41 write to these files. Many common debugging facilities, such as
42 ftrace, require the existence of debugfs.
44 config KERNEL_MIPS_FP_SUPPORT
46 default y if TARGET_pistachio
51 depends on (arm || aarch64)
53 config KERNEL_X86_VSYSCALL_EMULATION
54 bool "Enable vsyscall emulation"
58 This enables emulation of the legacy vsyscall page. Disabling
59 it is roughly equivalent to booting with vsyscall=none, except
60 that it will also disable the helpful warning if a program
61 tries to use a vsyscall. With this option set to N, offending
62 programs will just segfault, citing addresses of the form
65 This option is required by many programs built before 2013, and
66 care should be used even with newer programs if set to N.
68 Disabling this option saves about 7K of kernel size and
69 possibly 4K of additional runtime pagetable memory.
71 config KERNEL_PERF_EVENTS
72 bool "Compile the kernel with performance events and counters"
74 select KERNEL_ARM_PMU if (arm || aarch64)
76 config KERNEL_PROFILING
77 bool "Compile the kernel with profiling enabled"
79 select KERNEL_PERF_EVENTS
81 Enable the extended profiling support mechanisms used by profilers such
85 bool "Compile the kernel with undefined behaviour sanity checker"
87 This option enables undefined behaviour sanity checker
88 Compile-time instrumentation is used to detect various undefined
89 behaviours in runtime. Various types of checks may be enabled
90 via boot parameter ubsan_handle
91 (see: Documentation/dev-tools/ubsan.rst).
93 config KERNEL_UBSAN_SANITIZE_ALL
94 bool "Enable instrumentation for the entire kernel"
95 depends on KERNEL_UBSAN
98 This option activates instrumentation for the entire kernel.
99 If you don't enable this option, you have to explicitly specify
100 UBSAN_SANITIZE := y for the files/directories you want to check for UB.
101 Enabling this option will get kernel image size increased
104 config KERNEL_UBSAN_ALIGNMENT
105 bool "Enable checking of pointers alignment"
106 depends on KERNEL_UBSAN
108 This option enables detection of unaligned memory accesses.
109 Enabling this option on architectures that support unaligned
110 accesses may produce a lot of false positives.
112 config KERNEL_UBSAN_BOUNDS
113 bool "Perform array index bounds checking"
114 depends on KERNEL_UBSAN
116 This option enables detection of directly indexed out of bounds array
117 accesses, where the array size is known at compile time. Note that
118 this does not protect array overflows via bad calls to the
119 {str,mem}*cpy() family of functions (that is addressed by
122 config KERNEL_UBSAN_NULL
123 bool "Enable checking of null pointers"
124 depends on KERNEL_UBSAN
126 This option enables detection of memory accesses via a
129 config KERNEL_UBSAN_TRAP
130 bool "On Sanitizer warnings, abort the running kernel code"
131 depends on KERNEL_UBSAN
133 Building kernels with Sanitizer features enabled tends to grow the
134 kernel size by around 5%, due to adding all the debugging text on
135 failure paths. To avoid this, Sanitizer instrumentation can just
136 issue a trap. This reduces the kernel size overhead but turns all
137 warnings (including potentially harmless conditions) into full
138 exceptions that abort the running kernel code (regardless of context,
139 locks held, etc), which may destabilize the system. For some system
140 builders this is an acceptable trade-off.
143 bool "Compile the kernel with KASan: runtime memory debugger"
144 select KERNEL_SLUB_DEBUG
145 depends on (x86_64 || aarch64)
147 Enables kernel address sanitizer - runtime memory debugger,
148 designed to find out-of-bounds accesses and use-after-free bugs.
149 This is strictly a debugging feature and it requires a gcc version
150 of 4.9.2 or later. Detection of out of bounds accesses to stack or
151 global variables requires gcc 5.0 or later.
152 This feature consumes about 1/8 of available memory and brings about
153 ~x3 performance slowdown.
154 For better error detection enable CONFIG_STACKTRACE.
155 Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
156 (the resulting kernel does not boot).
158 config KERNEL_KASAN_EXTRA
159 bool "KAsan: extra checks"
160 depends on KERNEL_KASAN && KERNEL_DEBUG_KERNEL
162 This enables further checks in the kernel address sanitizer, for now
163 it only includes the address-use-after-scope check that can lead
164 to excessive kernel stack usage, frame size warnings and longer
166 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 has more
168 config KERNEL_KASAN_VMALLOC
169 bool "Back mappings in vmalloc space with real shadow memory"
170 depends on KERNEL_KASAN
172 By default, the shadow region for vmalloc space is the read-only
173 zero page. This means that KASAN cannot detect errors involving
176 Enabling this option will hook in to vmap/vmalloc and back those
177 mappings with real shadow memory allocated on demand. This allows
178 for KASAN to detect more sorts of errors (and to support vmapped
179 stacks), but at the cost of higher memory usage.
181 This option depends on HAVE_ARCH_KASAN_VMALLOC, but we can't
182 depend on that in here, so it is possible that enabling this
186 config KERNEL_KASAN_GENERIC
189 config KERNEL_KASAN_SW_TAGS
194 prompt "Instrumentation type"
195 depends on KERNEL_KASAN
196 default KERNEL_KASAN_OUTLINE
198 config KERNEL_KASAN_OUTLINE
199 bool "Outline instrumentation"
201 Before every memory access compiler insert function call
202 __asan_load*/__asan_store*. These functions performs check
203 of shadow memory. This is slower than inline instrumentation,
204 however it doesn't bloat size of kernel's .text section so
207 config KERNEL_KASAN_INLINE
208 bool "Inline instrumentation"
210 Compiler directly inserts code checking shadow memory before
211 memory accesses. This is faster than outline (in some workloads
212 it gives about x2 boost over outline instrumentation), but
213 make kernel's .text size much bigger.
214 This requires a gcc version of 5.0 or later.
219 bool "Compile the kernel with code coverage for fuzzing"
220 select KERNEL_DEBUG_FS
222 KCOV exposes kernel code coverage information in a form suitable
223 for coverage-guided fuzzing (randomized testing).
225 If RANDOMIZE_BASE is enabled, PC values will not be stable across
226 different machines and across reboots. If you need stable PC values,
227 disable RANDOMIZE_BASE.
229 For more details, see Documentation/kcov.txt.
231 config KERNEL_KCOV_ENABLE_COMPARISONS
232 bool "Enable comparison operands collection by KCOV"
233 depends on KERNEL_KCOV
235 KCOV also exposes operands of every comparison in the instrumented
236 code along with operand sizes and PCs of the comparison instructions.
237 These operands can be used by fuzzing engines to improve the quality
240 config KERNEL_KCOV_INSTRUMENT_ALL
241 bool "Instrument all code by default"
242 depends on KERNEL_KCOV
243 default y if KERNEL_KCOV
245 If you are doing generic system call fuzzing (like e.g. syzkaller),
246 then you will want to instrument the whole kernel and you should
247 say y here. If you are doing more targeted fuzzing (like e.g.
248 filesystem fuzzing with AFL) then you will want to enable coverage
249 for more specific subsets of files, and should say n here.
251 config KERNEL_TASKSTATS
252 bool "Compile the kernel with task resource/io statistics and accounting"
255 Enable the collection and publishing of task/io statistics and
256 accounting. Enable this option to enable i/o monitoring in system
261 config KERNEL_TASK_DELAY_ACCT
264 config KERNEL_TASK_IO_ACCOUNTING
267 config KERNEL_TASK_XACCT
272 config KERNEL_KALLSYMS
273 bool "Compile the kernel with symbol table information"
274 default y if !SMALL_FLASH
276 This will give you more information in stack traces from kernel oopses.
279 bool "Compile the kernel with tracing support"
280 depends on !TARGET_uml
283 config KERNEL_FTRACE_SYSCALLS
284 bool "Trace system calls"
285 depends on KERNEL_FTRACE
288 config KERNEL_ENABLE_DEFAULT_TRACERS
289 bool "Trace process context switches and events"
290 depends on KERNEL_FTRACE
293 config KERNEL_FUNCTION_TRACER
294 bool "Function tracer"
295 depends on KERNEL_FTRACE
298 config KERNEL_FUNCTION_GRAPH_TRACER
299 bool "Function graph tracer"
300 depends on KERNEL_FUNCTION_TRACER
303 config KERNEL_DYNAMIC_FTRACE
304 bool "Enable/disable function tracing dynamically"
305 depends on KERNEL_FUNCTION_TRACER
308 config KERNEL_FUNCTION_PROFILER
309 bool "Function profiler"
310 depends on KERNEL_FUNCTION_TRACER
313 config KERNEL_IRQSOFF_TRACER
314 bool "Interrupts-off Latency Tracer"
315 depends on KERNEL_FTRACE
317 This option measures the time spent in irqs-off critical
318 sections, with microsecond accuracy.
320 The default measurement method is a maximum search, which is
321 disabled by default and can be runtime (re-)started
324 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
326 (Note that kernel size and overhead increase with this option
327 enabled. This option and the preempt-off timing option can be
328 used together or separately.)
330 config KERNEL_PREEMPT_TRACER
331 bool "Preemption-off Latency Tracer"
332 depends on KERNEL_FTRACE
334 This option measures the time spent in preemption-off critical
335 sections, with microsecond accuracy.
337 The default measurement method is a maximum search, which is
338 disabled by default and can be runtime (re-)started
341 echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
343 (Note that kernel size and overhead increase with this option
344 enabled. This option and the irqs-off timing option can be
345 used together or separately.)
347 config KERNEL_HIST_TRIGGERS
348 bool "Histogram triggers"
349 depends on KERNEL_FTRACE
351 Hist triggers allow one or more arbitrary trace event fields to be
352 aggregated into hash tables and dumped to stdout by reading a
353 debugfs/tracefs file. They're useful for gathering quick and dirty
354 (though precise) summaries of event activity as an initial guide for
355 further investigation using more advanced tools.
357 Inter-event tracing of quantities such as latencies is also
358 supported using hist triggers under this option.
360 config KERNEL_DEBUG_KERNEL
364 config KERNEL_DEBUG_INFO
365 bool "Compile the kernel with debug information"
366 default y if !SMALL_FLASH
367 select KERNEL_DEBUG_KERNEL
369 This will compile your kernel and modules with debug information.
371 config KERNEL_DEBUG_LL_UART_NONE
376 config KERNEL_DEBUG_LL
380 select KERNEL_DEBUG_LL_UART_NONE
382 ARM low level debugging.
384 config KERNEL_DYNAMIC_DEBUG
385 bool "Compile the kernel with dynamic printk"
386 select KERNEL_DEBUG_FS
389 Compiles debug level messages into the kernel, which would not
390 otherwise be available at runtime. These messages can then be
391 enabled/disabled based on various levels of scope - per source file,
392 function, module, format string, and line number. This mechanism
393 implicitly compiles in all pr_debug() and dev_dbg() calls, which
394 enlarges the kernel text size by about 2%.
396 config KERNEL_EARLY_PRINTK
397 bool "Compile the kernel with early printk"
398 default y if TARGET_bcm53xx
401 select KERNEL_DEBUG_KERNEL
402 select KERNEL_DEBUG_LL if arm
404 Compile the kernel with early printk support. This is only useful for
405 debugging purposes to send messages over the serial console in early boot.
406 Enable this to debug early boot problems.
408 config KERNEL_KPROBES
409 bool "Compile the kernel with kprobes support"
412 select KERNEL_PERF_EVENTS
414 Compiles the kernel with KPROBES support, which allows you to trap
415 at almost any kernel address and execute a callback function.
416 register_kprobe() establishes a probepoint and specifies the
417 callback. Kprobes is useful for kernel debugging, non-intrusive
418 instrumentation and testing.
419 If in doubt, say "N".
421 config KERNEL_KPROBE_EVENTS
423 default y if KERNEL_KPROBES
426 bool "Compile the kernel with asynchronous IO support"
427 default y if !SMALL_FLASH
429 config KERNEL_IO_URING
430 bool "Compile the kernel with io_uring support"
431 default y if !SMALL_FLASH
433 config KERNEL_FHANDLE
434 bool "Compile the kernel with support for fhandle syscalls"
435 default y if !SMALL_FLASH
437 config KERNEL_FANOTIFY
438 bool "Compile the kernel with modern file notification support"
439 default y if !SMALL_FLASH
441 config KERNEL_BLK_DEV_BSG
442 bool "Compile the kernel with SCSI generic v4 support for any block device"
445 config KERNEL_TRANSPARENT_HUGEPAGE
449 prompt "Transparent Hugepage Support sysfs defaults"
450 depends on KERNEL_TRANSPARENT_HUGEPAGE
451 default KERNEL_TRANSPARENT_HUGEPAGE_ALWAYS
453 config KERNEL_TRANSPARENT_HUGEPAGE_ALWAYS
456 config KERNEL_TRANSPARENT_HUGEPAGE_MADVISE
460 config KERNEL_HUGETLBFS
463 config KERNEL_HUGETLB_PAGE
464 bool "Compile the kernel with HugeTLB support"
465 select KERNEL_TRANSPARENT_HUGEPAGE
466 select KERNEL_HUGETLBFS
469 config KERNEL_MAGIC_SYSRQ
470 bool "Compile the kernel with SysRq support"
473 config KERNEL_DEBUG_PINCTRL
474 bool "Compile the kernel with pinctrl debugging"
475 select KERNEL_DEBUG_KERNEL
477 config KERNEL_DEBUG_GPIO
478 bool "Compile the kernel with gpio debugging"
479 select KERNEL_DEBUG_KERNEL
481 config KERNEL_COREDUMP
484 config KERNEL_ELF_CORE
485 bool "Enable process core dump support"
486 select KERNEL_COREDUMP
487 default y if !SMALL_FLASH
489 config KERNEL_PROVE_LOCKING
490 bool "Enable kernel lock checking"
491 select KERNEL_DEBUG_KERNEL
494 config KERNEL_SOFTLOCKUP_DETECTOR
495 bool "Compile the kernel with detect Soft Lockups"
496 depends on KERNEL_DEBUG_KERNEL
498 Say Y here to enable the kernel to act as a watchdog to detect
501 Softlockups are bugs that cause the kernel to loop in kernel
502 mode for more than 20 seconds, without giving other tasks a
503 chance to run. The current stack trace is displayed upon
504 detection and the system will stay locked up.
506 config KERNEL_DETECT_HUNG_TASK
507 bool "Compile the kernel with detect Hung Tasks"
508 depends on KERNEL_DEBUG_KERNEL
509 default KERNEL_SOFTLOCKUP_DETECTOR
511 Say Y here to enable the kernel to detect "hung tasks",
512 which are bugs that cause the task to be stuck in
513 uninterruptible "D" state indefinitely.
515 When a hung task is detected, the kernel will print the
516 current stack trace (which you should report), but the
517 task will stay in uninterruptible state. If lockdep is
518 enabled then all held locks will also be reported. This
519 feature has negligible overhead.
521 config KERNEL_WQ_WATCHDOG
522 bool "Compile the kernel with detect Workqueue Stalls"
523 depends on KERNEL_DEBUG_KERNEL
525 Say Y here to enable stall detection on workqueues. If a
526 worker pool doesn't make forward progress on a pending work
527 item for over a given amount of time, 30s by default, a
528 warning message is printed along with dump of workqueue
529 state. This can be configured through kernel parameter
530 "workqueue.watchdog_thresh" and its sysfs counterpart.
532 config KERNEL_DEBUG_ATOMIC_SLEEP
533 bool "Compile the kernel with sleep inside atomic section checking"
534 depends on KERNEL_DEBUG_KERNEL
536 If you say Y here, various routines which may sleep will become very
537 noisy if they are called inside atomic sections: when a spinlock is
538 held, inside an rcu read side critical section, inside preempt disabled
539 sections, inside an interrupt, etc...
541 config KERNEL_DEBUG_VM
542 bool "Compile the kernel with debug VM"
543 depends on KERNEL_DEBUG_KERNEL
545 Enable this to turn on extended checks in the virtual-memory system
546 that may impact performance.
550 config KERNEL_PRINTK_TIME
551 bool "Enable printk timestamps"
554 config KERNEL_SLUB_DEBUG
557 config KERNEL_SLUB_DEBUG_ON
560 config KERNEL_SLABINFO
561 select KERNEL_SLUB_DEBUG
562 select KERNEL_SLUB_DEBUG_ON
563 bool "Enable /proc slab debug info"
565 config KERNEL_PROC_PAGE_MONITOR
566 bool "Enable /proc page monitoring"
572 bool "Enable kexec support"
574 config KERNEL_PROC_VMCORE
577 config KERNEL_PROC_KCORE
580 config KERNEL_CRASH_DUMP
581 depends on i386 || x86_64 || arm || armeb
583 select KERNEL_PROC_VMCORE
584 select KERNEL_PROC_KCORE
585 bool "Enable support for kexec crashdump"
589 bool "Enable rfkill support"
590 default RFKILL_SUPPORT
593 bool "Enable sparse check during kernel build"
596 config KERNEL_DEVTMPFS
597 bool "Compile the kernel with device tmpfs enabled"
600 devtmpfs is a simple, kernel-managed /dev filesystem. The kernel creates
601 devices nodes for all registered devices to simplify boot, but leaves more
602 complex tasks to userspace (e.g. udev).
606 config KERNEL_DEVTMPFS_MOUNT
607 bool "Automatically mount devtmpfs after root filesystem is mounted"
613 bool "Enable kernel access key retention support"
616 config KERNEL_PERSISTENT_KEYRINGS
617 bool "Enable kernel persistent keyrings"
618 depends on KERNEL_KEYS
621 config KERNEL_KEYS_REQUEST_CACHE
622 bool "Enable temporary caching of the last request_key() result"
623 depends on KERNEL_KEYS
626 config KERNEL_BIG_KEYS
627 bool "Enable large payload keys on kernel keyrings"
628 depends on KERNEL_KEYS
632 # CGROUP support symbols
635 config KERNEL_CGROUPS
636 bool "Enable kernel cgroups"
637 default y if !SMALL_FLASH
641 config KERNEL_CGROUP_DEBUG
642 bool "Example debug cgroup subsystem"
645 This option enables a simple cgroup subsystem that
646 exports useful debugging information about the cgroups
649 config KERNEL_FREEZER
652 config KERNEL_CGROUP_FREEZER
653 bool "legacy Freezer cgroup subsystem"
655 select KERNEL_FREEZER
657 Provides a way to freeze and unfreeze all tasks in a
659 (legacy cgroup1-only controller, in cgroup2 freezer
660 is integrated in the Memory controller)
662 config KERNEL_CGROUP_DEVICE
663 bool "legacy Device controller for cgroups"
666 Provides a cgroup implementing whitelists for devices which
667 a process in the cgroup can mknod or open.
668 (legacy cgroup1-only controller)
670 config KERNEL_CGROUP_HUGETLB
671 bool "HugeTLB controller"
673 select KERNEL_HUGETLB_PAGE
675 config KERNEL_CGROUP_PIDS
676 bool "PIDs cgroup subsystem"
679 Provides enforcement of process number limits in the scope of a
682 config KERNEL_CGROUP_RDMA
683 bool "RDMA controller for cgroups"
686 config KERNEL_CGROUP_BPF
687 bool "Support for eBPF programs attached to cgroups"
690 config KERNEL_CPUSETS
691 bool "Cpuset support"
694 This option will let you create and manage CPUSETs which
695 allow dynamically partitioning a system into sets of CPUs and
696 Memory Nodes and assigning tasks to run only within those sets.
697 This is primarily useful on large SMP or NUMA systems.
699 config KERNEL_PROC_PID_CPUSET
700 bool "Include legacy /proc/<pid>/cpuset file"
702 depends on KERNEL_CPUSETS
704 config KERNEL_CGROUP_CPUACCT
705 bool "Simple CPU accounting cgroup subsystem"
708 Provides a simple Resource Controller for monitoring the
709 total CPU consumed by the tasks in a cgroup.
711 config KERNEL_RESOURCE_COUNTERS
712 bool "Resource counters"
715 This option enables controller independent resource accounting
716 infrastructure that works with cgroups.
718 config KERNEL_MM_OWNER
720 default y if KERNEL_MEMCG
723 bool "Memory Resource Controller for Control Groups"
725 select KERNEL_FREEZER
726 depends on KERNEL_RESOURCE_COUNTERS || !LINUX_3_18
728 Provides a memory resource controller that manages both anonymous
729 memory and page cache. (See Documentation/cgroups/memory.txt)
731 Note that setting this option increases fixed memory overhead
732 associated with each page of memory in the system. By this,
733 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
734 usage tracking struct at boot. Total amount of this is printed out
737 Only enable when you're ok with these tradeoffs and really
738 sure you need the memory resource controller. Even when you enable
739 this, you can set "cgroup_disable=memory" at your boot option to
740 disable memory resource controller and you can avoid overheads
741 (but lose benefits of memory resource controller).
743 This config option also selects MM_OWNER config option, which
744 could in turn add some fork/exit overhead.
746 config KERNEL_MEMCG_SWAP
747 bool "Memory Resource Controller Swap Extension"
749 depends on KERNEL_MEMCG
751 Add swap management feature to memory resource controller. When you
752 enable this, you can limit mem+swap usage per cgroup. In other words,
753 when you disable this, memory resource controller has no cares to
754 usage of swap...a process can exhaust all of the swap. This extension
755 is useful when you want to avoid exhaustion swap but this itself
756 adds more overheads and consumes memory for remembering information.
757 Especially if you use 32bit system or small memory system, please
758 be careful about enabling this. When memory resource controller
759 is disabled by boot option, this will be automatically disabled and
760 there will be no overhead from this. Even when you set this config=y,
761 if boot option "swapaccount=0" is set, swap will not be accounted.
762 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
763 size is 4096bytes, 512k per 1Gbytes of swap.
765 config KERNEL_MEMCG_SWAP_ENABLED
766 bool "Memory Resource Controller Swap Extension enabled by default"
768 depends on KERNEL_MEMCG_SWAP
770 Memory Resource Controller Swap Extension comes with its price in
771 a bigger memory consumption. General purpose distribution kernels
772 which want to enable the feature but keep it disabled by default
773 and let the user enable it by swapaccount boot command line
774 parameter should have this option unselected.
776 Those who want to have the feature enabled by default should
777 select this option (if, for some reason, they need to disable it,
778 then swapaccount=0 does the trick).
781 config KERNEL_MEMCG_KMEM
782 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
784 depends on KERNEL_MEMCG
786 The Kernel Memory extension for Memory Resource Controller can limit
787 the amount of memory used by kernel objects in the system. Those are
788 fundamentally different from the entities handled by the standard
789 Memory Controller, which are page-based, and can be swapped. Users of
790 the kmem extension can use it to guarantee that no group of processes
791 will ever exhaust kernel resources alone.
793 config KERNEL_CGROUP_PERF
794 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
795 select KERNEL_PERF_EVENTS
798 This option extends the per-cpu mode to restrict monitoring to
799 threads which belong to the cgroup specified and run on the
802 menuconfig KERNEL_CGROUP_SCHED
803 bool "Group CPU scheduler"
806 This feature lets CPU scheduler recognize task groups and control CPU
807 bandwidth allocation to such task groups. It uses cgroups to group
810 if KERNEL_CGROUP_SCHED
812 config KERNEL_FAIR_GROUP_SCHED
813 bool "Group scheduling for SCHED_OTHER"
816 config KERNEL_CFS_BANDWIDTH
817 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
819 depends on KERNEL_FAIR_GROUP_SCHED
821 This option allows users to define CPU bandwidth rates (limits) for
822 tasks running within the fair group scheduler. Groups with no limit
823 set are considered to be unconstrained and will run with no
825 See tip/Documentation/scheduler/sched-bwc.txt for more information.
827 config KERNEL_RT_GROUP_SCHED
828 bool "Group scheduling for SCHED_RR/FIFO"
831 This feature lets you explicitly allocate real CPU bandwidth
832 to task groups. If enabled, it will also make it impossible to
833 schedule realtime tasks for non-root users until you allocate
834 realtime bandwidth for them.
838 config KERNEL_BLK_CGROUP
839 bool "Block IO controller"
842 Generic block IO controller cgroup interface. This is the common
843 cgroup interface which should be used by various IO controlling
846 Currently, CFQ IO scheduler uses it to recognize task groups and
847 control disk bandwidth allocation (proportional time slice allocation)
848 to such task groups. It is also used by bio throttling logic in
849 block layer to implement upper limit in IO rates on a device.
851 This option only enables generic Block IO controller infrastructure.
852 One needs to also enable actual IO controlling logic/policy. For
853 enabling proportional weight division of disk bandwidth in CFQ, set
854 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
855 CONFIG_BLK_DEV_THROTTLING=y.
859 config KERNEL_CFQ_GROUP_IOSCHED
860 bool "Proportional weight of disk bandwidth in CFQ"
862 config KERNEL_BLK_DEV_THROTTLING
863 bool "Enable throttling policy"
866 config KERNEL_BLK_DEV_THROTTLING_LOW
867 bool "Block throttling .low limit interface support (EXPERIMENTAL)"
868 depends on KERNEL_BLK_DEV_THROTTLING
871 config KERNEL_DEBUG_BLK_CGROUP
872 bool "Enable Block IO controller debugging"
874 depends on KERNEL_BLK_CGROUP
876 Enable some debugging help. Currently it exports additional stat
877 files in a cgroup which can be useful for debugging.
879 config KERNEL_NET_CLS_CGROUP
880 bool "legacy Control Group Classifier"
883 config KERNEL_CGROUP_NET_CLASSID
884 bool "legacy Network classid cgroup"
887 config KERNEL_CGROUP_NET_PRIO
888 bool "legacy Network priority cgroup"
894 # Namespace support symbols
897 config KERNEL_NAMESPACES
898 bool "Enable kernel namespaces"
899 default y if !SMALL_FLASH
907 In this namespace, tasks see different info provided
908 with the uname() system call.
914 In this namespace, tasks work with IPC ids which correspond to
915 different IPC objects in different namespaces.
917 config KERNEL_USER_NS
918 bool "User namespace (EXPERIMENTAL)"
921 This allows containers, i.e. vservers, to use user namespaces
922 to provide different user info for different servers.
925 bool "PID Namespaces"
928 Support process id namespaces. This allows having multiple
929 processes with the same pid as long as they are in different
930 pid namespaces. This is a building block of containers.
933 bool "Network namespace"
936 Allow user space to create what appear to be multiple instances
937 of the network stack.
941 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
942 bool "Support multiple instances of devpts"
943 default y if !SMALL_FLASH
945 Enable support for multiple instances of devpts filesystem.
946 If you want to have isolated PTY namespaces (eg: in containers),
947 say Y here. Otherwise, say N. If enabled, each mount of devpts
948 filesystem with the '-o newinstance' option will create an
949 independent PTY namespace.
951 config KERNEL_POSIX_MQUEUE
952 bool "POSIX Message Queues"
953 default y if !SMALL_FLASH
955 POSIX variant of message queues is a part of IPC. In POSIX message
956 queues every message has a priority which decides about succession
957 of receiving it by a process. If you want to compile and run
958 programs written e.g. for Solaris with use of its POSIX message
959 queues (functions mq_*) say Y here.
961 POSIX message queues are visible as a filesystem called 'mqueue'
962 and can be mounted somewhere if you want to do filesystem
963 operations on message queues.
966 config KERNEL_SECCOMP_FILTER
968 default y if !SMALL_FLASH
970 config KERNEL_SECCOMP
971 bool "Enable seccomp support"
972 depends on !(TARGET_uml)
973 select KERNEL_SECCOMP_FILTER
974 default y if !SMALL_FLASH
976 Build kernel with support for seccomp.
982 config KERNEL_IP_MROUTE
983 bool "Enable IPv4 multicast routing"
986 Multicast routing requires a multicast routing daemon in
987 addition to kernel support.
991 config KERNEL_IP_MROUTE_MULTIPLE_TABLES
994 config KERNEL_IP_PIMSM_V1
997 config KERNEL_IP_PIMSM_V2
1003 # IPv6 configuration
1011 config KERNEL_IPV6_MULTIPLE_TABLES
1014 config KERNEL_IPV6_SUBTREES
1017 config KERNEL_IPV6_MROUTE
1018 bool "Enable IPv6 multicast routing"
1021 Multicast routing requires a multicast routing daemon in
1022 addition to kernel support.
1024 if KERNEL_IPV6_MROUTE
1026 config KERNEL_IPV6_MROUTE_MULTIPLE_TABLES
1029 config KERNEL_IPV6_PIMSM_V2
1034 config KERNEL_IPV6_SEG6_LWTUNNEL
1035 bool "Enable support for lightweight tunnels"
1036 default y if !SMALL_FLASH
1038 Using lwtunnel (needed for IPv6 segment routing) requires ip-full package.
1040 config KERNEL_LWTUNNEL_BPF
1046 # Miscellaneous network configuration
1049 config KERNEL_NET_L3_MASTER_DEV
1050 bool "L3 Master device support"
1052 This module provides glue between core networking code and device
1053 drivers to support L3 master devices like VRF.
1056 # NFS related symbols
1058 config KERNEL_IP_PNP
1059 bool "Compile the kernel with rootfs on NFS"
1061 If you want to make your kernel boot off a NFS server as root
1062 filesystem, select Y here.
1066 config KERNEL_IP_PNP_DHCP
1069 config KERNEL_IP_PNP_BOOTP
1072 config KERNEL_IP_PNP_RARP
1075 config KERNEL_NFS_FS
1078 config KERNEL_NFS_V2
1081 config KERNEL_NFS_V3
1084 config KERNEL_ROOT_NFS
1089 menu "Filesystem ACL and attr support options"
1090 config USE_FS_ACL_ATTR
1091 bool "Use filesystem ACL and attr support by default"
1094 Make using ACLs (e.g. POSIX ACL, NFSv4 ACL) the default
1095 for kernel and packages, except tmpfs, flash filesystems,
1096 and old NFS. Also enable userspace extended attribute support
1097 by default. (OpenWrt already has an expection it will be
1098 present in the kernel).
1100 config KERNEL_FS_POSIX_ACL
1101 bool "Enable POSIX ACL support"
1102 default y if USE_FS_ACL_ATTR
1104 config KERNEL_BTRFS_FS_POSIX_ACL
1105 bool "Enable POSIX ACL for BtrFS Filesystems"
1106 select KERNEL_FS_POSIX_ACL
1107 default y if USE_FS_ACL_ATTR
1109 config KERNEL_EXT4_FS_POSIX_ACL
1110 bool "Enable POSIX ACL for Ext4 Filesystems"
1111 select KERNEL_FS_POSIX_ACL
1112 default y if USE_FS_ACL_ATTR
1114 config KERNEL_F2FS_FS_POSIX_ACL
1115 bool "Enable POSIX ACL for F2FS Filesystems"
1116 select KERNEL_FS_POSIX_ACL
1119 config KERNEL_JFFS2_FS_POSIX_ACL
1120 bool "Enable POSIX ACL for JFFS2 Filesystems"
1121 select KERNEL_FS_POSIX_ACL
1124 config KERNEL_TMPFS_POSIX_ACL
1125 bool "Enable POSIX ACL for TMPFS Filesystems"
1126 select KERNEL_FS_POSIX_ACL
1129 config KERNEL_CIFS_ACL
1130 bool "Enable CIFS ACLs"
1131 select KERNEL_FS_POSIX_ACL
1132 default y if USE_FS_ACL_ATTR
1134 config KERNEL_HFS_FS_POSIX_ACL
1135 bool "Enable POSIX ACL for HFS Filesystems"
1136 select KERNEL_FS_POSIX_ACL
1137 default y if USE_FS_ACL_ATTR
1139 config KERNEL_HFSPLUS_FS_POSIX_ACL
1140 bool "Enable POSIX ACL for HFS+ Filesystems"
1141 select KERNEL_FS_POSIX_ACL
1142 default y if USE_FS_ACL_ATTR
1144 config KERNEL_NFS_ACL_SUPPORT
1145 bool "Enable ACLs for NFS"
1146 default y if USE_FS_ACL_ATTR
1148 config KERNEL_NFS_V3_ACL_SUPPORT
1149 bool "Enable ACLs for NFSv3"
1152 config KERNEL_NFSD_V2_ACL_SUPPORT
1153 bool "Enable ACLs for NFSDv2"
1156 config KERNEL_NFSD_V3_ACL_SUPPORT
1157 bool "Enable ACLs for NFSDv3"
1160 config KERNEL_REISER_FS_POSIX_ACL
1161 bool "Enable POSIX ACLs for ReiserFS"
1162 select KERNEL_FS_POSIX_ACL
1163 default y if USE_FS_ACL_ATTR
1165 config KERNEL_XFS_POSIX_ACL
1166 bool "Enable POSIX ACLs for XFS"
1167 select KERNEL_FS_POSIX_ACL
1168 default y if USE_FS_ACL_ATTR
1170 config KERNEL_JFS_POSIX_ACL
1171 bool "Enable POSIX ACLs for JFS"
1172 select KERNEL_FS_POSIX_ACL
1173 default y if USE_FS_ACL_ATTR
1177 config KERNEL_DEVMEM
1178 bool "/dev/mem virtual device support"
1180 Say Y here if you want to support the /dev/mem device.
1181 The /dev/mem device is used to access areas of physical
1184 config KERNEL_DEVKMEM
1185 bool "/dev/kmem virtual device support"
1187 Say Y here if you want to support the /dev/kmem device. The
1188 /dev/kmem device is rarely used, but can be used for certain
1189 kind of kernel debugging operations.
1191 config KERNEL_SQUASHFS_FRAGMENT_CACHE_SIZE
1192 int "Number of squashfs fragments cached"
1193 default 2 if (SMALL_FLASH && !LOW_MEMORY_FOOTPRINT)
1196 config KERNEL_SQUASHFS_XATTR
1197 bool "Squashfs XATTR support"
1200 # compile optimization setting
1203 prompt "Compiler optimization level"
1204 default KERNEL_CC_OPTIMIZE_FOR_SIZE if SMALL_FLASH
1206 config KERNEL_CC_OPTIMIZE_FOR_PERFORMANCE
1207 bool "Optimize for performance"
1209 This is the default optimization level for the kernel, building
1210 with the "-O2" compiler flag for best performance and most
1211 helpful compile-time warnings.
1213 config KERNEL_CC_OPTIMIZE_FOR_SIZE
1214 bool "Optimize for size"
1216 Enabling this option will pass "-Os" instead of "-O2" to
1217 your compiler resulting in a smaller kernel.
1222 bool "Auditing support"
1224 config KERNEL_SECURITY
1225 bool "Enable different security models"
1227 config KERNEL_SECURITY_NETWORK
1228 bool "Socket and Networking Security Hooks"
1229 select KERNEL_SECURITY
1231 config KERNEL_SECURITY_SELINUX
1232 bool "NSA SELinux Support"
1233 select KERNEL_SECURITY_NETWORK
1236 config KERNEL_SECURITY_SELINUX_BOOTPARAM
1237 bool "NSA SELinux boot parameter"
1238 depends on KERNEL_SECURITY_SELINUX
1241 config KERNEL_SECURITY_SELINUX_DISABLE
1242 bool "NSA SELinux runtime disable"
1243 depends on KERNEL_SECURITY_SELINUX
1245 config KERNEL_SECURITY_SELINUX_DEVELOP
1246 bool "NSA SELinux Development Support"
1247 depends on KERNEL_SECURITY_SELINUX
1250 config KERNEL_SECURITY_SELINUX_SIDTAB_HASH_BITS
1252 depends on KERNEL_SECURITY_SELINUX
1255 config KERNEL_SECURITY_SELINUX_SID2STR_CACHE_SIZE
1257 depends on KERNEL_SECURITY_SELINUX
1262 default "lockdown,yama,loadpin,safesetid,integrity,selinux"
1263 depends on KERNEL_SECURITY_SELINUX
1265 config KERNEL_EXT4_FS_SECURITY
1266 bool "Ext4 Security Labels"
1268 config KERNEL_F2FS_FS_SECURITY
1269 bool "F2FS Security Labels"
1271 config KERNEL_UBIFS_FS_SECURITY
1272 bool "UBIFS Security Labels"
1274 config KERNEL_JFFS2_FS_SECURITY
1275 bool "JFFS2 Security Labels"