10 config LOCKDEP_SUPPORT
13 config STACKTRACE_SUPPORT
16 config RWSEM_GENERIC_SPINLOCK
19 config RWSEM_XCHGADD_ALGORITHM
22 config ARCH_HAS_ILOG2_U32
25 config ARCH_HAS_ILOG2_U64
28 config GENERIC_HWEIGHT
34 config GENERIC_BUG_RELATIVE_POINTERS
37 config ARCH_DMA_ADDR_T_64BIT
40 config GENERIC_LOCKBREAK
41 def_bool y if SMP && PREEMPT
46 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
62 config ARCH_SUPPORTS_UPROBES
70 select ARCH_HAS_DEVMEM_IS_ALLOWED
71 select ARCH_HAS_ELF_RANDOMIZE
72 select ARCH_HAS_GCOV_PROFILE_ALL
73 select ARCH_HAS_GIGANTIC_PAGE
75 select ARCH_HAS_SG_CHAIN
76 select ARCH_HAS_UBSAN_SANITIZE_ALL
77 select ARCH_HAVE_NMI_SAFE_CMPXCHG
78 select ARCH_INLINE_READ_LOCK
79 select ARCH_INLINE_READ_LOCK_BH
80 select ARCH_INLINE_READ_LOCK_IRQ
81 select ARCH_INLINE_READ_LOCK_IRQSAVE
82 select ARCH_INLINE_READ_TRYLOCK
83 select ARCH_INLINE_READ_UNLOCK
84 select ARCH_INLINE_READ_UNLOCK_BH
85 select ARCH_INLINE_READ_UNLOCK_IRQ
86 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
87 select ARCH_INLINE_SPIN_LOCK
88 select ARCH_INLINE_SPIN_LOCK_BH
89 select ARCH_INLINE_SPIN_LOCK_IRQ
90 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
91 select ARCH_INLINE_SPIN_TRYLOCK
92 select ARCH_INLINE_SPIN_TRYLOCK_BH
93 select ARCH_INLINE_SPIN_UNLOCK
94 select ARCH_INLINE_SPIN_UNLOCK_BH
95 select ARCH_INLINE_SPIN_UNLOCK_IRQ
96 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
97 select ARCH_INLINE_WRITE_LOCK
98 select ARCH_INLINE_WRITE_LOCK_BH
99 select ARCH_INLINE_WRITE_LOCK_IRQ
100 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
101 select ARCH_INLINE_WRITE_TRYLOCK
102 select ARCH_INLINE_WRITE_UNLOCK
103 select ARCH_INLINE_WRITE_UNLOCK_BH
104 select ARCH_INLINE_WRITE_UNLOCK_IRQ
105 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
106 select ARCH_SAVE_PAGE_KEYS if HIBERNATION
107 select ARCH_SUPPORTS_ATOMIC_RMW
108 select ARCH_SUPPORTS_NUMA_BALANCING
109 select ARCH_USE_BUILTIN_BSWAP
110 select ARCH_USE_CMPXCHG_LOCKREF
111 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
112 select ARCH_WANTS_PROT_NUMA_PROT_NONE
113 select ARCH_WANTS_UBSAN_NO_NULL
114 select ARCH_WANT_IPC_PARSE_VERSION
115 select BUILDTIME_EXTABLE_SORT
116 select CLONE_BACKWARDS2
117 select DYNAMIC_FTRACE if FUNCTION_TRACER
118 select GENERIC_CLOCKEVENTS
119 select GENERIC_CPU_AUTOPROBE
120 select GENERIC_CPU_DEVICES if !SMP
121 select GENERIC_CPU_VULNERABILITIES
122 select GENERIC_FIND_FIRST_BIT
123 select GENERIC_SMP_IDLE_THREAD
124 select GENERIC_TIME_VSYSCALL
125 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
126 select HAVE_ARCH_AUDITSYSCALL
127 select HAVE_ARCH_EARLY_PFN_TO_NID
128 select HAVE_ARCH_HARDENED_USERCOPY
129 select HAVE_ARCH_JUMP_LABEL
130 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
131 select HAVE_ARCH_SECCOMP_FILTER
132 select HAVE_ARCH_SOFT_DIRTY
133 select HAVE_ARCH_TRACEHOOK
134 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
135 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
136 select HAVE_CMPXCHG_DOUBLE
137 select HAVE_CMPXCHG_LOCAL
138 select HAVE_DEBUG_KMEMLEAK
139 select HAVE_DMA_API_DEBUG
140 select HAVE_DYNAMIC_FTRACE
141 select HAVE_DYNAMIC_FTRACE_WITH_REGS
142 select HAVE_EFFICIENT_UNALIGNED_ACCESS
143 select HAVE_EXIT_THREAD
144 select HAVE_FTRACE_MCOUNT_RECORD
145 select HAVE_FUNCTION_GRAPH_TRACER
146 select HAVE_FUNCTION_TRACER
147 select HAVE_FUTEX_CMPXCHG if FUTEX
148 select HAVE_KERNEL_BZIP2
149 select HAVE_KERNEL_GZIP
150 select HAVE_KERNEL_LZ4
151 select HAVE_KERNEL_LZMA
152 select HAVE_KERNEL_LZO
153 select HAVE_KERNEL_XZ
155 select HAVE_KRETPROBES
157 select HAVE_LIVEPATCH
159 select HAVE_MEMBLOCK_NODE_MAP
160 select HAVE_MEMBLOCK_PHYS_MAP
161 select HAVE_MOD_ARCH_SPECIFIC
163 select HAVE_PERF_EVENTS
164 select HAVE_REGS_AND_STACK_ACCESS_API
165 select HAVE_SYSCALL_TRACEPOINTS
166 select HAVE_VIRT_CPU_ACCOUNTING
167 select MODULES_USE_ELF_RELA
170 select OLD_SIGSUSPEND3
172 select SYSCTL_EXCEPTION_TRACE
174 select VIRT_CPU_ACCOUNTING
179 config SCHED_OMIT_FRAME_POINTER
182 config PGTABLE_LEVELS
186 source "init/Kconfig"
188 source "kernel/Kconfig.freezer"
190 source "kernel/livepatch/Kconfig"
192 menu "Processor type and features"
194 config HAVE_MARCH_Z900_FEATURES
197 config HAVE_MARCH_Z990_FEATURES
199 select HAVE_MARCH_Z900_FEATURES
201 config HAVE_MARCH_Z9_109_FEATURES
203 select HAVE_MARCH_Z990_FEATURES
205 config HAVE_MARCH_Z10_FEATURES
207 select HAVE_MARCH_Z9_109_FEATURES
209 config HAVE_MARCH_Z196_FEATURES
211 select HAVE_MARCH_Z10_FEATURES
213 config HAVE_MARCH_ZEC12_FEATURES
215 select HAVE_MARCH_Z196_FEATURES
217 config HAVE_MARCH_Z13_FEATURES
219 select HAVE_MARCH_ZEC12_FEATURES
222 prompt "Processor type"
226 bool "IBM zSeries model z800 and z900"
227 select HAVE_MARCH_Z900_FEATURES
229 Select this to enable optimizations for model z800/z900 (2064 and
230 2066 series). This will enable some optimizations that are not
231 available on older ESA/390 (31 Bit) only CPUs.
234 bool "IBM zSeries model z890 and z990"
235 select HAVE_MARCH_Z990_FEATURES
237 Select this to enable optimizations for model z890/z990 (2084 and
238 2086 series). The kernel will be slightly faster but will not work
243 select HAVE_MARCH_Z9_109_FEATURES
245 Select this to enable optimizations for IBM System z9 (2094 and
246 2096 series). The kernel will be slightly faster but will not work
250 bool "IBM System z10"
251 select HAVE_MARCH_Z10_FEATURES
253 Select this to enable optimizations for IBM System z10 (2097 and
254 2098 series). The kernel will be slightly faster but will not work
258 bool "IBM zEnterprise 114 and 196"
259 select HAVE_MARCH_Z196_FEATURES
261 Select this to enable optimizations for IBM zEnterprise 114 and 196
262 (2818 and 2817 series). The kernel will be slightly faster but will
263 not work on older machines.
266 bool "IBM zBC12 and zEC12"
267 select HAVE_MARCH_ZEC12_FEATURES
269 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
270 2827 series). The kernel will be slightly faster but will not work on
274 bool "IBM z13s and z13"
275 select HAVE_MARCH_Z13_FEATURES
277 Select this to enable optimizations for IBM z13s and z13 (2965 and
278 2964 series). The kernel will be slightly faster but will not work on
283 config MARCH_Z900_TUNE
284 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
286 config MARCH_Z990_TUNE
287 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
289 config MARCH_Z9_109_TUNE
290 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
292 config MARCH_Z10_TUNE
293 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
295 config MARCH_Z196_TUNE
296 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
298 config MARCH_ZEC12_TUNE
299 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
301 config MARCH_Z13_TUNE
302 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
305 prompt "Tune code generation"
308 Cause the compiler to tune (-mtune) the generated code for a machine.
309 This will make the code run faster on the selected machine but
310 somewhat slower on other machines.
311 This option only changes how the compiler emits instructions, not the
312 selection of instructions itself, so the resulting kernel will run on
318 Tune the generated code for the target processor for which the kernel
322 bool "IBM zSeries model z800 and z900"
325 bool "IBM zSeries model z890 and z990"
331 bool "IBM System z10"
334 bool "IBM zEnterprise 114 and 196"
337 bool "IBM zBC12 and zEC12"
349 prompt "Kernel support for 31 bit emulation"
350 select COMPAT_BINFMT_ELF if BINFMT_ELF
351 select ARCH_WANT_OLD_COMPAT_IPC
352 select COMPAT_OLD_SIGACTION
355 Select this option if you want to enable your system kernel to
356 handle system-calls from ELF binaries for 31 bit ESA. This option
357 (and some other stuff like libraries and such) is needed for
358 executing 31 bit applications. It is safe to say "Y".
360 config SYSVIPC_COMPAT
361 def_bool y if COMPAT && SYSVIPC
365 prompt "Symmetric multi-processing support"
367 This enables support for systems with more than one CPU. If you have
368 a system with only one CPU, like most personal computers, say N. If
369 you have a system with more than one CPU, say Y.
371 If you say N here, the kernel will run on uni- and multiprocessor
372 machines, but will use only one CPU of a multiprocessor machine. If
373 you say Y here, the kernel will run on many, but not all,
374 uniprocessor machines. On a uniprocessor machine, the kernel
375 will run faster if you say N here.
377 See also the SMP-HOWTO available at
378 <http://www.tldp.org/docs.html#howto>.
380 Even if you don't know what to do here, say Y.
383 int "Maximum number of CPUs (2-512)"
388 This allows you to specify the maximum number of CPUs which this
389 kernel will support. The maximum supported value is 512 and the
390 minimum value which makes sense is 2.
392 This is purely to save memory - each supported CPU adds
393 approximately sixteen kilobytes to the kernel image.
397 prompt "Support for hot-pluggable CPUs"
400 Say Y here to be able to turn CPUs off and on. CPUs
401 can be controlled through /sys/devices/system/cpu/cpu#.
402 Say N if you want to disable CPU hotplug.
404 # Some NUMA nodes have memory ranges that span
405 # other nodes. Even though a pfn is valid and
406 # between a node's start and end pfns, it may not
407 # reside on that node. See memmap_init_zone()
408 # for details. <- They meant memory holes!
409 config NODES_SPAN_OTHER_NODES
414 depends on SMP && SCHED_TOPOLOGY
419 This option adds NUMA support to the kernel.
421 An operation mode can be selected by appending
422 numa=<method> to the kernel command line.
424 The default behaviour is identical to appending numa=plain to
425 the command line. This will create just one node with all
426 available memory and all CPUs in it.
429 int "Maximum NUMA nodes (as a power of 2)"
434 Specify the maximum number of NUMA nodes available on the target
435 system. Increases memory reserved to accommodate various tables.
437 menu "Select NUMA modes"
441 bool "NUMA emulation"
444 Numa emulation mode will split the available system memory into
445 equal chunks which then are distributed over the configured number
446 of nodes in a round-robin manner.
448 The number of fake nodes is limited by the number of available memory
449 chunks (i.e. memory size / fake size) and the number of supported
452 The CPUs are assigned to the nodes in a way that partially respects
453 the original machine topology (if supported by the machine).
454 Fair distribution of the CPUs is not guaranteed.
457 hex "NUMA emulation memory chunk size"
459 range 0x400000 0x100000000
462 Select the default size by which the memory is chopped and then
463 assigned to emulated NUMA nodes.
465 This can be overridden by specifying
469 on the kernel command line where also suffixes K, M, G, and T are
486 config SCHED_TOPOLOGY
488 prompt "Topology scheduler support"
495 Topology scheduler support improves the CPU scheduler's decision
496 making when dealing with machines that have multi-threading,
497 multiple cores or multiple books.
499 source kernel/Kconfig.preempt
501 source kernel/Kconfig.hz
507 config ARCH_SPARSEMEM_ENABLE
509 select SPARSEMEM_VMEMMAP_ENABLE
510 select SPARSEMEM_VMEMMAP
512 config ARCH_SPARSEMEM_DEFAULT
515 config ARCH_SELECT_MEMORY_MODEL
518 config ARCH_ENABLE_MEMORY_HOTPLUG
519 def_bool y if SPARSEMEM
521 config ARCH_ENABLE_MEMORY_HOTREMOVE
524 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
527 config FORCE_MAX_ZONEORDER
535 prompt "Pack kernel stack"
537 This option enables the compiler option -mkernel-backchain if it
538 is available. If the option is available the compiler supports
539 the new stack layout which dramatically reduces the minimum stack
540 frame size. With an old compiler a non-leaf function needs a
541 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
542 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
543 and 24 byte on 64 bit.
545 Say Y if you are unsure.
549 prompt "Detect kernel stack overflow"
551 This option enables the compiler option -mstack-guard and
552 -mstack-size if they are available. If the compiler supports them
553 it will emit additional code to each function prolog to trigger
554 an illegal operation if the kernel stack is about to overflow.
556 Say N if you are unsure.
559 int "Size of the guard area (128-1024)"
561 depends on CHECK_STACK
564 This allows you to specify the size of the guard area at the lower
565 end of the kernel stack. If the kernel stack points into the guard
566 area on function entry an illegal operation is triggered. The size
567 needs to be a power of 2. Please keep in mind that the size of an
568 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
569 The minimum size for the stack guard should be 256 for 31 bit and
572 config WARN_DYNAMIC_STACK
574 prompt "Emit compiler warnings for function with dynamic stack usage"
576 This option enables the compiler option -mwarn-dynamicstack. If the
577 compiler supports this options generates warnings for functions
578 that dynamically allocate stack space using alloca.
580 Say N if you are unsure.
588 prompt "QDIO support"
590 This driver provides the Queued Direct I/O base support for
593 To compile this driver as a module, choose M here: the
594 module will be called qdio.
607 config PCI_NR_FUNCTIONS
608 int "Maximum number of PCI functions (1-4096)"
612 This allows you to specify the maximum number of PCI functions which
613 this kernel will support.
615 source "drivers/pci/Kconfig"
628 config NEED_SG_DMA_LENGTH
631 config NEED_DMA_MAP_STATE
636 prompt "Support for CHSC subchannels"
638 This driver allows usage of CHSC subchannels. A CHSC subchannel
639 is usually present on LPAR only.
640 The driver creates a device /dev/chsc, which may be used to
641 obtain I/O configuration information about the machine and
642 to issue asynchronous chsc commands (DANGEROUS).
643 You will usually only want to use this interface on a special
644 LPAR designated for system management.
646 To compile this driver as a module, choose M here: the
647 module will be called chsc_sch.
653 prompt "SCM bus driver"
655 Bus driver for Storage Class Memory.
659 prompt "Support for EADM subchannels"
662 This driver allows usage of EADM subchannels. EADM subchannels act
663 as a communication vehicle for SCM increments.
665 To compile this driver as a module, choose M here: the
666 module will be called eadm_sch.
673 bool "kernel crash dumps"
677 Generate crash dump after being started by kexec.
678 Crash dump kernels are loaded in the main kernel with kexec-tools
679 into a specially reserved region and then later executed after
680 a crash by kdump/kexec.
681 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
682 This option also enables s390 zfcpdump.
683 See also <file:Documentation/s390/zfcpdump.txt>
687 menu "Executable file formats / Emulations"
689 source "fs/Kconfig.binfmt"
693 prompt "Enable seccomp to safely compute untrusted bytecode"
696 This kernel feature is useful for number crunching applications
697 that may need to compute untrusted bytecode during their
698 execution. By using pipes or other transports made available to
699 the process as file descriptors supporting the read/write
700 syscalls, it's possible to isolate those applications in
701 their own address space using seccomp. Once seccomp is
702 enabled via /proc/<pid>/seccomp, it cannot be disabled
703 and the task is only allowed to execute a few safe syscalls
704 defined by each seccomp mode.
710 prompt "Enable modified branch prediction for the kernel by default"
712 If this option is selected the kernel will switch to a modified
713 branch prediction mode if the firmware interface is available.
714 The modified branch prediction mode improves the behaviour in
715 regard to speculative execution.
717 With the option enabled the kernel parameter "nobp=0" or "nospec"
718 can be used to run the kernel in the normal branch prediction mode.
720 With the option disabled the modified branch prediction mode is
721 enabled with the "nobp=1" kernel parameter.
727 prompt "Avoid speculative indirect branches in the kernel"
729 Compile the kernel with the expoline compiler options to guard
730 against kernel-to-user data leaks by avoiding speculative indirect
732 Requires a compiler with -mindirect-branch=thunk support for full
733 protection. The kernel may run slower.
738 prompt "Expoline default"
740 default EXPOLINE_FULL
743 bool "spectre_v2=off"
746 bool "spectre_v2=auto"
755 menu "Power Management"
757 config ARCH_HIBERNATION_POSSIBLE
760 source "kernel/power/Kconfig"
772 source "drivers/Kconfig"
776 source "arch/s390/Kconfig.debug"
778 source "security/Kconfig"
780 source "crypto/Kconfig"
784 menu "Virtualization"
788 prompt "Pseudo page fault support"
790 Select this option, if you want to use PFAULT pseudo page fault
791 handling under VM. If running native or in LPAR, this option
792 has no effect. If your VM does not support PFAULT, PAGEEX
793 pseudo page fault handling will be used.
794 Note that VM 4.2 supports PFAULT but has a bug in its
795 implementation that causes some problems.
796 Everybody who wants to run Linux under VM != VM4.2 should select
800 bool "VM shared kernel support"
801 depends on !JUMP_LABEL
802 depends on !ALTERNATIVES
804 Select this option, if you want to share the text segment of the
805 Linux kernel between different VM guests. This reduces memory
806 usage with lots of guests but greatly increases kernel size.
807 Also if a kernel was IPL'ed from a shared segment the kexec system
809 You should only select this option if you know what you are
810 doing and want to exploit this feature.
814 prompt "Cooperative memory management"
816 Select this option, if you want to enable the kernel interface
817 to reduce the memory size of the system. This is accomplished
818 by allocating pages of memory and put them "on hold". This only
819 makes sense for a system running under VM where the unused pages
820 will be reused by VM for other guest systems. The interface
821 allows an external monitor to balance memory of many systems.
822 Everybody who wants to run Linux under VM should select this
827 prompt "IUCV special message interface to cooperative memory management"
828 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
830 Select this option to enable the special message interface to
831 the cooperative memory management.
835 prompt "Linux - VM Monitor Stream, base infrastructure"
836 depends on PROC_SYSCTL
838 This provides a kernel interface for creating and updating z/VM APPLDATA
839 monitor records. The monitor records are updated at certain time
840 intervals, once the timer is started.
841 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
842 i.e. enables or disables monitoring on the Linux side.
843 A custom interval value (in seconds) can be written to
844 /proc/appldata/interval.
846 Defaults are 60 seconds interval and timer off.
847 The /proc entries can also be read from, showing the current settings.
851 prompt "Monitor memory management statistics"
852 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
854 This provides memory management related data to the Linux - VM Monitor
855 Stream, like paging/swapping rate, memory utilisation, etc.
856 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
857 APPLDATA monitor record, i.e. enables or disables monitoring this record
861 The /proc entry can also be read from, showing the current settings.
863 This can also be compiled as a module, which will be called
868 prompt "Monitor OS statistics"
869 depends on APPLDATA_BASE
871 This provides OS related data to the Linux - VM Monitor Stream, like
872 CPU utilisation, etc.
873 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
874 APPLDATA monitor record, i.e. enables or disables monitoring this record
878 This can also be compiled as a module, which will be called
881 config APPLDATA_NET_SUM
883 prompt "Monitor overall network statistics"
884 depends on APPLDATA_BASE && NET
886 This provides network related data to the Linux - VM Monitor Stream,
887 currently there is only a total sum of network I/O statistics, no
889 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
890 APPLDATA monitor record, i.e. enables or disables monitoring this record
894 This can also be compiled as a module, which will be called
899 prompt "s390 hypervisor file system support"
900 select SYS_HYPERVISOR
902 This is a virtual file system intended to provide accounting
903 information in an s390 hypervisor environment.
905 source "arch/s390/kvm/Kconfig"
909 prompt "s390 support for virtio devices"
911 select VIRTUALIZATION
913 select VIRTIO_CONSOLE
915 Enabling this option adds support for virtio based paravirtual device
918 Select this option if you want to run the kernel as a guest under
921 config S390_GUEST_OLD_TRANSPORT
923 prompt "Guest support for old s390 virtio transport (DEPRECATED)"
924 depends on S390_GUEST
926 Enable this option to add support for the old s390-virtio
927 transport (i.e. virtio devices NOT based on virtio-ccw). This
928 type of virtio devices is only available on the experimental
929 kuli userspace or with old (< 2.6) qemu. If you are running
930 with a modern version of qemu (which supports virtio-ccw since
931 1.4 and uses it by default since version 2.4), you probably won't