7 option env="KERNELVERSION"
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
16 default "$ARCH_DEFCONFIG"
17 default "arch/$ARCH/defconfig"
26 config BUILDTIME_EXTABLE_SORT
36 depends on BROKEN || !SMP
39 config INIT_ENV_ARG_LIMIT
44 Maximum of each of the number of arguments and environment
45 variables passed to init from the kernel command line.
49 string "Cross-compiler tool prefix"
51 Same as running 'make CROSS_COMPILE=prefix-' but stored for
52 default make runs in this kernel build directory. You don't
53 need to set this unless you want the configured kernel build
54 directory to select the cross-compiler automatically.
57 string "Local version - append to kernel release"
59 Append an extra string to the end of your kernel version.
60 This will show up when you type uname, for example.
61 The string you set here will be appended after the contents of
62 any files with a filename matching localversion* in your
63 object and source tree, in that order. Your total string can
64 be a maximum of 64 characters.
66 config LOCALVERSION_AUTO
67 bool "Automatically append version information to the version string"
70 This will try to automatically determine if the current tree is a
71 release tree by looking for git tags that belong to the current
74 A string of the format -gxxxxxxxx will be added to the localversion
75 if a git-based tree is found. The string generated by this will be
76 appended after any matching localversion* files, and after the value
77 set in CONFIG_LOCALVERSION.
79 (The actual string used here is the first eight characters produced
80 by running the command:
82 $ git rev-parse --verify HEAD
84 which is done within the script "scripts/setlocalversion".)
86 config HAVE_KERNEL_GZIP
89 config HAVE_KERNEL_BZIP2
92 config HAVE_KERNEL_LZMA
98 config HAVE_KERNEL_LZO
102 prompt "Kernel compression mode"
104 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
106 The linux kernel is a kind of self-extracting executable.
107 Several compression algorithms are available, which differ
108 in efficiency, compression and decompression speed.
109 Compression speed is only relevant when building a kernel.
110 Decompression speed is relevant at each boot.
112 If you have any problems with bzip2 or lzma compressed
113 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
114 version of this functionality (bzip2 only), for 2.4, was
115 supplied by Christian Ludwig)
117 High compression options are mostly useful for users, who
118 are low on disk space (embedded systems), but for whom ram
121 If in doubt, select 'gzip'
125 depends on HAVE_KERNEL_GZIP
127 The old and tried gzip compression. It provides a good balance
128 between compression ratio and decompression speed.
132 depends on HAVE_KERNEL_BZIP2
134 Its compression ratio and speed is intermediate.
135 Decompression speed is slowest among the choices. The kernel
136 size is about 10% smaller with bzip2, in comparison to gzip.
137 Bzip2 uses a large amount of memory. For modern kernels you
138 will need at least 8MB RAM or more for booting.
142 depends on HAVE_KERNEL_LZMA
144 This compression algorithm's ratio is best. Decompression speed
145 is between gzip and bzip2. Compression is slowest.
146 The kernel size is about 33% smaller with LZMA in comparison to gzip.
150 depends on HAVE_KERNEL_XZ
152 XZ uses the LZMA2 algorithm and instruction set specific
153 BCJ filters which can improve compression ratio of executable
154 code. The size of the kernel is about 30% smaller with XZ in
155 comparison to gzip. On architectures for which there is a BCJ
156 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
157 will create a few percent smaller kernel than plain LZMA.
159 The speed is about the same as with LZMA: The decompression
160 speed of XZ is better than that of bzip2 but worse than gzip
161 and LZO. Compression is slow.
165 depends on HAVE_KERNEL_LZO
167 Its compression ratio is the poorest among the choices. The kernel
168 size is about 10% bigger than gzip; however its speed
169 (both compression and decompression) is the fastest.
173 config DEFAULT_HOSTNAME
174 string "Default hostname"
177 This option determines the default system hostname before userspace
178 calls sethostname(2). The kernel traditionally uses "(none)" here,
179 but you may wish to use a different default here to make a minimal
180 system more usable with less configuration.
183 bool "Support for paging of anonymous memory (swap)"
184 depends on MMU && BLOCK
187 This option allows you to choose whether you want to have support
188 for so called swap devices or swap files in your kernel that are
189 used to provide more virtual memory than the actual RAM present
190 in your computer. If unsure say Y.
195 Inter Process Communication is a suite of library functions and
196 system calls which let processes (running programs) synchronize and
197 exchange information. It is generally considered to be a good thing,
198 and some programs won't run unless you say Y here. In particular, if
199 you want to run the DOS emulator dosemu under Linux (read the
200 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
201 you'll need to say Y here.
203 You can find documentation about IPC with "info ipc" and also in
204 section 6.4 of the Linux Programmer's Guide, available from
205 <http://www.tldp.org/guides.html>.
207 config SYSVIPC_SYSCTL
214 bool "POSIX Message Queues"
217 POSIX variant of message queues is a part of IPC. In POSIX message
218 queues every message has a priority which decides about succession
219 of receiving it by a process. If you want to compile and run
220 programs written e.g. for Solaris with use of its POSIX message
221 queues (functions mq_*) say Y here.
223 POSIX message queues are visible as a filesystem called 'mqueue'
224 and can be mounted somewhere if you want to do filesystem
225 operations on message queues.
229 config POSIX_MQUEUE_SYSCTL
231 depends on POSIX_MQUEUE
236 bool "open by fhandle syscalls"
239 If you say Y here, a user level program will be able to map
240 file names to handle and then later use the handle for
241 different file system operations. This is useful in implementing
242 userspace file servers, which now track files using handles instead
243 of names. The handle would remain the same even if file names
244 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
248 bool "Auditing support"
251 Enable auditing infrastructure that can be used with another
252 kernel subsystem, such as SELinux (which requires this for
253 logging of avc messages output). Does not do system-call
254 auditing without CONFIG_AUDITSYSCALL.
257 bool "Enable system-call auditing support"
258 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
259 default y if SECURITY_SELINUX
261 Enable low-overhead system-call auditing infrastructure that
262 can be used independently or with another kernel subsystem,
267 depends on AUDITSYSCALL
272 depends on AUDITSYSCALL
275 config AUDIT_LOGINUID_IMMUTABLE
276 bool "Make audit loginuid immutable"
279 The config option toggles if a task setting its loginuid requires
280 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
281 but should instead only allow setting its loginuid if it was never
282 previously set. On systems which use systemd or a similar central
283 process to restart login services this should be set to true. On older
284 systems in which an admin would typically have to directly stop and
285 start processes this should be set to false. Setting this to true allows
286 one to drop potentially dangerous capabilites from the login tasks,
287 but may not be backwards compatible with older init systems.
289 source "kernel/irq/Kconfig"
290 source "kernel/time/Kconfig"
292 menu "CPU/Task time and stats accounting"
294 config VIRT_CPU_ACCOUNTING
298 prompt "Cputime accounting"
299 default TICK_CPU_ACCOUNTING if !PPC64
300 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
302 # Kind of a stub config for the pure tick based cputime accounting
303 config TICK_CPU_ACCOUNTING
304 bool "Simple tick based cputime accounting"
305 depends on !S390 && !NO_HZ_FULL
307 This is the basic tick based cputime accounting that maintains
308 statistics about user, system and idle time spent on per jiffies
313 config VIRT_CPU_ACCOUNTING_NATIVE
314 bool "Deterministic task and CPU time accounting"
315 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
316 select VIRT_CPU_ACCOUNTING
318 Select this option to enable more accurate task and CPU time
319 accounting. This is done by reading a CPU counter on each
320 kernel entry and exit and on transitions within the kernel
321 between system, softirq and hardirq state, so there is a
322 small performance impact. In the case of s390 or IBM POWER > 5,
323 this also enables accounting of stolen time on logically-partitioned
326 config VIRT_CPU_ACCOUNTING_GEN
327 bool "Full dynticks CPU time accounting"
328 depends on HAVE_CONTEXT_TRACKING && 64BIT
329 select VIRT_CPU_ACCOUNTING
330 select CONTEXT_TRACKING
332 Select this option to enable task and CPU time accounting on full
333 dynticks systems. This accounting is implemented by watching every
334 kernel-user boundaries using the context tracking subsystem.
335 The accounting is thus performed at the expense of some significant
338 For now this is only useful if you are working on the full
339 dynticks subsystem development.
343 config IRQ_TIME_ACCOUNTING
344 bool "Fine granularity task level IRQ time accounting"
345 depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
347 Select this option to enable fine granularity task irq time
348 accounting. This is done by reading a timestamp on each
349 transitions between softirq and hardirq state, so there can be a
350 small performance impact.
352 If in doubt, say N here.
356 config BSD_PROCESS_ACCT
357 bool "BSD Process Accounting"
359 If you say Y here, a user level program will be able to instruct the
360 kernel (via a special system call) to write process accounting
361 information to a file: whenever a process exits, information about
362 that process will be appended to the file by the kernel. The
363 information includes things such as creation time, owning user,
364 command name, memory usage, controlling terminal etc. (the complete
365 list is in the struct acct in <file:include/linux/acct.h>). It is
366 up to the user level program to do useful things with this
367 information. This is generally a good idea, so say Y.
369 config BSD_PROCESS_ACCT_V3
370 bool "BSD Process Accounting version 3 file format"
371 depends on BSD_PROCESS_ACCT
374 If you say Y here, the process accounting information is written
375 in a new file format that also logs the process IDs of each
376 process and it's parent. Note that this file format is incompatible
377 with previous v0/v1/v2 file formats, so you will need updated tools
378 for processing it. A preliminary version of these tools is available
379 at <http://www.gnu.org/software/acct/>.
382 bool "Export task/process statistics through netlink"
386 Export selected statistics for tasks/processes through the
387 generic netlink interface. Unlike BSD process accounting, the
388 statistics are available during the lifetime of tasks/processes as
389 responses to commands. Like BSD accounting, they are sent to user
394 config TASK_DELAY_ACCT
395 bool "Enable per-task delay accounting"
398 Collect information on time spent by a task waiting for system
399 resources like cpu, synchronous block I/O completion and swapping
400 in pages. Such statistics can help in setting a task's priorities
401 relative to other tasks for cpu, io, rss limits etc.
406 bool "Enable extended accounting over taskstats"
409 Collect extended task accounting data and send the data
410 to userland for processing over the taskstats interface.
414 config TASK_IO_ACCOUNTING
415 bool "Enable per-task storage I/O accounting"
416 depends on TASK_XACCT
418 Collect information on the number of bytes of storage I/O which this
423 endmenu # "CPU/Task time and stats accounting"
428 prompt "RCU Implementation"
432 bool "Tree-based hierarchical RCU"
433 depends on !PREEMPT && SMP
435 This option selects the RCU implementation that is
436 designed for very large SMP system with hundreds or
437 thousands of CPUs. It also scales down nicely to
440 config TREE_PREEMPT_RCU
441 bool "Preemptible tree-based hierarchical RCU"
444 This option selects the RCU implementation that is
445 designed for very large SMP systems with hundreds or
446 thousands of CPUs, but for which real-time response
447 is also required. It also scales down nicely to
450 Select this option if you are unsure.
453 bool "UP-only small-memory-footprint RCU"
454 depends on !PREEMPT && !SMP
456 This option selects the RCU implementation that is
457 designed for UP systems from which real-time response
458 is not required. This option greatly reduces the
459 memory footprint of RCU.
461 config TINY_PREEMPT_RCU
462 bool "Preemptible UP-only small-memory-footprint RCU"
463 depends on PREEMPT && !SMP
465 This option selects the RCU implementation that is designed
466 for real-time UP systems. This option greatly reduces the
467 memory footprint of RCU.
472 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
474 This option enables preemptible-RCU code that is common between
475 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
477 config RCU_STALL_COMMON
478 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
480 This option enables RCU CPU stall code that is common between
481 the TINY and TREE variants of RCU. The purpose is to allow
482 the tiny variants to disable RCU CPU stall warnings, while
483 making these warnings mandatory for the tree variants.
485 config CONTEXT_TRACKING
489 bool "Consider userspace as in RCU extended quiescent state"
490 depends on HAVE_CONTEXT_TRACKING && SMP
491 select CONTEXT_TRACKING
493 This option sets hooks on kernel / userspace boundaries and
494 puts RCU in extended quiescent state when the CPU runs in
495 userspace. It means that when a CPU runs in userspace, it is
496 excluded from the global RCU state machine and thus doesn't
497 try to keep the timer tick on for RCU.
499 Unless you want to hack and help the development of the full
500 dynticks mode, you shouldn't enable this option. It also
501 adds unnecessary overhead.
505 config CONTEXT_TRACKING_FORCE
506 bool "Force context tracking"
507 depends on CONTEXT_TRACKING
508 default CONTEXT_TRACKING
510 Probe on user/kernel boundaries by default in order to
511 test the features that rely on it such as userspace RCU extended
513 This test is there for debugging until we have a real user like the
517 int "Tree-based hierarchical RCU fanout value"
520 depends on TREE_RCU || TREE_PREEMPT_RCU
524 This option controls the fanout of hierarchical implementations
525 of RCU, allowing RCU to work efficiently on machines with
526 large numbers of CPUs. This value must be at least the fourth
527 root of NR_CPUS, which allows NR_CPUS to be insanely large.
528 The default value of RCU_FANOUT should be used for production
529 systems, but if you are stress-testing the RCU implementation
530 itself, small RCU_FANOUT values allow you to test large-system
531 code paths on small(er) systems.
533 Select a specific number if testing RCU itself.
534 Take the default if unsure.
536 config RCU_FANOUT_LEAF
537 int "Tree-based hierarchical RCU leaf-level fanout value"
538 range 2 RCU_FANOUT if 64BIT
539 range 2 RCU_FANOUT if !64BIT
540 depends on TREE_RCU || TREE_PREEMPT_RCU
543 This option controls the leaf-level fanout of hierarchical
544 implementations of RCU, and allows trading off cache misses
545 against lock contention. Systems that synchronize their
546 scheduling-clock interrupts for energy-efficiency reasons will
547 want the default because the smaller leaf-level fanout keeps
548 lock contention levels acceptably low. Very large systems
549 (hundreds or thousands of CPUs) will instead want to set this
550 value to the maximum value possible in order to reduce the
551 number of cache misses incurred during RCU's grace-period
552 initialization. These systems tend to run CPU-bound, and thus
553 are not helped by synchronized interrupts, and thus tend to
554 skew them, which reduces lock contention enough that large
555 leaf-level fanouts work well.
557 Select a specific number if testing RCU itself.
559 Select the maximum permissible value for large systems.
561 Take the default if unsure.
563 config RCU_FANOUT_EXACT
564 bool "Disable tree-based hierarchical RCU auto-balancing"
565 depends on TREE_RCU || TREE_PREEMPT_RCU
568 This option forces use of the exact RCU_FANOUT value specified,
569 regardless of imbalances in the hierarchy. This is useful for
570 testing RCU itself, and might one day be useful on systems with
571 strong NUMA behavior.
573 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
577 config RCU_FAST_NO_HZ
578 bool "Accelerate last non-dyntick-idle CPU's grace periods"
579 depends on NO_HZ_COMMON && SMP
582 This option permits CPUs to enter dynticks-idle state even if
583 they have RCU callbacks queued, and prevents RCU from waking
584 these CPUs up more than roughly once every four jiffies (by
585 default, you can adjust this using the rcutree.rcu_idle_gp_delay
586 parameter), thus improving energy efficiency. On the other
587 hand, this option increases the duration of RCU grace periods,
588 for example, slowing down synchronize_rcu().
590 Say Y if energy efficiency is critically important, and you
591 don't care about increased grace-period durations.
593 Say N if you are unsure.
595 config TREE_RCU_TRACE
596 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
599 This option provides tracing for the TREE_RCU and
600 TREE_PREEMPT_RCU implementations, permitting Makefile to
601 trivially select kernel/rcutree_trace.c.
604 bool "Enable RCU priority boosting"
605 depends on RT_MUTEXES && PREEMPT_RCU
608 This option boosts the priority of preempted RCU readers that
609 block the current preemptible RCU grace period for too long.
610 This option also prevents heavy loads from blocking RCU
611 callback invocation for all flavors of RCU.
613 Say Y here if you are working with real-time apps or heavy loads
614 Say N here if you are unsure.
616 config RCU_BOOST_PRIO
617 int "Real-time priority to boost RCU readers to"
622 This option specifies the real-time priority to which long-term
623 preempted RCU readers are to be boosted. If you are working
624 with a real-time application that has one or more CPU-bound
625 threads running at a real-time priority level, you should set
626 RCU_BOOST_PRIO to a priority higher then the highest-priority
627 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
628 of 1 is appropriate in the common case, which is real-time
629 applications that do not have any CPU-bound threads.
631 Some real-time applications might not have a single real-time
632 thread that saturates a given CPU, but instead might have
633 multiple real-time threads that, taken together, fully utilize
634 that CPU. In this case, you should set RCU_BOOST_PRIO to
635 a priority higher than the lowest-priority thread that is
636 conspiring to prevent the CPU from running any non-real-time
637 tasks. For example, if one thread at priority 10 and another
638 thread at priority 5 are between themselves fully consuming
639 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
640 set to priority 6 or higher.
642 Specify the real-time priority, or take the default if unsure.
644 config RCU_BOOST_DELAY
645 int "Milliseconds to delay boosting after RCU grace-period start"
650 This option specifies the time to wait after the beginning of
651 a given grace period before priority-boosting preempted RCU
652 readers blocking that grace period. Note that any RCU reader
653 blocking an expedited RCU grace period is boosted immediately.
655 Accept the default if unsure.
658 bool "Offload RCU callback processing from boot-selected CPUs (EXPERIMENTAL"
659 depends on TREE_RCU || TREE_PREEMPT_RCU
662 Use this option to reduce OS jitter for aggressive HPC or
663 real-time workloads. It can also be used to offload RCU
664 callback invocation to energy-efficient CPUs in battery-powered
665 asymmetric multiprocessors.
667 This option offloads callback invocation from the set of
668 CPUs specified at boot time by the rcu_nocbs parameter.
669 For each such CPU, a kthread ("rcuox/N") will be created to
670 invoke callbacks, where the "N" is the CPU being offloaded,
671 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
672 "s" for RCU-sched. Nothing prevents this kthread from running
673 on the specified CPUs, but (1) the kthreads may be preempted
674 between each callback, and (2) affinity or cgroups can be used
675 to force the kthreads to run on whatever set of CPUs is desired.
677 Say Y here if you want to help to debug reduced OS jitter.
678 Say N here if you are unsure.
681 prompt "Build-forced no-CBs CPUs"
682 default RCU_NOCB_CPU_NONE
684 This option allows no-CBs CPUs to be specified at build time.
685 Additional no-CBs CPUs may be specified by the rcu_nocbs=
688 config RCU_NOCB_CPU_NONE
689 bool "No build_forced no-CBs CPUs"
690 depends on RCU_NOCB_CPU && !NO_HZ_FULL
692 This option does not force any of the CPUs to be no-CBs CPUs.
693 Only CPUs designated by the rcu_nocbs= boot parameter will be
696 config RCU_NOCB_CPU_ZERO
697 bool "CPU 0 is a build_forced no-CBs CPU"
698 depends on RCU_NOCB_CPU && !NO_HZ_FULL
700 This option forces CPU 0 to be a no-CBs CPU. Additional CPUs
701 may be designated as no-CBs CPUs using the rcu_nocbs= boot
702 parameter will be no-CBs CPUs.
704 Select this if CPU 0 needs to be a no-CBs CPU for real-time
705 or energy-efficiency reasons.
707 config RCU_NOCB_CPU_ALL
708 bool "All CPUs are build_forced no-CBs CPUs"
709 depends on RCU_NOCB_CPU
711 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
712 boot parameter will be ignored.
714 Select this if all CPUs need to be no-CBs CPUs for real-time
715 or energy-efficiency reasons.
719 endmenu # "RCU Subsystem"
722 tristate "Kernel .config support"
724 This option enables the complete Linux kernel ".config" file
725 contents to be saved in the kernel. It provides documentation
726 of which kernel options are used in a running kernel or in an
727 on-disk kernel. This information can be extracted from the kernel
728 image file with the script scripts/extract-ikconfig and used as
729 input to rebuild the current kernel or to build another kernel.
730 It can also be extracted from a running kernel by reading
731 /proc/config.gz if enabled (below).
734 bool "Enable access to .config through /proc/config.gz"
735 depends on IKCONFIG && PROC_FS
737 This option enables access to the kernel configuration file
738 through /proc/config.gz.
741 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
745 Select kernel log buffer size as a power of 2.
755 # Architectures with an unreliable sched_clock() should select this:
757 config HAVE_UNSTABLE_SCHED_CLOCK
760 config GENERIC_SCHED_CLOCK
764 # For architectures that want to enable the support for NUMA-affine scheduler
767 config ARCH_SUPPORTS_NUMA_BALANCING
770 # For architectures that (ab)use NUMA to represent different memory regions
771 # all cpu-local but of different latencies, such as SuperH.
773 config ARCH_WANT_NUMA_VARIABLE_LOCALITY
777 # For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
778 config ARCH_WANTS_PROT_NUMA_PROT_NONE
781 config ARCH_USES_NUMA_PROT_NONE
784 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
785 depends on NUMA_BALANCING
787 config NUMA_BALANCING_DEFAULT_ENABLED
788 bool "Automatically enable NUMA aware memory/task placement"
790 depends on NUMA_BALANCING
792 If set, autonumic NUMA balancing will be enabled if running on a NUMA
795 config NUMA_BALANCING
796 bool "Memory placement aware NUMA scheduler"
797 depends on ARCH_SUPPORTS_NUMA_BALANCING
798 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
799 depends on SMP && NUMA && MIGRATION
801 This option adds support for automatic NUMA aware memory/task placement.
802 The mechanism is quite primitive and is based on migrating memory when
803 it is references to the node the task is running on.
805 This system will be inactive on UMA systems.
808 boolean "Control Group support"
811 This option adds support for grouping sets of processes together, for
812 use with process control subsystems such as Cpusets, CFS, memory
813 controls or device isolation.
815 - Documentation/scheduler/sched-design-CFS.txt (CFS)
816 - Documentation/cgroups/ (features for grouping, isolation
817 and resource control)
824 bool "Example debug cgroup subsystem"
827 This option enables a simple cgroup subsystem that
828 exports useful debugging information about the cgroups
833 config CGROUP_FREEZER
834 bool "Freezer cgroup subsystem"
836 Provides a way to freeze and unfreeze all tasks in a
840 bool "Device controller for cgroups"
842 Provides a cgroup implementing whitelists for devices which
843 a process in the cgroup can mknod or open.
846 bool "Cpuset support"
848 This option will let you create and manage CPUSETs which
849 allow dynamically partitioning a system into sets of CPUs and
850 Memory Nodes and assigning tasks to run only within those sets.
851 This is primarily useful on large SMP or NUMA systems.
855 config PROC_PID_CPUSET
856 bool "Include legacy /proc/<pid>/cpuset file"
860 config CGROUP_CPUACCT
861 bool "Simple CPU accounting cgroup subsystem"
863 Provides a simple Resource Controller for monitoring the
864 total CPU consumed by the tasks in a cgroup.
866 config RESOURCE_COUNTERS
867 bool "Resource counters"
869 This option enables controller independent resource accounting
870 infrastructure that works with cgroups.
873 bool "Memory Resource Controller for Control Groups"
874 depends on RESOURCE_COUNTERS
877 Provides a memory resource controller that manages both anonymous
878 memory and page cache. (See Documentation/cgroups/memory.txt)
880 Note that setting this option increases fixed memory overhead
881 associated with each page of memory in the system. By this,
882 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
883 usage tracking struct at boot. Total amount of this is printed out
886 Only enable when you're ok with these trade offs and really
887 sure you need the memory resource controller. Even when you enable
888 this, you can set "cgroup_disable=memory" at your boot option to
889 disable memory resource controller and you can avoid overheads.
890 (and lose benefits of memory resource controller)
892 This config option also selects MM_OWNER config option, which
893 could in turn add some fork/exit overhead.
896 bool "Memory Resource Controller Swap Extension"
897 depends on MEMCG && SWAP
899 Add swap management feature to memory resource controller. When you
900 enable this, you can limit mem+swap usage per cgroup. In other words,
901 when you disable this, memory resource controller has no cares to
902 usage of swap...a process can exhaust all of the swap. This extension
903 is useful when you want to avoid exhaustion swap but this itself
904 adds more overheads and consumes memory for remembering information.
905 Especially if you use 32bit system or small memory system, please
906 be careful about enabling this. When memory resource controller
907 is disabled by boot option, this will be automatically disabled and
908 there will be no overhead from this. Even when you set this config=y,
909 if boot option "swapaccount=0" is set, swap will not be accounted.
910 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
911 size is 4096bytes, 512k per 1Gbytes of swap.
912 config MEMCG_SWAP_ENABLED
913 bool "Memory Resource Controller Swap Extension enabled by default"
914 depends on MEMCG_SWAP
917 Memory Resource Controller Swap Extension comes with its price in
918 a bigger memory consumption. General purpose distribution kernels
919 which want to enable the feature but keep it disabled by default
920 and let the user enable it by swapaccount boot command line
921 parameter should have this option unselected.
922 For those who want to have the feature enabled by default should
923 select this option (if, for some reason, they need to disable it
924 then swapaccount=0 does the trick).
926 bool "Memory Resource Controller Kernel Memory accounting"
928 depends on SLUB || SLAB
930 The Kernel Memory extension for Memory Resource Controller can limit
931 the amount of memory used by kernel objects in the system. Those are
932 fundamentally different from the entities handled by the standard
933 Memory Controller, which are page-based, and can be swapped. Users of
934 the kmem extension can use it to guarantee that no group of processes
935 will ever exhaust kernel resources alone.
937 config CGROUP_HUGETLB
938 bool "HugeTLB Resource Controller for Control Groups"
939 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
942 Provides a cgroup Resource Controller for HugeTLB pages.
943 When you enable this, you can put a per cgroup limit on HugeTLB usage.
944 The limit is enforced during page fault. Since HugeTLB doesn't
945 support page reclaim, enforcing the limit at page fault time implies
946 that, the application will get SIGBUS signal if it tries to access
947 HugeTLB pages beyond its limit. This requires the application to know
948 beforehand how much HugeTLB pages it would require for its use. The
949 control group is tracked in the third page lru pointer. This means
950 that we cannot use the controller with huge page less than 3 pages.
953 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
954 depends on PERF_EVENTS && CGROUPS
956 This option extends the per-cpu mode to restrict monitoring to
957 threads which belong to the cgroup specified and run on the
962 menuconfig CGROUP_SCHED
963 bool "Group CPU scheduler"
966 This feature lets CPU scheduler recognize task groups and control CPU
967 bandwidth allocation to such task groups. It uses cgroups to group
971 config FAIR_GROUP_SCHED
972 bool "Group scheduling for SCHED_OTHER"
973 depends on CGROUP_SCHED
977 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
978 depends on FAIR_GROUP_SCHED
981 This option allows users to define CPU bandwidth rates (limits) for
982 tasks running within the fair group scheduler. Groups with no limit
983 set are considered to be unconstrained and will run with no
985 See tip/Documentation/scheduler/sched-bwc.txt for more information.
987 config RT_GROUP_SCHED
988 bool "Group scheduling for SCHED_RR/FIFO"
989 depends on CGROUP_SCHED
992 This feature lets you explicitly allocate real CPU bandwidth
993 to task groups. If enabled, it will also make it impossible to
994 schedule realtime tasks for non-root users until you allocate
995 realtime bandwidth for them.
996 See Documentation/scheduler/sched-rt-group.txt for more information.
1001 bool "Block IO controller"
1005 Generic block IO controller cgroup interface. This is the common
1006 cgroup interface which should be used by various IO controlling
1009 Currently, CFQ IO scheduler uses it to recognize task groups and
1010 control disk bandwidth allocation (proportional time slice allocation)
1011 to such task groups. It is also used by bio throttling logic in
1012 block layer to implement upper limit in IO rates on a device.
1014 This option only enables generic Block IO controller infrastructure.
1015 One needs to also enable actual IO controlling logic/policy. For
1016 enabling proportional weight division of disk bandwidth in CFQ, set
1017 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
1018 CONFIG_BLK_DEV_THROTTLING=y.
1020 See Documentation/cgroups/blkio-controller.txt for more information.
1022 config DEBUG_BLK_CGROUP
1023 bool "Enable Block IO controller debugging"
1024 depends on BLK_CGROUP
1027 Enable some debugging help. Currently it exports additional stat
1028 files in a cgroup which can be useful for debugging.
1032 config CHECKPOINT_RESTORE
1033 bool "Checkpoint/restore support" if EXPERT
1036 Enables additional kernel features in a sake of checkpoint/restore.
1037 In particular it adds auxiliary prctl codes to setup process text,
1038 data and heap segment sizes, and a few additional /proc filesystem
1041 If unsure, say N here.
1043 menuconfig NAMESPACES
1044 bool "Namespaces support" if EXPERT
1047 Provides the way to make tasks work with different objects using
1048 the same id. For example same IPC id may refer to different objects
1049 or same user id or pid may refer to different tasks when used in
1050 different namespaces.
1055 bool "UTS namespace"
1058 In this namespace tasks see different info provided with the
1062 bool "IPC namespace"
1063 depends on (SYSVIPC || POSIX_MQUEUE)
1066 In this namespace tasks work with IPC ids which correspond to
1067 different IPC objects in different namespaces.
1070 bool "User namespace"
1071 depends on UIDGID_CONVERTED
1072 select UIDGID_STRICT_TYPE_CHECKS
1076 This allows containers, i.e. vservers, to use user namespaces
1077 to provide different user info for different servers.
1079 When user namespaces are enabled in the kernel it is
1080 recommended that the MEMCG and MEMCG_KMEM options also be
1081 enabled and that user-space use the memory control groups to
1082 limit the amount of memory a memory unprivileged users can
1088 bool "PID Namespaces"
1091 Support process id namespaces. This allows having multiple
1092 processes with the same pid as long as they are in different
1093 pid namespaces. This is a building block of containers.
1096 bool "Network namespace"
1100 Allow user space to create what appear to be multiple instances
1101 of the network stack.
1105 config UIDGID_CONVERTED
1106 # True if all of the selected software conmponents are known
1107 # to have uid_t and gid_t converted to kuid_t and kgid_t
1108 # where appropriate and are otherwise safe to use with
1109 # the user namespace.
1114 depends on XFS_FS = n
1116 config UIDGID_STRICT_TYPE_CHECKS
1117 bool "Require conversions between uid/gids and their internal representation"
1118 depends on UIDGID_CONVERTED
1121 While the nececessary conversions are being added to all subsystems this option allows
1122 the code to continue to build for unconverted subsystems.
1124 Say Y here if you want the strict type checking enabled
1126 config SCHED_AUTOGROUP
1127 bool "Automatic process group scheduling"
1131 select FAIR_GROUP_SCHED
1133 This option optimizes the scheduler for common desktop workloads by
1134 automatically creating and populating task groups. This separation
1135 of workloads isolates aggressive CPU burners (like build jobs) from
1136 desktop applications. Task group autogeneration is currently based
1142 config SYSFS_DEPRECATED
1143 bool "Enable deprecated sysfs features to support old userspace tools"
1147 This option adds code that switches the layout of the "block" class
1148 devices, to not show up in /sys/class/block/, but only in
1151 This switch is only active when the sysfs.deprecated=1 boot option is
1152 passed or the SYSFS_DEPRECATED_V2 option is set.
1154 This option allows new kernels to run on old distributions and tools,
1155 which might get confused by /sys/class/block/. Since 2007/2008 all
1156 major distributions and tools handle this just fine.
1158 Recent distributions and userspace tools after 2009/2010 depend on
1159 the existence of /sys/class/block/, and will not work with this
1162 Only if you are using a new kernel on an old distribution, you might
1165 config SYSFS_DEPRECATED_V2
1166 bool "Enable deprecated sysfs features by default"
1169 depends on SYSFS_DEPRECATED
1171 Enable deprecated sysfs by default.
1173 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1176 Only if you are using a new kernel on an old distribution, you might
1177 need to say Y here. Even then, odds are you would not need it
1178 enabled, you can always pass the boot option if absolutely necessary.
1181 bool "Kernel->user space relay support (formerly relayfs)"
1183 This option enables support for relay interface support in
1184 certain file systems (such as debugfs).
1185 It is designed to provide an efficient mechanism for tools and
1186 facilities to relay large amounts of data from kernel space to
1191 config BLK_DEV_INITRD
1192 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1193 depends on BROKEN || !FRV
1195 The initial RAM filesystem is a ramfs which is loaded by the
1196 boot loader (loadlin or lilo) and that is mounted as root
1197 before the normal boot procedure. It is typically used to
1198 load modules needed to mount the "real" root file system,
1199 etc. See <file:Documentation/initrd.txt> for details.
1201 If RAM disk support (BLK_DEV_RAM) is also included, this
1202 also enables initial RAM disk (initrd) support and adds
1203 15 Kbytes (more on some other architectures) to the kernel size.
1209 source "usr/Kconfig"
1213 config CC_OPTIMIZE_FOR_SIZE
1214 bool "Optimize for size"
1216 Enabling this option will pass "-Os" instead of "-O2" to gcc
1217 resulting in a smaller kernel.
1230 config SYSCTL_EXCEPTION_TRACE
1233 Enable support for /proc/sys/debug/exception-trace.
1235 config SYSCTL_ARCH_UNALIGN_NO_WARN
1238 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1239 Allows arch to define/use @no_unaligned_warning to possibly warn
1240 about unaligned access emulation going on under the hood.
1242 config SYSCTL_ARCH_UNALIGN_ALLOW
1245 Enable support for /proc/sys/kernel/unaligned-trap
1246 Allows arches to define/use @unaligned_enabled to runtime toggle
1247 the unaligned access emulation.
1248 see arch/parisc/kernel/unaligned.c for reference
1253 config HAVE_PCSPKR_PLATFORM
1257 bool "Configure standard kernel features (expert users)"
1258 # Unhide debug options, to make the on-by-default options visible
1261 This option allows certain base kernel options and settings
1262 to be disabled or tweaked. This is for specialized
1263 environments which can tolerate a "non-standard" kernel.
1264 Only use this if you really know what you are doing.
1267 bool "Enable 16-bit UID system calls" if EXPERT
1268 depends on HAVE_UID16
1271 This enables the legacy 16-bit UID syscall wrappers.
1273 config SYSCTL_SYSCALL
1274 bool "Sysctl syscall support" if EXPERT
1275 depends on PROC_SYSCTL
1279 sys_sysctl uses binary paths that have been found challenging
1280 to properly maintain and use. The interface in /proc/sys
1281 using paths with ascii names is now the primary path to this
1284 Almost nothing using the binary sysctl interface so if you are
1285 trying to save some space it is probably safe to disable this,
1286 making your kernel marginally smaller.
1288 If unsure say N here.
1291 bool "Load all symbols for debugging/ksymoops" if EXPERT
1294 Say Y here to let the kernel print out symbolic crash information and
1295 symbolic stack backtraces. This increases the size of the kernel
1296 somewhat, as all symbols have to be loaded into the kernel image.
1299 bool "Include all symbols in kallsyms"
1300 depends on DEBUG_KERNEL && KALLSYMS
1302 Normally kallsyms only contains the symbols of functions for nicer
1303 OOPS messages and backtraces (i.e., symbols from the text and inittext
1304 sections). This is sufficient for most cases. And only in very rare
1305 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1306 names of variables from the data sections, etc).
1308 This option makes sure that all symbols are loaded into the kernel
1309 image (i.e., symbols from all sections) in cost of increased kernel
1310 size (depending on the kernel configuration, it may be 300KiB or
1311 something like this).
1313 Say N unless you really need all symbols.
1317 bool "Enable support for printk" if EXPERT
1320 This option enables normal printk support. Removing it
1321 eliminates most of the message strings from the kernel image
1322 and makes the kernel more or less silent. As this makes it
1323 very difficult to diagnose system problems, saying N here is
1324 strongly discouraged.
1327 bool "BUG() support" if EXPERT
1330 Disabling this option eliminates support for BUG and WARN, reducing
1331 the size of your kernel image and potentially quietly ignoring
1332 numerous fatal conditions. You should only consider disabling this
1333 option for embedded systems with no facilities for reporting errors.
1339 bool "Enable ELF core dumps" if EXPERT
1341 Enable support for generating core dumps. Disabling saves about 4k.
1344 config PCSPKR_PLATFORM
1345 bool "Enable PC-Speaker support" if EXPERT
1346 depends on HAVE_PCSPKR_PLATFORM
1350 This option allows to disable the internal PC-Speaker
1351 support, saving some memory.
1355 bool "Enable full-sized data structures for core" if EXPERT
1357 Disabling this option reduces the size of miscellaneous core
1358 kernel data structures. This saves memory on small machines,
1359 but may reduce performance.
1362 bool "Enable futex support" if EXPERT
1366 Disabling this option will cause the kernel to be built without
1367 support for "fast userspace mutexes". The resulting kernel may not
1368 run glibc-based applications correctly.
1371 bool "Enable eventpoll support" if EXPERT
1375 Disabling this option will cause the kernel to be built without
1376 support for epoll family of system calls.
1379 bool "Enable signalfd() system call" if EXPERT
1383 Enable the signalfd() system call that allows to receive signals
1384 on a file descriptor.
1389 bool "Enable timerfd() system call" if EXPERT
1393 Enable the timerfd() system call that allows to receive timer
1394 events on a file descriptor.
1399 bool "Enable eventfd() system call" if EXPERT
1403 Enable the eventfd() system call that allows to receive both
1404 kernel notification (ie. KAIO) or userspace notifications.
1409 bool "Use full shmem filesystem" if EXPERT
1413 The shmem is an internal filesystem used to manage shared memory.
1414 It is backed by swap and manages resource limits. It is also exported
1415 to userspace as tmpfs if TMPFS is enabled. Disabling this
1416 option replaces shmem and tmpfs with the much simpler ramfs code,
1417 which may be appropriate on small systems without swap.
1420 bool "Enable AIO support" if EXPERT
1423 This option enables POSIX asynchronous I/O which may by used
1424 by some high performance threaded applications. Disabling
1425 this option saves about 7k.
1429 bool "Enable PCI quirk workarounds" if EXPERT
1432 This enables workarounds for various PCI chipset
1433 bugs/quirks. Disable this only if your target machine is
1434 unaffected by PCI quirks.
1437 bool "Embedded system"
1440 This option should be enabled if compiling the kernel for
1441 an embedded system so certain expert options are available
1444 config HAVE_PERF_EVENTS
1447 See tools/perf/design.txt for details.
1449 config PERF_USE_VMALLOC
1452 See tools/perf/design.txt for details
1454 menu "Kernel Performance Events And Counters"
1457 bool "Kernel performance events and counters"
1458 default y if PROFILING
1459 depends on HAVE_PERF_EVENTS
1463 Enable kernel support for various performance events provided
1464 by software and hardware.
1466 Software events are supported either built-in or via the
1467 use of generic tracepoints.
1469 Most modern CPUs support performance events via performance
1470 counter registers. These registers count the number of certain
1471 types of hw events: such as instructions executed, cachemisses
1472 suffered, or branches mis-predicted - without slowing down the
1473 kernel or applications. These registers can also trigger interrupts
1474 when a threshold number of events have passed - and can thus be
1475 used to profile the code that runs on that CPU.
1477 The Linux Performance Event subsystem provides an abstraction of
1478 these software and hardware event capabilities, available via a
1479 system call and used by the "perf" utility in tools/perf/. It
1480 provides per task and per CPU counters, and it provides event
1481 capabilities on top of those.
1485 config DEBUG_PERF_USE_VMALLOC
1487 bool "Debug: use vmalloc to back perf mmap() buffers"
1488 depends on PERF_EVENTS && DEBUG_KERNEL
1489 select PERF_USE_VMALLOC
1491 Use vmalloc memory to back perf mmap() buffers.
1493 Mostly useful for debugging the vmalloc code on platforms
1494 that don't require it.
1500 config VM_EVENT_COUNTERS
1502 bool "Enable VM event counters for /proc/vmstat" if EXPERT
1504 VM event counters are needed for event counts to be shown.
1505 This option allows the disabling of the VM event counters
1506 on EXPERT systems. /proc/vmstat will only show page counts
1507 if VM event counters are disabled.
1511 bool "Enable SLUB debugging support" if EXPERT
1512 depends on SLUB && SYSFS
1514 SLUB has extensive debug support features. Disabling these can
1515 result in significant savings in code size. This also disables
1516 SLUB sysfs support. /sys/slab will not exist and there will be
1517 no support for cache validation etc.
1520 bool "Disable heap randomization"
1523 Randomizing heap placement makes heap exploits harder, but it
1524 also breaks ancient binaries (including anything libc5 based).
1525 This option changes the bootup default to heap randomization
1526 disabled, and can be overridden at runtime by setting
1527 /proc/sys/kernel/randomize_va_space to 2.
1529 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1532 prompt "Choose SLAB allocator"
1535 This option allows to select a slab allocator.
1540 The regular slab allocator that is established and known to work
1541 well in all environments. It organizes cache hot objects in
1542 per cpu and per node queues.
1545 bool "SLUB (Unqueued Allocator)"
1547 SLUB is a slab allocator that minimizes cache line usage
1548 instead of managing queues of cached objects (SLAB approach).
1549 Per cpu caching is realized using slabs of objects instead
1550 of queues of objects. SLUB can use memory efficiently
1551 and has enhanced diagnostics. SLUB is the default choice for
1556 bool "SLOB (Simple Allocator)"
1558 SLOB replaces the stock allocator with a drastically simpler
1559 allocator. SLOB is generally more space efficient but
1560 does not perform as well on large systems.
1564 config MMAP_ALLOW_UNINITIALIZED
1565 bool "Allow mmapped anonymous memory to be uninitialized"
1566 depends on EXPERT && !MMU
1569 Normally, and according to the Linux spec, anonymous memory obtained
1570 from mmap() has it's contents cleared before it is passed to
1571 userspace. Enabling this config option allows you to request that
1572 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1573 providing a huge performance boost. If this option is not enabled,
1574 then the flag will be ignored.
1576 This is taken advantage of by uClibc's malloc(), and also by
1577 ELF-FDPIC binfmt's brk and stack allocator.
1579 Because of the obvious security issues, this option should only be
1580 enabled on embedded devices where you control what is run in
1581 userspace. Since that isn't generally a problem on no-MMU systems,
1582 it is normally safe to say Y here.
1584 See Documentation/nommu-mmap.txt for more information.
1587 bool "Profiling support"
1589 Say Y here to enable the extended profiling support mechanisms used
1590 by profilers such as OProfile.
1593 # Place an empty function call at each tracepoint site. Can be
1594 # dynamically changed for a probe function.
1599 source "arch/Kconfig"
1601 endmenu # General setup
1603 config HAVE_GENERIC_DMA_COHERENT
1610 depends on SLAB || SLUB_DEBUG
1618 default 0 if BASE_FULL
1619 default 1 if !BASE_FULL
1622 bool "Enable loadable module support"
1624 Kernel modules are small pieces of compiled code which can
1625 be inserted in the running kernel, rather than being
1626 permanently built into the kernel. You use the "modprobe"
1627 tool to add (and sometimes remove) them. If you say Y here,
1628 many parts of the kernel can be built as modules (by
1629 answering M instead of Y where indicated): this is most
1630 useful for infrequently used options which are not required
1631 for booting. For more information, see the man pages for
1632 modprobe, lsmod, modinfo, insmod and rmmod.
1634 If you say Y here, you will need to run "make
1635 modules_install" to put the modules under /lib/modules/
1636 where modprobe can find them (you may need to be root to do
1643 config MODULE_FORCE_LOAD
1644 bool "Forced module loading"
1647 Allow loading of modules without version information (ie. modprobe
1648 --force). Forced module loading sets the 'F' (forced) taint flag and
1649 is usually a really bad idea.
1651 config MODULE_UNLOAD
1652 bool "Module unloading"
1654 Without this option you will not be able to unload any
1655 modules (note that some modules may not be unloadable
1656 anyway), which makes your kernel smaller, faster
1657 and simpler. If unsure, say Y.
1659 config MODULE_FORCE_UNLOAD
1660 bool "Forced module unloading"
1661 depends on MODULE_UNLOAD
1663 This option allows you to force a module to unload, even if the
1664 kernel believes it is unsafe: the kernel will remove the module
1665 without waiting for anyone to stop using it (using the -f option to
1666 rmmod). This is mainly for kernel developers and desperate users.
1670 bool "Module versioning support"
1672 Usually, you have to use modules compiled with your kernel.
1673 Saying Y here makes it sometimes possible to use modules
1674 compiled for different kernels, by adding enough information
1675 to the modules to (hopefully) spot any changes which would
1676 make them incompatible with the kernel you are running. If
1679 config MODULE_SRCVERSION_ALL
1680 bool "Source checksum for all modules"
1682 Modules which contain a MODULE_VERSION get an extra "srcversion"
1683 field inserted into their modinfo section, which contains a
1684 sum of the source files which made it. This helps maintainers
1685 see exactly which source was used to build a module (since
1686 others sometimes change the module source without updating
1687 the version). With this option, such a "srcversion" field
1688 will be created for all modules. If unsure, say N.
1691 bool "Module signature verification"
1695 select ASYMMETRIC_KEY_TYPE
1696 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1697 select PUBLIC_KEY_ALGO_RSA
1700 select X509_CERTIFICATE_PARSER
1702 Check modules for valid signatures upon load: the signature
1703 is simply appended to the module. For more information see
1704 Documentation/module-signing.txt.
1706 !!!WARNING!!! If you enable this option, you MUST make sure that the
1707 module DOES NOT get stripped after being signed. This includes the
1708 debuginfo strip done by some packagers (such as rpmbuild) and
1709 inclusion into an initramfs that wants the module size reduced.
1711 config MODULE_SIG_FORCE
1712 bool "Require modules to be validly signed"
1713 depends on MODULE_SIG
1715 Reject unsigned modules or signed modules for which we don't have a
1716 key. Without this, such modules will simply taint the kernel.
1718 config MODULE_SIG_ALL
1719 bool "Automatically sign all modules"
1721 depends on MODULE_SIG
1723 Sign all modules during make modules_install. Without this option,
1724 modules must be signed manually, using the scripts/sign-file tool.
1726 comment "Do not forget to sign required modules with scripts/sign-file"
1727 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1730 prompt "Which hash algorithm should modules be signed with?"
1731 depends on MODULE_SIG
1733 This determines which sort of hashing algorithm will be used during
1734 signature generation. This algorithm _must_ be built into the kernel
1735 directly so that signature verification can take place. It is not
1736 possible to load a signed module containing the algorithm to check
1737 the signature on that module.
1739 config MODULE_SIG_SHA1
1740 bool "Sign modules with SHA-1"
1743 config MODULE_SIG_SHA224
1744 bool "Sign modules with SHA-224"
1745 select CRYPTO_SHA256
1747 config MODULE_SIG_SHA256
1748 bool "Sign modules with SHA-256"
1749 select CRYPTO_SHA256
1751 config MODULE_SIG_SHA384
1752 bool "Sign modules with SHA-384"
1753 select CRYPTO_SHA512
1755 config MODULE_SIG_SHA512
1756 bool "Sign modules with SHA-512"
1757 select CRYPTO_SHA512
1761 config MODULE_SIG_HASH
1763 depends on MODULE_SIG
1764 default "sha1" if MODULE_SIG_SHA1
1765 default "sha224" if MODULE_SIG_SHA224
1766 default "sha256" if MODULE_SIG_SHA256
1767 default "sha384" if MODULE_SIG_SHA384
1768 default "sha512" if MODULE_SIG_SHA512
1772 config INIT_ALL_POSSIBLE
1775 Back when each arch used to define their own cpu_online_mask and
1776 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
1777 with all 1s, and others with all 0s. When they were centralised,
1778 it was better to provide this option than to break all the archs
1779 and have several arch maintainers pursuing me down dark alleys.
1784 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1786 Need stop_machine() primitive.
1788 source "block/Kconfig"
1790 config PREEMPT_NOTIFIERS
1797 # Can be selected by architectures with broken toolchains
1798 # that get confused by correct const<->read_only section
1800 config BROKEN_RODATA
1806 Build a simple ASN.1 grammar compiler that produces a bytecode output
1807 that can be interpreted by the ASN.1 stream decoder and used to
1808 inform it as to what tags are to be expected in a stream and what
1809 functions to call on what tags.
1811 source "kernel/Kconfig.locks"
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