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 bool "Compile also drivers which will not load"
60 Some drivers can be compiled on a different platform than they are
61 intended to be run on. Despite they cannot be loaded there (or even
62 when they load they cannot be used due to missing HW support),
63 developers still, opposing to distributors, might want to build such
64 drivers to compile-test them.
66 If you are a developer and want to build everything available, say Y
67 here. If you are a user/distributor, say N here to exclude useless
68 drivers to be distributed.
71 string "Local version - append to kernel release"
73 Append an extra string to the end of your kernel version.
74 This will show up when you type uname, for example.
75 The string you set here will be appended after the contents of
76 any files with a filename matching localversion* in your
77 object and source tree, in that order. Your total string can
78 be a maximum of 64 characters.
80 config LOCALVERSION_AUTO
81 bool "Automatically append version information to the version string"
84 This will try to automatically determine if the current tree is a
85 release tree by looking for git tags that belong to the current
88 A string of the format -gxxxxxxxx will be added to the localversion
89 if a git-based tree is found. The string generated by this will be
90 appended after any matching localversion* files, and after the value
91 set in CONFIG_LOCALVERSION.
93 (The actual string used here is the first eight characters produced
94 by running the command:
96 $ git rev-parse --verify HEAD
98 which is done within the script "scripts/setlocalversion".)
100 config HAVE_KERNEL_GZIP
103 config HAVE_KERNEL_BZIP2
106 config HAVE_KERNEL_LZMA
109 config HAVE_KERNEL_XZ
112 config HAVE_KERNEL_LZO
116 prompt "Kernel compression mode"
118 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
120 The linux kernel is a kind of self-extracting executable.
121 Several compression algorithms are available, which differ
122 in efficiency, compression and decompression speed.
123 Compression speed is only relevant when building a kernel.
124 Decompression speed is relevant at each boot.
126 If you have any problems with bzip2 or lzma compressed
127 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
128 version of this functionality (bzip2 only), for 2.4, was
129 supplied by Christian Ludwig)
131 High compression options are mostly useful for users, who
132 are low on disk space (embedded systems), but for whom ram
135 If in doubt, select 'gzip'
139 depends on HAVE_KERNEL_GZIP
141 The old and tried gzip compression. It provides a good balance
142 between compression ratio and decompression speed.
146 depends on HAVE_KERNEL_BZIP2
148 Its compression ratio and speed is intermediate.
149 Decompression speed is slowest among the choices. The kernel
150 size is about 10% smaller with bzip2, in comparison to gzip.
151 Bzip2 uses a large amount of memory. For modern kernels you
152 will need at least 8MB RAM or more for booting.
156 depends on HAVE_KERNEL_LZMA
158 This compression algorithm's ratio is best. Decompression speed
159 is between gzip and bzip2. Compression is slowest.
160 The kernel size is about 33% smaller with LZMA in comparison to gzip.
164 depends on HAVE_KERNEL_XZ
166 XZ uses the LZMA2 algorithm and instruction set specific
167 BCJ filters which can improve compression ratio of executable
168 code. The size of the kernel is about 30% smaller with XZ in
169 comparison to gzip. On architectures for which there is a BCJ
170 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
171 will create a few percent smaller kernel than plain LZMA.
173 The speed is about the same as with LZMA: The decompression
174 speed of XZ is better than that of bzip2 but worse than gzip
175 and LZO. Compression is slow.
179 depends on HAVE_KERNEL_LZO
181 Its compression ratio is the poorest among the choices. The kernel
182 size is about 10% bigger than gzip; however its speed
183 (both compression and decompression) is the fastest.
187 config DEFAULT_HOSTNAME
188 string "Default hostname"
191 This option determines the default system hostname before userspace
192 calls sethostname(2). The kernel traditionally uses "(none)" here,
193 but you may wish to use a different default here to make a minimal
194 system more usable with less configuration.
197 bool "Support for paging of anonymous memory (swap)"
198 depends on MMU && BLOCK
201 This option allows you to choose whether you want to have support
202 for so called swap devices or swap files in your kernel that are
203 used to provide more virtual memory than the actual RAM present
204 in your computer. If unsure say Y.
209 Inter Process Communication is a suite of library functions and
210 system calls which let processes (running programs) synchronize and
211 exchange information. It is generally considered to be a good thing,
212 and some programs won't run unless you say Y here. In particular, if
213 you want to run the DOS emulator dosemu under Linux (read the
214 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
215 you'll need to say Y here.
217 You can find documentation about IPC with "info ipc" and also in
218 section 6.4 of the Linux Programmer's Guide, available from
219 <http://www.tldp.org/guides.html>.
221 config SYSVIPC_SYSCTL
228 bool "POSIX Message Queues"
231 POSIX variant of message queues is a part of IPC. In POSIX message
232 queues every message has a priority which decides about succession
233 of receiving it by a process. If you want to compile and run
234 programs written e.g. for Solaris with use of its POSIX message
235 queues (functions mq_*) say Y here.
237 POSIX message queues are visible as a filesystem called 'mqueue'
238 and can be mounted somewhere if you want to do filesystem
239 operations on message queues.
243 config POSIX_MQUEUE_SYSCTL
245 depends on POSIX_MQUEUE
250 bool "open by fhandle syscalls"
253 If you say Y here, a user level program will be able to map
254 file names to handle and then later use the handle for
255 different file system operations. This is useful in implementing
256 userspace file servers, which now track files using handles instead
257 of names. The handle would remain the same even if file names
258 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
262 bool "Auditing support"
265 Enable auditing infrastructure that can be used with another
266 kernel subsystem, such as SELinux (which requires this for
267 logging of avc messages output). Does not do system-call
268 auditing without CONFIG_AUDITSYSCALL.
271 bool "Enable system-call auditing support"
272 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
273 default y if SECURITY_SELINUX
275 Enable low-overhead system-call auditing infrastructure that
276 can be used independently or with another kernel subsystem,
281 depends on AUDITSYSCALL
286 depends on AUDITSYSCALL
289 config AUDIT_LOGINUID_IMMUTABLE
290 bool "Make audit loginuid immutable"
293 The config option toggles if a task setting its loginuid requires
294 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
295 but should instead only allow setting its loginuid if it was never
296 previously set. On systems which use systemd or a similar central
297 process to restart login services this should be set to true. On older
298 systems in which an admin would typically have to directly stop and
299 start processes this should be set to false. Setting this to true allows
300 one to drop potentially dangerous capabilites from the login tasks,
301 but may not be backwards compatible with older init systems.
303 source "kernel/irq/Kconfig"
304 source "kernel/time/Kconfig"
306 menu "CPU/Task time and stats accounting"
308 config VIRT_CPU_ACCOUNTING
312 prompt "Cputime accounting"
313 default TICK_CPU_ACCOUNTING if !PPC64
314 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
316 # Kind of a stub config for the pure tick based cputime accounting
317 config TICK_CPU_ACCOUNTING
318 bool "Simple tick based cputime accounting"
319 depends on !S390 && !NO_HZ_FULL
321 This is the basic tick based cputime accounting that maintains
322 statistics about user, system and idle time spent on per jiffies
327 config VIRT_CPU_ACCOUNTING_NATIVE
328 bool "Deterministic task and CPU time accounting"
329 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
330 select VIRT_CPU_ACCOUNTING
332 Select this option to enable more accurate task and CPU time
333 accounting. This is done by reading a CPU counter on each
334 kernel entry and exit and on transitions within the kernel
335 between system, softirq and hardirq state, so there is a
336 small performance impact. In the case of s390 or IBM POWER > 5,
337 this also enables accounting of stolen time on logically-partitioned
340 config VIRT_CPU_ACCOUNTING_GEN
341 bool "Full dynticks CPU time accounting"
342 depends on HAVE_CONTEXT_TRACKING && 64BIT
343 select VIRT_CPU_ACCOUNTING
344 select CONTEXT_TRACKING
346 Select this option to enable task and CPU time accounting on full
347 dynticks systems. This accounting is implemented by watching every
348 kernel-user boundaries using the context tracking subsystem.
349 The accounting is thus performed at the expense of some significant
352 For now this is only useful if you are working on the full
353 dynticks subsystem development.
357 config IRQ_TIME_ACCOUNTING
358 bool "Fine granularity task level IRQ time accounting"
359 depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
361 Select this option to enable fine granularity task irq time
362 accounting. This is done by reading a timestamp on each
363 transitions between softirq and hardirq state, so there can be a
364 small performance impact.
366 If in doubt, say N here.
370 config BSD_PROCESS_ACCT
371 bool "BSD Process Accounting"
373 If you say Y here, a user level program will be able to instruct the
374 kernel (via a special system call) to write process accounting
375 information to a file: whenever a process exits, information about
376 that process will be appended to the file by the kernel. The
377 information includes things such as creation time, owning user,
378 command name, memory usage, controlling terminal etc. (the complete
379 list is in the struct acct in <file:include/linux/acct.h>). It is
380 up to the user level program to do useful things with this
381 information. This is generally a good idea, so say Y.
383 config BSD_PROCESS_ACCT_V3
384 bool "BSD Process Accounting version 3 file format"
385 depends on BSD_PROCESS_ACCT
388 If you say Y here, the process accounting information is written
389 in a new file format that also logs the process IDs of each
390 process and it's parent. Note that this file format is incompatible
391 with previous v0/v1/v2 file formats, so you will need updated tools
392 for processing it. A preliminary version of these tools is available
393 at <http://www.gnu.org/software/acct/>.
396 bool "Export task/process statistics through netlink"
400 Export selected statistics for tasks/processes through the
401 generic netlink interface. Unlike BSD process accounting, the
402 statistics are available during the lifetime of tasks/processes as
403 responses to commands. Like BSD accounting, they are sent to user
408 config TASK_DELAY_ACCT
409 bool "Enable per-task delay accounting"
412 Collect information on time spent by a task waiting for system
413 resources like cpu, synchronous block I/O completion and swapping
414 in pages. Such statistics can help in setting a task's priorities
415 relative to other tasks for cpu, io, rss limits etc.
420 bool "Enable extended accounting over taskstats"
423 Collect extended task accounting data and send the data
424 to userland for processing over the taskstats interface.
428 config TASK_IO_ACCOUNTING
429 bool "Enable per-task storage I/O accounting"
430 depends on TASK_XACCT
432 Collect information on the number of bytes of storage I/O which this
437 endmenu # "CPU/Task time and stats accounting"
442 prompt "RCU Implementation"
446 bool "Tree-based hierarchical RCU"
447 depends on !PREEMPT && SMP
450 This option selects the RCU implementation that is
451 designed for very large SMP system with hundreds or
452 thousands of CPUs. It also scales down nicely to
455 config TREE_PREEMPT_RCU
456 bool "Preemptible tree-based hierarchical RCU"
459 This option selects the RCU implementation that is
460 designed for very large SMP systems with hundreds or
461 thousands of CPUs, but for which real-time response
462 is also required. It also scales down nicely to
465 Select this option if you are unsure.
468 bool "UP-only small-memory-footprint RCU"
469 depends on !PREEMPT && !SMP
471 This option selects the RCU implementation that is
472 designed for UP systems from which real-time response
473 is not required. This option greatly reduces the
474 memory footprint of RCU.
476 config TINY_PREEMPT_RCU
477 bool "Preemptible UP-only small-memory-footprint RCU"
478 depends on PREEMPT && !SMP
480 This option selects the RCU implementation that is designed
481 for real-time UP systems. This option greatly reduces the
482 memory footprint of RCU.
487 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
489 This option enables preemptible-RCU code that is common between
490 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
492 config RCU_STALL_COMMON
493 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
495 This option enables RCU CPU stall code that is common between
496 the TINY and TREE variants of RCU. The purpose is to allow
497 the tiny variants to disable RCU CPU stall warnings, while
498 making these warnings mandatory for the tree variants.
500 config CONTEXT_TRACKING
504 bool "Consider userspace as in RCU extended quiescent state"
505 depends on HAVE_CONTEXT_TRACKING && SMP
506 select CONTEXT_TRACKING
508 This option sets hooks on kernel / userspace boundaries and
509 puts RCU in extended quiescent state when the CPU runs in
510 userspace. It means that when a CPU runs in userspace, it is
511 excluded from the global RCU state machine and thus doesn't
512 try to keep the timer tick on for RCU.
514 Unless you want to hack and help the development of the full
515 dynticks mode, you shouldn't enable this option. It also
516 adds unnecessary overhead.
520 config CONTEXT_TRACKING_FORCE
521 bool "Force context tracking"
522 depends on CONTEXT_TRACKING
523 default CONTEXT_TRACKING
525 Probe on user/kernel boundaries by default in order to
526 test the features that rely on it such as userspace RCU extended
528 This test is there for debugging until we have a real user like the
532 int "Tree-based hierarchical RCU fanout value"
535 depends on TREE_RCU || TREE_PREEMPT_RCU
539 This option controls the fanout of hierarchical implementations
540 of RCU, allowing RCU to work efficiently on machines with
541 large numbers of CPUs. This value must be at least the fourth
542 root of NR_CPUS, which allows NR_CPUS to be insanely large.
543 The default value of RCU_FANOUT should be used for production
544 systems, but if you are stress-testing the RCU implementation
545 itself, small RCU_FANOUT values allow you to test large-system
546 code paths on small(er) systems.
548 Select a specific number if testing RCU itself.
549 Take the default if unsure.
551 config RCU_FANOUT_LEAF
552 int "Tree-based hierarchical RCU leaf-level fanout value"
553 range 2 RCU_FANOUT if 64BIT
554 range 2 RCU_FANOUT if !64BIT
555 depends on TREE_RCU || TREE_PREEMPT_RCU
558 This option controls the leaf-level fanout of hierarchical
559 implementations of RCU, and allows trading off cache misses
560 against lock contention. Systems that synchronize their
561 scheduling-clock interrupts for energy-efficiency reasons will
562 want the default because the smaller leaf-level fanout keeps
563 lock contention levels acceptably low. Very large systems
564 (hundreds or thousands of CPUs) will instead want to set this
565 value to the maximum value possible in order to reduce the
566 number of cache misses incurred during RCU's grace-period
567 initialization. These systems tend to run CPU-bound, and thus
568 are not helped by synchronized interrupts, and thus tend to
569 skew them, which reduces lock contention enough that large
570 leaf-level fanouts work well.
572 Select a specific number if testing RCU itself.
574 Select the maximum permissible value for large systems.
576 Take the default if unsure.
578 config RCU_FANOUT_EXACT
579 bool "Disable tree-based hierarchical RCU auto-balancing"
580 depends on TREE_RCU || TREE_PREEMPT_RCU
583 This option forces use of the exact RCU_FANOUT value specified,
584 regardless of imbalances in the hierarchy. This is useful for
585 testing RCU itself, and might one day be useful on systems with
586 strong NUMA behavior.
588 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
592 config RCU_FAST_NO_HZ
593 bool "Accelerate last non-dyntick-idle CPU's grace periods"
594 depends on NO_HZ_COMMON && SMP
597 This option permits CPUs to enter dynticks-idle state even if
598 they have RCU callbacks queued, and prevents RCU from waking
599 these CPUs up more than roughly once every four jiffies (by
600 default, you can adjust this using the rcutree.rcu_idle_gp_delay
601 parameter), thus improving energy efficiency. On the other
602 hand, this option increases the duration of RCU grace periods,
603 for example, slowing down synchronize_rcu().
605 Say Y if energy efficiency is critically important, and you
606 don't care about increased grace-period durations.
608 Say N if you are unsure.
610 config TREE_RCU_TRACE
611 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
614 This option provides tracing for the TREE_RCU and
615 TREE_PREEMPT_RCU implementations, permitting Makefile to
616 trivially select kernel/rcutree_trace.c.
619 bool "Enable RCU priority boosting"
620 depends on RT_MUTEXES && PREEMPT_RCU
623 This option boosts the priority of preempted RCU readers that
624 block the current preemptible RCU grace period for too long.
625 This option also prevents heavy loads from blocking RCU
626 callback invocation for all flavors of RCU.
628 Say Y here if you are working with real-time apps or heavy loads
629 Say N here if you are unsure.
631 config RCU_BOOST_PRIO
632 int "Real-time priority to boost RCU readers to"
637 This option specifies the real-time priority to which long-term
638 preempted RCU readers are to be boosted. If you are working
639 with a real-time application that has one or more CPU-bound
640 threads running at a real-time priority level, you should set
641 RCU_BOOST_PRIO to a priority higher then the highest-priority
642 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
643 of 1 is appropriate in the common case, which is real-time
644 applications that do not have any CPU-bound threads.
646 Some real-time applications might not have a single real-time
647 thread that saturates a given CPU, but instead might have
648 multiple real-time threads that, taken together, fully utilize
649 that CPU. In this case, you should set RCU_BOOST_PRIO to
650 a priority higher than the lowest-priority thread that is
651 conspiring to prevent the CPU from running any non-real-time
652 tasks. For example, if one thread at priority 10 and another
653 thread at priority 5 are between themselves fully consuming
654 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
655 set to priority 6 or higher.
657 Specify the real-time priority, or take the default if unsure.
659 config RCU_BOOST_DELAY
660 int "Milliseconds to delay boosting after RCU grace-period start"
665 This option specifies the time to wait after the beginning of
666 a given grace period before priority-boosting preempted RCU
667 readers blocking that grace period. Note that any RCU reader
668 blocking an expedited RCU grace period is boosted immediately.
670 Accept the default if unsure.
673 bool "Offload RCU callback processing from boot-selected CPUs (EXPERIMENTAL"
674 depends on TREE_RCU || TREE_PREEMPT_RCU
677 Use this option to reduce OS jitter for aggressive HPC or
678 real-time workloads. It can also be used to offload RCU
679 callback invocation to energy-efficient CPUs in battery-powered
680 asymmetric multiprocessors.
682 This option offloads callback invocation from the set of
683 CPUs specified at boot time by the rcu_nocbs parameter.
684 For each such CPU, a kthread ("rcuox/N") will be created to
685 invoke callbacks, where the "N" is the CPU being offloaded,
686 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
687 "s" for RCU-sched. Nothing prevents this kthread from running
688 on the specified CPUs, but (1) the kthreads may be preempted
689 between each callback, and (2) affinity or cgroups can be used
690 to force the kthreads to run on whatever set of CPUs is desired.
692 Say Y here if you want to help to debug reduced OS jitter.
693 Say N here if you are unsure.
696 prompt "Build-forced no-CBs CPUs"
697 default RCU_NOCB_CPU_NONE
699 This option allows no-CBs CPUs to be specified at build time.
700 Additional no-CBs CPUs may be specified by the rcu_nocbs=
703 config RCU_NOCB_CPU_NONE
704 bool "No build_forced no-CBs CPUs"
705 depends on RCU_NOCB_CPU && !NO_HZ_FULL
707 This option does not force any of the CPUs to be no-CBs CPUs.
708 Only CPUs designated by the rcu_nocbs= boot parameter will be
711 config RCU_NOCB_CPU_ZERO
712 bool "CPU 0 is a build_forced no-CBs CPU"
713 depends on RCU_NOCB_CPU && !NO_HZ_FULL
715 This option forces CPU 0 to be a no-CBs CPU. Additional CPUs
716 may be designated as no-CBs CPUs using the rcu_nocbs= boot
717 parameter will be no-CBs CPUs.
719 Select this if CPU 0 needs to be a no-CBs CPU for real-time
720 or energy-efficiency reasons.
722 config RCU_NOCB_CPU_ALL
723 bool "All CPUs are build_forced no-CBs CPUs"
724 depends on RCU_NOCB_CPU
726 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
727 boot parameter will be ignored.
729 Select this if all CPUs need to be no-CBs CPUs for real-time
730 or energy-efficiency reasons.
734 endmenu # "RCU Subsystem"
737 tristate "Kernel .config support"
739 This option enables the complete Linux kernel ".config" file
740 contents to be saved in the kernel. It provides documentation
741 of which kernel options are used in a running kernel or in an
742 on-disk kernel. This information can be extracted from the kernel
743 image file with the script scripts/extract-ikconfig and used as
744 input to rebuild the current kernel or to build another kernel.
745 It can also be extracted from a running kernel by reading
746 /proc/config.gz if enabled (below).
749 bool "Enable access to .config through /proc/config.gz"
750 depends on IKCONFIG && PROC_FS
752 This option enables access to the kernel configuration file
753 through /proc/config.gz.
756 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
760 Select kernel log buffer size as a power of 2.
770 # Architectures with an unreliable sched_clock() should select this:
772 config HAVE_UNSTABLE_SCHED_CLOCK
776 # For architectures that want to enable the support for NUMA-affine scheduler
779 config ARCH_SUPPORTS_NUMA_BALANCING
782 # For architectures that (ab)use NUMA to represent different memory regions
783 # all cpu-local but of different latencies, such as SuperH.
785 config ARCH_WANT_NUMA_VARIABLE_LOCALITY
789 # For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
790 config ARCH_WANTS_PROT_NUMA_PROT_NONE
793 config ARCH_USES_NUMA_PROT_NONE
796 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
797 depends on NUMA_BALANCING
799 config NUMA_BALANCING_DEFAULT_ENABLED
800 bool "Automatically enable NUMA aware memory/task placement"
802 depends on NUMA_BALANCING
804 If set, autonumic NUMA balancing will be enabled if running on a NUMA
807 config NUMA_BALANCING
808 bool "Memory placement aware NUMA scheduler"
809 depends on ARCH_SUPPORTS_NUMA_BALANCING
810 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
811 depends on SMP && NUMA && MIGRATION
813 This option adds support for automatic NUMA aware memory/task placement.
814 The mechanism is quite primitive and is based on migrating memory when
815 it is references to the node the task is running on.
817 This system will be inactive on UMA systems.
820 boolean "Control Group support"
823 This option adds support for grouping sets of processes together, for
824 use with process control subsystems such as Cpusets, CFS, memory
825 controls or device isolation.
827 - Documentation/scheduler/sched-design-CFS.txt (CFS)
828 - Documentation/cgroups/ (features for grouping, isolation
829 and resource control)
836 bool "Example debug cgroup subsystem"
839 This option enables a simple cgroup subsystem that
840 exports useful debugging information about the cgroups
845 config CGROUP_FREEZER
846 bool "Freezer cgroup subsystem"
848 Provides a way to freeze and unfreeze all tasks in a
852 bool "Device controller for cgroups"
854 Provides a cgroup implementing whitelists for devices which
855 a process in the cgroup can mknod or open.
858 bool "Cpuset support"
860 This option will let you create and manage CPUSETs which
861 allow dynamically partitioning a system into sets of CPUs and
862 Memory Nodes and assigning tasks to run only within those sets.
863 This is primarily useful on large SMP or NUMA systems.
867 config PROC_PID_CPUSET
868 bool "Include legacy /proc/<pid>/cpuset file"
872 config CGROUP_CPUACCT
873 bool "Simple CPU accounting cgroup subsystem"
875 Provides a simple Resource Controller for monitoring the
876 total CPU consumed by the tasks in a cgroup.
878 config RESOURCE_COUNTERS
879 bool "Resource counters"
881 This option enables controller independent resource accounting
882 infrastructure that works with cgroups.
885 bool "Memory Resource Controller for Control Groups"
886 depends on RESOURCE_COUNTERS
889 Provides a memory resource controller that manages both anonymous
890 memory and page cache. (See Documentation/cgroups/memory.txt)
892 Note that setting this option increases fixed memory overhead
893 associated with each page of memory in the system. By this,
894 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
895 usage tracking struct at boot. Total amount of this is printed out
898 Only enable when you're ok with these trade offs and really
899 sure you need the memory resource controller. Even when you enable
900 this, you can set "cgroup_disable=memory" at your boot option to
901 disable memory resource controller and you can avoid overheads.
902 (and lose benefits of memory resource controller)
904 This config option also selects MM_OWNER config option, which
905 could in turn add some fork/exit overhead.
908 bool "Memory Resource Controller Swap Extension"
909 depends on MEMCG && SWAP
911 Add swap management feature to memory resource controller. When you
912 enable this, you can limit mem+swap usage per cgroup. In other words,
913 when you disable this, memory resource controller has no cares to
914 usage of swap...a process can exhaust all of the swap. This extension
915 is useful when you want to avoid exhaustion swap but this itself
916 adds more overheads and consumes memory for remembering information.
917 Especially if you use 32bit system or small memory system, please
918 be careful about enabling this. When memory resource controller
919 is disabled by boot option, this will be automatically disabled and
920 there will be no overhead from this. Even when you set this config=y,
921 if boot option "swapaccount=0" is set, swap will not be accounted.
922 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
923 size is 4096bytes, 512k per 1Gbytes of swap.
924 config MEMCG_SWAP_ENABLED
925 bool "Memory Resource Controller Swap Extension enabled by default"
926 depends on MEMCG_SWAP
929 Memory Resource Controller Swap Extension comes with its price in
930 a bigger memory consumption. General purpose distribution kernels
931 which want to enable the feature but keep it disabled by default
932 and let the user enable it by swapaccount boot command line
933 parameter should have this option unselected.
934 For those who want to have the feature enabled by default should
935 select this option (if, for some reason, they need to disable it
936 then swapaccount=0 does the trick).
938 bool "Memory Resource Controller Kernel Memory accounting"
940 depends on SLUB || SLAB
942 The Kernel Memory extension for Memory Resource Controller can limit
943 the amount of memory used by kernel objects in the system. Those are
944 fundamentally different from the entities handled by the standard
945 Memory Controller, which are page-based, and can be swapped. Users of
946 the kmem extension can use it to guarantee that no group of processes
947 will ever exhaust kernel resources alone.
949 config CGROUP_HUGETLB
950 bool "HugeTLB Resource Controller for Control Groups"
951 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
954 Provides a cgroup Resource Controller for HugeTLB pages.
955 When you enable this, you can put a per cgroup limit on HugeTLB usage.
956 The limit is enforced during page fault. Since HugeTLB doesn't
957 support page reclaim, enforcing the limit at page fault time implies
958 that, the application will get SIGBUS signal if it tries to access
959 HugeTLB pages beyond its limit. This requires the application to know
960 beforehand how much HugeTLB pages it would require for its use. The
961 control group is tracked in the third page lru pointer. This means
962 that we cannot use the controller with huge page less than 3 pages.
965 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
966 depends on PERF_EVENTS && CGROUPS
968 This option extends the per-cpu mode to restrict monitoring to
969 threads which belong to the cgroup specified and run on the
974 menuconfig CGROUP_SCHED
975 bool "Group CPU scheduler"
978 This feature lets CPU scheduler recognize task groups and control CPU
979 bandwidth allocation to such task groups. It uses cgroups to group
983 config FAIR_GROUP_SCHED
984 bool "Group scheduling for SCHED_OTHER"
985 depends on CGROUP_SCHED
989 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
990 depends on FAIR_GROUP_SCHED
993 This option allows users to define CPU bandwidth rates (limits) for
994 tasks running within the fair group scheduler. Groups with no limit
995 set are considered to be unconstrained and will run with no
997 See tip/Documentation/scheduler/sched-bwc.txt for more information.
999 config RT_GROUP_SCHED
1000 bool "Group scheduling for SCHED_RR/FIFO"
1001 depends on CGROUP_SCHED
1004 This feature lets you explicitly allocate real CPU bandwidth
1005 to task groups. If enabled, it will also make it impossible to
1006 schedule realtime tasks for non-root users until you allocate
1007 realtime bandwidth for them.
1008 See Documentation/scheduler/sched-rt-group.txt for more information.
1013 bool "Block IO controller"
1017 Generic block IO controller cgroup interface. This is the common
1018 cgroup interface which should be used by various IO controlling
1021 Currently, CFQ IO scheduler uses it to recognize task groups and
1022 control disk bandwidth allocation (proportional time slice allocation)
1023 to such task groups. It is also used by bio throttling logic in
1024 block layer to implement upper limit in IO rates on a device.
1026 This option only enables generic Block IO controller infrastructure.
1027 One needs to also enable actual IO controlling logic/policy. For
1028 enabling proportional weight division of disk bandwidth in CFQ, set
1029 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
1030 CONFIG_BLK_DEV_THROTTLING=y.
1032 See Documentation/cgroups/blkio-controller.txt for more information.
1034 config DEBUG_BLK_CGROUP
1035 bool "Enable Block IO controller debugging"
1036 depends on BLK_CGROUP
1039 Enable some debugging help. Currently it exports additional stat
1040 files in a cgroup which can be useful for debugging.
1044 config CHECKPOINT_RESTORE
1045 bool "Checkpoint/restore support" if EXPERT
1048 Enables additional kernel features in a sake of checkpoint/restore.
1049 In particular it adds auxiliary prctl codes to setup process text,
1050 data and heap segment sizes, and a few additional /proc filesystem
1053 If unsure, say N here.
1055 menuconfig NAMESPACES
1056 bool "Namespaces support" if EXPERT
1059 Provides the way to make tasks work with different objects using
1060 the same id. For example same IPC id may refer to different objects
1061 or same user id or pid may refer to different tasks when used in
1062 different namespaces.
1067 bool "UTS namespace"
1070 In this namespace tasks see different info provided with the
1074 bool "IPC namespace"
1075 depends on (SYSVIPC || POSIX_MQUEUE)
1078 In this namespace tasks work with IPC ids which correspond to
1079 different IPC objects in different namespaces.
1082 bool "User namespace"
1083 depends on UIDGID_CONVERTED
1084 select UIDGID_STRICT_TYPE_CHECKS
1088 This allows containers, i.e. vservers, to use user namespaces
1089 to provide different user info for different servers.
1091 When user namespaces are enabled in the kernel it is
1092 recommended that the MEMCG and MEMCG_KMEM options also be
1093 enabled and that user-space use the memory control groups to
1094 limit the amount of memory a memory unprivileged users can
1100 bool "PID Namespaces"
1103 Support process id namespaces. This allows having multiple
1104 processes with the same pid as long as they are in different
1105 pid namespaces. This is a building block of containers.
1108 bool "Network namespace"
1112 Allow user space to create what appear to be multiple instances
1113 of the network stack.
1117 config UIDGID_CONVERTED
1118 # True if all of the selected software conmponents are known
1119 # to have uid_t and gid_t converted to kuid_t and kgid_t
1120 # where appropriate and are otherwise safe to use with
1121 # the user namespace.
1126 depends on XFS_FS = n
1128 config UIDGID_STRICT_TYPE_CHECKS
1129 bool "Require conversions between uid/gids and their internal representation"
1130 depends on UIDGID_CONVERTED
1133 While the nececessary conversions are being added to all subsystems this option allows
1134 the code to continue to build for unconverted subsystems.
1136 Say Y here if you want the strict type checking enabled
1138 config SCHED_AUTOGROUP
1139 bool "Automatic process group scheduling"
1143 select FAIR_GROUP_SCHED
1145 This option optimizes the scheduler for common desktop workloads by
1146 automatically creating and populating task groups. This separation
1147 of workloads isolates aggressive CPU burners (like build jobs) from
1148 desktop applications. Task group autogeneration is currently based
1154 config SYSFS_DEPRECATED
1155 bool "Enable deprecated sysfs features to support old userspace tools"
1159 This option adds code that switches the layout of the "block" class
1160 devices, to not show up in /sys/class/block/, but only in
1163 This switch is only active when the sysfs.deprecated=1 boot option is
1164 passed or the SYSFS_DEPRECATED_V2 option is set.
1166 This option allows new kernels to run on old distributions and tools,
1167 which might get confused by /sys/class/block/. Since 2007/2008 all
1168 major distributions and tools handle this just fine.
1170 Recent distributions and userspace tools after 2009/2010 depend on
1171 the existence of /sys/class/block/, and will not work with this
1174 Only if you are using a new kernel on an old distribution, you might
1177 config SYSFS_DEPRECATED_V2
1178 bool "Enable deprecated sysfs features by default"
1181 depends on SYSFS_DEPRECATED
1183 Enable deprecated sysfs by default.
1185 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1188 Only if you are using a new kernel on an old distribution, you might
1189 need to say Y here. Even then, odds are you would not need it
1190 enabled, you can always pass the boot option if absolutely necessary.
1193 bool "Kernel->user space relay support (formerly relayfs)"
1195 This option enables support for relay interface support in
1196 certain file systems (such as debugfs).
1197 It is designed to provide an efficient mechanism for tools and
1198 facilities to relay large amounts of data from kernel space to
1203 config BLK_DEV_INITRD
1204 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1205 depends on BROKEN || !FRV
1207 The initial RAM filesystem is a ramfs which is loaded by the
1208 boot loader (loadlin or lilo) and that is mounted as root
1209 before the normal boot procedure. It is typically used to
1210 load modules needed to mount the "real" root file system,
1211 etc. See <file:Documentation/initrd.txt> for details.
1213 If RAM disk support (BLK_DEV_RAM) is also included, this
1214 also enables initial RAM disk (initrd) support and adds
1215 15 Kbytes (more on some other architectures) to the kernel size.
1221 source "usr/Kconfig"
1225 config CC_OPTIMIZE_FOR_SIZE
1226 bool "Optimize for size"
1228 Enabling this option will pass "-Os" instead of "-O2" to gcc
1229 resulting in a smaller kernel.
1242 config SYSCTL_EXCEPTION_TRACE
1245 Enable support for /proc/sys/debug/exception-trace.
1247 config SYSCTL_ARCH_UNALIGN_NO_WARN
1250 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1251 Allows arch to define/use @no_unaligned_warning to possibly warn
1252 about unaligned access emulation going on under the hood.
1254 config SYSCTL_ARCH_UNALIGN_ALLOW
1257 Enable support for /proc/sys/kernel/unaligned-trap
1258 Allows arches to define/use @unaligned_enabled to runtime toggle
1259 the unaligned access emulation.
1260 see arch/parisc/kernel/unaligned.c for reference
1262 config HAVE_PCSPKR_PLATFORM
1266 bool "Configure standard kernel features (expert users)"
1267 # Unhide debug options, to make the on-by-default options visible
1270 This option allows certain base kernel options and settings
1271 to be disabled or tweaked. This is for specialized
1272 environments which can tolerate a "non-standard" kernel.
1273 Only use this if you really know what you are doing.
1276 bool "Enable 16-bit UID system calls" if EXPERT
1277 depends on HAVE_UID16
1280 This enables the legacy 16-bit UID syscall wrappers.
1282 config SYSCTL_SYSCALL
1283 bool "Sysctl syscall support" if EXPERT
1284 depends on PROC_SYSCTL
1288 sys_sysctl uses binary paths that have been found challenging
1289 to properly maintain and use. The interface in /proc/sys
1290 using paths with ascii names is now the primary path to this
1293 Almost nothing using the binary sysctl interface so if you are
1294 trying to save some space it is probably safe to disable this,
1295 making your kernel marginally smaller.
1297 If unsure say N here.
1300 bool "Load all symbols for debugging/ksymoops" if EXPERT
1303 Say Y here to let the kernel print out symbolic crash information and
1304 symbolic stack backtraces. This increases the size of the kernel
1305 somewhat, as all symbols have to be loaded into the kernel image.
1308 bool "Include all symbols in kallsyms"
1309 depends on DEBUG_KERNEL && KALLSYMS
1311 Normally kallsyms only contains the symbols of functions for nicer
1312 OOPS messages and backtraces (i.e., symbols from the text and inittext
1313 sections). This is sufficient for most cases. And only in very rare
1314 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1315 names of variables from the data sections, etc).
1317 This option makes sure that all symbols are loaded into the kernel
1318 image (i.e., symbols from all sections) in cost of increased kernel
1319 size (depending on the kernel configuration, it may be 300KiB or
1320 something like this).
1322 Say N unless you really need all symbols.
1326 bool "Enable support for printk" if EXPERT
1329 This option enables normal printk support. Removing it
1330 eliminates most of the message strings from the kernel image
1331 and makes the kernel more or less silent. As this makes it
1332 very difficult to diagnose system problems, saying N here is
1333 strongly discouraged.
1336 bool "BUG() support" if EXPERT
1339 Disabling this option eliminates support for BUG and WARN, reducing
1340 the size of your kernel image and potentially quietly ignoring
1341 numerous fatal conditions. You should only consider disabling this
1342 option for embedded systems with no facilities for reporting errors.
1348 bool "Enable ELF core dumps" if EXPERT
1350 Enable support for generating core dumps. Disabling saves about 4k.
1353 config PCSPKR_PLATFORM
1354 bool "Enable PC-Speaker support" if EXPERT
1355 depends on HAVE_PCSPKR_PLATFORM
1359 This option allows to disable the internal PC-Speaker
1360 support, saving some memory.
1364 bool "Enable full-sized data structures for core" if EXPERT
1366 Disabling this option reduces the size of miscellaneous core
1367 kernel data structures. This saves memory on small machines,
1368 but may reduce performance.
1371 bool "Enable futex support" if EXPERT
1375 Disabling this option will cause the kernel to be built without
1376 support for "fast userspace mutexes". The resulting kernel may not
1377 run glibc-based applications correctly.
1380 bool "Enable eventpoll support" if EXPERT
1384 Disabling this option will cause the kernel to be built without
1385 support for epoll family of system calls.
1388 bool "Enable signalfd() system call" if EXPERT
1392 Enable the signalfd() system call that allows to receive signals
1393 on a file descriptor.
1398 bool "Enable timerfd() system call" if EXPERT
1402 Enable the timerfd() system call that allows to receive timer
1403 events on a file descriptor.
1408 bool "Enable eventfd() system call" if EXPERT
1412 Enable the eventfd() system call that allows to receive both
1413 kernel notification (ie. KAIO) or userspace notifications.
1418 bool "Use full shmem filesystem" if EXPERT
1422 The shmem is an internal filesystem used to manage shared memory.
1423 It is backed by swap and manages resource limits. It is also exported
1424 to userspace as tmpfs if TMPFS is enabled. Disabling this
1425 option replaces shmem and tmpfs with the much simpler ramfs code,
1426 which may be appropriate on small systems without swap.
1429 bool "Enable AIO support" if EXPERT
1432 This option enables POSIX asynchronous I/O which may by used
1433 by some high performance threaded applications. Disabling
1434 this option saves about 7k.
1438 bool "Enable PCI quirk workarounds" if EXPERT
1441 This enables workarounds for various PCI chipset
1442 bugs/quirks. Disable this only if your target machine is
1443 unaffected by PCI quirks.
1446 bool "Embedded system"
1449 This option should be enabled if compiling the kernel for
1450 an embedded system so certain expert options are available
1453 config HAVE_PERF_EVENTS
1456 See tools/perf/design.txt for details.
1458 config PERF_USE_VMALLOC
1461 See tools/perf/design.txt for details
1463 menu "Kernel Performance Events And Counters"
1466 bool "Kernel performance events and counters"
1467 default y if PROFILING
1468 depends on HAVE_PERF_EVENTS
1472 Enable kernel support for various performance events provided
1473 by software and hardware.
1475 Software events are supported either built-in or via the
1476 use of generic tracepoints.
1478 Most modern CPUs support performance events via performance
1479 counter registers. These registers count the number of certain
1480 types of hw events: such as instructions executed, cachemisses
1481 suffered, or branches mis-predicted - without slowing down the
1482 kernel or applications. These registers can also trigger interrupts
1483 when a threshold number of events have passed - and can thus be
1484 used to profile the code that runs on that CPU.
1486 The Linux Performance Event subsystem provides an abstraction of
1487 these software and hardware event capabilities, available via a
1488 system call and used by the "perf" utility in tools/perf/. It
1489 provides per task and per CPU counters, and it provides event
1490 capabilities on top of those.
1494 config DEBUG_PERF_USE_VMALLOC
1496 bool "Debug: use vmalloc to back perf mmap() buffers"
1497 depends on PERF_EVENTS && DEBUG_KERNEL
1498 select PERF_USE_VMALLOC
1500 Use vmalloc memory to back perf mmap() buffers.
1502 Mostly useful for debugging the vmalloc code on platforms
1503 that don't require it.
1509 config VM_EVENT_COUNTERS
1511 bool "Enable VM event counters for /proc/vmstat" if EXPERT
1513 VM event counters are needed for event counts to be shown.
1514 This option allows the disabling of the VM event counters
1515 on EXPERT systems. /proc/vmstat will only show page counts
1516 if VM event counters are disabled.
1520 bool "Enable SLUB debugging support" if EXPERT
1521 depends on SLUB && SYSFS
1523 SLUB has extensive debug support features. Disabling these can
1524 result in significant savings in code size. This also disables
1525 SLUB sysfs support. /sys/slab will not exist and there will be
1526 no support for cache validation etc.
1529 bool "Disable heap randomization"
1532 Randomizing heap placement makes heap exploits harder, but it
1533 also breaks ancient binaries (including anything libc5 based).
1534 This option changes the bootup default to heap randomization
1535 disabled, and can be overridden at runtime by setting
1536 /proc/sys/kernel/randomize_va_space to 2.
1538 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1541 prompt "Choose SLAB allocator"
1544 This option allows to select a slab allocator.
1549 The regular slab allocator that is established and known to work
1550 well in all environments. It organizes cache hot objects in
1551 per cpu and per node queues.
1554 bool "SLUB (Unqueued Allocator)"
1556 SLUB is a slab allocator that minimizes cache line usage
1557 instead of managing queues of cached objects (SLAB approach).
1558 Per cpu caching is realized using slabs of objects instead
1559 of queues of objects. SLUB can use memory efficiently
1560 and has enhanced diagnostics. SLUB is the default choice for
1565 bool "SLOB (Simple Allocator)"
1567 SLOB replaces the stock allocator with a drastically simpler
1568 allocator. SLOB is generally more space efficient but
1569 does not perform as well on large systems.
1573 config MMAP_ALLOW_UNINITIALIZED
1574 bool "Allow mmapped anonymous memory to be uninitialized"
1575 depends on EXPERT && !MMU
1578 Normally, and according to the Linux spec, anonymous memory obtained
1579 from mmap() has it's contents cleared before it is passed to
1580 userspace. Enabling this config option allows you to request that
1581 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1582 providing a huge performance boost. If this option is not enabled,
1583 then the flag will be ignored.
1585 This is taken advantage of by uClibc's malloc(), and also by
1586 ELF-FDPIC binfmt's brk and stack allocator.
1588 Because of the obvious security issues, this option should only be
1589 enabled on embedded devices where you control what is run in
1590 userspace. Since that isn't generally a problem on no-MMU systems,
1591 it is normally safe to say Y here.
1593 See Documentation/nommu-mmap.txt for more information.
1596 bool "Profiling support"
1598 Say Y here to enable the extended profiling support mechanisms used
1599 by profilers such as OProfile.
1602 # Place an empty function call at each tracepoint site. Can be
1603 # dynamically changed for a probe function.
1608 source "arch/Kconfig"
1610 endmenu # General setup
1612 config HAVE_GENERIC_DMA_COHERENT
1619 depends on SLAB || SLUB_DEBUG
1627 default 0 if BASE_FULL
1628 default 1 if !BASE_FULL
1631 bool "Enable loadable module support"
1633 Kernel modules are small pieces of compiled code which can
1634 be inserted in the running kernel, rather than being
1635 permanently built into the kernel. You use the "modprobe"
1636 tool to add (and sometimes remove) them. If you say Y here,
1637 many parts of the kernel can be built as modules (by
1638 answering M instead of Y where indicated): this is most
1639 useful for infrequently used options which are not required
1640 for booting. For more information, see the man pages for
1641 modprobe, lsmod, modinfo, insmod and rmmod.
1643 If you say Y here, you will need to run "make
1644 modules_install" to put the modules under /lib/modules/
1645 where modprobe can find them (you may need to be root to do
1652 config MODULE_FORCE_LOAD
1653 bool "Forced module loading"
1656 Allow loading of modules without version information (ie. modprobe
1657 --force). Forced module loading sets the 'F' (forced) taint flag and
1658 is usually a really bad idea.
1660 config MODULE_UNLOAD
1661 bool "Module unloading"
1663 Without this option you will not be able to unload any
1664 modules (note that some modules may not be unloadable
1665 anyway), which makes your kernel smaller, faster
1666 and simpler. If unsure, say Y.
1668 config MODULE_FORCE_UNLOAD
1669 bool "Forced module unloading"
1670 depends on MODULE_UNLOAD
1672 This option allows you to force a module to unload, even if the
1673 kernel believes it is unsafe: the kernel will remove the module
1674 without waiting for anyone to stop using it (using the -f option to
1675 rmmod). This is mainly for kernel developers and desperate users.
1679 bool "Module versioning support"
1681 Usually, you have to use modules compiled with your kernel.
1682 Saying Y here makes it sometimes possible to use modules
1683 compiled for different kernels, by adding enough information
1684 to the modules to (hopefully) spot any changes which would
1685 make them incompatible with the kernel you are running. If
1688 config MODULE_SRCVERSION_ALL
1689 bool "Source checksum for all modules"
1691 Modules which contain a MODULE_VERSION get an extra "srcversion"
1692 field inserted into their modinfo section, which contains a
1693 sum of the source files which made it. This helps maintainers
1694 see exactly which source was used to build a module (since
1695 others sometimes change the module source without updating
1696 the version). With this option, such a "srcversion" field
1697 will be created for all modules. If unsure, say N.
1700 bool "Module signature verification"
1704 select ASYMMETRIC_KEY_TYPE
1705 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1706 select PUBLIC_KEY_ALGO_RSA
1709 select X509_CERTIFICATE_PARSER
1711 Check modules for valid signatures upon load: the signature
1712 is simply appended to the module. For more information see
1713 Documentation/module-signing.txt.
1715 !!!WARNING!!! If you enable this option, you MUST make sure that the
1716 module DOES NOT get stripped after being signed. This includes the
1717 debuginfo strip done by some packagers (such as rpmbuild) and
1718 inclusion into an initramfs that wants the module size reduced.
1720 config MODULE_SIG_FORCE
1721 bool "Require modules to be validly signed"
1722 depends on MODULE_SIG
1724 Reject unsigned modules or signed modules for which we don't have a
1725 key. Without this, such modules will simply taint the kernel.
1727 config MODULE_SIG_ALL
1728 bool "Automatically sign all modules"
1730 depends on MODULE_SIG
1732 Sign all modules during make modules_install. Without this option,
1733 modules must be signed manually, using the scripts/sign-file tool.
1735 comment "Do not forget to sign required modules with scripts/sign-file"
1736 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1739 prompt "Which hash algorithm should modules be signed with?"
1740 depends on MODULE_SIG
1742 This determines which sort of hashing algorithm will be used during
1743 signature generation. This algorithm _must_ be built into the kernel
1744 directly so that signature verification can take place. It is not
1745 possible to load a signed module containing the algorithm to check
1746 the signature on that module.
1748 config MODULE_SIG_SHA1
1749 bool "Sign modules with SHA-1"
1752 config MODULE_SIG_SHA224
1753 bool "Sign modules with SHA-224"
1754 select CRYPTO_SHA256
1756 config MODULE_SIG_SHA256
1757 bool "Sign modules with SHA-256"
1758 select CRYPTO_SHA256
1760 config MODULE_SIG_SHA384
1761 bool "Sign modules with SHA-384"
1762 select CRYPTO_SHA512
1764 config MODULE_SIG_SHA512
1765 bool "Sign modules with SHA-512"
1766 select CRYPTO_SHA512
1770 config MODULE_SIG_HASH
1772 depends on MODULE_SIG
1773 default "sha1" if MODULE_SIG_SHA1
1774 default "sha224" if MODULE_SIG_SHA224
1775 default "sha256" if MODULE_SIG_SHA256
1776 default "sha384" if MODULE_SIG_SHA384
1777 default "sha512" if MODULE_SIG_SHA512
1781 config INIT_ALL_POSSIBLE
1784 Back when each arch used to define their own cpu_online_mask and
1785 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
1786 with all 1s, and others with all 0s. When they were centralised,
1787 it was better to provide this option than to break all the archs
1788 and have several arch maintainers pursuing me down dark alleys.
1793 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1795 Need stop_machine() primitive.
1797 source "block/Kconfig"
1799 config PREEMPT_NOTIFIERS
1806 # Can be selected by architectures with broken toolchains
1807 # that get confused by correct const<->read_only section
1809 config BROKEN_RODATA
1815 Build a simple ASN.1 grammar compiler that produces a bytecode output
1816 that can be interpreted by the ASN.1 stream decoder and used to
1817 inform it as to what tags are to be expected in a stream and what
1818 functions to call on what tags.
1820 source "kernel/Kconfig.locks"