need to set this unless you want the configured kernel build
directory to select the cross-compiler automatically.
+config COMPILE_TEST
+ bool "Compile also drivers which will not load"
+ default n
+ help
+ Some drivers can be compiled on a different platform than they are
+ intended to be run on. Despite they cannot be loaded there (or even
+ when they load they cannot be used due to missing HW support),
+ developers still, opposing to distributors, might want to build such
+ drivers to compile-test them.
+
+ If you are a developer and want to build everything available, say Y
+ here. If you are a user/distributor, say N here to exclude useless
+ drivers to be distributed.
+
config LOCALVERSION
string "Local version - append to kernel release"
help
config HAVE_KERNEL_LZO
bool
+config HAVE_KERNEL_LZ4
+ bool
+
choice
prompt "Kernel compression mode"
default KERNEL_GZIP
- depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
+ depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4
help
The linux kernel is a kind of self-extracting executable.
Several compression algorithms are available, which differ
size is about 10% bigger than gzip; however its speed
(both compression and decompression) is the fastest.
+config KERNEL_LZ4
+ bool "LZ4"
+ depends on HAVE_KERNEL_LZ4
+ help
+ LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
+ A preliminary version of LZ4 de/compression tool is available at
+ <https://code.google.com/p/lz4/>.
+
+ Its compression ratio is worse than LZO. The size of the kernel
+ is about 8% bigger than LZO. But the decompression speed is
+ faster than LZO.
+
endchoice
config DEFAULT_HOSTNAME
depends on SYSCTL
default y
+config CROSS_MEMORY_ATTACH
+ bool "Enable process_vm_readv/writev syscalls"
+ depends on MMU
+ default y
+ help
+ Enabling this option adds the system calls process_vm_readv and
+ process_vm_writev which allow a process with the correct privileges
+ to directly read from or write to another process' address space.
+ See the man page for more details.
+
config FHANDLE
bool "open by fhandle syscalls"
select EXPORTFS
get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
syscalls.
+config USELIB
+ bool "uselib syscall"
+ default y
+ help
+ This option enables the uselib syscall, a system call used in the
+ dynamic linker from libc5 and earlier. glibc does not use this
+ system call. If you intend to run programs built on libc5 or
+ earlier, you may need to enable this syscall. Current systems
+ running glibc can safely disable this.
+
config AUDIT
bool "Auditing support"
depends on NET
logging of avc messages output). Does not do system-call
auditing without CONFIG_AUDITSYSCALL.
+config HAVE_ARCH_AUDITSYSCALL
+ bool
+
config AUDITSYSCALL
bool "Enable system-call auditing support"
- depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
+ depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
default y if SECURITY_SELINUX
help
Enable low-overhead system-call auditing infrastructure that
depends on AUDITSYSCALL
select FSNOTIFY
-config AUDIT_LOGINUID_IMMUTABLE
- bool "Make audit loginuid immutable"
- depends on AUDIT
- help
- The config option toggles if a task setting its loginuid requires
- CAP_SYS_AUDITCONTROL or if that task should require no special permissions
- but should instead only allow setting its loginuid if it was never
- previously set. On systems which use systemd or a similar central
- process to restart login services this should be set to true. On older
- systems in which an admin would typically have to directly stop and
- start processes this should be set to false. Setting this to true allows
- one to drop potentially dangerous capabilites from the login tasks,
- but may not be backwards compatible with older init systems.
-
source "kernel/irq/Kconfig"
source "kernel/time/Kconfig"
config VIRT_CPU_ACCOUNTING_GEN
bool "Full dynticks CPU time accounting"
- depends on HAVE_CONTEXT_TRACKING && 64BIT
+ depends on HAVE_CONTEXT_TRACKING
+ depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
select VIRT_CPU_ACCOUNTING
select CONTEXT_TRACKING
help
config BSD_PROCESS_ACCT
bool "BSD Process Accounting"
+ depends on MULTIUSER
help
If you say Y here, a user level program will be able to instruct the
kernel (via a special system call) to write process accounting
config TASKSTATS
bool "Export task/process statistics through netlink"
depends on NET
+ depends on MULTIUSER
default n
help
Export selected statistics for tasks/processes through the
config TASK_DELAY_ACCT
bool "Enable per-task delay accounting"
depends on TASKSTATS
+ select SCHED_INFO
help
Collect information on time spent by a task waiting for system
resources like cpu, synchronous block I/O completion and swapping
menu "RCU Subsystem"
-choice
- prompt "RCU Implementation"
- default TREE_RCU
-
config TREE_RCU
- bool "Tree-based hierarchical RCU"
- depends on !PREEMPT && SMP
- select IRQ_WORK
+ bool
+ default y if !PREEMPT && SMP
help
This option selects the RCU implementation that is
designed for very large SMP system with hundreds or
thousands of CPUs. It also scales down nicely to
smaller systems.
-config TREE_PREEMPT_RCU
- bool "Preemptible tree-based hierarchical RCU"
- depends on PREEMPT
+config PREEMPT_RCU
+ bool
+ default y if PREEMPT
help
This option selects the RCU implementation that is
designed for very large SMP systems with hundreds or
Select this option if you are unsure.
config TINY_RCU
- bool "UP-only small-memory-footprint RCU"
- depends on !PREEMPT && !SMP
+ bool
+ default y if !PREEMPT && !SMP
help
This option selects the RCU implementation that is
designed for UP systems from which real-time response
is not required. This option greatly reduces the
memory footprint of RCU.
-config TINY_PREEMPT_RCU
- bool "Preemptible UP-only small-memory-footprint RCU"
- depends on PREEMPT && !SMP
+config RCU_EXPERT
+ bool "Make expert-level adjustments to RCU configuration"
+ default n
help
- This option selects the RCU implementation that is designed
- for real-time UP systems. This option greatly reduces the
- memory footprint of RCU.
+ This option needs to be enabled if you wish to make
+ expert-level adjustments to RCU configuration. By default,
+ no such adjustments can be made, which has the often-beneficial
+ side-effect of preventing "make oldconfig" from asking you all
+ sorts of detailed questions about how you would like numerous
+ obscure RCU options to be set up.
-endchoice
+ Say Y if you need to make expert-level adjustments to RCU.
-config PREEMPT_RCU
- def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
+ Say N if you are unsure.
+
+config SRCU
+ bool
help
- This option enables preemptible-RCU code that is common between
- the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
+ This option selects the sleepable version of RCU. This version
+ permits arbitrary sleeping or blocking within RCU read-side critical
+ sections.
+
+config TASKS_RCU
+ bool
+ default n
+ select SRCU
+ help
+ This option enables a task-based RCU implementation that uses
+ only voluntary context switch (not preemption!), idle, and
+ user-mode execution as quiescent states.
config RCU_STALL_COMMON
- def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
+ def_bool ( TREE_RCU || PREEMPT_RCU || RCU_TRACE )
help
This option enables RCU CPU stall code that is common between
the TINY and TREE variants of RCU. The purpose is to allow
config CONTEXT_TRACKING
bool
-config RCU_USER_QS
- bool "Consider userspace as in RCU extended quiescent state"
- depends on HAVE_CONTEXT_TRACKING && SMP
- select CONTEXT_TRACKING
- help
- This option sets hooks on kernel / userspace boundaries and
- puts RCU in extended quiescent state when the CPU runs in
- userspace. It means that when a CPU runs in userspace, it is
- excluded from the global RCU state machine and thus doesn't
- try to keep the timer tick on for RCU.
-
- Unless you want to hack and help the development of the full
- dynticks mode, you shouldn't enable this option. It also
- adds unnecessary overhead.
-
- If unsure say N
-
config CONTEXT_TRACKING_FORCE
bool "Force context tracking"
depends on CONTEXT_TRACKING
- default CONTEXT_TRACKING
+ default y if !NO_HZ_FULL
help
- Probe on user/kernel boundaries by default in order to
- test the features that rely on it such as userspace RCU extended
- quiescent states.
- This test is there for debugging until we have a real user like the
- full dynticks mode.
+ The major pre-requirement for full dynticks to work is to
+ support the context tracking subsystem. But there are also
+ other dependencies to provide in order to make the full
+ dynticks working.
+
+ This option stands for testing when an arch implements the
+ context tracking backend but doesn't yet fullfill all the
+ requirements to make the full dynticks feature working.
+ Without the full dynticks, there is no way to test the support
+ for context tracking and the subsystems that rely on it: RCU
+ userspace extended quiescent state and tickless cputime
+ accounting. This option copes with the absence of the full
+ dynticks subsystem by forcing the context tracking on all
+ CPUs in the system.
+
+ Say Y only if you're working on the development of an
+ architecture backend for the context tracking.
+
+ Say N otherwise, this option brings an overhead that you
+ don't want in production.
+
config RCU_FANOUT
int "Tree-based hierarchical RCU fanout value"
range 2 64 if 64BIT
range 2 32 if !64BIT
- depends on TREE_RCU || TREE_PREEMPT_RCU
+ depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT
default 64 if 64BIT
default 32 if !64BIT
help
config RCU_FANOUT_LEAF
int "Tree-based hierarchical RCU leaf-level fanout value"
- range 2 RCU_FANOUT if 64BIT
- range 2 RCU_FANOUT if !64BIT
- depends on TREE_RCU || TREE_PREEMPT_RCU
+ range 2 64 if 64BIT
+ range 2 32 if !64BIT
+ depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT
default 16
help
This option controls the leaf-level fanout of hierarchical
Take the default if unsure.
-config RCU_FANOUT_EXACT
- bool "Disable tree-based hierarchical RCU auto-balancing"
- depends on TREE_RCU || TREE_PREEMPT_RCU
- default n
- help
- This option forces use of the exact RCU_FANOUT value specified,
- regardless of imbalances in the hierarchy. This is useful for
- testing RCU itself, and might one day be useful on systems with
- strong NUMA behavior.
-
- Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
-
- Say N if unsure.
-
config RCU_FAST_NO_HZ
bool "Accelerate last non-dyntick-idle CPU's grace periods"
- depends on NO_HZ_COMMON && SMP
+ depends on NO_HZ_COMMON && SMP && RCU_EXPERT
default n
help
This option permits CPUs to enter dynticks-idle state even if
Say N if you are unsure.
config TREE_RCU_TRACE
- def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
+ def_bool RCU_TRACE && ( TREE_RCU || PREEMPT_RCU )
select DEBUG_FS
help
This option provides tracing for the TREE_RCU and
- TREE_PREEMPT_RCU implementations, permitting Makefile to
+ PREEMPT_RCU implementations, permitting Makefile to
trivially select kernel/rcutree_trace.c.
config RCU_BOOST
bool "Enable RCU priority boosting"
- depends on RT_MUTEXES && PREEMPT_RCU
+ depends on RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT
default n
help
This option boosts the priority of preempted RCU readers that
Say Y here if you are working with real-time apps or heavy loads
Say N here if you are unsure.
-config RCU_BOOST_PRIO
- int "Real-time priority to boost RCU readers to"
- range 1 99
- depends on RCU_BOOST
- default 1
- help
- This option specifies the real-time priority to which long-term
- preempted RCU readers are to be boosted. If you are working
- with a real-time application that has one or more CPU-bound
- threads running at a real-time priority level, you should set
- RCU_BOOST_PRIO to a priority higher then the highest-priority
- real-time CPU-bound thread. The default RCU_BOOST_PRIO value
- of 1 is appropriate in the common case, which is real-time
+config RCU_KTHREAD_PRIO
+ int "Real-time priority to use for RCU worker threads"
+ range 1 99 if RCU_BOOST
+ range 0 99 if !RCU_BOOST
+ default 1 if RCU_BOOST
+ default 0 if !RCU_BOOST
+ depends on RCU_EXPERT
+ help
+ This option specifies the SCHED_FIFO priority value that will be
+ assigned to the rcuc/n and rcub/n threads and is also the value
+ used for RCU_BOOST (if enabled). If you are working with a
+ real-time application that has one or more CPU-bound threads
+ running at a real-time priority level, you should set
+ RCU_KTHREAD_PRIO to a priority higher than the highest-priority
+ real-time CPU-bound application thread. The default RCU_KTHREAD_PRIO
+ value of 1 is appropriate in the common case, which is real-time
applications that do not have any CPU-bound threads.
Some real-time applications might not have a single real-time
thread that saturates a given CPU, but instead might have
multiple real-time threads that, taken together, fully utilize
- that CPU. In this case, you should set RCU_BOOST_PRIO to
+ that CPU. In this case, you should set RCU_KTHREAD_PRIO to
a priority higher than the lowest-priority thread that is
conspiring to prevent the CPU from running any non-real-time
tasks. For example, if one thread at priority 10 and another
thread at priority 5 are between themselves fully consuming
- the CPU time on a given CPU, then RCU_BOOST_PRIO should be
+ the CPU time on a given CPU, then RCU_KTHREAD_PRIO should be
set to priority 6 or higher.
Specify the real-time priority, or take the default if unsure.
Accept the default if unsure.
config RCU_NOCB_CPU
- bool "Offload RCU callback processing from boot-selected CPUs (EXPERIMENTAL"
- depends on TREE_RCU || TREE_PREEMPT_RCU
+ bool "Offload RCU callback processing from boot-selected CPUs"
+ depends on TREE_RCU || PREEMPT_RCU
+ depends on RCU_EXPERT || NO_HZ_FULL
default n
help
Use this option to reduce OS jitter for aggressive HPC or
choice
prompt "Build-forced no-CBs CPUs"
default RCU_NOCB_CPU_NONE
+ depends on RCU_NOCB_CPU
help
- This option allows no-CBs CPUs to be specified at build time.
- Additional no-CBs CPUs may be specified by the rcu_nocbs=
- boot parameter.
+ This option allows no-CBs CPUs (whose RCU callbacks are invoked
+ from kthreads rather than from softirq context) to be specified
+ at build time. Additional no-CBs CPUs may be specified by
+ the rcu_nocbs= boot parameter.
config RCU_NOCB_CPU_NONE
bool "No build_forced no-CBs CPUs"
- depends on RCU_NOCB_CPU && !NO_HZ_FULL
help
This option does not force any of the CPUs to be no-CBs CPUs.
Only CPUs designated by the rcu_nocbs= boot parameter will be
- no-CBs CPUs.
+ no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU
+ kthreads whose names begin with "rcuo". All other CPUs will
+ invoke their own RCU callbacks in softirq context.
+
+ Select this option if you want to choose no-CBs CPUs at
+ boot time, for example, to allow testing of different no-CBs
+ configurations without having to rebuild the kernel each time.
config RCU_NOCB_CPU_ZERO
bool "CPU 0 is a build_forced no-CBs CPU"
- depends on RCU_NOCB_CPU && !NO_HZ_FULL
help
- This option forces CPU 0 to be a no-CBs CPU. Additional CPUs
- may be designated as no-CBs CPUs using the rcu_nocbs= boot
- parameter will be no-CBs CPUs.
+ This option forces CPU 0 to be a no-CBs CPU, so that its RCU
+ callbacks are invoked by a per-CPU kthread whose name begins
+ with "rcuo". Additional CPUs may be designated as no-CBs
+ CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs.
+ All other CPUs will invoke their own RCU callbacks in softirq
+ context.
Select this if CPU 0 needs to be a no-CBs CPU for real-time
- or energy-efficiency reasons.
+ or energy-efficiency reasons, but the real reason it exists
+ is to ensure that randconfig testing covers mixed systems.
config RCU_NOCB_CPU_ALL
bool "All CPUs are build_forced no-CBs CPUs"
- depends on RCU_NOCB_CPU
help
This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
- boot parameter will be ignored.
+ boot parameter will be ignored. All CPUs' RCU callbacks will
+ be executed in the context of per-CPU rcuo kthreads created for
+ this purpose. Assuming that the kthreads whose names start with
+ "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter
+ on the remaining CPUs, but might decrease memory locality during
+ RCU-callback invocation, thus potentially degrading throughput.
Select this if all CPUs need to be no-CBs CPUs for real-time
or energy-efficiency reasons.
endchoice
+config RCU_EXPEDITE_BOOT
+ bool
+ default n
+ help
+ This option enables expedited grace periods at boot time,
+ as if rcu_expedite_gp() had been invoked early in boot.
+ The corresponding rcu_unexpedite_gp() is invoked from
+ rcu_end_inkernel_boot(), which is intended to be invoked
+ at the end of the kernel-only boot sequence, just before
+ init is exec'ed.
+
+ Accept the default if unsure.
+
endmenu # "RCU Subsystem"
+config BUILD_BIN2C
+ bool
+ default n
+
config IKCONFIG
tristate "Kernel .config support"
+ select BUILD_BIN2C
---help---
This option enables the complete Linux kernel ".config" file
contents to be saved in the kernel. It provides documentation
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
- range 12 21
+ range 12 25
default 17
+ depends on PRINTK
help
- Select kernel log buffer size as a power of 2.
+ Select the minimal kernel log buffer size as a power of 2.
+ The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
+ parameter, see below. Any higher size also might be forced
+ by "log_buf_len" boot parameter.
+
Examples:
- 17 => 128 KB
+ 17 => 128 KB
16 => 64 KB
- 15 => 32 KB
- 14 => 16 KB
+ 15 => 32 KB
+ 14 => 16 KB
13 => 8 KB
12 => 4 KB
+config LOG_CPU_MAX_BUF_SHIFT
+ int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
+ depends on SMP
+ range 0 21
+ default 12 if !BASE_SMALL
+ default 0 if BASE_SMALL
+ depends on PRINTK
+ help
+ This option allows to increase the default ring buffer size
+ according to the number of CPUs. The value defines the contribution
+ of each CPU as a power of 2. The used space is typically only few
+ lines however it might be much more when problems are reported,
+ e.g. backtraces.
+
+ The increased size means that a new buffer has to be allocated and
+ the original static one is unused. It makes sense only on systems
+ with more CPUs. Therefore this value is used only when the sum of
+ contributions is greater than the half of the default kernel ring
+ buffer as defined by LOG_BUF_SHIFT. The default values are set
+ so that more than 64 CPUs are needed to trigger the allocation.
+
+ Also this option is ignored when "log_buf_len" kernel parameter is
+ used as it forces an exact (power of two) size of the ring buffer.
+
+ The number of possible CPUs is used for this computation ignoring
+ hotplugging making the compuation optimal for the the worst case
+ scenerio while allowing a simple algorithm to be used from bootup.
+
+ Examples shift values and their meaning:
+ 17 => 128 KB for each CPU
+ 16 => 64 KB for each CPU
+ 15 => 32 KB for each CPU
+ 14 => 16 KB for each CPU
+ 13 => 8 KB for each CPU
+ 12 => 4 KB for each CPU
+
#
# Architectures with an unreliable sched_clock() should select this:
#
config HAVE_UNSTABLE_SCHED_CLOCK
bool
+config GENERIC_SCHED_CLOCK
+ bool
+
#
# For architectures that want to enable the support for NUMA-affine scheduler
# balancing logic:
config ARCH_SUPPORTS_NUMA_BALANCING
bool
-# For architectures that (ab)use NUMA to represent different memory regions
-# all cpu-local but of different latencies, such as SuperH.
#
-config ARCH_WANT_NUMA_VARIABLE_LOCALITY
+# For architectures that prefer to flush all TLBs after a number of pages
+# are unmapped instead of sending one IPI per page to flush. The architecture
+# must provide guarantees on what happens if a clean TLB cache entry is
+# written after the unmap. Details are in mm/rmap.c near the check for
+# should_defer_flush. The architecture should also consider if the full flush
+# and the refill costs are offset by the savings of sending fewer IPIs.
+config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
bool
#
-# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
-config ARCH_WANTS_PROT_NUMA_PROT_NONE
+# For architectures that know their GCC __int128 support is sound
+#
+config ARCH_SUPPORTS_INT128
bool
-config ARCH_USES_NUMA_PROT_NONE
+# For architectures that (ab)use NUMA to represent different memory regions
+# all cpu-local but of different latencies, such as SuperH.
+#
+config ARCH_WANT_NUMA_VARIABLE_LOCALITY
bool
- default y
- depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
- depends on NUMA_BALANCING
-
-config NUMA_BALANCING_DEFAULT_ENABLED
- bool "Automatically enable NUMA aware memory/task placement"
- default y
- depends on NUMA_BALANCING
- help
- If set, autonumic NUMA balancing will be enabled if running on a NUMA
- machine.
config NUMA_BALANCING
bool "Memory placement aware NUMA scheduler"
help
This option adds support for automatic NUMA aware memory/task placement.
The mechanism is quite primitive and is based on migrating memory when
- it is references to the node the task is running on.
+ it has references to the node the task is running on.
This system will be inactive on UMA systems.
+config NUMA_BALANCING_DEFAULT_ENABLED
+ bool "Automatically enable NUMA aware memory/task placement"
+ default y
+ depends on NUMA_BALANCING
+ help
+ If set, automatic NUMA balancing will be enabled if running on a NUMA
+ machine.
+
menuconfig CGROUPS
- boolean "Control Group support"
- depends on EVENTFD
+ bool "Control Group support"
+ select KERNFS
help
This option adds support for grouping sets of processes together, for
use with process control subsystems such as Cpusets, CFS, memory
Provides a way to freeze and unfreeze all tasks in a
cgroup.
+config CGROUP_PIDS
+ bool "PIDs cgroup subsystem"
+ help
+ Provides enforcement of process number limits in the scope of a
+ cgroup. Any attempt to fork more processes than is allowed in the
+ cgroup will fail. PIDs are fundamentally a global resource because it
+ is fairly trivial to reach PID exhaustion before you reach even a
+ conservative kmemcg limit. As a result, it is possible to grind a
+ system to halt without being limited by other cgroup policies. The
+ PIDs cgroup subsystem is designed to stop this from happening.
+
+ It should be noted that organisational operations (such as attaching
+ to a cgroup hierarchy will *not* be blocked by the PIDs subsystem),
+ since the PIDs limit only affects a process's ability to fork, not to
+ attach to a cgroup.
+
config CGROUP_DEVICE
bool "Device controller for cgroups"
help
Provides a simple Resource Controller for monitoring the
total CPU consumed by the tasks in a cgroup.
-config RESOURCE_COUNTERS
- bool "Resource counters"
+config CGROUP_SCHEDTUNE
+ bool "CFS tasks boosting cgroup subsystem (EXPERIMENTAL)"
+ depends on SCHED_TUNE
help
- This option enables controller independent resource accounting
- infrastructure that works with cgroups.
+ This option provides the "schedtune" controller which improves the
+ flexibility of the task boosting mechanism by introducing the support
+ to define "per task" boost values.
+
+ This new controller:
+ 1. allows only a two layers hierarchy, where the root defines the
+ system-wide boost value and its direct childrens define each one a
+ different "class of tasks" to be boosted with a different value
+ 2. supports up to 16 different task classes, each one which could be
+ configured with a different boost value
+
+ Say N if unsure.
+
+config PAGE_COUNTER
+ bool
config MEMCG
bool "Memory Resource Controller for Control Groups"
- depends on RESOURCE_COUNTERS
- select MM_OWNER
+ select PAGE_COUNTER
+ select EVENTFD
help
Provides a memory resource controller that manages both anonymous
memory and page cache. (See Documentation/cgroups/memory.txt)
- Note that setting this option increases fixed memory overhead
- associated with each page of memory in the system. By this,
- 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
- usage tracking struct at boot. Total amount of this is printed out
- at boot.
-
- Only enable when you're ok with these trade offs and really
- sure you need the memory resource controller. Even when you enable
- this, you can set "cgroup_disable=memory" at your boot option to
- disable memory resource controller and you can avoid overheads.
- (and lose benefits of memory resource controller)
-
- This config option also selects MM_OWNER config option, which
- could in turn add some fork/exit overhead.
-
config MEMCG_SWAP
bool "Memory Resource Controller Swap Extension"
depends on MEMCG && SWAP
Memory Resource Controller Swap Extension comes with its price in
a bigger memory consumption. General purpose distribution kernels
which want to enable the feature but keep it disabled by default
- and let the user enable it by swapaccount boot command line
+ and let the user enable it by swapaccount=1 boot command line
parameter should have this option unselected.
For those who want to have the feature enabled by default should
select this option (if, for some reason, they need to disable it
config CGROUP_HUGETLB
bool "HugeTLB Resource Controller for Control Groups"
- depends on RESOURCE_COUNTERS && HUGETLB_PAGE
+ depends on HUGETLB_PAGE
+ select PAGE_COUNTER
default n
help
Provides a cgroup Resource Controller for HugeTLB pages.
Enable some debugging help. Currently it exports additional stat
files in a cgroup which can be useful for debugging.
+config CGROUP_WRITEBACK
+ bool
+ depends on MEMCG && BLK_CGROUP
+ default y
+
endif # CGROUPS
config CHECKPOINT_RESTORE
bool "Checkpoint/restore support" if EXPERT
+ select PROC_CHILDREN
default n
help
Enables additional kernel features in a sake of checkpoint/restore.
menuconfig NAMESPACES
bool "Namespaces support" if EXPERT
+ depends on MULTIUSER
default !EXPERT
help
Provides the way to make tasks work with different objects using
config USER_NS
bool "User namespace"
- depends on UIDGID_CONVERTED
- select UIDGID_STRICT_TYPE_CHECKS
-
default n
help
This allows containers, i.e. vservers, to use user namespaces
endif # NAMESPACES
-config UIDGID_CONVERTED
- # True if all of the selected software conmponents are known
- # to have uid_t and gid_t converted to kuid_t and kgid_t
- # where appropriate and are otherwise safe to use with
- # the user namespace.
- bool
- default y
-
- # Filesystems
- depends on XFS_FS = n
-
-config UIDGID_STRICT_TYPE_CHECKS
- bool "Require conversions between uid/gids and their internal representation"
- depends on UIDGID_CONVERTED
- default n
- help
- While the nececessary conversions are being added to all subsystems this option allows
- the code to continue to build for unconverted subsystems.
-
- Say Y here if you want the strict type checking enabled
-
config SCHED_AUTOGROUP
bool "Automatic process group scheduling"
- select EVENTFD
select CGROUPS
select CGROUP_SCHED
select FAIR_GROUP_SCHED
desktop applications. Task group autogeneration is currently based
upon task session.
-config MM_OWNER
- bool
+config SCHED_TUNE
+ bool "Boosting for CFS tasks (EXPERIMENTAL)"
+ help
+ This option enables the system-wide support for task boosting.
+ When this support is enabled a new sysctl interface is exposed to
+ userspace via:
+ /proc/sys/kernel/sched_cfs_boost
+ which allows to set a system-wide boost value in range [0..100].
+
+ The currently boosting strategy is implemented in such a way that:
+ - a 0% boost value requires to operate in "standard" mode by
+ scheduling all tasks at the minimum capacities required by their
+ workload demand
+ - a 100% boost value requires to push at maximum the task
+ performances, "regardless" of the incurred energy consumption
+
+ A boost value in between these two boundaries is used to bias the
+ power/performance trade-off, the higher the boost value the more the
+ scheduler is biased toward performance boosting instead of energy
+ efficiency.
+
+ Since this support exposes a single system-wide knob, the specified
+ boost value is applied to all (CFS) tasks in the system.
+
+ If unsure, say N.
config SYSFS_DEPRECATED
bool "Enable deprecated sysfs features to support old userspace tools"
config CC_OPTIMIZE_FOR_SIZE
bool "Optimize for size"
help
- Enabling this option will pass "-Os" instead of "-O2" to gcc
- resulting in a smaller kernel.
+ Enabling this option will pass "-Os" instead of "-O2" to
+ your compiler resulting in a smaller kernel.
If unsure, say N.
the unaligned access emulation.
see arch/parisc/kernel/unaligned.c for reference
-config HOTPLUG
- def_bool y
-
config HAVE_PCSPKR_PLATFORM
bool
-config PANIC_TIMEOUT
- int "Default panic timeout"
- default 0
- help
- Set default panic timeout.
+# interpreter that classic socket filters depend on
+config BPF
+ bool
menuconfig EXPERT
bool "Configure standard kernel features (expert users)"
config UID16
bool "Enable 16-bit UID system calls" if EXPERT
- depends on HAVE_UID16
+ depends on HAVE_UID16 && MULTIUSER
default y
help
This enables the legacy 16-bit UID syscall wrappers.
+config MULTIUSER
+ bool "Multiple users, groups and capabilities support" if EXPERT
+ default y
+ help
+ This option enables support for non-root users, groups and
+ capabilities.
+
+ If you say N here, all processes will run with UID 0, GID 0, and all
+ possible capabilities. Saying N here also compiles out support for
+ system calls related to UIDs, GIDs, and capabilities, such as setuid,
+ setgid, and capset.
+
+ If unsure, say Y here.
+
+config SGETMASK_SYSCALL
+ bool "sgetmask/ssetmask syscalls support" if EXPERT
+ def_bool PARISC || MN10300 || BLACKFIN || M68K || PPC || MIPS || X86 || SPARC || CRIS || MICROBLAZE || SUPERH
+ ---help---
+ sys_sgetmask and sys_ssetmask are obsolete system calls
+ no longer supported in libc but still enabled by default in some
+ architectures.
+
+ If unsure, leave the default option here.
+
+config SYSFS_SYSCALL
+ bool "Sysfs syscall support" if EXPERT
+ default y
+ ---help---
+ sys_sysfs is an obsolete system call no longer supported in libc.
+ Note that disabling this option is more secure but might break
+ compatibility with some systems.
+
+ If unsure say Y here.
+
config SYSCTL_SYSCALL
bool "Sysctl syscall support" if EXPERT
depends on PROC_SYSCTL
If unsure, say Y.
+# syscall, maps, verifier
+config BPF_SYSCALL
+ bool "Enable bpf() system call"
+ select ANON_INODES
+ select BPF
+ default n
+ help
+ Enable the bpf() system call that allows to manipulate eBPF
+ programs and maps via file descriptors.
+
config SHMEM
bool "Use full shmem filesystem" if EXPERT
default y
by some high performance threaded applications. Disabling
this option saves about 7k.
+config ADVISE_SYSCALLS
+ bool "Enable madvise/fadvise syscalls" if EXPERT
+ default y
+ help
+ This option enables the madvise and fadvise syscalls, used by
+ applications to advise the kernel about their future memory or file
+ usage, improving performance. If building an embedded system where no
+ applications use these syscalls, you can disable this option to save
+ space.
+
+config USERFAULTFD
+ bool "Enable userfaultfd() system call"
+ select ANON_INODES
+ depends on MMU
+ help
+ Enable the userfaultfd() system call that allows to intercept and
+ handle page faults in userland.
+
config PCI_QUIRKS
default y
bool "Enable PCI quirk workarounds" if EXPERT
bugs/quirks. Disable this only if your target machine is
unaffected by PCI quirks.
+config MEMBARRIER
+ bool "Enable membarrier() system call" if EXPERT
+ default y
+ help
+ Enable the membarrier() system call that allows issuing memory
+ barriers across all running threads, which can be used to distribute
+ the cost of user-space memory barriers asymmetrically by transforming
+ pairs of memory barriers into pairs consisting of membarrier() and a
+ compiler barrier.
+
+ If unsure, say Y.
+
config EMBEDDED
bool "Embedded system"
+ option allnoconfig_y
select EXPERT
help
This option should be enabled if compiling the kernel for
depends on HAVE_PERF_EVENTS
select ANON_INODES
select IRQ_WORK
+ select SRCU
help
Enable kernel support for various performance events provided
by software and hardware.
config DEBUG_PERF_USE_VMALLOC
default n
bool "Debug: use vmalloc to back perf mmap() buffers"
- depends on PERF_EVENTS && DEBUG_KERNEL
+ depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
select PERF_USE_VMALLOC
help
Use vmalloc memory to back perf mmap() buffers.
endchoice
+config SLUB_CPU_PARTIAL
+ default y
+ depends on SLUB && SMP
+ bool "SLUB per cpu partial cache"
+ help
+ Per cpu partial caches accellerate objects allocation and freeing
+ that is local to a processor at the price of more indeterminism
+ in the latency of the free. On overflow these caches will be cleared
+ which requires the taking of locks that may cause latency spikes.
+ Typically one would choose no for a realtime system.
+
config MMAP_ALLOW_UNINITIALIZED
bool "Allow mmapped anonymous memory to be uninitialized"
depends on EXPERT && !MMU
See Documentation/nommu-mmap.txt for more information.
+config SYSTEM_DATA_VERIFICATION
+ def_bool n
+ select SYSTEM_TRUSTED_KEYRING
+ select KEYS
+ select CRYPTO
+ select ASYMMETRIC_KEY_TYPE
+ select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+ select PUBLIC_KEY_ALGO_RSA
+ select ASN1
+ select OID_REGISTRY
+ select X509_CERTIFICATE_PARSER
+ select PKCS7_MESSAGE_PARSER
+ help
+ Provide PKCS#7 message verification using the contents of the system
+ trusted keyring to provide public keys. This then can be used for
+ module verification, kexec image verification and firmware blob
+ verification.
+
config PROFILING
bool "Profiling support"
help
default y
config RT_MUTEXES
- boolean
+ bool
config BASE_SMALL
int
menuconfig MODULES
bool "Enable loadable module support"
+ option modules
help
Kernel modules are small pieces of compiled code which can
be inserted in the running kernel, rather than being
config MODULE_SIG
bool "Module signature verification"
depends on MODULES
- select KEYS
- select CRYPTO
- select ASYMMETRIC_KEY_TYPE
- select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
- select PUBLIC_KEY_ALGO_RSA
- select ASN1
- select OID_REGISTRY
- select X509_CERTIFICATE_PARSER
+ select SYSTEM_DATA_VERIFICATION
help
Check modules for valid signatures upon load: the signature
is simply appended to the module. For more information see
Documentation/module-signing.txt.
+ Note that this option adds the OpenSSL development packages as a
+ kernel build dependency so that the signing tool can use its crypto
+ library.
+
!!!WARNING!!! If you enable this option, you MUST make sure that the
module DOES NOT get stripped after being signed. This includes the
debuginfo strip done by some packagers (such as rpmbuild) and
default "sha384" if MODULE_SIG_SHA384
default "sha512" if MODULE_SIG_SHA512
+config MODULE_COMPRESS
+ bool "Compress modules on installation"
+ depends on MODULES
+ help
+
+ Compresses kernel modules when 'make modules_install' is run; gzip or
+ xz depending on "Compression algorithm" below.
+
+ module-init-tools MAY support gzip, and kmod MAY support gzip and xz.
+
+ Out-of-tree kernel modules installed using Kbuild will also be
+ compressed upon installation.
+
+ Note: for modules inside an initrd or initramfs, it's more efficient
+ to compress the whole initrd or initramfs instead.
+
+ Note: This is fully compatible with signed modules.
+
+ If in doubt, say N.
+
+choice
+ prompt "Compression algorithm"
+ depends on MODULE_COMPRESS
+ default MODULE_COMPRESS_GZIP
+ help
+ This determines which sort of compression will be used during
+ 'make modules_install'.
+
+ GZIP (default) and XZ are supported.
+
+config MODULE_COMPRESS_GZIP
+ bool "GZIP"
+
+config MODULE_COMPRESS_XZ
+ bool "XZ"
+
+endchoice
+
endif # MODULES
+config MODULES_TREE_LOOKUP
+ def_bool y
+ depends on PERF_EVENTS || TRACING
+
config INIT_ALL_POSSIBLE
bool
help
it was better to provide this option than to break all the archs
and have several arch maintainers pursuing me down dark alleys.
-config STOP_MACHINE
- bool
- default y
- depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
- help
- Need stop_machine() primitive.
-
source "block/Kconfig"
config PREEMPT_NOTIFIERS
projects / firefly-linux-kernel-4.4.55.git / blobdiff