int
default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
+config CC_CAN_LINK
+ def_bool $(success,$(srctree)/scripts/cc-can-link.sh $(CC))
+
config CC_HAS_ASM_GOTO
def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
+config TOOLS_SUPPORT_RELR
+ def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
+
+config CC_HAS_ASM_INLINE
+ def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
+
config CC_HAS_WARN_MAYBE_UNINITIALIZED
def_bool $(cc-option,-Wmaybe-uninitialized)
help
config CONSTRUCTORS
bool
- depends on !UML
config IRQ_WORK
bool
here. If you are a user/distributor, say N here to exclude useless
drivers to be distributed.
+config HEADER_TEST
+ bool "Compile test headers that should be standalone compilable"
+ help
+ Compile test headers listed in header-test-y target to ensure they are
+ self-contained, i.e. compilable as standalone units.
+
+ If you are a developer or tester and want to ensure the requested
+ headers are self-contained, say Y here. Otherwise, choose N.
+
+config KERNEL_HEADER_TEST
+ bool "Compile test kernel headers"
+ depends on HEADER_TEST
+ help
+ Headers in include/ are used to build external moduls.
+ Compile test them to ensure they are self-contained, i.e.
+ compilable as standalone units.
+
+ If you are a developer or tester and want to ensure the headers
+ in include/ are self-contained, say Y here. Otherwise, choose N.
+
+config UAPI_HEADER_TEST
+ bool "Compile test UAPI headers"
+ depends on HEADER_TEST && HEADERS_INSTALL && CC_CAN_LINK
+ help
+ Compile test headers exported to user-space to ensure they are
+ self-contained, i.e. compilable as standalone units.
+
+ If you are a developer or tester and want to ensure the exported
+ headers are self-contained, say Y here. Otherwise, choose N.
+
config LOCALVERSION
string "Local version - append to kernel release"
help
have cpu.pressure, memory.pressure, and io.pressure files,
which aggregate pressure stalls for the grouped tasks only.
- For more details see Documentation/accounting/psi.txt.
+ For more details see Documentation/accounting/psi.rst.
Say N if unsure.
config GENERIC_SCHED_CLOCK
bool
+menu "Scheduler features"
+
+config UCLAMP_TASK
+ bool "Enable utilization clamping for RT/FAIR tasks"
+ depends on CPU_FREQ_GOV_SCHEDUTIL
+ help
+ This feature enables the scheduler to track the clamped utilization
+ of each CPU based on RUNNABLE tasks scheduled on that CPU.
+
+ With this option, the user can specify the min and max CPU
+ utilization allowed for RUNNABLE tasks. The max utilization defines
+ the maximum frequency a task should use while the min utilization
+ defines the minimum frequency it should use.
+
+ Both min and max utilization clamp values are hints to the scheduler,
+ aiming at improving its frequency selection policy, but they do not
+ enforce or grant any specific bandwidth for tasks.
+
+ If in doubt, say N.
+
+config UCLAMP_BUCKETS_COUNT
+ int "Number of supported utilization clamp buckets"
+ range 5 20
+ default 5
+ depends on UCLAMP_TASK
+ help
+ Defines the number of clamp buckets to use. The range of each bucket
+ will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the
+ number of clamp buckets the finer their granularity and the higher
+ the precision of clamping aggregation and tracking at run-time.
+
+ For example, with the minimum configuration value we will have 5
+ clamp buckets tracking 20% utilization each. A 25% boosted tasks will
+ be refcounted in the [20..39]% bucket and will set the bucket clamp
+ effective value to 25%.
+ If a second 30% boosted task should be co-scheduled on the same CPU,
+ that task will be refcounted in the same bucket of the first task and
+ it will boost the bucket clamp effective value to 30%.
+ The clamp effective value of a bucket is reset to its nominal value
+ (20% in the example above) when there are no more tasks refcounted in
+ that bucket.
+
+ An additional boost/capping margin can be added to some tasks. In the
+ example above the 25% task will be boosted to 30% until it exits the
+ CPU. If that should be considered not acceptable on certain systems,
+ it's always possible to reduce the margin by increasing the number of
+ clamp buckets to trade off used memory for run-time tracking
+ precision.
+
+ If in doubt, use the default value.
+
+endmenu
+
#
# For architectures that want to enable the support for NUMA-affine scheduler
# balancing logic:
use with process control subsystems such as Cpusets, CFS, memory
controls or device isolation.
See
- - Documentation/scheduler/sched-design-CFS.txt (CFS)
- - Documentation/cgroup-v1/ (features for grouping, isolation
+ - Documentation/scheduler/sched-design-CFS.rst (CFS)
+ - Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
and resource control)
Say N if unsure.
CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
CONFIG_BLK_DEV_THROTTLING=y.
- See Documentation/cgroup-v1/blkio-controller.txt for more information.
-
-config DEBUG_BLK_CGROUP
- bool "IO controller debugging"
- depends on BLK_CGROUP
- default n
- ---help---
- Enable some debugging help. Currently it exports additional stat
- files in a cgroup which can be useful for debugging.
+ See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
config CGROUP_WRITEBACK
bool
tasks running within the fair group scheduler. Groups with no limit
set are considered to be unconstrained and will run with no
restriction.
- See Documentation/scheduler/sched-bwc.txt for more information.
+ See Documentation/scheduler/sched-bwc.rst for more information.
config RT_GROUP_SCHED
bool "Group scheduling for SCHED_RR/FIFO"
to task groups. If enabled, it will also make it impossible to
schedule realtime tasks for non-root users until you allocate
realtime bandwidth for them.
- See Documentation/scheduler/sched-rt-group.txt for more information.
+ See Documentation/scheduler/sched-rt-group.rst for more information.
endif #CGROUP_SCHED
+config UCLAMP_TASK_GROUP
+ bool "Utilization clamping per group of tasks"
+ depends on CGROUP_SCHED
+ depends on UCLAMP_TASK
+ default n
+ help
+ This feature enables the scheduler to track the clamped utilization
+ of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
+
+ When this option is enabled, the user can specify a min and max
+ CPU bandwidth which is allowed for each single task in a group.
+ The max bandwidth allows to clamp the maximum frequency a task
+ can use, while the min bandwidth allows to define a minimum
+ frequency a task will always use.
+
+ When task group based utilization clamping is enabled, an eventually
+ specified task-specific clamp value is constrained by the cgroup
+ specified clamp value. Both minimum and maximum task clamping cannot
+ be bigger than the corresponding clamping defined at task group level.
+
+ If in doubt, say N.
+
config CGROUP_PIDS
bool "PIDs controller"
help
default CC_OPTIMIZE_FOR_PERFORMANCE
config CC_OPTIMIZE_FOR_PERFORMANCE
- bool "Optimize for performance"
+ bool "Optimize for performance (-O2)"
help
This is the default optimization level for the kernel, building
with the "-O2" compiler flag for best performance and most
helpful compile-time warnings.
-config CC_OPTIMIZE_FOR_SIZE
- bool "Optimize for size"
+config CC_OPTIMIZE_FOR_PERFORMANCE_O3
+ bool "Optimize more for performance (-O3)"
+ depends on ARC
imply CC_DISABLE_WARN_MAYBE_UNINITIALIZED # avoid false positives
help
- Enabling this option will pass "-Os" instead of "-O2" to
- your compiler resulting in a smaller kernel.
+ Choosing this option will pass "-O3" to your compiler to optimize
+ the kernel yet more for performance.
- If unsure, say N.
+config CC_OPTIMIZE_FOR_SIZE
+ bool "Optimize for size (-Os)"
+ imply CC_DISABLE_WARN_MAYBE_UNINITIALIZED # avoid false positives
+ help
+ Choosing this option will pass "-Os" to your compiler resulting
+ in a smaller kernel.
endchoice
help
Many kernel heap attacks try to target slab cache metadata and
other infrastructure. This options makes minor performance
- sacrifies to harden the kernel slab allocator against common
+ sacrifices to harden the kernel slab allocator against common
freelist exploit methods.
config SHUFFLE_PAGE_ALLOCATOR
depends on SLUB && SMP
bool "SLUB per cpu partial cache"
help
- Per cpu partial caches accellerate objects allocation and freeing
+ Per cpu partial caches accelerate 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.
default 0 if BASE_FULL
default 1 if !BASE_FULL
+config MODULE_SIG_FORMAT
+ def_bool n
+ select SYSTEM_DATA_VERIFICATION
+
menuconfig MODULES
bool "Enable loadable module support"
option modules
make them incompatible with the kernel you are running. If
unsure, say N.
+config ASM_MODVERSIONS
+ bool
+ default HAVE_ASM_MODVERSIONS && MODVERSIONS
+ help
+ This enables module versioning for exported symbols also from
+ assembly. This can be enabled only when the target architecture
+ supports it.
+
config MODULE_REL_CRCS
bool
depends on MODVERSIONS
config MODULE_SIG
bool "Module signature verification"
- depends on MODULES
- select SYSTEM_DATA_VERIFICATION
+ select MODULE_SIG_FORMAT
help
Check modules for valid signatures upon load: the signature
is simply appended to the module. For more information see
config MODULE_COMPRESS
bool "Compress modules on installation"
- depends on MODULES
help
Compresses kernel modules when 'make modules_install' is run; gzip or
endchoice
+config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
+ bool "Allow loading of modules with missing namespace imports"
+ help
+ Symbols exported with EXPORT_SYMBOL_NS*() are considered exported in
+ a namespace. A module that makes use of a symbol exported with such a
+ namespace is required to import the namespace via MODULE_IMPORT_NS().
+ There is no technical reason to enforce correct namespace imports,
+ but it creates consistency between symbols defining namespaces and
+ users importing namespaces they make use of. This option relaxes this
+ requirement and lifts the enforcement when loading a module.
+
+ If unsure, say N.
+
+config UNUSED_SYMBOLS
+ bool "Enable unused/obsolete exported symbols"
+ default y if X86
+ help
+ Unused but exported symbols make the kernel needlessly bigger. For
+ that reason most of these unused exports will soon be removed. This
+ option is provided temporarily to provide a transition period in case
+ some external kernel module needs one of these symbols anyway. If you
+ encounter such a case in your module, consider if you are actually
+ using the right API. (rationale: since nobody in the kernel is using
+ this in a module, there is a pretty good chance it's actually the
+ wrong interface to use). If you really need the symbol, please send a
+ mail to the linux kernel mailing list mentioning the symbol and why
+ you really need it, and what the merge plan to the mainline kernel for
+ your module is.
+
config TRIM_UNUSED_KSYMS
bool "Trim unused exported kernel symbols"
- depends on MODULES && !UNUSED_SYMBOLS
+ depends on !UNUSED_SYMBOLS
help
The kernel and some modules make many symbols available for
other modules to use via EXPORT_SYMBOL() and variants. Depending
projects / linux-2.6-microblaze.git / blobdiff