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
+ bool
+ default y if !PREEMPT && SMP
help
This option selects the RCU implementation that is
designed for very large SMP system with hundreds or
smaller systems.
config PREEMPT_RCU
- bool "Preemptible tree-based hierarchical RCU"
- depends on PREEMPT
+ 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.
-endchoice
+config RCU_EXPERT
+ bool "Make expert-level adjustments to RCU configuration"
+ default y if PREEMPT_RT_FULL
+ help
+ 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.
+
+ Say Y if you need to make expert-level adjustments to RCU.
+
+ Say N if you are unsure.
config SRCU
bool
sections.
config TASKS_RCU
- bool "Task_based RCU implementation using voluntary context switch"
+ bool
default n
select SRCU
help
only voluntary context switch (not preemption!), idle, and
user-mode execution as quiescent states.
- If unsure, say N.
-
config RCU_STALL_COMMON
def_bool ( TREE_RCU || PREEMPT_RCU || RCU_TRACE )
help
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
int "Tree-based hierarchical RCU fanout value"
range 2 64 if 64BIT
range 2 32 if !64BIT
- depends on TREE_RCU || 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 || 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 || 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 && !PREEMPT_RT_FULL
+ depends on NO_HZ_COMMON && SMP && RCU_EXPERT && !PREEMPT_RT_FULL
default n
help
This option permits CPUs to enter dynticks-idle state even if
config RCU_BOOST
bool "Enable RCU priority boosting"
- depends on RT_MUTEXES && PREEMPT_RCU
+ depends on RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT
default y if PREEMPT_RT_FULL
help
This option boosts the priority of preempted RCU readers that
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
config RCU_NOCB_CPU
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
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
config ARCH_SUPPORTS_NUMA_BALANCING
bool
+#
+# 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 know their GCC __int128 support is sound
#
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
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.
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
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.
See Documentation/nommu-mmap.txt for more information.
-config SYSTEM_TRUSTED_KEYRING
- bool "Provide system-wide ring of trusted keys"
- depends on KEYS
+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 a system keyring to which trusted keys can be added. Keys in
- the keyring are considered to be trusted. Keys may be added at will
- by the kernel from compiled-in data and from hardware key stores, but
- userspace may only add extra keys if those keys can be verified by
- keys already in the keyring.
-
- Keys in this keyring are used by module signature checking.
+ 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"
config MODULE_SIG
bool "Module signature verification"
depends on MODULES
- 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 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
bool "Compress modules on installation"
depends on MODULES
help
- This option compresses the kernel modules when 'make
- modules_install' is run.
- The modules will be compressed either using gzip or xz depend on the
- choice made in "Compression algorithm".
+ 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.
- module-init-tools has support for gzip format while kmod handle gzip
- and xz compressed modules.
+ Out-of-tree kernel modules installed using Kbuild will also be
+ compressed upon installation.
- When a kernel module is installed from outside of the main kernel
- source and uses the Kbuild system for installing modules then that
- kernel module will also be compressed when it is installed.
+ Note: for modules inside an initrd or initramfs, it's more efficient
+ to compress the whole initrd or initramfs instead.
- This option provides little benefit when the modules are to be used inside
- an initrd or initramfs, it generally is more efficient to compress the whole
- initrd or initramfs instead.
+ Note: This is fully compatible with signed modules.
- This is fully compatible with signed modules while the signed module is
- compressed. module-init-tools or kmod handles decompression and provide to
- other layer the uncompressed but signed payload.
+ If in doubt, say N.
choice
prompt "Compression algorithm"
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
Code Review / kvmfornfv.git / blobdiff