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-config CGROUPS
- bool "Control Group support"
- help
- This option will let you use process cgroup subsystems
- such as Cpusets
-
- Say N if unsure.
-
-config CGROUP_DEBUG
- bool "Example debug cgroup subsystem"
- depends on CGROUPS
- default n
- help
- This option enables a simple cgroup subsystem that
- exports useful debugging information about the cgroups
- framework
-
- Say N if unsure
-
-config CGROUP_NS
- bool "Namespace cgroup subsystem"
- depends on CGROUPS
- help
- Provides a simple namespace cgroup subsystem to
- provide hierarchical naming of sets of namespaces,
- for instance virtual servers and checkpoint/restart
- jobs.
-
-config CGROUP_FREEZER
- bool "control group freezer subsystem"
- depends on CGROUPS
- help
- Provides a way to freeze and unfreeze all tasks in a
- cgroup.
-
-config CGROUP_DEVICE
- bool "Device controller for cgroups"
- depends on CGROUPS && EXPERIMENTAL
- help
- Provides a cgroup implementing whitelists for devices which
- a process in the cgroup can mknod or open.
-
-config CPUSETS
- bool "Cpuset support"
- depends on SMP && CGROUPS
- help
- This option will let you create and manage CPUSETs which
- allow dynamically partitioning a system into sets of CPUs and
- Memory Nodes and assigning tasks to run only within those sets.
- This is primarily useful on large SMP or NUMA systems.
-
- Say N if unsure.
-
#
# Architectures with an unreliable sched_clock() should select this:
#
help
This feature lets CPU scheduler recognize task groups and control CPU
bandwidth allocation to such task groups.
+ In order to create a group from arbitrary set of processes, use
+ CONFIG_CGROUPS. (See Control Group support.)
config FAIR_GROUP_SCHED
bool "Group scheduling for SCHED_OTHER"
setting below. 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/sched-rt-group.txt for more information.
+ See Documentation/scheduler/sched-rt-group.txt for more information.
choice
depends on GROUP_SCHED
endchoice
+menu "Control Group support"
+config CGROUPS
+ bool "Control Group support"
+ help
+ This option add support for grouping sets of processes together, for
+ use with process control subsystems such as Cpusets, CFS, memory
+ controls or device isolation.
+ See
+ - Documentation/cpusets.txt (Cpusets)
+ - Documentation/scheduler/sched-design-CFS.txt (CFS)
+ - Documentation/cgroups/ (features for grouping, isolation)
+ - Documentation/controllers/ (features for resource control)
+
+ Say N if unsure.
+
+config CGROUP_DEBUG
+ bool "Example debug cgroup subsystem"
+ depends on CGROUPS
+ default n
+ help
+ This option enables a simple cgroup subsystem that
+ exports useful debugging information about the cgroups
+ framework
+
+ Say N if unsure
+
+config CGROUP_NS
+ bool "Namespace cgroup subsystem"
+ depends on CGROUPS
+ help
+ Provides a simple namespace cgroup subsystem to
+ provide hierarchical naming of sets of namespaces,
+ for instance virtual servers and checkpoint/restart
+ jobs.
+
+config CGROUP_FREEZER
+ bool "control group freezer subsystem"
+ depends on CGROUPS
+ help
+ Provides a way to freeze and unfreeze all tasks in a
+ cgroup.
+
+config CGROUP_DEVICE
+ bool "Device controller for cgroups"
+ depends on CGROUPS && EXPERIMENTAL
+ help
+ Provides a cgroup implementing whitelists for devices which
+ a process in the cgroup can mknod or open.
+
+config CPUSETS
+ bool "Cpuset support"
+ depends on SMP && CGROUPS
+ help
+ This option will let you create and manage CPUSETs which
+ allow dynamically partitioning a system into sets of CPUs and
+ Memory Nodes and assigning tasks to run only within those sets.
+ This is primarily useful on large SMP or NUMA systems.
+
+ Say N if unsure.
+
config CGROUP_CPUACCT
bool "Simple CPU accounting cgroup subsystem"
depends on CGROUPS
infrastructure that works with cgroups
depends on CGROUPS
-config MM_OWNER
- bool
-
config CGROUP_MEM_RES_CTLR
bool "Memory Resource Controller for Control Groups"
depends on CGROUPS && RESOURCE_COUNTERS
select MM_OWNER
help
- Provides a memory resource controller that manages both page cache and
- RSS memory.
+ Provides a memory resource controller that manages both anonymous
+ memory and page cache. (See Documentation/controllers/memory.txt)
Note that setting this option increases fixed memory overhead
- associated with each page of memory in the system by 4/8 bytes
- and also increases cache misses because struct page on many 64bit
- systems will not fit into a single cache line anymore.
+ 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.
+ 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 MM_OWNER
+ bool
+
+config CGROUP_MEM_RES_CTLR_SWAP
+ bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
+ depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
+ help
+ Add swap management feature to memory resource controller. When you
+ enable this, you can limit mem+swap usage per cgroup. In other words,
+ when you disable this, memory resource controller has no cares to
+ usage of swap...a process can exhaust all of the swap. This extension
+ is useful when you want to avoid exhaustion swap but this itself
+ adds more overheads and consumes memory for remembering information.
+ Especially if you use 32bit system or small memory system, please
+ be careful about enabling this. When memory resource controller
+ is disabled by boot option, this will be automatically disabled and
+ there will be no overhead from this. Even when you set this config=y,
+ if boot option "noswapaccount" is set, swap will not be accounted.
+
+
+endmenu
+
config SYSFS_DEPRECATED
bool
config SYSFS_DEPRECATED_V2
- bool "Create deprecated sysfs files"
+ bool "Create deprecated sysfs layout for older userspace tools"
depends on SYSFS
default y
select SYSFS_DEPRECATED
help
- This option creates deprecated symlinks such as the
- "device"-link, the <subsystem>:<name>-link, and the
- "bus"-link. It may also add deprecated key in the
- uevent environment.
- None of these features or values should be used today, as
- they export driver core implementation details to userspace
- or export properties which can't be kept stable across kernel
- releases.
-
- If enabled, this option will also move any device structures
- that belong to a class, back into the /sys/class hierarchy, in
- order to support older versions of udev and some userspace
- programs.
-
- If you are using a distro with the most recent userspace
- packages, it should be safe to say N here.
+ This option switches the layout of sysfs to the deprecated
+ version.
+
+ The current sysfs layout features a unified device tree at
+ /sys/devices/, which is able to express a hierarchy between
+ class devices. If the deprecated option is set to Y, the
+ unified device tree is split into a bus device tree at
+ /sys/devices/ and several individual class device trees at
+ /sys/class/. The class and bus devices will be connected by
+ "<subsystem>:<name>" and the "device" links. The "block"
+ class devices, will not show up in /sys/class/block/. Some
+ subsystems will suppress the creation of some devices which
+ depend on the unified device tree.
+
+ This option is not a pure compatibility option that can
+ be safely enabled on newer distributions. It will change the
+ layout of sysfs to the non-extensible deprecated version,
+ and disable some features, which can not be exported without
+ confusing older userspace tools. Since 2007/2008 all major
+ distributions do not enable this option, and ship no tools which
+ depend on the deprecated layout or this option.
+
+ If you are using a new kernel on an older distribution, or use
+ older userspace tools, you might need to say Y here. Do not say Y,
+ if the original kernel, that came with your distribution, has
+ this option set to N.
config PROC_PID_CPUSET
bool "Include legacy /proc/<pid>/cpuset file"
Say N.
+config KALLSYMS_STRIP_GENERATED
+ bool "Strip machine generated symbols from kallsyms"
+ depends on KALLSYMS_ALL
+ default y
+ help
+ Say N if you want kallsyms to retain even machine generated symbols.
+
config KALLSYMS_EXTRA_PASS
bool "Do an extra kallsyms pass"
depends on KALLSYMS
config PCI_QUIRKS
default y
- bool "Enable PCI quirk workarounds" if EMBEDDED && PCI
+ bool "Enable PCI quirk workarounds" if EMBEDDED
+ depends on PCI
help
This enables workarounds for various PCI chipset
bugs/quirks. Disable this only if your target machine is
help
The regular slab allocator that is established and known to work
well in all environments. It organizes cache hot objects in
- per cpu and per node queues. SLAB is the default choice for
- a slab allocator.
+ per cpu and per node queues.
config SLUB
bool "SLUB (Unqueued Allocator)"
instead of managing queues of cached objects (SLAB approach).
Per cpu caching is realized using slabs of objects instead
of queues of objects. SLUB can use memory efficiently
- and has enhanced diagnostics.
+ and has enhanced diagnostics. SLUB is the default choice for
+ a slab allocator.
config SLOB
depends on EMBEDDED
config MARKERS
bool "Activate markers"
+ depends on TRACEPOINTS
help
Place an empty function call at each marker site. Can be
dynamically changed for a probe function.
boolean
select PLIST
-config TINY_SHMEM
- default !SHMEM
- bool
-
config BASE_SMALL
int
default 0 if BASE_FULL
the version). With this option, such a "srcversion" field
will be created for all modules. If unsure, say N.
-config KMOD
- def_bool y
- help
- This is being removed soon. These days, CONFIG_MODULES
- implies CONFIG_KMOD, so use that instead.
-
endif # MODULES
+config INIT_ALL_POSSIBLE
+ bool
+ help
+ Back when each arch used to define their own cpu_online_map and
+ cpu_possible_map, some of them chose to initialize cpu_possible_map
+ with all 1s, and others with all 0s. When they were centralised,
+ it was better to provide this option than to break all the archs
+ and have several arch maintainers persuing me down dark alleys.
+
config STOP_MACHINE
bool
default y
config PREEMPT_NOTIFIERS
bool
+choice
+ prompt "RCU Implementation"
+ default CLASSIC_RCU
+
config CLASSIC_RCU
- def_bool !PREEMPT_RCU
+ bool "Classic RCU"
help
This option selects the classic RCU implementation that is
designed for best read-side performance on non-realtime
- systems. Classic RCU is the default. Note that the
- PREEMPT_RCU symbol is used to select/deselect this option.
+ systems.
+
+ Select this option if you are unsure.
+
+config TREE_RCU
+ bool "Tree-based hierarchical RCU"
+ help
+ This option selects the RCU implementation that is
+ designed for very large SMP system with hundreds or
+ thousands of CPUs.
+
+config PREEMPT_RCU
+ bool "Preemptible RCU"
+ depends on PREEMPT
+ help
+ This option reduces the latency of the kernel by making certain
+ RCU sections preemptible. Normally RCU code is non-preemptible, if
+ this option is selected then read-only RCU sections become
+ preemptible. This helps latency, but may expose bugs due to
+ now-naive assumptions about each RCU read-side critical section
+ remaining on a given CPU through its execution.
+
+endchoice
+
+config RCU_TRACE
+ bool "Enable tracing for RCU"
+ depends on TREE_RCU || PREEMPT_RCU
+ help
+ This option provides tracing in RCU which presents stats
+ in debugfs for debugging RCU implementation.
+
+ Say Y here if you want to enable RCU tracing
+ Say N if you are unsure.
+
+config RCU_FANOUT
+ int "Tree-based hierarchical RCU fanout value"
+ range 2 64 if 64BIT
+ range 2 32 if !64BIT
+ depends on TREE_RCU
+ default 64 if 64BIT
+ default 32 if !64BIT
+ help
+ This option controls the fanout of hierarchical implementations
+ of RCU, allowing RCU to work efficiently on machines with
+ large numbers of CPUs. This value must be at least the cube
+ root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
+ systems and up to 262,144 for 64-bit systems.
+
+ Select a specific number if testing RCU itself.
+ Take the default if unsure.
+
+config RCU_FANOUT_EXACT
+ bool "Disable tree-based hierarchical RCU auto-balancing"
+ depends on TREE_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 TREE_RCU_TRACE
+ def_bool RCU_TRACE && TREE_RCU
+ select DEBUG_FS
+ help
+ This option provides tracing for the TREE_RCU implementation,
+ permitting Makefile to trivially select kernel/rcutree_trace.c.
+
+config PREEMPT_RCU_TRACE
+ def_bool RCU_TRACE && PREEMPT_RCU
+ select DEBUG_FS
+ help
+ This option provides tracing for the PREEMPT_RCU implementation,
+ permitting Makefile to trivially select kernel/rcupreempt_trace.c.