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-rw-r--r--init/Kconfig111
1 files changed, 72 insertions, 39 deletions
diff --git a/init/Kconfig b/init/Kconfig
index 2de5b1cbadd..fdfd97efe0e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -21,6 +21,13 @@ config CONSTRUCTORS
depends on !UML
default y
+config HAVE_IRQ_WORK
+ bool
+
+config IRQ_WORK
+ bool
+ depends on HAVE_IRQ_WORK
+
menu "General setup"
config EXPERIMENTAL
@@ -64,7 +71,7 @@ config BROKEN_ON_SMP
config LOCK_KERNEL
bool
- depends on SMP || PREEMPT
+ depends on (SMP || PREEMPT) && BKL
default y
config INIT_ENV_ARG_LIMIT
@@ -332,6 +339,8 @@ config AUDIT_TREE
depends on AUDITSYSCALL
select FSNOTIFY
+source "kernel/irq/Kconfig"
+
menu "RCU Subsystem"
choice
@@ -340,6 +349,7 @@ choice
config TREE_RCU
bool "Tree-based hierarchical RCU"
+ depends on !PREEMPT && SMP
help
This option selects the RCU implementation that is
designed for very large SMP system with hundreds or
@@ -347,7 +357,7 @@ config TREE_RCU
smaller systems.
config TREE_PREEMPT_RCU
- bool "Preemptable tree-based hierarchical RCU"
+ bool "Preemptible tree-based hierarchical RCU"
depends on PREEMPT
help
This option selects the RCU implementation that is
@@ -365,8 +375,22 @@ config TINY_RCU
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 !SMP && PREEMPT
+ help
+ This option selects the RCU implementation that is designed
+ for real-time UP systems. This option greatly reduces the
+ memory footprint of RCU.
+
endchoice
+config PREEMPT_RCU
+ def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
+ help
+ This option enables preemptible-RCU code that is common between
+ the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
+
config RCU_TRACE
bool "Enable tracing for RCU"
depends on TREE_RCU || TREE_PREEMPT_RCU
@@ -387,9 +411,12 @@ config RCU_FANOUT
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.
+ large numbers of CPUs. This value must be at least the fourth
+ root of NR_CPUS, which allows NR_CPUS to be insanely large.
+ The default value of RCU_FANOUT should be used for production
+ systems, but if you are stress-testing the RCU implementation
+ itself, small RCU_FANOUT values allow you to test large-system
+ code paths on small(er) systems.
Select a specific number if testing RCU itself.
Take the default if unsure.
@@ -634,11 +661,14 @@ config BLK_CGROUP
Currently, CFQ IO scheduler uses it to recognize task groups and
control disk bandwidth allocation (proportional time slice allocation)
- to such task groups.
+ to such task groups. It is also used by bio throttling logic in
+ block layer to implement upper limit in IO rates on a device.
This option only enables generic Block IO controller infrastructure.
- One needs to also enable actual IO controlling logic in CFQ for it
- to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).
+ One needs to also enable actual IO controlling logic/policy. For
+ enabling proportional weight division of disk bandwidth in CFQ seti
+ CONFIG_CFQ_GROUP_IOSCHED=y and for enabling throttling policy set
+ CONFIG_BLK_THROTTLE=y.
See Documentation/cgroups/blkio-controller.txt for more information.
@@ -656,40 +686,42 @@ config MM_OWNER
bool
config SYSFS_DEPRECATED
- bool
-
-config SYSFS_DEPRECATED_V2
bool "enable deprecated sysfs features to support old userspace tools"
depends on SYSFS
default n
- select SYSFS_DEPRECATED
- help
- This option switches the layout of sysfs to the deprecated
- version. Do not use it on recent distributions.
-
- 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.
+ help
+ This option adds code that switches the layout of the "block" class
+ devices, to not show up in /sys/class/block/, but only in
+ /sys/block/.
+
+ This switch is only active when the sysfs.deprecated=1 boot option is
+ passed or the SYSFS_DEPRECATED_V2 option is set.
+
+ This option allows new kernels to run on old distributions and tools,
+ which might get confused by /sys/class/block/. Since 2007/2008 all
+ major distributions and tools handle this just fine.
+
+ Recent distributions and userspace tools after 2009/2010 depend on
+ the existence of /sys/class/block/, and will not work with this
+ option enabled.
+
+ Only if you are using a new kernel on an old distribution, you might
+ need to say Y here.
+
+config SYSFS_DEPRECATED_V2
+ bool "enabled deprecated sysfs features by default"
+ default n
+ depends on SYSFS
+ depends on SYSFS_DEPRECATED
+ help
+ Enable deprecated sysfs by default.
+
+ See the CONFIG_SYSFS_DEPRECATED option for more details about this
+ option.
+
+ Only if you are using a new kernel on an old distribution, you might
+ need to say Y here. Even then, odds are you would not need it
+ enabled, you can always pass the boot option if absolutely necessary.
config RELAY
bool "Kernel->user space relay support (formerly relayfs)"
@@ -987,6 +1019,7 @@ config PERF_EVENTS
default y if (PROFILING || PERF_COUNTERS)
depends on HAVE_PERF_EVENTS
select ANON_INODES
+ select IRQ_WORK
help
Enable kernel support for various performance events provided
by software and hardware.