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-rw-r--r--init/Kconfig70
1 files changed, 34 insertions, 36 deletions
diff --git a/init/Kconfig b/init/Kconfig
index fed6dc31b0da..8e8b76d8a272 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -16,6 +16,11 @@ config DEFCONFIG_LIST
default "$ARCH_DEFCONFIG"
default "arch/$ARCH/defconfig"
+config CONSTRUCTORS
+ bool
+ depends on !UML
+ default y
+
menu "General setup"
config EXPERIMENTAL
@@ -311,38 +316,28 @@ choice
prompt "RCU Implementation"
default TREE_RCU
-config CLASSIC_RCU
- bool "Classic RCU"
- help
- This option selects the classic RCU implementation that is
- designed for best read-side performance on non-realtime
- 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.
+ thousands of CPUs. It also scales down nicely to
+ smaller systems.
-config PREEMPT_RCU
- bool "Preemptible RCU"
+config TREE_PREEMPT_RCU
+ bool "Preemptable tree-based hierarchical 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.
+ This option selects the RCU implementation that is
+ designed for very large SMP systems with hundreds or
+ thousands of CPUs, but for which real-time response
+ is also required.
endchoice
config RCU_TRACE
bool "Enable tracing for RCU"
- depends on TREE_RCU || PREEMPT_RCU
+ depends on TREE_RCU || TREE_PREEMPT_RCU
help
This option provides tracing in RCU which presents stats
in debugfs for debugging RCU implementation.
@@ -354,7 +349,7 @@ config RCU_FANOUT
int "Tree-based hierarchical RCU fanout value"
range 2 64 if 64BIT
range 2 32 if !64BIT
- depends on TREE_RCU
+ depends on TREE_RCU || TREE_PREEMPT_RCU
default 64 if 64BIT
default 32 if !64BIT
help
@@ -369,7 +364,7 @@ config RCU_FANOUT
config RCU_FANOUT_EXACT
bool "Disable tree-based hierarchical RCU auto-balancing"
- depends on TREE_RCU
+ depends on TREE_RCU || TREE_PREEMPT_RCU
default n
help
This option forces use of the exact RCU_FANOUT value specified,
@@ -382,18 +377,12 @@ config RCU_FANOUT_EXACT
Say N if unsure.
config TREE_RCU_TRACE
- def_bool RCU_TRACE && TREE_RCU
+ def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_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.
+ This option provides tracing for the TREE_RCU and
+ TREE_PREEMPT_RCU implementations, permitting Makefile to
+ trivially select kernel/rcutree_trace.c.
endmenu # "RCU Subsystem"
@@ -616,13 +605,13 @@ config SYSFS_DEPRECATED
bool
config SYSFS_DEPRECATED_V2
- bool "Create deprecated sysfs layout for older userspace tools"
+ bool "remove sysfs features which may confuse old userspace tools"
depends on SYSFS
- default y
+ default n
select SYSFS_DEPRECATED
help
This option switches the layout of sysfs to the deprecated
- version.
+ 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
@@ -935,6 +924,7 @@ menu "Performance Counters"
config PERF_COUNTERS
bool "Kernel Performance Counters"
+ default y if PROFILING
depends on HAVE_PERF_COUNTERS
select ANON_INODES
help
@@ -956,9 +946,17 @@ config PERF_COUNTERS
Say Y if unsure.
config EVENT_PROFILE
- bool "Tracepoint profile sources"
- depends on PERF_COUNTERS && EVENT_TRACER
+ bool "Tracepoint profiling sources"
+ depends on PERF_COUNTERS && EVENT_TRACING
default y
+ help
+ Allow the use of tracepoints as software performance counters.
+
+ When this is enabled, you can create perf counters based on
+ tracepoints using PERF_TYPE_TRACEPOINT and the tracepoint ID
+ found in debugfs://tracing/events/*/*/id. (The -e/--events
+ option to the perf tool can parse and interpret symbolic
+ tracepoints, in the subsystem:tracepoint_name format.)
endmenu
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