default "$ARCH_DEFCONFIG"
default "arch/$ARCH/defconfig"
+config CONSTRUCTORS
+ bool
+ depends on !UML
+ default y
+
menu "General setup"
config EXPERIMENTAL
config AUDITSYSCALL
bool "Enable system-call auditing support"
- depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
+ depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
default y if SECURITY_SELINUX
help
Enable low-overhead system-call auditing infrastructure that
config AUDIT_TREE
def_bool y
- depends on AUDITSYSCALL && INOTIFY
+ depends on AUDITSYSCALL
+ select INOTIFY
menu "RCU Subsystem"
choice
prompt "RCU Implementation"
- default CLASSIC_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.
+ default TREE_RCU
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. It also scales down nicely to
+ smaller systems.
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.
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
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,
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"
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
you wait for kallsyms to be fixed.
-config STRIP_ASM_SYMS
- bool "Strip assembler-generated symbols during link"
- default n
- help
- Strip internal assembler-generated symbols during a link (symbols
- that look like '.Lxxx') so they don't pollute the output of
- get_wchan() and suchlike.
-
config HOTPLUG
bool "Support for hot-pluggable devices" if EMBEDDED
default y
by some high performance threaded applications. Disabling
this option saves about 7k.
-config HAVE_PERF_COUNTERS
+config HAVE_PERF_EVENTS
bool
+ help
+ See tools/perf/design.txt for details.
-menu "Performance Counters"
+config PERF_USE_VMALLOC
+ bool
+ help
+ See tools/perf/design.txt for details
-config PERF_COUNTERS
- bool "Kernel Performance Counters"
- depends on HAVE_PERF_COUNTERS
+menu "Kernel Performance Events And Counters"
+
+config PERF_EVENTS
+ bool "Kernel performance events and counters"
+ default y if (PROFILING || PERF_COUNTERS)
+ depends on HAVE_PERF_EVENTS
select ANON_INODES
help
- Enable kernel support for performance counter hardware.
+ Enable kernel support for various performance events provided
+ by software and hardware.
+
+ Software events are supported either build-in or via the
+ use of generic tracepoints.
- Performance counters are special hardware registers available
- on most modern CPUs. These registers count the number of certain
+ Most modern CPUs support performance events via performance
+ counter registers. These registers count the number of certain
types of hw events: such as instructions executed, cachemisses
suffered, or branches mis-predicted - without slowing down the
kernel or applications. These registers can also trigger interrupts
when a threshold number of events have passed - and can thus be
used to profile the code that runs on that CPU.
- The Linux Performance Counter subsystem provides an abstraction of
- these hardware capabilities, available via a system call. It
+ The Linux Performance Event subsystem provides an abstraction of
+ these software and hardware cevent apabilities, available via a
+ system call and used by the "perf" utility in tools/perf/. It
provides per task and per CPU counters, and it provides event
capabilities on top of those.
Say Y if unsure.
config EVENT_PROFILE
- bool "Tracepoint profile sources"
- depends on PERF_COUNTERS && EVENT_TRACER
+ bool "Tracepoint profiling sources"
+ depends on PERF_EVENTS && EVENT_TRACING
default y
+ help
+ Allow the use of tracepoints as software performance events.
+
+ When this is enabled, you can create perf events 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.)
+
+config PERF_COUNTERS
+ bool "Kernel performance counters (old config option)"
+ depends on HAVE_PERF_EVENTS
+ help
+ This config has been obsoleted by the PERF_EVENTS
+ config option - please see that one for details.
+
+ It has no effect on the kernel whether you enable
+ it or not, it is a compatibility placeholder.
+
+ Say N if unsure.
+
+config DEBUG_PERF_USE_VMALLOC
+ default n
+ bool "Debug: use vmalloc to back perf mmap() buffers"
+ depends on PERF_EVENTS && DEBUG_KERNEL
+ select PERF_USE_VMALLOC
+ help
+ Use vmalloc memory to back perf mmap() buffers.
+
+ Mostly useful for debugging the vmalloc code on platforms
+ that don't require it.
+
+ Say N if unsure.
endmenu
config TRACEPOINTS
bool
-config MARKERS
- bool "Activate markers"
- select TRACEPOINTS
- help
- Place an empty function call at each marker site. Can be
- dynamically changed for a probe function.
-
source "arch/Kconfig"
config SLOW_WORK