Merge branch 'linus' into perfcounters/core

[linux-2.6-block.git] / init / Kconfig

diff --git a/init/Kconfig b/init/Kconfig
index 8a63c404ef449d391a08ffd5760f46325f76babf..c38ae71a5e195c5c58d657bb5f5ec00cb3fd905b 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -739,6 +739,36 @@ config AIO
           by some high performance threaded applications. Disabling
           this option saves about 7k.
 
+config HAVE_PERF_COUNTERS
+       bool
+
+menu "Performance Counters"
+
+config PERF_COUNTERS
+       bool "Kernel Performance Counters"
+       depends on HAVE_PERF_COUNTERS
+       default y
+       select ANON_INODES
+       help
+         Enable kernel support for performance counter hardware.
+
+         Performance counters are special hardware registers available
+         on most modern CPUs. 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
+         provides per task and per CPU counters, and it provides event
+         capabilities on top of those.
+
+         Say Y if unsure.
+
+endmenu
+
 config VM_EVENT_COUNTERS
        default y
        bool "Enable VM event counters for /proc/vmstat" if EMBEDDED