Merge branch 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-2.6-omap-h63xx.git] / init / Kconfig

diff --git a/init/Kconfig b/init/Kconfig
index b3782c6d5ede57f94446de710213a2b20deed283..f6281711166d5dbeba4f55121547396d00b6ff2e 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -588,6 +588,13 @@ config KALLSYMS_ALL
 
           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
@@ -938,10 +945,90 @@ source "block/Kconfig"
 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.