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authorIngo Molnar <mingo@elte.hu>2008-12-25 09:31:28 +0100
committerIngo Molnar <mingo@elte.hu>2008-12-25 09:31:28 +0100
commit12d79bafb75639f406a9f71aab94808c414c836e (patch)
tree2d7ba81720be2ec8c897dd3ab6781cccd973249c /kernel/Kconfig.preempt
parent64db4cfff99c04cd5f550357edcc8780f96b54a2 (diff)
downloadlwn-12d79bafb75639f406a9f71aab94808c414c836e.tar.gz
lwn-12d79bafb75639f406a9f71aab94808c414c836e.zip
rcu: provide RCU options on non-preempt architectures too
Impact: build fix Some old architectures still do not use kernel/Kconfig.preempt, so the moving of the RCU options there broke their build: In file included from /home/mingo/tip/include/linux/sem.h:81, from /home/mingo/tip/include/linux/sched.h:69, from /home/mingo/tip/arch/alpha/kernel/asm-offsets.c:9: /home/mingo/tip/include/linux/rcupdate.h:62:2: error: #error "Unknown RCU implementation specified to kernel configuration" Move these options back to init/Kconfig, which every architecture includes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/Kconfig.preempt')
-rw-r--r--kernel/Kconfig.preempt75
1 files changed, 0 insertions, 75 deletions
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index 463f29743ea0..bf987b95b356 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -52,78 +52,3 @@ config PREEMPT
endchoice
-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.
-
-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.
-
-