[patch] paravirt: allow NO_HZ, remove NO_IDLE_HZ dependency

From: Ingo Molnar
Date: Mon Mar 05 2007 - 06:37:56 EST


Subject: [patch] paravirt: remove NO_IDLE_HZ dependency
From: Ingo Molnar <mingo@xxxxxxx>

PARAVIRT forces CONFIG_NO_HZ off - this is bad and prevents sane
paravirtual guests like KVM from being able to use dynticks-enabled
Linux guests. Remove this. Vmi-timer needs to be updated properly to
make use of dynticks.

furthermore, remove the mistaken turning on of NO_IDLE_HZ on
x86+PARAVIRT kernels, it's an obsolete, limited form of dynticks.

must-have for v2.6.21.

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/i386/Kconfig | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)

Index: linux/arch/i386/Kconfig
===================================================================
--- linux.orig/arch/i386/Kconfig
+++ linux/arch/i386/Kconfig
@@ -224,7 +224,7 @@ config PARAVIRT

config VMI
bool "VMI Paravirt-ops support"
- depends on PARAVIRT && !NO_HZ
+ depends on PARAVIRT
default y
help
VMI provides a paravirtualized interface to multiple hypervisors
@@ -1291,12 +1291,3 @@ config X86_TRAMPOLINE
config KTIME_SCALAR
bool
default y
-
-config NO_IDLE_HZ
- bool
- depends on PARAVIRT
- default y
- help
- Switches the regular HZ timer off when the system is going idle.
- This helps a hypervisor detect that the Linux system is idle,
- reducing the overhead of idle systems.
-
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