Merge branch 'linus' into core/iommu

Merge reason: This branch was on an -rc5 base so pull almost-2.6.30
              to resync with the latest upstream fixes and make sure
              the combination works fine.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 13 insertions, 0 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index df9e885eee1..a6efe0a2e9a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -498,6 +498,19 @@ config PARAVIRT
           over full virtualization.  However, when run without a hypervisor
           the kernel is theoretically slower and slightly larger.
 
+config PARAVIRT_SPINLOCKS
+        bool "Paravirtualization layer for spinlocks"
+        depends on PARAVIRT && SMP && EXPERIMENTAL
+        ---help---
+          Paravirtualized spinlocks allow a pvops backend to replace the
+          spinlock implementation with something virtualization-friendly
+          (for example, block the virtual CPU rather than spinning).
+
+          Unfortunately the downside is an up to 5% performance hit on
+          native kernels, with various workloads.
+
+          If you are unsure how to answer this question, answer N.
+
 config PARAVIRT_CLOCK
         bool
         default n