vmx: Change the default Pause-Loop-Exiting "Gap" parameter

PLE_Gap controls teh maximum allowable time between executions of
PAUSE in a busy loop. Essentially this controls the sensitivity of the
processor's busy-loop detection.

Changed the default PLE_Gap to 128 for
1. not using odd number like 41
2. getting a little bit more PLE vmexits to improve performance

Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>

diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 598ca156333eb5b0f1b54716d2698e6f3507d380..52594de9319d10f8c2f0ff08d8b54d096973e230 100644 (file)
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -53,7 +53,7 @@ boolean_param("unrestricted_guest", opt_unrestricted_guest_enabled);
  * Time is measured based on a counter that runs at the same rate as the TSC,
  * refer SDM volume 3b section 21.6.13 & 22.1.3.
  */
-static unsigned int __read_mostly ple_gap = 41;
+static unsigned int __read_mostly ple_gap = 128;
 integer_param("ple_gap", ple_gap);
 static unsigned int __read_mostly ple_window = 4096;
 integer_param("ple_window", ple_window);