kernel-fxtec-pro1x/arch/x86
Zhai, Edwin 4b8d54f972 KVM: VMX: Add support for Pause-Loop Exiting
New NHM processors will support Pause-Loop Exiting by adding 2 VM-execution
control fields:
PLE_Gap    - upper bound on the amount of time between two successive
             executions of PAUSE in a loop.
PLE_Window - upper bound on the amount of time a guest is allowed to execute in
             a PAUSE loop

If the time, between this execution of PAUSE and previous one, exceeds the
PLE_Gap, processor consider this PAUSE belongs to a new loop.
Otherwise, processor determins the the total execution time of this loop(since
1st PAUSE in this loop), and triggers a VM exit if total time exceeds the
PLE_Window.
* Refer SDM volume 3b section 21.6.13 & 22.1.3.

Pause-Loop Exiting can be used to detect Lock-Holder Preemption, where one VP
is sched-out after hold a spinlock, then other VPs for same lock are sched-in
to waste the CPU time.

Our tests indicate that most spinlocks are held for less than 212 cycles.
Performance tests show that with 2X LP over-commitment we can get +2% perf
improvement for kernel build(Even more perf gain with more LPs).

Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-12-03 09:32:17 +02:00
..
boot
configs
crypto
ia32
include/asm KVM: VMX: Add support for Pause-Loop Exiting 2009-12-03 09:32:17 +02:00
kernel Merge remote branch 'tip/x86/entry' into kvm-updates/2.6.33 2009-12-03 09:30:06 +02:00
kvm KVM: VMX: Add support for Pause-Loop Exiting 2009-12-03 09:32:17 +02:00
lguest
lib
math-emu
mm x86: Fix error return sequence in __ioremap_caller() 2009-11-08 12:48:58 +01:00
oprofile
pci
power
vdso
video
xen xen: mask extended topology info in cpuid 2009-11-03 11:09:12 -08:00
Kbuild
Kconfig Merge remote branch 'tip/x86/entry' into kvm-updates/2.6.33 2009-12-03 09:30:06 +02:00
Kconfig.cpu
Kconfig.debug
Makefile
Makefile_32.cpu