Timekeeping in VMware Virtual Machines（计时在VMware虚拟机）.pdf

Timekeeping in VMware Virtual Machines VMware vSphere 5.0, Workstation 8.0, Fusion 4.0 INFORMA TION GUIDE Timekeeping in VMware Virtual Machines VMware vSphere 5.0, Workstation 8.0, Fusion 4.0 Table of Contents Introduction 4 Timekeeping Basics 4 Tick Counting 4 Tickless Timekeeping5 Initializing and Correcting Wall-Clock Time6 PC Timer Hardware 6 PIT7 CMOS RTC 8 Local APIC Timer 8 ACPI Timer8 TSC 8 HPET9 VMware Timer Virtualization9 Virtual PIT9 Virtual CMOS RTC 10 Virtual Local APIC Timer 11 Virtual ACPI Timer 11 Virtual TSC 11 Pseudoperformance Counters 13 Virtual HPET 13 Other Time-Dependent Devices 13 VMI Paravirtual Timer 14 Timekeeping in Specific Operating Systems 14 Microsoft Windows14 Linux 15 Kernels Before Clocksource 16 Clocksource Kernels 18 Paravirtual Kernels 18 Solaris 18 Synchronizing Virtual Machines and Hosts with Real Time 19 Using VMware Tools Clock Synchronization 20 Enabling Periodic Synchronization 20 Disabling All Synchronization 21 Using Microsoft W32Time in Windows Guests 22 Using NTP in Linux and Other Guests 23 Host Clock Synchronization 23 Time and Performance Measurements Within a Virtual Machine 24 Time Measurements 24 Performance Measurements24 Event Counts 25 Memory Usage 25 CPU Usage 25 I N F O R M A T I O N