On Mon, Feb 27, 2012 at 2:20 PM, Zhi Yong Wu <zwu.ker...@gmail.com> wrote: > On Sun, Feb 26, 2012 at 10:55 PM, Stefan Hajnoczi > <stefa...@linux.vnet.ibm.com> wrote: >> The QED dirty bit timer marks the file clean after allocating writes >> have drained. This is cheaper than clearing/setting the dirty bit on >> each allocating write because the timer introduces a grace period which >> can be extended if more allocating writes arrive. >> >> The vm_clock was used in an attempt to prevent modifying the image file > Why can vm_clock do this work but other clock can not? If you're > available, can you elaborate what the difference among the three > clocks is? such as vm_clock, rt_clock, and host_clock.
See qemu-timer.h. Stefan
