W dniu 2015-08-14 o 03:23, Li, Liang Z pisze:
On Thu, Aug 13, 2015 at 01:25:29AM +0000, Li, Liang Z wrote:
Hi Paolo & Marcelo,
Could please point out what issue the patch 317b0a6d8ba44e try to fix? I
found in live migration the cpu_synchronize_all_states will be called twice,
and it will take more than 1 ms sometimes. I try to do some optimization but
lack the knowledge about the background.
What the code in 317b0a6d8ba44e requires is to retrieve the TSC value from
the kernel.
I know 317b0a6d8ba44e is to retrieve the TSC value, but I don't understand why it is
needed. During the live migration, the cpu_synchronize_all_states will be called
later after stopping kvm-clock. The env->tsc will be updated, is that not enough?
Or is there some case like call the 'stop_vm(RUN_STATE_PAUSED )' or ' 'stop_vm
(RUN_STATE_DEBUG) ', that require updating the env->tsc? By google, I find that
your patch try to fix some issue, but I don't know what the exact issue.
I remember testing these, and I afair that was the reason:
http://lists.gnu.org/archive/html/qemu-devel/2014-06/msg00472.html
--
mg
