Hi Jan, I found the restore process of the live migration is quit long, so I try to find out what's going on. By debugging, I found the most time consuming process is restore the VM's MTRR MSR, The process is done in the function hvm_load_mtrr_msr(), it will call the memory_type_changed(), which eventually call the time consuming function flush_all().
All this is caused by adding the memory_type_changed in your patch, here is the link http://lists.xen.org/archives/html/xen-devel/2014-03/msg03792.html, I am not sure if it's necessary to call flush_all, even it's necessary, call the function hvm_load_mtrr_msr one time will cause dozens call of flush_all, and each call of the flush_all function will consume about 8 milliseconds, in my test environment, the VM has 4 VCPUs, the hvm_load_mtrr_msr() will be called four times, and totally consumes about 500 milliseconds. Obviously, there are too many flush_all calls. I think something should be done to solve this issue, do you think so? Liang _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
