Re: [Qemu-devel] [PATCH v8 3/3] Force auto-convegence of live migration

[Juan Quintela]

Chegu Vinod <address@hidden> wrote:
> If a user chooses to turn on the auto-converge migration capability
> these changes detect the lack of convergence and throttle down the
> guest. i.e. force the VCPUs out of the guest for some duration
> and let the migration thread catchup and help converge.
>
> Verified the convergence using the following :
>  - Java Warehouse workload running on a 20VCPU/256G guest(~80% busy)
>  - OLTP like workload running on a 80VCPU/512G guest (~80% busy)
>
> Sample results with Java warehouse workload : (migrate speed set to 20Gb and
> migrate downtime set to 4seconds).
>
>  (qemu) info migrate
>  capabilities: xbzrle: off auto-converge: off  <----
>  Migration status: active
>  total time: 1487503 milliseconds
>  expected downtime: 519 milliseconds
>  transferred ram: 383749347 kbytes
>  remaining ram: 2753372 kbytes
>  total ram: 268444224 kbytes
>  duplicate: 65461532 pages
>  skipped: 64901568 pages
>  normal: 95750218 pages
>  normal bytes: 383000872 kbytes
>  dirty pages rate: 67551 pages
>
>  ---
>
>  (qemu) info migrate
>  capabilities: xbzrle: off auto-converge: on   <----
>  Migration status: completed
>  total time: 241161 milliseconds
>  downtime: 6373 milliseconds
>  transferred ram: 28235307 kbytes
>  remaining ram: 0 kbytes
>  total ram: 268444224 kbytes
>  duplicate: 64946416 pages
>  skipped: 64903523 pages
>  normal: 7044971 pages
>  normal bytes: 28179884 kbytes
>
> Signed-off-by: Chegu Vinod <address@hidden>

Reviewed-by: Juan Quintela <address@hidden>