Re: [Qemu-devel] [PATCH v8 00/54] Postcopy implementation

[Bharata B Rao]

On Mon, Sep 28, 2015 at 05:51:39PM +0100, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
> 
>   This is the 8th cut of my version of postcopy.
> 
> The userfaultfd linux kernel code is now in the upstream kernel
> tree, and so 4.3-rc3 can be used without modification.
> 
> This qemu series can be found at:
> https://github.com/orbitfp7/qemu.git
> on the wp3-postcopy-v8 tag
> 
> 
> Testing status:
>   * Tested heavily on x86
>   * Smoke tested on aarch64 (so it does work on different page sizes)
>   * Power is unhappy for me (but gets further than the htab problem
>     v7 used to have) (I get a kvm run failed)

Seems to be completing successfully on Power. But it takes 2min for the
migration status to transition from setup to active.

Host: 4.3.0-rc3+
Guest: 4.3.0-rc3+
QEMU: wp3-postcopy-v8 of your tree.

# ./ppc64-softmmu/qemu-system-ppc64 --enable-kvm --nographic -machine pseries 
-m 8G,slots=32,maxmem=32G -device virtio-blk-pci,drive=rootdisk -drive 
file=/home/bharata/F20-snap1,if=none,cache=none,id=rootdisk,format=qcow2 -vga 
none -net nic,model=virtio -net user -redir tcp:2000::22 -smp 16,maxcpus=32 
-serial pty

(qemu) migrate_set_capability x-postcopy-ram on
(qemu) migrate -d tcp:localhost:4444
(qemu) info migrate
capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off 
compress: off events: off x-postcopy-ram: on 
Migration status: setup
total time: 0 milliseconds

same status for around 2min...

(qemu) info migrate
capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off 
compress: off events: off x-postcopy-ram: on 
Migration status: active
total time: 130089 milliseconds
expected downtime: 300 milliseconds
setup: 24 milliseconds
transferred ram: 79454 kbytes
throughput: 50.09 mbps
remaining ram: 7670688 kbytes
total ram: 8388864 kbytes
duplicate: 160684 pages
skipped: 0 pages
normal: 18860 pages
normal bytes: 75440 kbytes
dirty sync count: 1

(qemu) migrate_start_postcopy

(qemu) info migrate
capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off 
compress: off events: off x-postcopy-ram: on 
Migration status: postcopy-active
total time: 135627 milliseconds
expected downtime: 43 milliseconds
setup: 24 milliseconds
transferred ram: 338598 kbytes
throughput: 74.02 mbps
remaining ram: 1688384 kbytes
total ram: 8388864 kbytes
duplicate: 1600406 pages
skipped: 0 pages
normal: 75258 pages
normal bytes: 301032 kbytes
dirty sync count: 0
dirty pages rate: 98 pages

(qemu) info migrate
capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off 
compress: off events: off x-postcopy-ram: on 
Migration status: completed
total time: 136898 milliseconds
downtime: 685 milliseconds
setup: 24 milliseconds
transferred ram: 1194196 kbytes
throughput: 72.00 mbps
remaining ram: 0 kbytes
total ram: 8388864 kbytes
duplicate: 1810921 pages
skipped: 0 pages
normal: 286839 pages
normal bytes: 1147356 kbytes
dirty sync count: 2