From: "Michael R. Hines" <mrhi...@us.ibm.com>
Please pull.
Changes since v7:
This fixes the problems experienced by others when
the x-rdma-pin-all feature appeared to freeze the VM.
By moving this operation out of the connection setup
time and instead moving it to ram_save_setup() code, we no longer
execute pinning inside the BQL and thus the pinning is parallelized
with the VM execution and also properly accounted for inside the
QMP migrate total time statistics.
Wiki: http://wiki.qemu.org/Features/RDMALiveMigration
Github: g...@github.com:hinesmr/qemu.git
Here is a brief summary of total migration time and downtime using RDMA:
Using a 40gbps infiniband link performing a worst-case stress test,
using an 8GB RAM virtual machine:
Using the following command:
$ apt-get install stress
$ stress --vm-bytes 7500M --vm 1 --vm-keep
RESULTS:
1. Migration throughput: 26 gigabits/second.
2. Downtime (stop time) varies between 15 and 100 milliseconds.
EFFECTS of memory registration on bulk phase round:
For example, in the same 8GB RAM example with all 8GB of memory in
active use and the VM itself is completely idle using the same 40 gbps
infiniband link:
1. x-rdma-pin-all disabled total time: approximately 7.5 seconds @ 9.5 Gbps
2. x-rdma-pin-all enabled total time: approximately 4 seconds @ 26 Gbps
These numbers would of course scale up to whatever size virtual machine
you have to migrate using RDMA.
Enabling this feature does *not* have any measurable affect on
migration *downtime*. This is because, without this feature, all of the
memory will have already been registered already in advance during
the bulk round and does not need to be re-registered during the successive
iteration rounds.
The following changes since commit f3aa844bbb2922a5b8393d17620eca7d7e921ab3:
build: include config-{, all-}devices.mak after defining CONFIG_SOFTMMU and
CONFIG_USER_ONLY (2013-04-24 12:18:41 -0500)
are available in the git repository at:
g...@github.com:hinesmr/qemu.git rdma_patch_v6
for you to fetch changes up to 75e6fac1f642885b93cefe6e1874d648e9850f8f:
rdma: send pc.ram (2013-04-24 14:55:01 -0400)
Reviewed-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>
----------------------------------------------------------------
Michael R. Hines (13):
rdma: add documentation
rdma: introduce qemu_update_position()
rdma: export yield_until_fd_readable()
rdma: export throughput w/ MigrationStats QMP
rdma: introduce qemu_file_mode_is_not_valid()
rdma: export qemu_fflush()
rdma: introduce ram_handle_compressed()
rdma: introduce qemu_ram_foreach_block()
rdma: new QEMUFileOps hooks
rdma: introduce capability x-rdma-pin-all
rdma: core logic
rdma: send pc.ram
rdma: fix mlock() freezes and accounting
Makefile.objs | 1 +
arch_init.c | 69 +-
configure | 29 +
docs/rdma.txt | 415 ++++++
exec.c | 9 +
hmp.c | 2 +
include/block/coroutine.h | 6 +
include/exec/cpu-common.h | 5 +
include/migration/migration.h | 31 +
include/migration/qemu-file.h | 32 +
migration-rdma.c | 2812 +++++++++++++++++++++++++++++++++++++++++
migration.c | 23 +
qapi-schema.json | 12 +-
qemu-coroutine-io.c | 23 +
savevm.c | 114 +-
15 files changed, 3536 insertions(+), 47 deletions(-)
create mode 100644 docs/rdma.txt
create mode 100644 migration-rdma.c
--
1.7.10.4
