Re: [Qemu-devel] [PATCH v5 00/12] rdma: migration support

[Anthony Liguori <aliguori@us.ibm.com>]

"Michael R. Hines" <mrhines@linux.vnet.ibm.com> writes:

> On 04/23/2013 01:50 PM, Anthony Liguori wrote:
>> mrhines@linux.vnet.ibm.com writes:
>>
>>> From: "Michael R. Hines" <mrhines@us.ibm.com>
>>>
>>> Juan, Please pull.
>> I assume this is actually v6, not v5?
>>
>> I don't see collected Reviewed-bys...
>>
>> That said, we're pretty close to hard freeze.  I think this should wait
>> until 1.6 opens up although I'm open to suggestion if people think this
>> is low risk.  I don't like the idea of adding a new protocol this close
>> to the end of a cycle.
>>
>> Regards,
>>
>> Anthony Liguori
>
> There are no instructions/procedures documented on the qemu.org
> website on how to automatically generate "Reviewed-by" signatures.

I suspect there's some confusion here.  Addressed review comments !=
Reviewed-by.  There can always be additional comments.  Someone has to
explicitly offer a Reviewed-by indicating that they are happy with the
patches overall.  I've gone through the history on these patches and I
don't see any explicit Reviewed-by's other than Eric's most recent one.

Give the series a little more time for people to look over it, it'll get
Reviewed-bys when people are ready to offer them.

Regards,

Anthony Liguori

>
> How do you guys do that?
>
> - Michael
>
>>> Changes since v4:
>>>
>>> - Re-ran checkpatch.pl
>>> - Added new QEMUFileOps function: qemu_get_max_size()
>>> - Renamed capability to x-pin-all, disabled by default
>>> - Added numbers for x-pin-all to performance section in docs/rdma.txt
>>> - Included performance numbers in this cover letter
>>> - Converted throughput patch to a MigrationStats statistic in QMP
>>> - Better QMP error message delivery
>>> - Updated documentation
>>> - Moved docs/rdma.txt up to top of patch series
>>> - Fixed all v4 changes requested
>>> - Finished additional cleanup requests
>>> - Updated copyright for migration-rdma.c
>>>
>>> Wiki: http://wiki.qemu.org/Features/RDMALiveMigration
>>> Github: git@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.
>>>
>>> Michael R. Hines (12):
>>>    rdma: add documentation
>>>    rdma: export yield_until_fd_readable()
>>>    rdma: export throughput w/ MigrationStats QMP
>>>    rdma: introduce qemu_get_max_size()
>>>    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
>>>
>>>   Makefile.objs                 |    1 +
>>>   arch_init.c                   |   59 +-
>>>   configure                     |   29 +
>>>   docs/rdma.txt                 |  404 ++++++
>>>   exec.c                        |    9 +
>>>   hmp.c                         |    2 +
>>>   include/block/coroutine.h     |    6 +
>>>   include/exec/cpu-common.h     |    5 +
>>>   include/migration/migration.h |   24 +
>>>   include/migration/qemu-file.h |   44 +
>>>   migration-rdma.c              | 2727 +++++++++++++++++++++++++++++++++++++++++
>>>   migration.c                   |   22 +-
>>>   qapi-schema.json              |   12 +-
>>>   qemu-coroutine-io.c           |   23 +
>>>   savevm.c                      |  133 +-
>>>   15 files changed, 3451 insertions(+), 49 deletions(-)
>>>   create mode 100644 docs/rdma.txt
>>>   create mode 100644 migration-rdma.c
>>>
>>> -- 
>>> 1.7.10.4