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Re: [Qemu-devel] [PATCH v5 10/12] rdma: introduce capability x-rdma-pin-
From: |
Eric Blake |
Subject: |
Re: [Qemu-devel] [PATCH v5 10/12] rdma: introduce capability x-rdma-pin-all |
Date: |
Mon, 22 Apr 2013 14:24:49 -0600 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130402 Thunderbird/17.0.5 |
On 04/21/2013 03:17 PM, address@hidden wrote:
> From: "Michael R. Hines" <address@hidden>
>
> This capability allows you to disable dynamic chunk registration
> for better throughput on high-performance links.
>
> For example, using an 8GB RAM virtual machine with all 8GB of memory in
> active use and the VM itself is completely idle using a 40 gbps infiniband
> link:
>
> 1. x-pin-all disabled total time: approximately 7.5 seconds @ 9.5 Gbps
> 2. x-pin-all enabled total time: approximately 4 seconds @ 26 Gbps
Naming here doesn't match the actual bit name; but it is obvious enough
to know what you meant.
Thanks for doing this, by the way - the default-to-disabled is a bit
nicer to manage from libvirt's perspective.
>
> 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.
>
> Signed-off-by: Michael R. Hines <address@hidden>
> ---
> include/migration/migration.h | 2 ++
> migration.c | 9 +++++++++
> qapi-schema.json | 7 ++++++-
> 3 files changed, 17 insertions(+), 1 deletion(-)
> +++ b/qapi-schema.json
> @@ -602,10 +602,15 @@
> # This feature allows us to minimize migration traffic for certain
> work
> # loads, by sending compressed difference of the pages
> #
> +# @x-rdma-pin-all: (since 1.5) Controls whether or not the entire VM memory
> footprint is
Trailing whitespace, and line longer than 80 columns. You ought to
rewrap this, and make sure it passes checkpatch.pl.
But since that is whitespace-only, feel free to add:
Reviewed-by: Eric Blake <address@hidden>
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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- [Qemu-devel] [PATCH v5 00/12] rdma: migration support, mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 09/12] rdma: new QEMUFileOps hooks, mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 05/12] rdma: introduce qemu_file_mode_is_not_valid(), mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 04/12] rdma: introduce qemu_get_max_size(), mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 03/12] rdma: export throughput w/ MigrationStats QMP, mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 08/12] rdma: introduce qemu_ram_foreach_block(), mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 10/12] rdma: introduce capability x-rdma-pin-all, mrhines, 2013/04/21
- Re: [Qemu-devel] [PATCH v5 10/12] rdma: introduce capability x-rdma-pin-all,
Eric Blake <=
- [Qemu-devel] [PATCH v5 06/12] rdma: export qemu_fflush(), mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 11/12] rdma: core logic, mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 12/12] rdma: send pc.ram, mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 07/12] rdma: introduce ram_handle_compressed(), mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 01/12] rdma: add documentation, mrhines, 2013/04/21
- [Qemu-devel] [PATCH v5 02/12] rdma: export yield_until_fd_readable(), mrhines, 2013/04/21