Re: [Qemu-devel] [PATCH 00/16] Multifd v4

[Dr. David Alan Gilbert]

* Juan Quintela (address@hidden) wrote:
> Hi
> 
> This is the 4th version of multifd. Changes:
> - XBZRLE don't need to be checked for
> - Documentation and defaults are consistent
> - split socketArgs
> - use iovec instead of creating something similar.
> - We use now the exported size of target page (another HACK removal)
> - created qio_chanel_{wirtev,readv}_all functions.  the _full() name
>   was already taken.
>   What they do is the same that the without _all() function, but if it
>   returns due to blocking it redo the call.
> - it is checkpatch.pl clean now.
> 
> Please comment, Juan.

High level things,
  a) I think you probably need to do some bandwidth measurements to show
    that multifd is managing to have some benefit - it would be good
    for the cover letter.
  b) By my count I think this is actually v5 (And I think you're missing
     the -v to git)

Dave
    
> 
> 
> 
> [v3]
> 
> - comments for previous verion addressed
> - lots of bugs fixed
> - remove DPRINTF from ram.c
> 
> - add multifd-group parameter, it gives how many pages we sent each
>   time to the worker threads.  I am open to better names.
> - Better flush support.
> - with migration_set_speed 2G it is able to migrate "stress -vm 2
>   -vm-bytes 512M" over loopback.
> 
> Please review.
> 
> Thanks, Juan.
> 
> [v2]
> 
> This is a version against current code.  It is based on top of QIO
> work. It improves the thread synchronization and fixes the problem
> when we could have two threads handing the same page.
> 
> Please comment, Juan.
> 
> 
> Juan Quintela (16):
>   qio: create new qio_channel_write_all
>   qio: create new qio_channel_read_all
>   migration: Test for disabled features on reception
>   migration: Don't create decompression threads if not enabled
>   migration: Add multifd capability
>   migration: Create x-multifd-threads parameter
>   migration: Create x-multifd-group parameter
>   migration: Create multifd migration threads
>   migration: Start of multiple fd work
>   migration: Create ram_multifd_page
>   migration: Really use multiple pages at a time
>   migration: Send the fd number which we are going to use for this page
>   migration: Create thread infrastructure for multifd recv side
>   migration: Test new fd infrastructure
>   migration: Transfer pages over new channels
>   migration: Flush receive queue
> 
>  hmp.c                         |  18 ++
>  include/io/channel.h          |  46 ++++
>  include/migration/migration.h |  17 ++
>  io/channel.c                  |  76 ++++++
>  migration/migration.c         |  85 ++++++-
>  migration/qemu-file-channel.c |  29 +--
>  migration/ram.c               | 522 
> +++++++++++++++++++++++++++++++++++++++++-
>  migration/socket.c            |  67 +++++-
>  qapi-schema.json              |  30 ++-
>  9 files changed, 848 insertions(+), 42 deletions(-)
> 
> -- 
> 2.9.3
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK