Re: [PATCH QEMU v8 2/9] qapi/migration: Introduce x-vcpu-dirty-limit-period parameter

[Markus Armbruster]

~hyman <hyman@git.sr.ht> writes:

> From: Hyman Huang(黄勇) <yong.huang@smartx.com>
>
> Introduce "x-vcpu-dirty-limit-period" migration experimental
> parameter, which is in the range of 1 to 1000ms and used to
> make dirtyrate calculation period configurable.

dirty rate

>
> Currently with the "x-vcpu-dirty-limit-period" varies, the

Currently, as the

> total time of live migration changes, test results show the

Suggest period instead of comma.

> optimal value of "x-vcpu-dirty-limit-period" ranges from
> 500ms to 1000 ms. "x-vcpu-dirty-limit-period" should be made
> stable once it proves best value can not be determined with
> developer's experiments.
>
> Signed-off-by: Hyman Huang(黄勇) <yong.huang@smartx.com>
> Reviewed-by: Markus Armbruster <armbru@redhat.com>
> Reviewed-by: Juan Quintela <quintela@redhat.com>

[...]

> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -789,9 +789,14 @@
>  #     Nodes are mapped to their block device name if there is one, and
>  #     to their node name otherwise.  (Since 5.2)
>  #
> +# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty
> +#     limit during live migration. Should be in the range 1 to 1000ms,
> +#     defaults to 1000ms. (Since 8.1)

Two spaces after sentence-ending punctuation, please:

   # @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty
   #     limit during live migration.  Should be in the range 1 to
   #     1000ms, defaults to 1000ms.  (Since 8.1)

> +#
>  # Features:
>  #
> -# @unstable: Member @x-checkpoint-delay is experimental.
> +# @unstable: Members @x-checkpoint-delay and
> +#     @x-vcpu-dirty-limit-period are experimental.
>  #
>  # Since: 2.4
>  ##
> @@ -809,8 +814,10 @@
>             'multifd-channels',
>             'xbzrle-cache-size', 'max-postcopy-bandwidth',
>             'max-cpu-throttle', 'multifd-compression',
> -           'multifd-zlib-level' ,'multifd-zstd-level',
> -           'block-bitmap-mapping' ] }
> +           'multifd-zlib-level', 'multifd-zstd-level',
> +           'block-bitmap-mapping',
> +           { 'name': 'x-vcpu-dirty-limit-period',
> +             'features': ['unstable'] } ] }
>  
>  ##
>  # @MigrateSetParameters:
> @@ -945,9 +952,14 @@
>  #     Nodes are mapped to their block device name if there is one, and
>  #     to their node name otherwise.  (Since 5.2)
>  #
> +# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty
> +#     limit during live migration. Should be in the range 1 to 1000ms,
> +#     defaults to 1000ms. (Since 8.1)

Likewise.

> +#
>  # Features:
>  #
> -# @unstable: Member @x-checkpoint-delay is experimental.
> +# @unstable: Members @x-checkpoint-delay and
> +#     @x-vcpu-dirty-limit-period are experimental.
>  #
>  # TODO: either fuse back into MigrationParameters, or make
>  #     MigrationParameters members mandatory
> @@ -982,7 +994,9 @@
>              '*multifd-compression': 'MultiFDCompression',
>              '*multifd-zlib-level': 'uint8',
>              '*multifd-zstd-level': 'uint8',
> -            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } }
> +            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ],
> +            '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
> +                                            'features': [ 'unstable' ] } } }
>  
>  ##
>  # @migrate-set-parameters:
> @@ -1137,9 +1151,14 @@
>  #     Nodes are mapped to their block device name if there is one, and
>  #     to their node name otherwise.  (Since 5.2)
>  #
> +# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty
> +#     limit during live migration. Should be in the range 1 to 1000ms,
> +#     defaults to 1000ms. (Since 8.1)

Likewise.

> +#
>  # Features:
>  #
> -# @unstable: Member @x-checkpoint-delay is experimental.
> +# @unstable: Members @x-checkpoint-delay and
> +#     @x-vcpu-dirty-limit-period are experimental.
>  #
>  # Since: 2.4
>  ##
> @@ -1171,7 +1190,9 @@
>              '*multifd-compression': 'MultiFDCompression',
>              '*multifd-zlib-level': 'uint8',
>              '*multifd-zstd-level': 'uint8',
> -            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } }
> +            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ],
> +            '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
> +                                            'features': [ 'unstable' ] } } }
>  
>  ##
>  # @query-migrate-parameters:

The issues I'm pointing out don't justfy yet another respin.  But if you
need to respin the series for some other reason, plase take care of them.