Re: [Qemu-devel] [PATCH v11 2/6] qmp: Use ThrottleLimits structure

[Pradeep Jagadeesh]

On 9/18/2017 6:04 PM, Manos Pitsidianakis wrote:
> On Thu, Sep 14, 2017 at 06:40:06AM -0400, Pradeep Jagadeesh wrote:
> > This patch factors out code to use the ThrottleLimits
> > strurcture.
> >
> > Signed-off-by: Pradeep Jagadeesh <address@hidden>
> > Reviewed-by: Greg Kurz <address@hidden>
> > Reviewed-by: Eric Blake <address@hidden>
> > Reviewed-by: Alberto Garcia <address@hidden>
> > Reviewed-by: Markus Armbruster <address@hidden>
> > ---
> > qapi/block-core.json | 78
> > +++-------------------------------------------------
> > 1 file changed, 4 insertions(+), 74 deletions(-)
> >
> > diff --git a/qapi/block-core.json b/qapi/block-core.json
> > index bb11815..d0ccfda 100644
> > --- a/qapi/block-core.json
> > +++ b/qapi/block-core.json
> > @@ -1826,84 +1826,13 @@
> > #
> > # @device: Block device name (deprecated, use @id instead)
> > #
> > -# @id: The name or QOM path of the guest device (since: 2.8)
> > -#
> > -# @bps: total throughput limit in bytes per second
> > -#
> > -# @bps_rd: read throughput limit in bytes per second
> > -#
> > -# @bps_wr: write throughput limit in bytes per second
> > -#
> > -# @iops: total I/O operations per second
> > -#
> > -# @iops_rd: read I/O operations per second
> > -#
> > -# @iops_wr: write I/O operations per second
> > -#
> > -# @bps_max: total throughput limit during bursts,
> > -#                     in bytes (Since 1.7)
> > -#
> > -# @bps_rd_max: read throughput limit during bursts,
> > -#                        in bytes (Since 1.7)
> > -#
> > -# @bps_wr_max: write throughput limit during bursts,
> > -#                        in bytes (Since 1.7)
> > -#
> > -# @iops_max: total I/O operations per second during bursts,
> > -#                      in bytes (Since 1.7)
> > -#
> > -# @iops_rd_max: read I/O operations per second during bursts,
> > -#                         in bytes (Since 1.7)
> > -#
> > -# @iops_wr_max: write I/O operations per second during bursts,
> > -#                         in bytes (Since 1.7)
> > -#
> > -# @bps_max_length: maximum length of the @bps_max burst
> > -#                            period, in seconds. It must only
> > -#                            be set if @bps_max is set as well.
> > -#                            Defaults to 1. (Since 2.6)
> > -#
> > -# @bps_rd_max_length: maximum length of the @bps_rd_max
> > -#                               burst period, in seconds. It must only
> > -#                               be set if @bps_rd_max is set as well.
> > -#                               Defaults to 1. (Since 2.6)
> > -#
> > -# @bps_wr_max_length: maximum length of the @bps_wr_max
> > -#                               burst period, in seconds. It must only
> > -#                               be set if @bps_wr_max is set as well.
> > -#                               Defaults to 1. (Since 2.6)
> > -#
> > -# @iops_max_length: maximum length of the @iops burst
> > -#                             period, in seconds. It must only
> > -#                             be set if @iops_max is set as well.
> > -#                             Defaults to 1. (Since 2.6)
> > -#
> > -# @iops_rd_max_length: maximum length of the @iops_rd_max
> > -#                                burst period, in seconds. It must only
> > -#                                be set if @iops_rd_max is set as well.
> > -#                                Defaults to 1. (Since 2.6)
> > -#
> > -# @iops_wr_max_length: maximum length of the @iops_wr_max
> > -#                                burst period, in seconds. It must only
> > -#                                be set if @iops_wr_max is set as well.
> > -#                                Defaults to 1. (Since 2.6)
> > -#
> > -# @iops_size: an I/O size in bytes (Since 1.7)
> > -#
> > # @group: throttle group name (Since 2.4)
>
> BlockIOThrottle and ThrottleLimits are not directly compatible, for
> example here we have iops_rd_max_length as a name,
>
> > #
> > # Since: 1.1
> > ##
> > { 'struct': 'BlockIOThrottle',
> > -  'data': { '*device': 'str', '*id': 'str', 'bps': 'int', 'bps_rd':
> > 'int',
> > -            'bps_wr': 'int', 'iops': 'int', 'iops_rd': 'int',
> > 'iops_wr': 'int',
> > -            '*bps_max': 'int', '*bps_rd_max': 'int',
> > -            '*bps_wr_max': 'int', '*iops_max': 'int',
> > -            '*iops_rd_max': 'int', '*iops_wr_max': 'int',
> > -            '*bps_max_length': 'int', '*bps_rd_max_length': 'int',
> > -            '*bps_wr_max_length': 'int', '*iops_max_length': 'int',
> > -            '*iops_rd_max_length': 'int', '*iops_wr_max_length': 'int',
> > -            '*iops_size': 'int', '*group': 'str' } }
> > +  'base': 'ThrottleLimits',
> > +  'data': { '*device': 'str', '*group': 'str' } }
> >
> > ##
> > # @ThrottleLimits:
> > @@ -1913,6 +1842,7 @@
> > # transaction. All fields are optional. When setting limits, if a
> > field is
> > # missing the current value is not changed.
> > #
> > +# @id:                     device id
> > # @iops-total:             limit total I/O operations per second
> > # @iops-total-max:         I/O operations burst
> > # @iops-total-max-length:  length of the iops-total-max burst period,
> > in seconds
> > @@ -1942,7 +1872,7 @@
> > # Since: 2.11
> > ##
> > { 'struct': 'ThrottleLimits',
> > -  'data': { '*iops-total' : 'int', '*iops-total-max' : 'int',
> > +  'data': { '*id' : 'str', '*iops-total' : 'int', '*iops-total-max' :
> > 'int',
> >             '*iops-total-max-length' : 'int', '*iops-read' : 'int',
> >             '*iops-read-max' : 'int', '*iops-read-max-length' : 'int',
> >             '*iops-write' : 'int', '*iops-write-max' : 'int',
>
> And here it's iops-read-max-length. This breaks the block layer's old
> throttling API. Do we want the old API replaced for 2.11? I don't know
> which maintainer is responsible for this, so I CC'd armbru.

I do not think its going to break. It just exist we neither try to set 
that or to query.

-Pradeep