Re: [Qemu-devel] [PATCH 05/12] migration: show the statistics of compression

[Eric Blake]

On 06/04/2018 04:55 AM, address@hidden wrote:
> From: Xiao Guangrong <address@hidden>
>
> Then the uses can adjust the parameters based on this info
>
> Currently, it includes:
> pages: amount of pages compressed and transferred to the target VM
> busy: amount of count that no free thread to compress data
> busy-rate: rate of thread busy
> reduced-size: amount of bytes reduced by compression
> compression-rate: rate of compressed size
>
> Signed-off-by: Xiao Guangrong <address@hidden>
> ---

> +++ b/qapi/migration.json
> @@ -72,6 +72,26 @@
>              'cache-miss': 'int', 'cache-miss-rate': 'number',
>              'overflow': 'int' } }
>   
> +##
> +# @CompressionStats:
> +#
> +# Detailed compression migration statistics

Sounds better as s/compression migration/migration compression/

> +#
> +# @pages: amount of pages compressed and transferred to the target VM
> +#
> +# @busy: amount of count that no free thread to compress data

Not sure what was meant, maybe:

@busy: count of times that no free thread was available to compress data

> +#
> +# @busy-rate: rate of thread busy

In what unit? pages per second?

> +#
> +# @reduced-size: amount of bytes reduced by compression
> +#
> +# @compression-rate: rate of compressed size

In what unit?

> +#
> +##

Missing a 'Since: 3.0' tag

> +{ 'struct': 'CompressionStats',
> +  'data': {'pages': 'int', 'busy': 'int', 'busy-rate': 'number',
> +          'reduced-size': 'int', 'compression-rate': 'number' } }
> +
>   ##
>   # @MigrationStatus:
>   #
> @@ -169,6 +189,8 @@
>   #           only present when the postcopy-blocktime migration capability
>   #           is enabled. (Since 2.13)

Pre-existing - we need to fix this 2.13 to be 3.0 (if it isn't already 
fixed)

>   #
> +# @compression: compression migration statistics, only returned if compression
> +#           feature is on and status is 'active' or 'completed' (Since 2.14)

There will not be a 2.14 (for that matter, not even a 2.13).  The next 
release is 3.0.

>   #
>   # Since: 0.14.0
>   ##
> @@ -183,7 +205,8 @@
>              '*cpu-throttle-percentage': 'int',
>              '*error-desc': 'str',
>              '*postcopy-blocktime' : 'uint32',
> -           '*postcopy-vcpu-blocktime': ['uint32']} }
> +           '*postcopy-vcpu-blocktime': ['uint32'],
> +           '*compression': 'CompressionStats'} }
>   
>   ##
>   # @query-migrate:

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org