Hao Xiang <hao.xi...@bytedance.com> writes:
> This change extends the MigrationStatus interface to track zero pages
> and zero bytes counter.
>
> Signed-off-by: Hao Xiang <hao.xi...@bytedance.com>
[...]
> diff --git a/qapi/migration.json b/qapi/migration.json
> index ca9561fbf1..03b850bab7 100644
> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -63,6 +63,10 @@
> # between 0 and @dirty-sync-count * @multifd-channels. (since
> # 7.1)
> #
> +# @zero-pages: number of zero pages (since 9.0)
> +#
> +# @zero-bytes: number of zero bytes sent (since 9.0)
> +#
Discussion of v3 has led me to believe:
1. A page is either migrated as a normal page or as a zero page.
2. The following equations hold:
@normal-bytes = @normal * @page-size
@zero-bytes = @zero-pages * @page-size
3. @zero-pages is the same as @duplicate, with a better name. We intend
to drop @duplicate eventually.
If this is correct, I'd like you to
A. Name it @zero for consistency with @normal. Disregard my advice to
name it @zero-pages; two consistent bad names are better than one bad
name, one good name, and inconsistency.
B. Add @zero and @zero-bytes next to @normal and @normal-bytes.
C. Deprecate @duplicate (item 3). Separate patch, please.
D. Consider documenting more clearly what normal and zero pages are
(item 1), and how @FOO, @FOO-pages and @page-size are related (item
2). Could be done in a followup patch.
> # Features:
> #
> # @deprecated: Member @skipped is always zero since 1.5.3
> @@ -81,7 +85,8 @@
> 'multifd-bytes': 'uint64', 'pages-per-second': 'uint64',
> 'precopy-bytes': 'uint64', 'downtime-bytes': 'uint64',
> 'postcopy-bytes': 'uint64',
> - 'dirty-sync-missed-zero-copy': 'uint64' } }
> + 'dirty-sync-missed-zero-copy': 'uint64',
> + 'zero-pages': 'int', 'zero-bytes': 'size' } }
>
[...]
