Re: [PATCH v4 1/1] util/async-teardown: wire up query-command-line-options

[Markus Armbruster]

Claudio Imbrenda <imbrenda@linux.ibm.com> writes:

> The recently introduced -async-teardown commandline option was not
> wired up properly and did not show up in the output of the QMP command
> query-command-line-options. This means that libvirt had no way to
> discover whether the feature was supported.

Excuse the pedantry...  The option *was* wired up correctly, just in a
way that isn't visible in query-command-line-options.  Suggest "The
recently introduced -async-teardown command line option -async-teardown
is not visible in query-command-line-options."

> This patch fixes the issue by replacing the -async-teardown option with
> a new -teardown option with a new async=on|off parameter.

Why we can drop -async-teardown right away, without a deprecating it
first?  The commit message needs to make the argument.

If we can drop it right away, you need to update
about/removed-features.rst.

Else, you need to update docs/about/deprecated.rst, and emit a warning
when the option is used.  Something like

    warn_reportf("-async-teardown is deprecated, use -teardown async=on 
instead");

> The new option is correctly wired up so that it appears in the output
> of query-command-line-options.

Suggest

  Add new -teardown option with an async=on|off parameter.  It is
  visible in query-command-line-options.

Then either

  Option -async-teardown is now redundant.  We'd normally deprecate it
  and remove it after a grace period, but <argument goes here...>
  Drop it.

or

  Option -async-teardown is now redundant.  Deprecate it.

> Reported-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
> Fixes: c891c24b1a ("os-posix: asynchronous teardown for shutdown on Linux")
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>