Re: [PATCH v20210209 3/4] xl: optionally print timestamps when running xl commands

[Ian Jackson <iwj@xxxxxxxxxxxxxx>]

Olaf Hering writes ("[PATCH v20210209 3/4] xl: optionally print timestamps when 
running xl commands"):
> Add a global option "-T" to xl to enable timestamps in the output from
> libxl and libxc. This is most useful with long running commands such
> as "migrate".
> 
> During 'xl -v.. migrate domU host' a large amount of debug is generated.
> It is difficult to map each line to the sending and receiving side.
> Also the time spent for migration is not reported.
> 
> With 'xl -T migrate domU host' both sides will print timestamps and
> also the pid of the invoked xl process to make it more obvious which
> side produced a given log line.
> 
> Note: depending on the command, xl itself also produces other output
> which does not go through libxentoollog. As a result such output will
> not have timestamps prepended.

Reviewed-by: Ian Jackson <iwj@xxxxxxxxxxxxxx>

This is a new feature so it needs a release risk analysis.

The changes are entirely to xl command line handling.  The worst /
most likely bug would probably be something to do with the way the
logger is created.  Such a bug would be easy to fix.  Or, this patch
could easily be reverted.

Release-Acked-by: Ian Jackson <iwj@xxxxxxxxxxxxxx>

> This change adds also the missing "-t" flag to "xl help" output.

This part of the commit message talks about -t rather than -T.  I will
fix that on commit.

I'm going to commit the first three now.

Ian.