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From: Peter Xu <peterx@redhat.com>
To: Markus Armbruster <armbru@redhat.com>
Cc: qemu-devel@nongnu.org,
	"Dr . David Alan Gilbert" <dave@treblig.org>,
	Fabiano Rosas <farosas@suse.de>
Subject: Re: [PATCH] hmp/migration: Fix documents for "migrate" command
Date: Fri, 3 May 2024 10:36:06 -0400	[thread overview]
Message-ID: <ZjT2Vp5PoUUmHc8A@x1n> (raw)
In-Reply-To: <87h6ffvvgy.fsf@pond.sub.org>

On Fri, May 03, 2024 at 04:08:45PM +0200, Markus Armbruster wrote:
> If there's still time, suggest to tweak the subject to
> 
>     hmp/migration: Fix "migrate" command's documentation

Yes there is. :)

> 
> Peter Xu <peterx@redhat.com> writes:
> 
> > On Fri, May 03, 2024 at 08:58:09AM +0200, Markus Armbruster wrote:
> >> Peter Xu <peterx@redhat.com> writes:
> >> 
> >> > Peter missed the Sphinx HMP document for the "resume/-r" flag in commit
> >> > 7a4da28b26 ("qmp: hmp: add migrate "resume" option").  Add it.  Avoid
> >> > adding a Fixes to make life easier for the stable maintainer.
> >> 
> >> I'm curious: how does not adding Fixes: make life easier?
> >
> > Because if I attach Fixes then IIUC Michael will read it through and judge
> > whether it should apply to stable, where I want to skip that for him
> > because I think this doesn't apply to stable.  Reasons:
> >
> >   - This is a document update, IIUC we normally only keep the latest
> >     document uptodate, not all the stable versions (especiailly for HMP,
> >     which isn't a stable ABI)?  I assume it applies the same when a qtest
> >     case got a slight fixup.
> >
> >   - This patch is even more special as it will need explicit backport due
> >     to the removal of block migration, and I really don't think any of us
> >     should spend time on that..
> 
> Right.  But Fixes: is also for downstreams, who may want to make their
> own decisions.
> 
> I think I'd always add Fixes:.  When I think there's a need to steer
> stable away from it, I'd say so in the commit message.  I doubt needed
> here, as the subject states it's just a doc fix for HMP.

OK, I'll attach a Fixes.

> 
> >> > When at it, slightly cleanup the lines, move "detach/-d" to a separate
> >> > section rather than appending it at the end of the command description.
> >> >
> >> > Cc: Dr. David Alan Gilbert <dave@treblig.org>
> >> > Cc: Fabiano Rosas <farosas@suse.de>
> >> > Cc: Markus Armbruster <armbru@redhat.com>
> >> > Signed-off-by: Peter Xu <peterx@redhat.com>
> >> > ---
> >> >
> >> > Based-on: <20240430142737.29066-1-farosas@suse.de>
> >> > ("[PATCH v3 0/6] migration removals & deprecations")
> >> > ---
> >> >  hmp-commands.hx | 9 +++++++--
> >> >  1 file changed, 7 insertions(+), 2 deletions(-)
> >> >
> >> > diff --git a/hmp-commands.hx b/hmp-commands.hx
> >> > index ebca2cdced..484a8a1c3a 100644
> >> > --- a/hmp-commands.hx
> >> > +++ b/hmp-commands.hx
> >> > @@ -918,8 +918,13 @@ ERST
> >>        {
> >>            .name       = "migrate",
> >>            .args_type  = "detach:-d,blk:-b,inc:-i,resume:-r,uri:s",
> >>            .params     = "[-d] [-b] [-i] [-r] uri",
> >>            .help       = "migrate to URI (using -d to not wait for completion)"
> >>                          "\n\t\t\t -b for migration without shared storage with"
> >>                          " full copy of disk\n\t\t\t -i for migration without "
> >>                          "shared storage with incremental copy of disk "
> >>                          "(base image shared between src and destination)"
> >>                          "\n\t\t\t -r to resume a paused migration",
> >>            .cmd        = hmp_migrate,
> >>        },
> >> >  
> >> >  
> >> >  SRST
> >> > -``migrate [-d]`` *uri*
> >> > -  Migrate to *uri* (using -d to not wait for completion).
> >> > +``migrate [-d] [-r]`` *uri*
> >> > +  Migrate the current VM to *uri*.
> >> 
> >> Could there be any other VM than the current one?  Scratch "current"?
> >
> > I didn't have "current" until I generated the doc and read, then I see
> > right below "migrate_cancel" has it:
> >
> > SRST
> > ``migrate_cancel``
> >   Cancel the current VM migration.
> > ERST
> >
> > But maybe it means "current migration", not "current VM".. So yeah I can
> > drop it.
> >
> >> 
> >> > +
> >> > +  ``-d``
> >> > +    Run this command asynchronously, so that the command doesn't wait for completion.
> >> 
> >> What is run asynchronously, and what isn't waiting?  These are two
> >> different entities, aren't they?  Calling them "this command" and "the
> >> command" is confusing :)
> >> 
> >> Perhaps
> >> 
> >>        Start the migration process, but do not wait for its completion.
> >> 
> >> Maybe add a hint on how to wait or poll for completion?
> >
> > Yes this reads better; I will add the hint too.
> >
> >> 
> >> > +  ``-r``
> >> > +    Resume a paused postcopy migration.
> >> 
> >> .help doesn't have "postcopy".  Should it?
> >
> > It should.
> >
> > This is the fixup I'll squash when sending v2, let me know if there's other
> > early comments, thanks.
> >
> > ===8<===
> >
> > diff --git a/hmp-commands.hx b/hmp-commands.hx
> > index 484a8a1c3a..06746f0afc 100644
> > --- a/hmp-commands.hx
> > +++ b/hmp-commands.hx
> > @@ -912,17 +912,18 @@ ERST
> >          .args_type  = "detach:-d,resume:-r,uri:s",
> >          .params     = "[-d] [-r] uri",
> >          .help       = "migrate to URI (using -d to not wait for completion)"
> > -                     "\n\t\t\t -r to resume a paused migration",
> > +                     "\n\t\t\t -r to resume a paused postcopy migration",
> >          .cmd        = hmp_migrate,
> >      },
> >  
> >  
> >  SRST
> >  ``migrate [-d] [-r]`` *uri*
> > -  Migrate the current VM to *uri*.
> > +  Migrate the VM to *uri*.
> >  
> >    ``-d``
> > -    Run this command asynchronously, so that the command doesn't wait for completion.
> > +    Start the migration process, but do not wait for its completion.  To
> > +    query an ongoing migration process, use "info migrate".
> >    ``-r``
> >      Resume a paused postcopy migration.
> >  ERST
> 
> Reviewed-by: Markus Armbruster <armbru@redhat.com>

Thank you!

-- 
Peter Xu



      reply	other threads:[~2024-05-03 14:36 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-02 15:47 [PATCH] hmp/migration: Fix documents for "migrate" command Peter Xu
2024-05-02 17:34 ` Fabiano Rosas
2024-05-03  6:58 ` Markus Armbruster
2024-05-03 13:54   ` Peter Xu
2024-05-03 14:08     ` Markus Armbruster
2024-05-03 14:36       ` Peter Xu [this message]

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