"Some people seem to be using 'Acked-by' to mean, 'seems good to me', without necessarily doing a full review of the patch, and instead of trying to change the meaning of 'Acked-by', [the plan is] to have a new sign off which is a bit more explicitly about what it means," Theodore Tso explained in a recent thread on the Linux Kernel mailing list. He continued:

"This was proposed by Andrew and discussed at the Kernel Summit; the basic idea is that it is a formal indication that the person has done a *full* review of the patch (a few random comments from the local whitespace police don't count), and is willing to vouch that the patch is correct, safe, extremely unlikely to cause regressions, etc. If the patch does need to be reverted or fixed because it was buggy, then both the original submitter and the reviewer would bear responsibility and subsystem maintainers might take that into account when assessing the reputations of the submitter and reviewer in the future when deciding whether or not to accept a patch."

Andrew Morton noted that the idea isn't fully fleshed out yet, "we will start introducing Reviewed-by: (I haven't yet quite worked out how yet) but it will be a quite formal thing and it would be something which the reviewer explicitly provided. For now, let's please stick with acked-by". Theodore added, "there was also some discussion about whether or not patches would not be accepted at all without a Reviewed-by, but that probably won't happen initially. The general consensus was to gently ease into it and see how well it works first."

From: Andrew Morton [email blocked]
Subject: Re: [patch 1/6] Linux Kernel Markers - Architecture Independent Code
Date:	Thu, 6 Sep 2007 16:04:29 -0700

> On Thu, 6 Sep 2007 16:00:01 -0700 Randy Dunlap <randy.dunlap@oracle.com> wrote:
> On Thu, 06 Sep 2007 16:07:34 -0400 Mathieu Desnoyers wrote:
> 
> > Changelog:
> > - markers_mutex now nests inside module_mutex rather than the opposite.
> > 
> > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> > Reviewed-by: Christoph Hellwig [email blocked]
> > Reviewed-by: Rusty Russell [email blocked]
> > Reviewed-by: "Frank Ch. Eigler" [email blocked]
> 
> Documentation/SubmittingPatches recognizes Signed-off-by: and
> Acked-by:.  Nothing about Reviewed-by.  Quote:
> 
>   Acked-by: is not as formal as Signed-off-by:.  It is a record that the acker
>   has at least reviewed the patch and has indicated acceptance.
> 
> Reviewed-by: carries no such connotation or indication IMO.
> Please use Acked-by if that's what these reviewers have done.

Yeah.  We will start introducing Reviewed-by: (I haven't yet quite worked
out how yet) but it will be a quite formal thing and it would be something
which the reviewer explicitly provided.  For now, let's please stick with
acked-by (if those individuals did indeed send an acked-by)



From:	Randy Dunlap <randy.dunlap@oracle.com>
Subject: Re: [patch 1/6] Linux Kernel Markers - Architecture Independent Code
Date:	Thu, 6 Sep 2007 16:37:37 -0700

On Thu, 6 Sep 2007 16:04:29 -0700 Andrew Morton wrote:

> > On Thu, 6 Sep 2007 16:00:01 -0700 Randy Dunlap <randy.dunlap@oracle.com> wrote:
> > On Thu, 06 Sep 2007 16:07:34 -0400 Mathieu Desnoyers wrote:
> > 
> > > Changelog:
> > > - markers_mutex now nests inside module_mutex rather than the opposite.
> > > 
> > > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> > > Reviewed-by: Christoph Hellwig [email blocked]
> > > Reviewed-by: Rusty Russell [email blocked]
> > > Reviewed-by: "Frank Ch. Eigler" [email blocked]
> > 
> > Documentation/SubmittingPatches recognizes Signed-off-by: and
> > Acked-by:.  Nothing about Reviewed-by.  Quote:
> > 
> >   Acked-by: is not as formal as Signed-off-by:.  It is a record that the acker
> >   has at least reviewed the patch and has indicated acceptance.
> > 
> > Reviewed-by: carries no such connotation or indication IMO.
> > Please use Acked-by if that's what these reviewers have done.
> 
> Yeah.  We will start introducing Reviewed-by: (I haven't yet quite worked
> out how yet) but it will be a quite formal thing and it would be something
> which the reviewer explicitly provided.  For now, let's please stick with
> acked-by (if those individuals did indeed send an acked-by)
> -

Thanks.  I look forward to the explanation of Reviewed-by, what it
means, and how it differs from Acked-by.


---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***



From:	Theodore Tso [email blocked]
Subject: Re: [patch 1/6] Linux Kernel Markers - Architecture Independent Code
Date:	Fri, 7 Sep 2007 12:04:45 -0400

On Thu, Sep 06, 2007 at 04:37:37PM -0700, Randy Dunlap wrote:
> Thanks.  I look forward to the explanation of Reviewed-by, what it
> means, and how it differs from Acked-by.

This was proposed by Andrew and discussed at the Kernel Summit; the
basic idea is that it is a formal indication that the person has done
a *full* review of the patch (a few random comments from the local
whitespace police don't count), and is willing to vouch that the patch
is correct, safe, extremely unlikely to cause regressions, etc.  If
the patch does need to be reverted or fixed because it was buggy, then
both the original submitter and the reviewer would bear responsibility
and subsystem maintainers might take that into account when assessing
the reputations of the submitter and reviewer in the future when
deciding whether or not to accept a patch.

Basically, some people seem to be using "Acked-by" to mean, "seems
good to me", without necessarily doing a full review of the patch, and
instead of trying to change the meaning of "Acked-by", to have a new
sign off which is a bit more explicitly about what it means.  (Hmmm,
thinking about it afterwards, maybe "Vouched-by:" would be even
better....)

There was some thought about negative attention (i.e., "public
mockery") given to people who sign off on a patch via Reviewed-by:
that subsequently turns out to be buggy or cause a regression, but the
concern with that is that we have enough trouble finding people to
review patches, and we wouldn't want to scare off reviewers.  But it
would be fair to say that the consequences of reviewing patches
successfully or unsuccessfully would naturally impact people's
reputations.

There was also some discussion about whether or not patches would not
be accepted at all without a Reviewed-by, but that probably won't
happen initially.  The general consensus was to gently ease into it
and see how well it works first.

        					- Ted

• Archive of above thread
• KernelTrap interview with Andrew Morton