On Tue, 2013-06-04 at 10:38 +0100, George Dunlap wrote:
In this context, I would read "Acked-by" as "I agree that this should go
in", or at very least, "I am happy for this to go in"; whereas to me
"Reviewed-by" to me sounds like, "I took a close look at the code and
didn't see anything wrong, but otherwise have no opinion on the matter."
I think we decided (somewhat informally I think) that we interpreted
Foo-by according to Linux's Documentation/SubmittingPatches:
If a person was not directly involved in the preparation or handling
of a
patch but wishes to signify and record their approval of it then they
can
arrange to have an Acked-by: line added to the patch's changelog.
Acked-by: is often used by the maintainer of the affected code when
that
maintainer neither contributed to nor forwarded the patch.
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. Hence
patch
mergers will sometimes manually convert an acker's "yep, looks good to
me"
into an Acked-by:.
Acked-by: does not necessarily indicate acknowledgement of the entire
patch.
For example, if a patch affects multiple subsystems and has an
Acked-by: from
one subsystem maintainer then this usually indicates acknowledgement
of just
the part which affects that maintainer's code. Judgement should be
used here.
When in doubt people should refer to the original discussion in the
mailing
list archives.
[...]
Reviewed-by is somehow more formal:
Reviewed-by:, instead, indicates that the patch has been reviewed and
found
acceptable according to the Reviewer's Statement:
Reviewer's statement of oversight
By offering my Reviewed-by: tag, I state that:
(a) I have carried out a technical review of this patch to
evaluate its appropriateness and readiness for inclusion
into
the mainline kernel.
(b) Any problems, concerns, or questions relating to the patch
have been communicated back to the submitter. I am
satisfied
with the submitter's response to my comments.
(c) While there may be things that could be improved with this
submission, I believe that it is, at this time, (1) a
worthwhile modification to the kernel, and (2) free of
known
issues which would argue against its inclusion.
(d) While I have reviewed the patch and believe it to be
sound, I
do not (unless explicitly stated elsewhere) make any
warranties or guarantees that it will achieve its stated
purpose or function properly in any given situation.
A Reviewed-by tag is a statement of opinion that the patch is an
appropriate modification of the kernel without any remaining serious
technical issues. Any interested reviewer (who has done the work) can
offer a Reviewed-by tag for a patch. This tag serves to give credit to
reviewers and to inform maintainers of the degree of review which has
been
done on the patch. Reviewed-by: tags, when supplied by reviewers
known to
understand the subject area and to perform thorough reviews, will
normally
increase the likelihood of your patch getting into the kernel.
Acked-by is supposedly something which is offered by the maintainer of
the relevant code to indicate they are happy for it to go in. In the
Linux world that might be via a different maintainer's tree (for cross
subsystem stuff) or be an indication from e.g. a driver maintainer to
the subsystem maintainer that the patch can be applied. In the Xen world
I think we interpret an Ack from someone in MAINTAINERS as a signal to
the committers that the patch should be committed.
