Re: [RFC] to rebase or not to rebase on linux-next

From: Stefan Richter
Date: Mon Oct 26 2009 - 14:03:01 EST


Theodore Tso wrote:
> On Sun, Oct 25, 2009 at 09:53:41PM -0700, Luck, Tony wrote:
>> If the "rewind" is simply to add "signed-off-by" notations, update
>> commit comments (or code comments) ... then it does seem useful to
>> keep the commit chain anchored to the original commit, as the testing
>> that has been done is all still valid.
>>
>> But as soon as you talk about fixing bugs ... then you ought to
>> just do a "rebase". The code you are adding has changed, so it is
>> incorrect to preserve the illusion that these changes have had
>> extensive testing against the old commit base. The code has changed,
>> so the testing clock gets reset to zero.
>
> I don't think anyone should (or does?) use the base version of a patch
> series as an indication of how much testing a patch series has
> received. It doesn't make much sense.

FWIW, I agree to the above. But the below...

> Suppose I update the 40th patch of a 50th patch series to add check
> for kmalloc() returning NULL that had been inadvertently left out, or
> some other error checking is added. Or suppose I add a new tracepoint
> definition to a 50 patch series.

...are bad examples in the context of linux-next, IMO. A missing
allocation failure check or a missing tracepoint don't break
bisectability. So why discard this history? (It was already published
in a release preview.)

> Sorry, I'm not going to rewind the
> entire patch series because someone thinks the base version of the
> patch series somehow is a magic "test clock" indicator....

Indeed. Not even the commit date of individual patches says something
about how extensive they were tested. Besides, testers might never have
tested that particular head; it's more likely that they ran a merge
result which was never published anywhere, or they tested a patch
stand-alone on top of whatever kernel they happened to have at hand
(e.g. a distro kernel) when the patch author asked them to test some fix
or feature.
--
Stefan Richter
-=====-==--= =-=- ==-=-
http://arcgraph.de/sr/
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