Re: bisecting with wireless-testing

Re: bisecting with wireless-testing

[Luis R. Rodriguez]

Renaming subject and adding linux-wireless.

On Wed, Aug 19, 2009 at 10:58:09AM -0700, John W. Linville wrote:
> On Tue, Aug 18, 2009 at 02:57:48PM -0700, Luis R. Rodriguez wrote:
> > On Tue, Aug 18, 2009 at 02:45:00PM -0700, Pavel Roskin wrote:
> > > On Tue, 2009-08-18 at 14:24 -0700, Luis R. Rodriguez wrote:
> > >
> > > > > Anyway, why is it better for bisecting?

Just for reference for linux-wireles readers here I had indicated
wireless-next-2.6 was better for bisecting than wireless-testing.

> > > >
> > > > Because to help developers not have to do:
> > > >
> > > > git branch -m poo
> > > > git checkout -b master origin/master
> > > > # Then apply patches manually
> > > >
> > > > Instead of the better rebasing:
> > > >
> > > > git branch -m save-my-stuff
> > > > git checkout -b master origin/master
> > > > git checkout save-my-stuff
> > > > git rebase master
> > >
> > > I use STGit, so perhaps I miss all that fun.  I have never had any
> > > trouble tracking wireless-testing while keeping my patches.
> >
> > Oh this was a long time ago, pre ath5k I think.
> >
> > > > john reverts his patches on wireless-testing before rebasing to Linus'
> > > > tree. There may be some other added benefit other than helping us
> > > > rebase cleanly, not sure. But I do remember before that I never was
> > > > able to rebase my patches, and now rebasing works quite nicely.
> > >
> > > You mean it's better to track wireless-next-2.6 for those of us trying
> > > to stay on top of the wireless development?
> >
> > No, not at all, I meant wireless-next-2.6 is best for bisecting.
> >
> > wireless-testing is indeed the place to look at for development.
> >
> > > I must have missed the
> > > memo.
> >
> > I don't think we ever really publized this much, because technically
> > the reverting won't happen unless John rebases and typically between
> > rebases to a next RC kernel you *could* technically bisect an issue.
> > But not all the times.
> >
> > > Indeed, wireless-next-2.6 has a couple of commits that
> > > wireless-testing doesn't have yet.
> > >
> > > I agree that having to bisect through reverts is not fun, and it takes
> > > one or two extra iterations.
> >
> > Right, which is why I wanted to mention it, will extend the info on
> > the wiki on the development section once John ACKs/NACKs this.
> 
> It should not be necessary to bisect through reverts.  I maintain
> different tags for such purposes.
>
> Always use the lastest merge-* tag as the base for bisection.
> This should be equivalent to whichever -rc release from Linus is the
> current base for wireless-testing.  If you need to go any earlier
> than that, you should be using linux-2.6.
>
> So for example with current tree:
> 
>         git bisect start
>         git bisect bad master-2009-08-19
>         git bisect good merge-2009-08-14
> 
> This should include all of the current wireless patches in
> wireless-testing but not in the base linux-2.6 kernel.

This does indeed help alot. Just to be clear let me provide an
example. So say git tag -l | grep merge | tail -3 yields:

merge-2009-07-24
merge-2009-08-03
merge-2009-08-14

I believe what you are indicating if you are bisecting using to avoid
running into the reverts you'd have to ensure then that you bisect between
a bad commit and the next dated merge tag. So if you ran into a snag say
on master-2009-08-06, you should test if merge-2009-08-03 is good first,
and if its not then consider using linux-2.6.git ? If so wouldn't
the code on master-2009-08-06 not yet be available on linux-2.6.git?

> I haven't tracked-down this thread in the archives...am I addressing
> the issue correctly?

Indeed! Thanks a lot.

  Luis

Re: bisecting with wireless-testing

[John W. Linville]

On Wed, Aug 19, 2009 at 11:34:16AM -0700, Luis R. Rodriguez wrote:
> Renaming subject and adding linux-wireless.
> 
> On Wed, Aug 19, 2009 at 10:58:09AM -0700, John W. Linville wrote:

> > It should not be necessary to bisect through reverts.  I maintain
> > different tags for such purposes.
> >
> > Always use the lastest merge-* tag as the base for bisection.
> > This should be equivalent to whichever -rc release from Linus is the
> > current base for wireless-testing.  If you need to go any earlier
> > than that, you should be using linux-2.6.
> >
> > So for example with current tree:
> > 
> >         git bisect start
> >         git bisect bad master-2009-08-19
> >         git bisect good merge-2009-08-14
> > 
> > This should include all of the current wireless patches in
> > wireless-testing but not in the base linux-2.6 kernel.
> 
> This does indeed help alot. Just to be clear let me provide an
> example. So say git tag -l | grep merge | tail -3 yields:
> 
> merge-2009-07-24
> merge-2009-08-03
> merge-2009-08-14
> 
> I believe what you are indicating if you are bisecting using to avoid
> running into the reverts you'd have to ensure then that you bisect between
> a bad commit and the next dated merge tag. So if you ran into a snag say
> on master-2009-08-06, you should test if merge-2009-08-03 is good first,
> and if its not then consider using linux-2.6.git ? If so wouldn't
> the code on master-2009-08-06 not yet be available on linux-2.6.git?

If you look, merge-2009-08-03 is identical to 2.6.31-rc5:

	git diff merge-2009-08-03..v2.6.31-rc5

So if you have a problem in master-2009-08-06, then either the
problem exists in v2.6.31-rc5 or it is between merge-2009-08-03 and
master-2009-08-06.  (Read the tags carefully, they look similar.)

The point is, it never makes sense to use a good marker any
farther back than the most recent merge-* tag when trying to bisect
wireless-testing.  Otherwise, all the reverts and such will cause
confusion.  If the problem still exists at the most recent merge-*
tag, then the problem is in linux-2.6 and should be bisected there.

John
-- 
John W. Linville		Someday the world will need a hero, and you
linville@tuxdriver.com			might be all we have.  Be ready.