Re: [RFC GIT PULL, v2] RCU changes for v4.12

[Paul E. McKenney]

On Wed, May 10, 2017 at 01:17:54PM -0700, Linus Torvalds wrote:
> On Wed, May 10, 2017 at 12:54 PM, Paul E. McKenney
> <paulmck@xxxxxxxxxxxxxxxxxx> wrote:
> >
> > I am testing a merge with current linus/master, and I looked through
> > the commits in -next selected by:
> >
> >         gitk v4.11.. --no-merges --all-match --grep=drm --grep=selftest
> >
> > I didn't find anything obvious.  If the tests complete successfully,
> > I will try running the DRM selftest.
> 
> The drivers/gpu/drm/i915/selftests/mock_gem_device.c had a new use of
> SLAB_DESTROY_BY_RCU, which obviously conflicted with the rename to
> SLAB_TYPESAFE_BY_RCU.
> 
> It doesn't show up as a merge-time code conflict, only as a build-time
> failure. It's why I do allmodconfig builds after every pull. That
> doesn't catch everything (I only do it for x86-64, for example), but
> it catches a lot.
> 
> And no, it's not a problem. These things happen, and it's literally my
> job to make sure my merges work out.
> 
> I don't actually expect submaintainers to figure things like that out,
> although this *did* show up in linux-next, and it's a bit
> disappointing how that information got lost somewhere on the way.
> 
> It kind of implies that the prep work that linux-next does doesn't get
> fully used.

I did see that from linux-next.  For future reference, what should I
have done with it?  Added it to my pull request or to the commit log of
my merge commit?

> Normally I wouldn't even have mentioned it, if it wasn't for the fact
> that I got a 300kB data dump in my mailbox, and that huge amount of
> data wasn't actually even very relevant.

Well, my testing did find a lockdep splat, so the effort was
not wasted.  ;-)

						Thanx, Paul