Re: linux-next: manual merge of the tip tree with the net-next tree

Peter Zijlstra
2017-11-01T08:55:46Z

On Wed, Nov 01, 2017 at 09:27:43AM +0100, Ingo Molnar wrote:
>
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > On Wed, Nov 01, 2017 at 06:15:54PM +1100, Stephen Rothwell wrote:
> > > Hi all,
> > >
> > > Today's linux-next merge of the tip tree got a conflict in:
> > >
> > > kernel/trace/bpf_trace.c
> > >
> > > between commits:
> > >
> > > 97562633bcba ("bpf: perf event change needed for subsequent bpf helpers")
> > > and more changes ...
> > >
> > > from the net-next tree and commit:
> > >
> > > 7d9285e82db5 ("perf/bpf: Extend the perf_event_read_local() interface, a.k.a. "bpf: perf event change needed for subsequent bpf helpers"")
> > >
> > > from the tip tree.
> >
> > So those should be the exact same patch; except for Changelog and
> > subject. Code wise there shouldn't be a conflict.
>
> So the problem is that then we have:
>
> 0d3d73aac2ff ("perf/core: Rewrite event timekeeping")
>
> which changes the code. This is a known conflict generation pattern: Git isn't
> smart enough to sort out that (probably because it would make merges too
> expensive) - and it's a bad flow in any case.

Hmm, I thought having that same base patch in both trees would allow it
to resolve that conflict. A well..