Re: RCU branching for the v4.19 merge window

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 17 May 2018 07:40:44 -0700
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote:

> Hello, Steve!
> 
> Another year, another difficult-to-branch set of RCU commits.
> 
> In happy contrast to last year, I can make some branches (SRCU, some
> of the torture commits, and a few miscellaneous commits), but I will
> likely end up with several short branches and one huge one.  My thought
> is to keep the long branch, but email the patches out in a few separate
> serieses, with each depending on its predecessor.  For example, one series
> from the big branch would be folding the ->gpnum and ->completed fields
> into a single ->gp_seq, which helps the RCU-flavor consolidation task.
> Another series suppresses some rare false-positive splats that have been
> plaguing me for more than a year.  Yet another series within this huge
> branch applies and optimizes funnel locking for grace-period startup.
> 
> The problem is that the conversion to ->gp_seq has a very large footprint,
> which of course generates lots of conflicts.  I could of course collapse
> these commits into a single commit, but if I did that I would also defer
> to the merge window following v4.19 due to the resulting loss of bisection
> within that change.
> 
> Any advice?
> 
> The commits are for-mingo..rcu/dev in my -rcu tree.

I don't see these branches (and I don't pull tags).

How bad are the conflicts? Or is it too late to respond to help (sorry,
was on vacation :-)

-- Steve