Re: [RFC] Tux3 for review

[Dave Chinner <david@fromorbit.com>]

On Sat, Jun 21, 2014 at 12:29:01PM -0700, James Bottomley wrote:
> On Thu, 2014-06-19 at 14:58 -0700, Daniel Phillips wrote:
> > On Thursday, June 19, 2014 2:26:48 AM PDT, Lukáš Czerner wrote:
> > > Let me remind you some more important problems Dave brought up,
> > > including page forking:
> > >
> > > "
> > >  The hacks around VFS and MM functionality need to have demonstrated
> > >  methods for being removed.
> > 
> > We already removed 450 lines of core kernel workarounds from Tux3 with an 
> > approach that was literally cut and pasted from one of Dave's emails. Then 
> > Dave changed his mind. Now the Tux3 team has been assigned a research 
> > project to improve core kernel writeback instead of simply adapting the 
> > approach that is already proven to work well enough. That is a rather 
> > blatant example of "perfect is the enemy of good enough". Please read the 
> > thread.
> 
> That's a bit disingenuous: the concern has always been how page forking
> interacted with writeback.  It's not new, it was one of the major things
> brought up at LSF 14 months ago, so you weren't just assigned this.

BTW, it's worth noting that reviewers are *allowed* to change their
mind at any time during a discussion or during review cycles.
Indeed, this occurs quite commonly. It's no different to multiple
reviewers disagreeing on what the best way to make the improvement
is - sometimes it takes an implementation to solidify opinion on the
best approach to solving a problem.

i.e. it took an implementation of the writeback hook tailored
specifically to tux3's requirements to understand the best way to
solve the infrastructure problem for *everyone*. This is how review
is supposed to work - take an idea, and refine it into something
better that works for everyone.

We'd have been stuck way up the creek without a paddle a long time
ago if reviewers weren't allowed to change their minds....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com