Re: [PATCH] proc: move the adding option Ngid to the end of proc/PID/status

[Tejun Heo <tj@kernel.org>]

On Tue, Apr 21, 2015 at 05:00:07PM +0300, Alexey Dobriyan wrote:
> > The only reason for changing the position is because
> > there's this specific breakage.  The goal should be working around
> > that specific case while keeping the impact minimum on everyone else.
> 
> If there are TWO incorrect parsers, one for TracerPid, another for Ngid,
> you CAN'T workaround it. And if you can't workaround you choose code
> which was written first, namely, TracerPid one.

Not when the code has been out for 1.5 years.  Minimizing the
disturbance is the better course of action.  Look at the file.  If you
move ngid to the end now, it's gonna shift most of the file content,
which is what caused the problem in the first place.

We don't know what's out there which again was the same problem which
triggered this thread in the first place.  Why would you take the same
amount of risk when you can fix the known issue with less amount of
changes?  Just put ngid after tracerpid.  That way, we can fix the
known problems while changing the offsets of only four fields.  At
this point, no change to the file layout is "right".  Such thing isn't
defined regardless of who came first.  The only thing we can do is
working around the known cases while minimizing possible impacts.

Thanks.

-- 
tejun