Re: [RFC PATCH resend 3/6] mm: Add refcount for preserving mm_struct without pgd

[John Hubbard]

On 11/3/20 5:21 AM, Jason Gunthorpe wrote:
> On Tue, Nov 03, 2020 at 04:19:11AM +0100, Jann Horn wrote:
> > On Tue, Nov 3, 2020 at 3:11 AM Jann Horn <jannh@xxxxxxxxxx> wrote:
> > > On Sat, Oct 17, 2020 at 2:30 AM Jann Horn <jannh@xxxxxxxxxx> wrote:
> > > > On Sat, Oct 17, 2020 at 1:21 AM Jason Gunthorpe <jgg@xxxxxxxx> wrote:
> > > > > On Sat, Oct 17, 2020 at 01:09:12AM +0200, Jann Horn wrote:
> > > > > > Currently, mm_struct has two refcounts:
...
> Either way can work, I liked the suggestion because it suggests an
> good name for the ref: 'mmget_pgd' or somesuch
>
> What I don't like is how nonsensical the names here are becoming:
> mmget/mmgrab/mm_ref
>
> Gives no impression at the callsite what is right/wrong
>
> Names like this:
>   mmget_struct
>   mmget_pgd
>   mmget_tables

What?! I had just resigned myself to a bimonthly exercise, re-memorizing
the mm_struct naming correlation between grab, drop, get, put, count,
and users. And now you want to make it directly understandable? :)

> Make alot more sense to me..
>
> I think this patch needs to do something about the naming..

A third counter also seems like the tipping point, to me.

thanks,
--
John Hubbard
NVIDIA