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Subject: Re: [RFC PATCH v2 15/19] mm/gup: Introduce vaddr_pin_pages()
To:     Ira Weiny <ira.weiny@intel.com>
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From:   John Hubbard <jhubbard@nvidia.com>
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On 8/12/19 2:00 PM, Ira Weiny wrote:
> On Fri, Aug 09, 2019 at 05:09:54PM -0700, John Hubbard wrote:
>> On 8/9/19 3:58 PM, ira.weiny@intel.com wrote:
>>> From: Ira Weiny <ira.weiny@intel.com>
...
> 
> At one point I wanted to (and had in my tree) a new flag but I went away from
> it.  Prior to the discussion on mlock last week I did not think we needed it.
> But I'm ok to add it back in.
> 
> I was not ignoring the idea for this RFC I just wanted to get this out there
> for people to see.  I see that you threw out a couple of patches which add this
> flag in.
> 
> FWIW, I think it would be good to differentiate between an indefinite pinned
> page vs a referenced "gotten" page.
> 
> What you and I have been working on is the former.  So it would be easy to
> change your refcounting patches to simply key off of FOLL_PIN.
> 
> Would you like me to add in your FOLL_PIN patches to this series?

Sure, that would be perfect. They don't make any sense on their own, and
it's all part of the same design idea.

thanks,
-- 
John Hubbard
NVIDIA