Re: [PATCH v2 0/3] mm/gup: introduce vaddr_pin_pages_remote(), FOLL_PIN

From: John Hubbard <jhubbard@nvidia.com>
To: Ira Weiny <ira.weiny@intel.com>
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
	"Christoph Hellwig" <hch@infradead.org>,
	"Dan Williams" <dan.j.williams@intel.com>,
	"Dave Chinner" <david@fromorbit.com>, "Jan Kara" <jack@suse.cz>,
	"Jason Gunthorpe" <jgg@ziepe.ca>,
	"Jérôme Glisse" <jglisse@redhat.com>,
	"Vlastimil Babka" <vbabka@suse.cz>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
	linux-rdma@vger.kernel.org
Subject: Re: [PATCH v2 0/3] mm/gup: introduce vaddr_pin_pages_remote(), FOLL_PIN
Date: Thu, 22 Aug 2019 17:36:07 -0700	[thread overview]
Message-ID: <2f91e1a2-f82f-406a-600a-939bc07a0651@nvidia.com> (raw)
In-Reply-To: <20190823002443.GA19517@iweiny-DESK2.sc.intel.com>

On 8/22/19 5:24 PM, Ira Weiny wrote:
> On Tue, Aug 20, 2019 at 09:07:24PM -0700, John Hubbard wrote:
>> Hi Ira,
>>
>> This is for your tree. I'm dropping the RFC because this aspect is
>> starting to firm up pretty well.
>>
>> I've moved FOLL_PIN inside the vaddr_pin_*() routines, and moved
>> FOLL_LONGTERM outside, based on our recent discussions. This is
>> documented pretty well within the patches.
>>
>> Note that there are a lot of references in comments and commit
>> logs, to vaddr_pin_pages(). We'll want to catch all of those if
>> we rename that. I am pushing pretty hard to rename it to
>> vaddr_pin_user_pages().
>>
>> v1 of this may be found here:
>> https://lore.kernel.org/r/20190812015044.26176-1-jhubbard@nvidia.com
> 
> I am really sorry about this...
> 
> I think it is fine to pull these in...  There are some nits which are wrong but
> I think with the XDP complication and Daves' objection I think the vaddr_pin
> information is going to need reworking.  So the documentation there is probably
> wrong.  But until we know what it is going to be we should just take this.
> 

Sure, I was thinking the same thing: FOLL_PIN is clearing up, but vaddr_pin_pages() 
is still under heavy discussion.

> Do you have a branch with this on it?
> 

Yes, it's on: git@github.com:johnhubbard/linux.git , branch: vaddr_FOLL_PIN_next

> The patches don't seem to apply.  Looks like they got corrupted somewhere...
> 

Lately I'm trying out .nvidia.com outgoing servers for git-send-email, so I'm 
still nervous about potential email-based patch problems. I suspect, though,
that it's really just a "must be on exactly the right commit in order to apply"
situation. Please let me know, so I can make any corrections necessary on this end.

thanks,
-- 
John Hubbard
NVIDIA