From: John Hubbard <jhubbard@nvidia.com>
To: Ira Weiny <ira.weiny@intel.com>, Jan Kara <jack@suse.cz>
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
"Christoph Hellwig" <hch@infradead.org>,
"Dan Williams" <dan.j.williams@intel.com>,
"Dave Chinner" <david@fromorbit.com>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
"Jérôme Glisse" <jglisse@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-rdma@vger.kernel.org
Subject: Re: [RFC PATCH 2/2] mm/gup: introduce vaddr_pin_pages_remote()
Date: Thu, 15 Aug 2019 19:14:08 -0700 [thread overview]
Message-ID: <58b75fa9-1272-b683-cb9f-722cc316bf8f@nvidia.com> (raw)
In-Reply-To: <b378a363-f523-518d-9864-e2f8e5bd0c34@nvidia.com>
On 8/15/19 10:41 AM, John Hubbard wrote:
> On 8/15/19 10:32 AM, Ira Weiny wrote:
>> On Thu, Aug 15, 2019 at 03:35:10PM +0200, Jan Kara wrote:
>>> On Thu 15-08-19 15:26:22, Jan Kara wrote:
>>>> On Wed 14-08-19 20:01:07, John Hubbard wrote:
>>>>> On 8/14/19 5:02 PM, John Hubbard wrote:
...
>> Ok just to make this clear I threw up my current tree with your patches here:
>>
>> https://github.com/weiny2/linux-kernel/commits/mmotm-rdmafsdax-b0-v4
>>
>> I'm talking about dropping the final patch:
>> 05fd2d3afa6b rdma/umem_odp: Use vaddr_pin_pages_remote() in ODP
>>
>> The other 2 can stay. I split out the *_remote() call. We don't have a user
>> but I'll keep it around for a bit.
>>
>> This tree is still WIP as I work through all the comments. So I've not changed
>> names or variable types etc... Just wanted to settle this.
>>
>
> Right. And now that ODP is not a user, I'll take a quick look through my other
> call site conversions and see if I can find an easy one, to include here as
> the first user of vaddr_pin_pages_remote(). I'll send it your way if that
> works out.
>
OK, there was only process_vm_access.c, plus (sort of) Bharath's sgi-gru
patch, maybe eventually [1]. But looking at process_vm_access.c, I think
it is one of the patches that is no longer applicable, and I can just
drop it entirely...I'd welcome a second opinion on that...
So we might be all out of potential users for vaddr_pin_pages_remote()!
For quick reference, it looks like this:
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index 357aa7bef6c0..4d29d54ec93f 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -96,7 +96,7 @@ static int process_vm_rw_single_vec(unsigned long addr,
flags |= FOLL_WRITE;
while (!rc && nr_pages && iov_iter_count(iter)) {
- int pages = min(nr_pages, max_pages_per_loop);
+ int pinned_pages = min(nr_pages, max_pages_per_loop);
int locked = 1;
size_t bytes;
@@ -106,14 +106,15 @@ static int process_vm_rw_single_vec(unsigned long addr,
* current/current->mm
*/
down_read(&mm->mmap_sem);
- pages = get_user_pages_remote(task, mm, pa, pages, flags,
- process_pages, NULL, &locked);
+ pinned_pages = get_user_pages_remote(task, mm, pa, pinned_pages,
+ flags, process_pages, NULL,
+ &locked);
if (locked)
up_read(&mm->mmap_sem);
- if (pages <= 0)
+ if (pinned_pages <= 0)
return -EFAULT;
- bytes = pages * PAGE_SIZE - start_offset;
+ bytes = pinned_pages * PAGE_SIZE - start_offset;
if (bytes > len)
bytes = len;
@@ -122,10 +123,9 @@ static int process_vm_rw_single_vec(unsigned long addr,
vm_write);
len -= bytes;
start_offset = 0;
- nr_pages -= pages;
- pa += pages * PAGE_SIZE;
- while (pages)
- put_page(process_pages[--pages]);
+ nr_pages -= pinned_pages;
+ pa += pinned_pages * PAGE_SIZE;
+ put_user_pages(process_pages, pinned_pages);
}
return rc;
[1] https://lore.kernel.org/r/1565379497-29266-2-git-send-email-linux.bhar@gmail.com
thanks,
--
John Hubbard
NVIDIA
next prev parent reply other threads:[~2019-08-16 2:14 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-12 1:50 [RFC PATCH 0/2] mm/gup: introduce vaddr_pin_pages_remote(), FOLL_PIN john.hubbard
2019-08-12 1:50 ` [RFC PATCH 1/2] mm/gup: introduce FOLL_PIN flag for get_user_pages() john.hubbard
2019-08-12 1:50 ` [RFC PATCH 2/2] mm/gup: introduce vaddr_pin_pages_remote() john.hubbard
2019-08-12 22:03 ` Ira Weiny
2019-08-12 22:21 ` John Hubbard
2019-08-12 23:49 ` Ira Weiny
2019-08-13 0:07 ` John Hubbard
2019-08-13 21:08 ` Ira Weiny
2019-08-14 0:51 ` John Hubbard
2019-08-14 0:56 ` John Hubbard
2019-08-14 23:50 ` Ira Weiny
2019-08-15 0:02 ` John Hubbard
2019-08-15 3:01 ` John Hubbard
2019-08-15 13:26 ` Jan Kara
2019-08-15 13:35 ` Jan Kara
2019-08-15 14:51 ` Jason Gunthorpe
2019-08-15 17:32 ` Ira Weiny
2019-08-15 17:41 ` John Hubbard
2019-08-16 2:14 ` John Hubbard [this message]
2019-08-16 15:41 ` Jan Kara
2019-08-16 18:33 ` Ira Weiny
2019-08-16 18:50 ` John Hubbard
2019-08-16 21:59 ` Ira Weiny
2019-08-16 22:36 ` John Hubbard
2019-08-16 8:47 ` Vlastimil Babka
2019-08-16 15:44 ` Jan Kara
2019-08-16 15:52 ` Jerome Glisse
2019-08-16 16:13 ` Jan Kara
2019-08-16 16:31 ` Jason Gunthorpe
2019-08-16 16:54 ` Jerome Glisse
2019-08-16 17:04 ` Jason Gunthorpe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=58b75fa9-1272-b683-cb9f-722cc316bf8f@nvidia.com \
--to=jhubbard@nvidia.com \
--cc=akpm@linux-foundation.org \
--cc=dan.j.williams@intel.com \
--cc=david@fromorbit.com \
--cc=hch@infradead.org \
--cc=ira.weiny@intel.com \
--cc=jack@suse.cz \
--cc=jgg@ziepe.ca \
--cc=jglisse@redhat.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-rdma@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).