From: Jason Gunthorpe <jgg@mellanox.com>
To: Christoph Hellwig <hch@lst.de>
Cc: "Ralph Campbell" <rcampbell@nvidia.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Jérôme Glisse" <jglisse@redhat.com>
Subject: Re: [PATCH 2/2] mm/hmm: make full use of walk_page_range()
Date: Wed, 24 Jul 2019 11:53:42 +0000 [thread overview]
Message-ID: <20190724115338.GA30264@mellanox.com> (raw)
In-Reply-To: <20190724065146.GA2061@lst.de>
On Wed, Jul 24, 2019 at 08:51:46AM +0200, Christoph Hellwig wrote:
> On Tue, Jul 23, 2019 at 04:30:16PM -0700, Ralph Campbell wrote:
> > hmm_range_snapshot() and hmm_range_fault() both call find_vma() and
> > walk_page_range() in a loop. This is unnecessary duplication since
> > walk_page_range() calls find_vma() in a loop already.
> > Simplify hmm_range_snapshot() and hmm_range_fault() by defining a
> > walk_test() callback function to filter unhandled vmas.
>
> I like the approach a lot!
>
> But we really need to sort out the duplication between hmm_range_fault
> and hmm_range_snapshot first, as they are basically the same code. I
> have patches here:
>
> http://git.infradead.org/users/hch/misc.git/commitdiff/a34ccd30ee8a8a3111d9e91711c12901ed7dea74
>
> http://git.infradead.org/users/hch/misc.git/commitdiff/81f442ebac7170815af7770a1efa9c4ab662137e
Yeah, that is a straightforward improvement, maybe Ralph should grab
these two as part of his series?
> That being said we don't really have any users for the snapshot mode
> or non-blocking faults, and I don't see any in the immediate pipeline
> either.
If this code was production ready I'd use it in ODP right away.
When we first create a ODP MR we'd want to snapshot to pre-load the
NIC tables with something other than page fault, but not fault
anything.
This would be a big performance improvement for ODP.
Jason
next prev parent reply other threads:[~2019-07-24 11:53 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-23 23:30 [PATCH 0/2] mm/hmm: more HMM clean up Ralph Campbell
2019-07-23 23:30 ` [PATCH 1/2] mm/hmm: a few more C style and comment clean ups Ralph Campbell
2019-07-23 23:57 ` Jason Gunthorpe
2019-07-24 5:41 ` Christoph Hellwig
2019-07-23 23:30 ` [PATCH 2/2] mm/hmm: make full use of walk_page_range() Ralph Campbell
2019-07-24 6:51 ` Christoph Hellwig
2019-07-24 11:53 ` Jason Gunthorpe [this message]
2019-07-24 19:50 ` Ralph Campbell
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=20190724115338.GA30264@mellanox.com \
--to=jgg@mellanox.com \
--cc=hch@lst.de \
--cc=jglisse@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=rcampbell@nvidia.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.