From: Anna Schumaker <schumaker.anna@gmail.com>
To: Zach Brown <zab@redhat.com>, Christoph Hellwig <hch@infradead.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-nfs@vger.kernel.org,
Trond Myklebust <Trond.Myklebust@netapp.com>,
Bryan Schumaker <bjschuma@netapp.com>,
"Martin K. Petersen" <mkp@mkp.net>, Jens Axboe <axboe@kernel.dk>,
Mark Fasheh <mfasheh@suse.com>, Joel Becker <jlbec@evilplan.org>,
Eric Wong <normalperson@yhbt.net>
Subject: Re: [RFC] extending splice for copy offloading
Date: Wed, 18 Dec 2013 12:26:11 -0500 [thread overview]
Message-ID: <52B1DAB3.6060302@gmail.com> (raw)
In-Reply-To: <20131218171044.GK14533@lenny.home.zabbo.net>
On 12/18/2013 12:10 PM, Zach Brown wrote:
> On Wed, Dec 18, 2013 at 04:41:26AM -0800, Christoph Hellwig wrote:
>> On Wed, Sep 11, 2013 at 10:06:47AM -0700, Zach Brown wrote:
>>> When I first started on this stuff I followed the lead of previous
>>> work and added a new syscall for the copy operation:
>>>
>>> https://lkml.org/lkml/2013/5/14/618
>>>
>>> Towards the end of that thread Eric Wong asked why we didn't just
>>> extend splice. I immediately replied with some dumb dismissive
>>> answer. Once I sat down and looked at it, though, it does make a
>>> lot of sense. So good job, Eric. +10 Dummie points for me.
>>>
>>> Extending splice avoids all the noise of adding a new syscall and
>>> naturally falls back to buffered copying as that's what the direct
>>> splice path does for sendfile() today.
>> Given the convolute mess that the splice code already is I'd rather
>> prefer not overloading it even further.
> I agree after trying to weave the copy offloading API into the splice
> interface. There are also weird cases that we haven't really discussed
> so far (preserving unwritten allocations between the copied files?) that
> would muddy the waters even further.
>
> The further the APIs drift from each other, the more I'm prefering
> giving copy offloading its own clean syscall. Even if the argument
> types superficially match the splice() ABI.
>
>> We can still fall back to the splice code as a fallback if no option
>> is provided as a last resort, but I think making the splice code handle
>> even more totally different cases is the wrong direction.
> I'm with you. I'll have another version out sometime after the US
> holiday break.. say in a few weeks?
That'll work for me, I'll update my NFS code once your new patches are out.
Anna
>
> - z
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
prev parent reply other threads:[~2013-12-18 17:26 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-11 17:06 [RFC] extending splice for copy offloading Zach Brown
2013-09-11 17:06 ` [PATCH 1/3] splice: add DIRECT flag for splicing between files Zach Brown
2013-09-11 17:06 ` [PATCH 2/3] splice: add f_op->splice_direct Zach Brown
2013-09-11 17:06 ` [PATCH 3/3] btrfs: implement .splice_direct extent copying Zach Brown
2013-09-11 21:17 ` [RFC] extending splice for copy offloading Eric Wong
2013-09-16 19:44 ` Rob Landley
2013-09-19 12:59 ` Jeff Layton
2013-09-20 9:49 ` Szeredi Miklos
2013-09-25 18:38 ` Zach Brown
2013-09-25 19:02 ` Anna Schumaker
2013-09-25 19:06 ` Zach Brown
2013-09-25 19:55 ` J. Bruce Fields
2013-09-25 21:07 ` Zach Brown
2013-09-26 8:58 ` Miklos Szeredi
2013-09-26 15:34 ` J. Bruce Fields
2013-09-26 16:46 ` Ric Wheeler
2013-09-26 18:06 ` Miklos Szeredi
2013-09-26 19:06 ` Zach Brown
2013-09-26 19:53 ` Miklos Szeredi
2013-09-26 21:23 ` Ric Wheeler
2013-09-27 4:47 ` Miklos Szeredi
2013-09-27 14:00 ` Ric Wheeler
2013-09-27 14:39 ` Miklos Szeredi
2013-10-06 8:42 ` Rob Landley
2013-09-26 18:55 ` Zach Brown
2013-09-26 21:26 ` Ric Wheeler
2013-09-27 20:05 ` J. Bruce Fields
2013-09-27 20:50 ` Zach Brown
2013-09-28 5:49 ` Miklos Szeredi
2013-09-28 15:20 ` Myklebust, Trond
2013-09-28 21:20 ` Ric Wheeler
2013-09-30 12:20 ` Miklos Szeredi
2013-09-30 14:34 ` J. Bruce Fields
2013-09-30 14:48 ` Ric Wheeler
2013-09-30 14:51 ` Miklos Szeredi
2013-09-30 14:52 ` Ric Wheeler
2013-09-30 15:24 ` Miklos Szeredi
2013-09-30 14:28 ` Ric Wheeler
2013-09-30 15:33 ` Myklebust, Trond
2013-09-30 15:38 ` Miklos Szeredi
2013-09-30 14:41 ` Ric Wheeler
2013-09-30 15:46 ` Miklos Szeredi
2013-09-30 14:49 ` Ric Wheeler
2013-09-30 15:57 ` Miklos Szeredi
2013-09-30 16:31 ` Miklos Szeredi
2013-09-30 17:17 ` Bernd Schubert
2013-09-30 17:44 ` Myklebust, Trond
2013-09-30 17:48 ` Bernd Schubert
2013-09-30 18:02 ` Myklebust, Trond
2013-09-30 18:49 ` Bernd Schubert
2013-09-30 19:34 ` Myklebust, Trond
2013-09-30 20:00 ` Bernd Schubert
2013-09-30 20:08 ` Ric Wheeler
2013-09-30 20:27 ` Myklebust, Trond
2013-09-30 20:10 ` Myklebust, Trond
2013-10-01 18:42 ` J. Bruce Fields
2013-10-01 19:58 ` Zach Brown
2013-10-02 12:58 ` Jan Kara
2013-10-02 13:31 ` David Lang
2013-12-18 12:41 ` Christoph Hellwig
2013-12-18 17:10 ` Zach Brown
2013-12-18 17:26 ` Anna Schumaker [this message]
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=52B1DAB3.6060302@gmail.com \
--to=schumaker.anna@gmail.com \
--cc=Trond.Myklebust@netapp.com \
--cc=axboe@kernel.dk \
--cc=bjschuma@netapp.com \
--cc=hch@infradead.org \
--cc=jlbec@evilplan.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=mfasheh@suse.com \
--cc=mkp@mkp.net \
--cc=normalperson@yhbt.net \
--cc=zab@redhat.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 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).