From: Jens Axboe <jens.axboe@oracle.com>
To: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>,
Andrew Morton <akpm@linux-foundation.org>,
Greg Ungerer <gerg@snapgear.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH -mm] splice: Disable vmsplice on nommu.
Date: Tue, 11 Sep 2007 13:25:27 +0200 [thread overview]
Message-ID: <20070911112526.GK15405@kernel.dk> (raw)
In-Reply-To: <9949.1189505419@redhat.com>
On Tue, Sep 11 2007, David Howells wrote:
> Jens Axboe <jens.axboe@oracle.com> wrote:
>
> > It's a bit of a sledge hammer... Since get_user_pages() appears to work
> > on nummu, we can just disable the vmsplice-to-userspace bits and leave
> > the (working) vmsplice-from-userspace in place.
>
> That sounds about right. I don't think you can do the latter without
> an MMU, but I may be wrong about what it does.
You mean the former? The latter is vmsplice() filling a pipe with user
pages, using get_user_pages() to set them up. And that looks like it
should work on nommu.
The former is vmsplice() using mmap like functionality to map pages into
a user vma.
Just making sure we agree :-)
--
Jens Axboe
next prev parent reply other threads:[~2007-09-11 11:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-11 8:23 [PATCH -mm] splice: Disable vmsplice on nommu Paul Mundt
2007-09-11 9:35 ` Jens Axboe
2007-09-11 10:10 ` David Howells
2007-09-11 11:25 ` Jens Axboe [this message]
2007-09-11 16:57 ` David Howells
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=20070911112526.GK15405@kernel.dk \
--to=jens.axboe@oracle.com \
--cc=akpm@linux-foundation.org \
--cc=dhowells@redhat.com \
--cc=gerg@snapgear.com \
--cc=lethal@linux-sh.org \
--cc=linux-kernel@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