From: "Jörn Engel" <joern@wohnheim.fh-wedel.de>
To: dean gaudet <dean-list-linux-kernel@arctic.org>
Cc: Folkert van Heusden <folkert@vanheusden.com>,
linux-kernel@vger.kernel.org
Subject: Re: zero-copy read() interface
Date: Fri, 19 Aug 2005 10:33:32 +0200 [thread overview]
Message-ID: <20050819083332.GC29333@wohnheim.fh-wedel.de> (raw)
In-Reply-To: <Pine.LNX.4.63.0508181633510.20705@twinlark.arctic.org>
On Thu, 18 August 2005 16:34:18 -0700, dean gaudet wrote:
> On Thu, 18 Aug 2005, Folkert van Heusden wrote:
>
> > Doesn't that one also use copying? I've also heard that using mmap is
> > expensive due to pagefaulting. I've found, for example, that copying a
> > 1.3GB file using read/write instead of mmap & memcpy is seconds faster.
>
> why would you memcpy if you're using mmap()? just write() the mmap()d
> region.
Still unnecessary. Userspace doesn't want to see the data at all, so
it shouldn't. The solution should either be sendfile(2), which Linus
doesn't like much, or the upcoming pipe stuff.
Jörn
--
Linux [...] existed just for discussion between people who wanted
to show off how geeky they were.
-- Rob Enderle
next prev parent reply other threads:[~2005-08-19 8:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-18 10:01 Folkert van Heusden
2005-08-18 10:05 ` Jörn Engel
2005-08-18 10:41 ` Folkert van Heusden
2005-08-18 13:13 ` Jörn Engel
2005-08-18 23:34 ` dean gaudet
2005-08-19 8:33 ` Jörn Engel [this message]
2005-08-21 9:01 ` Andrew Morton
2005-08-18 10:06 ` Christoph Hellwig
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=20050819083332.GC29333@wohnheim.fh-wedel.de \
--to=joern@wohnheim.fh-wedel.de \
--cc=dean-list-linux-kernel@arctic.org \
--cc=folkert@vanheusden.com \
--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
all inboxes | Powered by JetHome®