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From: Chris Friesen <cfriesen@nortelnetworks.com>
To: Mark Mielke <mark@mark.mielke.cc>
Cc: "Pål Halvorsen" <paalh@ifi.uio.no>, "bert hubert" <ahu@ds9a.nl>,
	linux-kernel@vger.kernel.org
Subject: Re: sendfile
Date: Fri, 02 May 2003 00:19:25 -0400	[thread overview]
Message-ID: <3EB1F1CD.4060702@nortelnetworks.com> (raw)
In-Reply-To: 20030502024147.GA523@mark.mielke.cc

Mark Mielke wrote:

> As far as I understand, sendfile() still requires the data to get from the
> disk to a page in memory, similar to how send() referencing an mmap()'d page
> may cause a page fault, reading the data from disk to a page in memory. One
> copy each. I don't know of a kernel interface that lets data be copied from
> disk to ethernet card without involving a temporary copy to be in paged
> memory at some point in time... perhaps the iSCSI stuff can do this? I dunno.

According to this:

http://asia.cnet.com/builder/program/dev/0,39009360,39062783,00.htm

using sendfile() is easier on the CPU due to less trashing of the TLB.


I do get your point about protocol limitiations though.

Chris

-- 
Chris Friesen                    | MailStop: 043/33/F10
Nortel Networks                  | work: (613) 765-0557
3500 Carling Avenue              | fax:  (613) 765-2986
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  reply	other threads:[~2003-05-02  4:07 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-04-30 14:28 sendfile Pål Halvorsen
2003-04-30 16:51 ` sendfile bert hubert
2003-04-30 19:12   ` sendfile Pål Halvorsen
2003-04-30 19:28     ` sendfile bert hubert
2003-04-30 21:57       ` sendfile Pål Halvorsen
2003-04-30 22:18         ` sendfile Mark Mielke
2003-04-30 22:34           ` sendfile Pål Halvorsen
2003-05-01  4:28             ` sendfile Mark Mielke
2003-05-01 15:25               ` sendfile Joseph Malicki
2003-05-01 21:17               ` sendfile Pål Halvorsen
2003-05-01 22:31                 ` sendfile Chris Friesen
2003-05-01 23:32                   ` sendfile Ketil Froyn
2003-05-02  9:02                     ` sendfile Bernd Eckenfels
2003-05-02  2:41                   ` sendfile Mark Mielke
2003-05-02  4:19                     ` Chris Friesen [this message]
2003-05-02 21:06                       ` sendfile Mark Mielke
2003-05-03  0:42                         ` sendfile Miquel van Smoorenburg
2003-05-03 15:04                           ` sendfile Mark Mielke
2003-05-03 12:52                         ` sendfile Pål Halvorsen
2003-05-03 21:01                         ` sendfile Pål Halvorsen
2003-05-04  0:53                           ` sendfile Miquel van Smoorenburg
  -- strict thread matches above, loose matches on Subject: below --
2001-05-24  8:44 sendfile Pål Halvorsen

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