Re: sendfile

From: Chris Friesen (cfriesen@nortelnetworks.com)
Date: Thu May 01 2003 - 23:19:25 EST


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
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