On Tue, Sep 06, 2005 at 08:57:57PM -0700, David S. Miller ([EMAIL PROTECTED])
wrote:
> From: Evgeniy Polyakov <[EMAIL PROTECTED]>
> Date: Fri, 2 Sep 2005 18:00:55 +0400
>
> > sock_sendfile() and generic_file_sendpage() were implemented
> > and presented in the attached patch.
> > Such methods allows to use sendfile() for any file descriptor <-> file
> > descriptor usage, especially usefull it is in the case socket -> file,
> > when there are no copy_from_user() cases when writing the data.
>
> I do not understand the socket sendfile() implementation, you
> seem to just be looping back the data to recvmsg(). How does
> this work?
It does recvmsg(), but main purpose was to not copy this into userspace,
when destination is file descriptor/socket.
It does memcpy() unfortunately, but eliminating such a copy will require
completely new system call, like recvfile(), which will first prepare a
page, and then doing network receiving into it.
--
Evgeniy Polyakov
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