Re: [PLEASE-TESTME] Zerocopy networking patch, 2.4.0-1

Christoph Hellwig (hch@ns.caldera.de)
Tue, 9 Jan 2001 22:12:55 +0100


On Tue, Jan 09, 2001 at 12:55:51PM -0800, Linus Torvalds wrote:
>
>
> On Tue, 9 Jan 2001, Christoph Hellwig wrote:
> >
> > Also the tuple argument you gave earlier isn't right in this specific case:
> >
> > when doing sendfile from pagecache to an fs, you have a bunch of pages,
> > an offset in the first and a length that makes the data end before last
> > page's end.
>
> No.
>
> Look at sendfile(). You do NOT have a "bunch" of pages.
>
> Sendfile() is very much a page-at-a-time thing, and expects the actual IO
> layers to do it's own scatter-gather.
>
> So sendfile() doesn't want any array at all: it only wants a single
> page-offset-length tuple interface.

The current implementations does.
But others are possible. I could post one in a few days to show that it is
possible.

Christoph

-- 
Whip me.  Beat me.  Make me maintain AIX.
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