(unknown charset) Re: speeding up ugen by an order of magnitude.

From: (unknown charset) Julian Elischer <julian_at_elischer.org>
Date: Wed, 7 Jul 2004 16:16:22 -0700 (PDT)
On Wed, 7 Jul 2004, Scott Long wrote:

> On Wed, 7 Jul 2004, Poul-Henning Kamp wrote:
> > In message <200407072129.15095.mycroft_at_netbsd.org>, "Charles M. Hannum" writes:
> > >On Wednesday 07 July 2004 20:46, Charles M. Hannum wrote:
> > >> 1) You'll need to add an interface for assigning pipes for read and write,
> > >> since there may be more than just bulk pipes (and may be more than one bulk
> > >> pipe in each direction), and we only have have device node to work with.
> > >
> > >Seems I misspoke there.  That part looks fine.
> > >
> > >I think you're going to be screwed by the buffer alignment, though.  This also
> > >causes some issues with umass if you're not using a bounce buffer.
> >
> > We've already had that issue with ATA for the børked Geode controller:
> > physio does nothing for alignment and relies on userland doing something
> > sensible.
> >
> > I think this is pretty reasonable for the kind of hardware-near
> > work that physio is usually employed in (including if we use it for
> > ugen).
> >
> > Obviously, if the alignment is not OK, EINVAL should be returned,
> > and that means that the driver should explicitly check the alignment.
> 
> Note that busdma can handle alignment now for loaded buffers by using
> bounce pages.

Since we have a relatively highly weighted priority on keeping this 
code common with teh NetBSD version, how does that go for NetBSD?


> 
> Scott
> 
Received on Wed Jul 07 2004 - 21:16:27 UTC

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