This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [XenPPC] PATCH: Inline assembler for clear_page() and copy_page()

On Mon, 2006-08-28 at 11:58 -0400, Jimi Xenidis wrote:
> On Aug 28, 2006, at 11:49 AM, Hollis Blanchard wrote:
> > On Mon, 2006-08-28 at 11:31 -0400, Jimi Xenidis wrote:
> >> On Aug 28, 2006, at 10:50 AM, Hollis Blanchard wrote:
> >>
> >>>
> >>> Also, it looks like you've removed support for mambo_memcpy(). I  
> >>> don't
> >>> use Mambo *ahem* systemsim myself, but that seems worth keeping. I
> >>> guess
> >>> you could rename the function while you're in there. :)
> >>
> >> if we get these down to dcbz's then system performance is fine and am
> >> happy to drop.
> >
> > I think you're saying that if we have a clear_page() loop that uses
> > dcbz, systemsim performance is fine. Is that correct?
> yes

Is that just because it reduces the number of loops? Using 128 byte
increments instead of 8 would reduce the iterations from 512 to 32.

> >
> > Is that also the case for copy_page()?
> No but it is not called to often, infact not at all AFAICT. I just  
> removed it and build fine :)
> Thats not to say that there aren't any opportunities to use it.

Right. As long as we're changing this code, let's include copy_page().

... which brings us back to the original patch a) removing the call to
mambo_memcpy(), and b) missing dcbtst.

Hollis Blanchard
IBM Linux Technology Center

Xen-ppc-devel mailing list