Re: CVS commit: src/sys/uvm

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Tue, Jan 04, 2011 at 08:35:48AM -0800, Matt Thomas wrote:
> 
> On Jan 4, 2011, at 8:33 AM, Manuel Bouyer wrote:
> 
> > On Tue, Jan 04, 2011 at 08:03:33AM -0800, Matt Thomas wrote:
> >>> I fixed this issue in arch/x86/x86/x86_machdep.c 1.37, I wonder if your 
> >>> change
> >>> has reintroduced this problem ...
> >> 
> >> Since it's not turned on by default, I doubt it.
> > 
> > I guess if you wrote it, you expect to use it for something :)
> > in which cases do you intend to turn it on ? A kernel config option,
> > or for some ports ?
> 
> I turn it on for MIPS.
> 
> BTW, MIPS has separate freelists for <512MB, <4GB, and then everything else.

OK, so the question remains for mips :) how do you prevent kernel memory
from stealing all DMA-capable memory ?
Or do maybe you expect to always have something free in the <512MB list ?
BTW, x86 has <16MB, <4GB and everything else. the <16MB list was not enough to
cover the bus_dma(9) needs. Maybe the <512MB list will, provided it's not
already starved by other needs.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--