Re: news about IDE PIO HIGHMEM bug

William Lee Irwin III
2004-10-28T00:18:52Z

Christoph Hellwig wrote:
>> I think this is the wrong level of interface exposed. Just add two hepler
>> kmap_atomic_sg/kunmap_atomic_sg that gurantee to map/unmap a sg list entry,
>> even if it's bigger than a page.

On Wed, Oct 27, 2004 at 02:33:45PM -0400, Jeff Garzik wrote:
> Why bother mapping anything larger than a page, when none of the users
> need it?
> P.S. In your scheme you would need four helpers; you forgot kmap_sg()
> and kunmap_sg().

The scheme hch suggested is highly invasive in the area of architecture-
specific fixmap layout and introduces a dependency of fixmap layout on
maximum segment size, which may make it current normal maximum segment
sizes use prohibitive amounts of vmallocspace on 32-bit architectures.

So I'd drop that suggestion, though it's not particularly farfetched.

-- wli