Re: 2.5.67-mm3

Antonio Vargas
2003-04-15T05:52:29Z

On Mon, Apr 14, 2003 at 09:17:59PM -0700, William Lee Irwin III wrote:
> On Mon, Apr 14, 2003 at 07:00:57PM -0700, William Lee Irwin III wrote:
> > Hence, this "FIXME: do not do for zone highmem". Presumably this is a
>
> Another FIXME patch:
>
>
> It's a bit of an open question as to how much of a difference this one
> makes now, but it says "FIXME". fault_in_pages_writeable() and
> fault_in_pages_readable() have a limited "range" with respect to the
> size of the region they can prefault; as they are now, they are only
> meant to handle spanning a page boundary. This converts them to iterate
> over the virtual address range specified and so touch each virtual page
> within it once as specified. As per the comment within the "FIXME",
> this is only an issue if PAGE_SIZE < PAGE_CACHE_SIZE.
>
> [patch snip]

Page clustering? I did a simple patch yesterday called "cow-ahead", which
may be related: on a write to a COW page, it breaks the COW from several pages
at the same time. The implementation survived a complete debian 2.2 boot
and a fork bomb. Please have a look. The idea came from a discussion with
Martin J. Bligh... we liked the name too much not to implement it.

Greets, Antonio.