Re: empty_zero_page

[Gerald Schaefer <gerald.schaefer@gmail.com>]

On 7/5/05, David S. Miller <davem@davemloft.net> wrote:
> 
> Why does mm/filemap_xip.c make an explicit reference to
> "empty_zero_page"?  That's bogus, and ZERO_PAGE() is how
> generic code should get at this thing.
> 
> In fact, what the mm/filemap_xip.c code wants is the page
> struct, not the address of the page itself, because it
> does a virt_to_page() on empty_zero_page in every such
> reference.
> 
> This causes build failures for XIP support on sparc64.
> 
> When moving mm/filemap_xip.c over to ZERO_PAGE(), we will
> need to determine the virtual address at which the ZERO_PAGE()
> will be mapped.  This shouldn't be difficult to determine,
> and it's incredibly important to get this right, wrt. page
> coloring concerns, particularly on MIPS which does make use
> of the 'vaddr' argument to ZERO_PAGE().

Good point, seems like there is no reason to use empty_zero_page instead
of ZERO_PAGE. Carsten is out of the office this week, but we will get back
to this next week.