On Sun, Jan 23, 2022 at 11:52:07PM -0800, John Hubbard wrote:
> To ground this in reality, one of the partial call stacks is:
>
> do_direct_IO()
> dio_zero_block()
> page = ZERO_PAGE(0); <-- This is a problem
>
> I'm not sure what to use, instead of that zero page! The zero page
> doesn't need to be allocated nor tracked, and so any replacement
> approaches would need either other storage, or some horrid scheme that I
> won't go so far as to write on the screen. :)
I'm not really sure what the problem is.
include/linux/mm.h: is_zero_pfn(page_to_pfn(page));
and release_pages() already contains:
if (is_huge_zero_page(page))
continue;
Why can't the BIO release function contain an is_zero_pfn() check?
