Re: Does io_remap_page_range() take 5 or 6 args?

[William Lee Irwin III <wli@holomorphy.com>]

On Wed, Aug 18, 2004 at 03:00:01PM -0700, William Lee Irwin III wrote:
> Or, if not pgoff_t, introduce a pfn_t for this purpose, an unsigned
> arithmetic type of architecture-dependent width (such systems may not
> want 64-bit page indices and the like for various reasons). But
> exhibiting a system with the need for such is yet to be done, and in
> fact, even with a 32B struct page, 16TB RAM (the minimum required to
> trigger more physical address bits >= BITS_PER_LONG + PAGE_SHIFT) has
> a 128GB mem_map[] with 4KB pages, an 8GB mem_map[] with 64KB pages,
> and so will have far, far deeper support issues than pfn overflows.
> Even supposing a kernel could be made to boot and the like, the massive
> internal fragmentation from using a large enough emulated PAGE_SIZE to
> get mem_map[] to fit within virtualspace will surely render such a
> machine completely useless, likely to the point of being unable to run
> userspace, or panicking much earlier from boot-time allocation failures.

Given this, will a pfn suffice?


-- wli