Re: [Xen-ia64-devel] [Patch 4/4] [RFC] Xwindow: Modify pci_acpi_scan_root()

[Isaku Yamahata <yamahata@xxxxxxxxxxxxx>]

On Tue, Jun 05, 2007 at 01:29:11PM +0900, Jun Kamada wrote:

> Could you explain more about the PAGE_SIZE optimization?
> 
> Current code merges overlapped address ranges without awareness of
> PAGE_SIZE and page alignment. Merged address range should
> be divided by PAGE_SIZE?

ioremap hypercall works in PAGE_SIZE unit so that we can safely
enlarge the region to be page aligned.
What I wanted to suggest is somthing like the followings.
(I assume that end is inclusive. If wrong, please correct it.)

static int
__add_issue_list(unsigned long start, unsigned long end,
                ioremap_issue_list_t *top)
...
-       new->start = start;
-       new->end   = end;
+       new->start = start & ~(PAGE_SIZE - 1);
+       new->end   = end | (PAGE_SIZE - 1);


-- 
yamahata

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