Messages in this thread | | | Date | Fri, 03 Mar 2000 15:32:18 +0100 | From | Manfred Spraul <> | Subject | Re: HIGH MEMORY access |
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Ingo Molnar wrote: > > On Fri, 3 Mar 2000, Manfred Spraul wrote: > > > Now I'm confused: I thought that ioremap() should be used for reserved > > memory, and kmap() for normal memory (e820: ram) with > > page->virtual==NULL. > > well you can use kmap() for anything, not just high memory.
kmap() assumes that a "struct page" exists.
It's not guaranteed that a "struct page" exists for reserved memory: this could happen if you boot with "mem=32M", or if the ACPI tables are the last element in the e820 map:
* max_pfn is set to the end if the last usable block. * then the ACPI tables follow --> they are behind max_pfn --> behind the end of mem_map.
Not everyone has 8 GB memory :-(
-- Manfred
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