Messages in this thread |  | | | Date | Fri, 11 Aug 2006 00:05:32 +0900 | | From | KAMEZAWA Hiroyuki <> | | Subject | Re: Re : sparsemem usage |
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On Thu, 10 Aug 2006 14:46:01 +0000 (GMT) moreau francis <francis_moreau2000@yahoo.fr> wrote: > Why not implementing page_exist() by simply using mem_map[] ? When > allocating mem_map[], we can just fill it with a special value. And > then when registering memory area, we clear this special value with > the "reserved" value. Hence for flatmem model, we can have: > > #define page_exist(pfn) (mem_map[pfn] != SPECIAL_VALUE) > putting a special value to a page struct at mem_map + pfn ?
> and it should work for sparsemem too and other models that will use > mem_map[]. > > Another point, is page_exist() going to replace page_valid() ? what is page_valid() here ? pfn_valid() (in current kernel) ?
> I mean page_exist() is going to be something more accurate than > page_valid(). All tests on page_valid() _only_ will be fine to test > page_exist(). But all tests such: > > if (page_valid(x) && page_is_ram(x)) > > can be replaced by > > if (page_exist(x)) > > So, again, why not simply improving page_valid() definition rather > than introduce a new service ? > I welcome to do that if implementation is sane. pfn_valid() --- check there is a page struct page_exist() --- check there is a physical memory.
but discussing without patch is not very good. please post your patch. Then we can discuss more concrete things.
-Kame
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