On Tue, Jul 13, 2010 at 12:03:15PM +0900, KAMEZAWA Hiroyuki wrote: > On Tue, 13 Jul 2010 11:05:26 +0900 > Minchan Kim <minchan.kim@xxxxxxxxx> wrote: > > > On Tue, Jul 13, 2010 at 9:25 AM, KAMEZAWA Hiroyuki > > <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > > > > For example, prepare a page filled with (1 << PG_reserved). > > > and replace it with unnecessary memmap rather than freeing a page for memmap. > > > > Hmm. I don't got your point. > > The problem is that we access struct page by pfn number not address. > > > > You mean let's remain memmap on hole with changing PageReseved instead of free? > > > Like a ZERO_PAGE, preparing RESERVED_PAGE, > which is filled with (1 << PG_reserved) as > > 0x00000400,0x00000400,0x00000400,0x00000400 > ..... > > And map this pages to every hole. Then, you only waste a page to fill all holes > because "struct page" is aligned to 4bytes. > I like this idea. It would allow memmap_valid_within to be thrown away altogether and it maintains the assumptions of the memory model and sounds "cheap". > > > I think it's not a good idea to add new flag. If > > Kame. Could you review my RFC patch which makes pfn_valid check more > > tightly on sparsemem? > Sure. > > Thanks, > -Kame > -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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