On Tue, Jul 13, 2010 at 10:38:15AM +0100, Russell King - ARM Linux wrote: > On Tue, Jul 13, 2010 at 10:26:58AM +0100, Mel Gorman wrote: > > There is also an assumption that a section is fully populated or empty. > > That is absolutely absurd. Arguably, violating the memory model by punching unexpected holes in it is a also absurd. > So, I have a platform which has 256MB at > 64MB intervals in 4 chunks. I can fit 512kB to any slot. I'm afraid I'm not quite getting your example. If the granularity of the banks is 64MB and the alignment is 256MB, I don't see what hole you'd be punching anyway. > It starts > at 0x10000000. Do I really need 1024 sparsemem sections to cater for > this? > Not necessarily, just don't punch holes within section boundaries when using sparsemem. If mapping in a PageReserved page is not an option due to complexity (it's possible by remapping pages in kernel space which x86 used to do for discontig) then the size of mem_section as suggested by Minchan Kim would be another option. This would increase the overhead of sparsemem in terms of space and performance. - at worst by an amount matching the memory freed by memmap. -- 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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