On Sun, 1 Apr 2007, Andi Kleen wrote: > Hmm, this means there is at least 2MB worth of struct page on every node? > Or do you have overlaps with other memory (I think you have) > In that case you have to handle the overlap in change_page_attr()
Correct. 2MB worth of struct page is 128 mb of memory. Are there nodes with smaller amounts of memory? Note also that the default sparsemem section size is (include/asm-x86_64/sparsemem.h) #define SECTION_SIZE_BITS 27 /* matt - 128 is convenient right now */ 128MB .... So you currently cannot have smaller sections of memory anyways. > Also your "generic" vmemmap code doesn't look very generic, but > rather x86 specific. I didn't think huge pages could be easily > set up this way in many other architectures. We do this pmd special casing in other parts of the core VM. I have also a patch for IA64 that workks with this. > Do you have any benchmarks numbers to prove it? There seem to be a few > benchmarks where the discontig virt_to_page is a problem > (although I know ways to make it more efficient), and sparsemem > is normally slower. Still some numbers would be good. You want a benchmark to prove that the removal of memory references and code improves performance? - To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
