On Nov 12, 2007 7:42 PM, Christoph Lameter <[EMAIL PROTECTED]> wrote: > Ok here is the patch to remove DISCONTIG and FLATMEM > > x86_64: Make sparsemem/vmemmap the default memory model > > Use sparsemem as the only memory model for UP, SMP and NUMA. > Measurements indicate that DISCONTIGMEM has a higher overhead > than sparsemem. And FLATMEMs benefits are minimal. So I think its > best to simply standardize on sparsemem. > > Results of page allocator tests (test can be had via git from slab git > tree branch tests) > > Measurements in cycle counts. 1000 allocations were performed and then the > average cycle count was calculated. > > Order FlatMem Discontig SparseMem > 0 639 665 641 > 1 567 647 593 > 2 679 774 692 > 3 763 967 781 > 4 961 1501 962 > 5 1356 2344 1392 > 6 2224 3982 2336 > 7 4869 7225 5074 > 8 12500 14048 12732 > 9 27926 28223 28165 > 10 58578 58714 58682
Discontig obviously needs to die. However, FlatMem is consistently faster, averaging about 2.1% better overall for your numbers above. Is the page allocator not, erm, a fast path, where that matters? Order Flat Sparse % diff 0 639 641 0.3 1 567 593 4.4 2 679 692 1.9 3 763 781 2.3 4 961 962 0.1 5 1356 1392 2.6 6 2224 2336 4.8 7 4869 5074 4.0 8 12500 12732 1.8 9 27926 28165 0.8 10 58578 58682 0.2 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
