On Wed, 20 Sep 2023 16:33:56 GMT, Paul Sandoz <psan...@openjdk.org> wrote:
>>> > Alan, you mentioned that DualPivotQuicksort will need detailed review. >>> > Can we go ahead and start reviewing? Laurent checked performance, JMH >>> > results look fine. >>> >>> As before, I think the main question with this change is whether adding >>> radix sort to the mix is worth the complexity and additional code to >>> maintain. Also as we discussed in the previous PR, the additional memory >>> needed for the radix sort may have an effect on other things that are going >>> on concurrently. I know it has been updated to handle OOME but I think >>> potential reviewers would need to be comfortable with that part. >> >> I too share concerns about the potential increased use of memory for sorting >> ints/longs/floats/doubles. With modern SIMD hardware and data parallel >> techniques we can apply quicksort much more efficiently. I think it is >> important to determine to what extent this reduces the need for radix sort. >> To determine that we would need to carefully measure against the AVX-512 >> implementation (with ongoing improvements) with appropriately initialized >> data to sort, and further measure against an AVX2 version. > >> Hi Paul (@PaulSandoz), Alan (@AlanBateman), Any update? Do you agree with >> Radix sort in parallel case only? > > I think its definitely a better fit, but another aspect of my previous > comment was wondering if we need a radix sort if the vectorized quicksort > implementation is fast enough. IMO we need to compare performance results > with the vectorized quick sort, and be aware of future enhancements to that. Hi Paul (@PaulSandoz), Alan (@AlanBateman), Any update? What do you think? ------------- PR Comment: https://git.openjdk.org/jdk/pull/13568#issuecomment-1777492279
