On Sun, 21 Sep 2025 19:47:14 GMT, Vladimir Yaroslavskiy <[email protected]> wrote:
> The goal of the PR is to improve both, sequential and parallel, sorting of > primitives. > > **The main achievements** > > - introduced Radix in parallel sorting which shows several times boost of > performance and has linear complexity instead of n*ln(n) > - improved mixed insertion sort (makes whole sorting faster) > - improved merging sort for almost sorted data > - optimized parallel sorting > - improved step for pivot candidates and pivot partitioning > - suggested better buffer allocation: if no memory, it is switched to > in-place sorting with no OutOfMemoryError > - minor javadoc and comment changes > > - extended existing tests > - added tests for radix sort, heap sort, insertion sort > - added benchmarking JMH tests > - improved test coverage > > **The summary of benchmarking:** > > **Sequential sorting (Arrays.sort)** > > byte: up to 50% faster > char: 4-7 times faster > short: 2-6 times faster > int: 1.2-5 times faster > long: 1.2-5 times faster > float: 1.2-5 times faster > double: 1.2-4 times faster > > **Parallel sorting (Arrays.parallelSort)** > > int: 1.2-9 times faster > long: 1.2-9 times faster > float: 1.2-4 times faster > double: 1.2-4 times faster > > **AVX512 support** > > Vamsi Parasa suggested faster sort routines by taking advantage of AVX512 > instructions, see https://github.com/openjdk/jdk/pull/14227, sources of > sorting were modified. Therefore, I performed benchmarking of the final > version (which includes optimizations by Vamsi Parasa and optimizations from > my side) on a server with CPUs supported AVX512 instructions, no regression > of performance was found, see detailed benchmarking results. > > I'm going on previous PRs https://github.com/openjdk/jdk/pull/3938 and > https://github.com/openjdk/jdk/pull/13568 It would be nice to have a high-level chart showing how the actual sorting algorithm is selected based on parallel/sequential, input size and whatever else. For an outsider, it's hard to grasp the whole picture. Is radix sort used for parallel sorting only? Sorry if such a chart already exists and I missed it. If improvements of parallel sorting and sequential sorting are at least partially independent, I think it may make sense to deliver them in separate PRs. This would really simplify the review process. ------------- PR Comment: https://git.openjdk.org/jdk/pull/27411#issuecomment-3317553265
