Hi Uwe, OK, I'll test with NIOFSDirectory as well ... that's a good idea.
I do remember testing earlier Java 9 builds long ago, but I can't remember what the outcome was. Mike McCandless http://blog.mikemccandless.com On Mon, Mar 13, 2017 at 6:35 AM, Uwe Schindler <uschind...@apache.org> wrote: > Hi Andrew, > > yes that was my impression, too. > > Just for cross-checking: Mike, is it possible to also add a perf > comparison between Java 8 and Java 9 when using SimpleFSDirectory or > NIOFSDirectory (which are both FileChannel based since Java 7, the name is > just backwards-compatibility)? If we see a slowdown there (maybe even > larger) than it is not related to ByteBuffer positional/byte-wise reads and > there is a general performance issue somewhere else. > > > Right, but ByteBuffers were significantly rewritten for a significant > > performance *increase*. Any slowdown shows that something has gone > > very wrong indeed. > > That would be a pity, because of that we should check the above case with > non-mmap based, conventional index access. As far as I remember: at the > time when you announced the bytebuffer improvements we did some performance > measurements and were impressed by the speedup. I think Robert Muir did > something. Mike, do you know? > > Maybe we should check with a Java 9 preview build from that time. I know > that you can download older builds by changing the build number in the > download URL. > > Uwe > >
