Lucene could really make use of this method. When a segment merge takes place, we can read & write many GB of data, which without madvise on many OSs would effectively flush the IO cache (thus hurting our search performance).
Mike On Mon, Jun 15, 2009 at 6:01 PM, Jason Rutherglen<jason.rutherg...@gmail.com> wrote: > Thanks Alan. > > I cross posted this to the Lucene dev list where we are discussing using > madvise for minimizing unnecessary IO cache usage when merging segments > (where we really want the newly merged segments in the IO cache rather than > the old segment files). > > How would the advise method work? Would there need to be a hint in the > FileChannel.map method? > > -J > > On Mon, Jun 15, 2009 at 12:36 AM, Alan Bateman <alan.bate...@sun.com> wrote: >> >> Jason Rutherglen wrote: >>> >>> Is there going to be a way to do this in the new Java IO APIs? >> >> Good question, as it has come up a few times and is needed for some >> important use-cases. A while back I looked into adding a >> MappedByteBuffer#advise method to allow the application provide hints on the >> expected usage but didn't complete it. We should probably look at this again >> for jdk7. >> >> -Alan. >> > > --------------------------------------------------------------------- To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org For additional commands, e-mail: java-dev-h...@lucene.apache.org
