Ah, so the memory sections that are now smaller are basically the GC's internal data structures, rather than the general heap?
That kind of puts things in perspective. Still a great improvement. Has it been tested by how much the overall memory footprint of the JVM decreases in larger benchmarks? On Fri, 6 May 2022 at 23:28, charlie hunt <charlie.h...@oracle.com> wrote: > Hi Stefan, > > The graph Thomas shows in his blog is the GC part of the NMT output which > does not include metadata. > > The GC part of NMT output includes native memory allocated on behalf of > the GC itself such as a card table or remembered set .. those things that > GC needs to do its work. The native memory allocated for the Java heap are > in the "Java Heap" section of the NMT output. Class metadata is in the > "Class" section of the NMT output. > > There is a "Native Memory Tracking Memory Categories" table that lists the > sections / categories reported by NMT and a description of each at: > > https://docs.oracle.com/en/java/javase/17/troubleshoot/diagnostic-tools.html#GUID-5EF7BB07-C903-4EBD-A9C2-EC0E44048D37 > > hths, > > Charlie > On 5/6/22 2:13 PM, Stefan Reich wrote: > > I'm right now just trying to get over how amazing this graph is: > https://tschatzl.github.io/2022/03/14/jdk18-g1-parallel-gc-changes.html > > 35-40% savings in memory use just by using JDK 18??? Who would have > expected such a major improvement after 17 iterations of the language! > > Just so I'm sure I'm reading it correctly... the graph basically shows the > Java heap's memory footprint in terms of committed native memory. Right? > > So it would include Eden, tenured generations, humongous objects, but not > metadata and code. Is that correct? > > Basically tell me how much I should celebrate this. lol > > I did switch another small, pretty crammed (8 GB RAM) server over to JDK > 18 and it does feel like there's a lot more memory available on it now and > everything is a lot faster too. > > Cheers > Stefan > > -- > == Gaz.AI == > > _______________________________________________ > hotspot-gc-use mailing > listhotspot-gc-...@openjdk.java.nethttps://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use > > -- == Gaz.AI ==
_______________________________________________ hotspot-gc-use mailing list hotspot-gc-use@openjdk.java.net https://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use
