The heap size difference among Parallel, CMS, and G1

Hi All, I'm testing the performance of Parallel, CMS, and G1. I found that their available heap sizes are different under the same -Xmx configuration. For example, I set the -Xmx to 6.5GB (6656m) and use Runtime.getRuntime().maxMemory() to obtain the real heap size. The output is as follows.

Re: OOM error caused by large array allocation in G1

Hi Thomas, Sorry for the late reply and thanks for your nice interpretation. I added some comments and questions inline. Thanks, Lijie On Sat, Nov 18, 2017 at 11:37 PM, Thomas Schatzl <thomas.scha...@oracle.com> wrote: > Hi, > > On Sat, 2017-11-18 at 20:53 +0800, Lijie Xu wr

"Allocated < Usage" problem in G1 log

Hi all, I currently found a "allocated < usage" problem in the G1 log as follows. [Eden: 342.0M(3296.0M)->0.0B(3890.0M) Survivors: 1024.0K->1024.0K Heap: 5541.2M(6655.0M)->1886.0M(6655.0M)] [Times: user=0.03 sys=0.00, real=0.02 secs] This log reveals that (1) The allocated space of