Hi, On Tue, 2017-02-07 at 19:06 +0530, Amit Balode wrote: > Any thoughts on how we could find how much space is fragmented in G1 > regions?
-XX:+G1PrintRegionLivenessInfo prints region information containing its type after every marking (use gc+liveness=trace for jdk9) twice. The first "post-marking" output is what you want. The "post-sorting" one is only interesting for getting details about the collection set (and this one does not contain free regions). The first column contains information about the type of the region: FREE -> free region SURV -> survivor region EDEN -> eden region HUMS -> humongous (start) HUMC -> humongous (continuation) OLD -> old region ARC -> archive regions (jdk9 only I think, not sure, maybe also jdk8) From that you can deduce the size and how many contiguous free regions are available at the moment. There is also -XX:+PrintHeapAtGC and -XX:+PrintHeapAtGCExtended which print the region layout at every GC. Thanks, Thomas _______________________________________________ hotspot-gc-use mailing list hotspot-gc-use@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use
