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Pinned topic -Xgc:stdGlobalCompactToSatisfyAllocate option description?

‏2019-03-23T18:19:09Z |


some resources mention (recommend) the use of -Xgc option stdGlobalCompactToSatisfyAllocate if the gencon garbage collector policy is in use.

I tried to find any documentation describing the effect of this option, however couldn't find any at all.

Could please someone from the development team provide a description of what this option does 9e.g. what's the default GC behaviour without it and what's the GC behaviour with it)?


Note: Thanks to opensourcing the J9 I was able to find something in the sources.

I think based on that I partly understand what it does, however I'm not completely sure.


What I'm trying to achieve is reduction of the GC compactions "compact on aggressive collection" which sometimes occur (about once a day) and take a really long time (about 30s). On a quick glance it seems it may have some effect here.