Testing done by [~huntch] suggests that it would be useful to reclaim SoftReferences a bit more aggressively. The SoftRefLRUPolicyMSPerMB parameter, which today defaults to 1000, seems to be tuned for STW collectors (no one really seems to know or remember how this value was picked). In concurrent collectors a lower value (like 200) seems be a better fit. This tends to result in SoftReferences being reclaimed more gradually as apposed to all-or-nothing, which can sometimes be observed. These observations can also be backed up by how JRockit did this. There concurrent collectors also defaulted to using a lower value (200) for SoftRefLRUPolicyMSPerMB. The proposal is to adjust the default value for SoftRefLRUPolicyMSPerMB to 200 for ZGC.