JEP 248: Make G1 the Default Garbage Collector (original) (raw)

Ben Evans ben at jclarity.com
Mon Jun 1 17:54:37 UTC 2015

One question that may be worth pondering … suppose G1 happened to be the default GC today, and there was a JEP to make Parallel GC the default GC. What would your reaction to that JEP be? I’m asking that question since I’d like to get a sense if your concerns are more about conservatism (not wanting to change behavior), stability of G1 or otherwise.

Primarily conservatism. Of course, if G1 had been default, the "unknown unknowns" would have been resolved by now, so there would be no need to worry. I think that if G1 was default, and the platform was as successful across the same range of workloads as it is today, I'd be advocating for no change. Is that because you think G1 would offer a better out of the box experience than Parallel GC, or because you would not want to see a change made to the JVM’s default GC?

I would not want to see a change made to the default behaviour that could potentially negatively affect a large number of apps and in doing so harm the long-term perception of the platform as a "safe pair of hands".

Thanks,

Ben

Ben Evans, Co-founder jClarity @jclarity

More information about the hotspot-dev mailing list