RFR: 8079315: UseCondCardMark broken in conjunction with CMS precleaning

[Andrew Haley]

On 06/05/15 15:10, Vitaly Davidovich wrote:
> 
> Having said that, you guys are in better position to make the call.  If
> nothing else, I think this change should be highlighted in whichever
> release(s) it appears in as people should be on the lookout for possible
> perf regressions associated with this.

CondCardMark is for highly-parallel programs running on many cores.
In such situations surely you make the choice to sacrifice some local
performance for much better global scaling.  Given that, barriers are
not such a big deal, IMO, but correctness surely is.

Andrew.