review request (S) 6866585 debug code in ciObjectFactory too slow
John.Rose at Sun.COM
Thu Aug 6 11:13:12 PDT 2009
On Aug 6, 2009, at 11:07 AM, Y.S.Ramakrishna at Sun.COM wrote:
> Current GCs in hotspot will never reorder perm gen objects.
And that's been true in all the years since we wrote the paranoid CI
code. It's just waiting for that day when all its fears are
> Of course having the check at every full gc seems fine in debug
> mode. The diagnostic mode may be paranoid given our current GC's,
> but is fine to have if you feel that would still be worthwhile.
Would it be possible to put the check into the GC epilogue? Probably
not, since ciEnv guys are not statically allocated and not easy to
enumerate (one per active compile-thread task). I guess I do like the
idea of checking a GC tick counter from the CI, to throttle the
paranoid check. Best of all would be to have some explicit linkage
from the GC epilogue code to the CI, which somehow documents and
enforces the order invariance. You can see why this is awkward: It
is an invariant shared by the CI and the GC.
More information about the hotspot-compiler-dev