review (L) for 7017732: move static fields into Class to prepare for perm gen removal

Y. S. Ramakrishna y.s.ramakrishna at
Wed Mar 16 17:05:39 PDT 2011

Hi Tom --

ah, now that i went and looked at the code and the bug you filed (thanks!)
i understand the problem, and your fix. I agree that there was a race before
and that your moving the fix_oop_relocations() into that epilogue method
effectively fixes that by delaying the latter until the scavenge is
effectively complete.

-- ramki

PS: Ideally i'd like this to some day get integrated into a subsequent parallel
weak oops phase of the GC infrastructure so that it can be done MT once
weak oops processing is made entirely parallel, and also since it feels
like the kind of work that's done for weak roots.
I am guessing the lack of parallelism in this phase is nothing to lose
one's sleep over at the moment (and may be never, but still FWIW).

On 03/16/11 15:13, Tom Rodriguez wrote:
> Hopefully this is the final version of this webrev.  I found and fixed a preexisting bug with ScavengeRootsInCode that boiled down to a race between updating the oops in the nmethod and rewriting the oops in the instruction stream.  The fix is to call fix_oop_relocations after all the nmethods have been visited by the scavenger.  That changes nmethod.cpp and codeCache.cpp which you can see in the updated version of the webrev.  I plan on pushing this to hotspot-gc once the weekly sync and promotion has been done.  Thanks for all the reviews.
> tom

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