Request for reviews (XXS): 6940520: CodeCache::scavenge_root_nmethods_do must fix oop relocations

Tom Rodriguez tom.rodriguez at oracle.com
Fri Apr 2 11:12:32 PDT 2010


That looks good.  We still need logic to prune the list of scavengeable nmethods since over time the oops should move out of eden and we can then stop scanning those nmethods.  Additionally we may want GC to automatically promote oops referenced by nmethods since they are pretty much guaranteed to be long lived.  I don't know if there's any easy way to do that.

tom

On Apr 2, 2010, at 5:39 AM, Christian Thalinger wrote:

> http://cr.openjdk.java.net/~twisti/6940520/webrev.01/
> 
> 6940520: CodeCache::scavenge_root_nmethods_do must fix oop relocations
> Summary: ScavengeRootsInCode can lead to unfixed code-embedded oops.
> Reviewed-by:
> 
> During testing of JSR 292's SPARC C2 port I found a couple of crashes
> which came from unfixed code-embedded oops.
> 
> This can be triggered with ScavengeRootsInCode={1,2}.
> 
> The fix is to call fix_oop_relocations in
> CodeCache::scavenge_root_nmethods_do after oops may have been updated.
> 
> src/share/vm/code/codeCache.cpp
> 
> 



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