[9] RFR(M): 7194669: CodeCache::mark_for_deoptimization should avoid verifying dependencies multiple times

Albert Noll albert.noll at oracle.com
Fri Jan 10 05:28:24 PST 2014


I've evaluated the performance difference (nashorn + octane) between 
binary search
and a linear search. The linear-search version uses one 
for each dependency type. The difference in dependency checking time is 
15-20%, i.e., binary
search is 15-20% faster than linear search. However, using linear search 
to cache checked
dependencies is still ~4X faster compared to checking all dependencies.

I guess 15-20% is not enough to justify using the new data structure. 
Here is the new
webrev that uses linear search:


On 01/09/2014 06:57 PM, Roland Westrelin wrote:
>> As I recall running some nashorn benchmarks takes about 10X more time when using fastdebug VM if VerifyDependencies is not switched off.
> Thanks Vladimir.
> What about simply pushing the dependency signatures to an unsorted growableArray() and doing a linear search? Maybe that’s good enough?
> Roland.

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