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

Christian Thalinger christian.thalinger at oracle.com
Fri Jan 10 12:59:50 PST 2014

This looks good. Just a suggestion (you can ignore that if you want): GrowableArray has find() and contains() methods. If you would override operator== in DependencySignature you could use GrowableArray::find().

On Jan 10, 2014, at 5:28 AM, Albert Noll <albert.noll at oracle.com> wrote:

Hi,

I've evaluated the performance difference (nashorn + octane) between binary search and a linear search. The linear-search version uses one GrowableArray<DependencySignature*> 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: http://cr.openjdk.java.net/~anoll/7194669/webrev.01/ Best, Albert 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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