RFR(L): 8029075 - String deduplication in G1

[Thomas Schatzl]

Hi Per,

On Mon, 2014-03-03 at 14:33 +0100, Per Liden wrote:
> Hi,
> 
> Could I please have this patch reviewed.

  this is not a complete review (still working on it), but some comments
about measuring the time taken.

When printing thread processing times, is it possible to provide
per-thread times for the specific parts (queue processing, table
processing) and the total?

E.g. instead of only the total time for weak root fixup, provide also
string table processing time.

This would help finding issues with particular phases of the weak root
fixup, and in particular string dedup. Per thread times (at maximum
logging level) will help finding issues. 

Potentially this code is trying to distribute little work on hundreds of
threads after all and this would help identifying the problem quickly.

Something like:

[Weak Root Fixup ....]
  [String Dedup ...]

(Additionally, probably better in a separate CR, add timing for
processing the JNI weak root handles).

Thanks,
  Thomas