RFR (S): 8155229: Tune thread usage for live data clearing
mikael.gerdin at oracle.com
Thu Apr 28 14:28:20 UTC 2016
On 2016-04-28 13:16, Thomas Schatzl wrote:
> Hi all,
> during testing of 8077144 I found that live bitmap clear can be
> significantly sped up by not using that many threads.
> A good conservative estimate (tends to use too many threads) that still
> cuts mark bitmap clear time by >50% is to give each thread at least 1
> MB of data to clear.
The fix looks good.
One thing though,
now that I think about it, would it make sense to add an additional
logging tag to
+ log_debug(gc, ergo)("Running %s using %u workers for " SIZE_FORMAT "
work units.", cl.name(), num_workers, num_chunks);
Since these logging statements are not really about GC ergonomics but
rather GC worker ergonomics.
This can be fixed further on too, I just want to hear if anyone else
gets the same feeling.
> jprt, webrev, various performance tests
> Depends on 8155232.
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