Bulk operations performance: juggling external conditions
aleksey.shipilev at oracle.com
Wed Aug 1 05:29:28 PDT 2012
On 08/01/2012 04:16 PM, Doug Lea wrote:
> The remaining utilization issues seem to be in line with
> some of my in-progress suggestions for improvements that amount to
> (1) reducing the sequential bottlenecks in front of subtask
> generation (mainly via an alternative to Spliterator) and
Interesting. My tests use custom Splitterables which do not block during
split at all.
> (2) reducing the impact of GC stalls etc on worker availability
> (mainly by using CountedCompleters).
I see the issues about wasting threads on join()'s, seems to be
completely unrelated to GC. This is something fixable by
CountedCompleter. More in separate thread.
> Do you see any other systematic issues?
I'm trying to confirm some of them with precise tests. FWIW, this huge
experiment gives the high-level picture where to look for troubles, not
where the troubles really are. Stay tuned.
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