RFR(XXS): 8017070: G1: assert(_card_counts[card_num] <= G1ConcRSHotCardLimit) failed
tao.mao at oracle.com
Fri Jun 28 19:35:05 UTC 2013
looks good to me.
On 6/28/13 12:01 PM, John Cuthbertson wrote:
> Hi All,
> Can I couple of volunteers review this extremely small change? The
> webrev can be found at:
> The assert that fired is invalid. A card can be added to more than one
> update buffer since reads and writes to the card table are not atomic.
> If two threads end up refining the card at the same time then the
> count for that card can be incremented twice. If count is just below
> the hot threshold, the double increment will trip the assert. Since
> the card was enqueued by two different threads we do want the the
> double increment to more accurately reflect how hot the card is. I
> have removed the invalid assert and use a bounding expression to
> assign the new count value.
> Weblogic+medrec on the failing SQE machine (though I couldn't
> reproduce the original problem)
> Weblogic+medrec on an Intel Haswell machine
> GC test suite
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