RFR: 8061254: SPECjvm2008-XML performance regressions in 9-b33 (original) (raw)

Alan Bateman Alan.Bateman at oracle.com
Fri May 15 13:23:27 UTC 2015

On 13/05/2015 12:51, Claes Redestad wrote:

Hi,

9-b33 introduced a sustained regression in SPECjvm2008 xml.transform on a number of our test setups. JDK-8058643 removed the check on value.length > 0, which means repeated calls to "".hashCode() now do a store of the calculated value (0) to the hash field. This has potential to cause excessive cache coherence traffic in xml.transform[1] I remember the original change but of course didn't spot that empty String would result in a write of 0. I like Shipilev's First Law.

The patch looks good to me.

-Alan.

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