RFR [M][7/7]: 8197932: Better split work in rebuild remembered sets phase (original) (raw)

Thomas Schatzl thomas.schatzl at oracle.com
Mon Mar 5 15:51:55 UTC 2018


Hi all,

(last one for now :)) (resend because I forgot to change the subject)

please have a look at this change that improves TTSP during the rebuild remembered set phase.

So in the original change G1 yields only after processing a particular region - in case of humongous objArrays at e.g. 32M region size with lots of references this can take a bit.

This change modifies the rebuild remembered set closure to yield more finely grained. Still a single thread processes a single region, there is a different CR out there for improving that a bit.

The default "chunk size" of 256K of references has been measured to take <1ms in the large majority of cases on my setup on some of these densely occupied humongous objArrays, there are log messages for that, and is configurable.

CR: https://bugs.openjdk.java.net/browse/JDK-8197932 Webrev: http://cr.openjdk.java.net/~tschatzl/8197932/webrev/ Testing: see main thread

Thanks, Thomas



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