RFR (S): 8154528: Reclaim regions emptied by marking in Remark pause (original) (raw)

Thomas Schatzl thomas.schatzl at oracle.com
Thu Mar 29 14:49:20 UTC 2018

Hi all,

can I have reviews for this change that moves the space reclamation of empty regions into the Remark pause, which makes these regions available much sooner than before, with the obvious benefits of doing so.

The Cleanup pause now only contains updating the remembered set states after rebuilding remembered sets and determining the collection set candidates. In the future we might be able to make those concurrent and drop the Cleanup pause completely.

There is not much too say here, after all the recent refactorings this patch is almost trivial :)

From a timing POV this adds a few ms to the Remark pause in my measurements, mostly from the code root purging moved here. I think there is enough opportunity in the remark pause to decrease its duration in the future that outweighs the mentioned benefits.

Thanks go to everyone reviewing so far, particularly StefanJ and Sangheon!

Depends on JDK-8178105.

CR: https://bugs.openjdk.java.net/browse/JDK-8154528 Webrev: http://cr.openjdk.java.net/~tschatzl/8154528/webrev/ Testing: hs-tier 1-5

Thanks, Thomas

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