RFR (S): 8079555: REDO - Determining the desired PLAB size adjusts to the the number of threads at the wrong place
sangheon.kim at oracle.com
Fri Jun 5 22:34:43 UTC 2015
Please review this REDO change to determine the desired PLAB size for
current gc worker threads.
The reason for back out of previous
change(https://bugs.openjdk.java.net/browse/JDK-8073204) was it wouldn't
guarantee to be '>= PLAB minimum size'. So added MAX2(min_size(),) to
Currently we calculate an optimal PLAB size with current number of gc
When the number of workers changes dynamically
(-XX:+UseDynamicNumberOfGCThreads), the desired PLAB size returned(by
desired_plab_sz()) is still tuned to the number of gc workers that has
been used previously.
This change is, firstly calculate the desired PLAB value for a single gc
worker and then return desired PLAB size which is bigger(or equal) than
PLAB min size according to the current number of threads.
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