RFR(s): 8150362: G1 base elapsed time prediction is wrong because rs_length prediction is wrong (original) (raw)
sangheon sangheon.kim at oracle.com
Tue Mar 8 18:08:10 UTC 2016
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Hi all,
Could I have some reviews for this change?
We predict remembered set length as follows from G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards): size_t rs_length = predict_rs_length_diff();
This is incomplete and it is inconsistent when compare with the use case of the function from G1CollectorPolicy::calculate_young_list_target_length(). 'adj_rs_lengths = rs_lengths + predict_rs_length_diff()' In this case, we use rs_length + rs_length_diff.
I am proposing to use the sum of rs_length and rs_length_diff. i.e. 'rs length + rs length diff'.
CR: https://bugs.openjdk.java.net/browse/JDK-8150362 Webrev: http://cr.openjdk.java.net/~sangheki/8150362/webrev.00 Testing: JPRT, some performance tests showed no big difference.
Thanks, Sangheon
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