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Enhancement
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Resolution: Fixed
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P4
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7u4
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b07
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generic
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generic
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Not verified
Issue | Fix Version | Assignee | Priority | Status | Resolution | Resolved In Build |
---|---|---|---|---|---|---|
JDK-2218988 | 8 | John Cuthbertson | P4 | Resolved | Fixed | b18 |
JDK-2219032 | 7u4 | John Cuthbertson | P4 | Closed | Fixed | b05 |
While running a workload that was designed to see how the GC performs when the heap occupancy was at 60% of capacity, there were several *long* evacuation pauses where the major contributor to the duration of the pause was "Other" time.
During the workload run (which was for a 26Gb heap, 18 GC workers), "Other" times of ~1800ms were not uncommon. The crucial pattern was that these lonbg pauses were always seen during marking cycles.
An investigation indicated that the main culprit was the "complete_marking_in_collection_set" closure, and this was confirmed with some changes to the PrintGCDetails output. The reason why this code was taking so long is that it is current purely a serial iteration over the collection set.
Since this code will be going away when the changes foir 6888336 are implemented, it has been decided that a quick fix would be to parallelize the existing serial code.
During the workload run (which was for a 26Gb heap, 18 GC workers), "Other" times of ~1800ms were not uncommon. The crucial pattern was that these lonbg pauses were always seen during marking cycles.
An investigation indicated that the main culprit was the "complete_marking_in_collection_set" closure, and this was confirmed with some changes to the PrintGCDetails output. The reason why this code was taking so long is that it is current purely a serial iteration over the collection set.
Since this code will be going away when the changes foir 6888336 are implemented, it has been decided that a quick fix would be to parallelize the existing serial code.
- backported by
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JDK-2218988 G1: Reduce overhead of marking closure during evacuation pauses
- Resolved
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JDK-2219032 G1: Reduce overhead of marking closure during evacuation pauses
- Closed
- relates to
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JDK-6888336 G1: avoid explicitly marking and pushing objects in survivor spaces
- Closed