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Type: Enhancement
Resolution: Fixed
Priority: P4
Fix Version/s: 12
Affects Version/s: None
Component/s: hotspot
Labels:
- gc-pending-review

Subcomponent:
gc
Introduced In Version:

1.3.1
Resolved In Build:
b09
CPU:

generic
OS:

generic

Recent posting to hotspot-gc-dev@openjdk.java.net shows very high JNI weak reference processing times, i.e. over 6 seconds during a parallel CMS remark.

Here is a GC log entry for a CMS Remark:
2015-02-03T03:24:27.419-0800: 17917.047: [Rescan (parallel) , 0.0625400 secs]2015-02-03T03:24:27.482-0800: 17917.110: [weak refs processing2015-02-03T03:24:27.482-0800: 17917.110: [SoftReference, 1 refs, 0.0010820 secs]2015-02-03T03:24:27.483-0800: 17917.111: [WeakReference, 0 refs, 0.0015340 secs]2015-02-03T03:24:27.484-0800: 17917.112: [FinalReference, 0 refs, 0.0007930 secs]2015-02-03T03:24:27.485-0800: 17917.113: [PhantomReference, 0 refs, 0.0008860 secs]2015-02-03T03:24:27.486-0800: 17917.114: [JNI Weak Reference, 6.1104040 secs], 6.1148360 secs]2015-02-03T03:24:33.596-0800: 17923.225: [scrub string table, 0.0006670 secs] [1 CMS-remark: 531682K(5242880K)] 1827698K(7759488K), 6.1785190 secs] [Times: user=7.22 sys=0.00, real=6.18 secs]

AFAIK, all HotSpot collectors (G1 GC, Parallel GC, CMS GC and Serial GC) are single threaded when it comes to processing JNI weak references even with -XX:+ParallelRefProcEnabled.
This enhancement request is for multi-threading the processing of JNI weak references.

blocks

JDK-8204505 Performance: jweak references not suitable for robust cache architecture

Resolved

JDK-8176454 Performance: jweak references not suitable for robust cache architecture

Closed

is blocked by

JDK-8200557 OopStorage parallel iteration scales poorly

Resolved

relates to

JDK-8235247 WorkerDataArray leaks C heap memory for associated work items

Resolved

JDK-8210164 building Minimal VM fails with error: comparison of unsigned expression < 0 is always false [-Werror=type-limits]

Closed

JDK-8202813 Move vm_weak processing from SystemDictionary to WeakProcessor

Resolved

JDK-8210100 ParallelGC should use parallel WeakProcessor

Resolved

JDK-8204505 Performance: jweak references not suitable for robust cache architecture

Resolved

JDK-8210131 vmTestbase/nsk/jvmti/scenarios/allocation/AP10/ap10t001/TestDescription.java failed with ObjectFree: GetCurrentThreadCpuTimerInfo returned unexpected error code

Resolved

JDK-8176454 Performance: jweak references not suitable for robust cache architecture

Closed

JDK-8043575 Dynamically parallelize reference processing work

Resolved

JDK-8194312 Support parallel and concurrent JNI global handle processing

Resolved

JDK-8210148 Minimal VM build has new warnings after JDK-8072498 (Multi-thread JNI weak reference processing)

Closed

(8 relates to)

Assignee:: Kim Barrett

Reporter:: Charlie Hunt

Votes:: 0 Vote for this issue

Watchers:: 4 Start watching this issue

Created:: 2015-02-04 12:45

Updated:: 2019-12-03 04:53

Resolved:: 2018-08-28 10:02

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