RFR: 8311163: Parallel: Improve large object handling during evacuation

[Albert Mingkun Yang]

On Tue, 27 Aug 2024 00:16:10 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

> Please review this change to ParallelGC young generation collection's handling
> of large objArrays, to now use the infrastructure provided by JDK-8253237 and
> JDK-8337709.  (That's the same infrastructure used by G1 young/mixed
> collections.)
> 
> Testing: mach5 tier1-5

Using `-Xmx3g -XX:+UseParallelGC -XX:ParallelGCThreads=6 DelayInducer.java`, I can see large regression on my box (nproc=12). Have you seen sth similar?


# baseline
[0.002s][info][gc] Using Parallel
[1.252s][info][gc] GC(0) Pause Young (Allocation Failure) 381M->296M(479M) 50.696ms
[1.490s][info][gc] GC(1) Pause Young (Allocation Failure) 422M->422M(674M) 165.177ms
[1.864s][info][gc] GC(2) Pause Young (Allocation Failure) 673M->674M(925M) 212.106ms
[2.243s][info][gc] GC(3) Pause Young (Allocation Failure) 925M->925M(1428M) 229.982ms

# new
[0.005s][info][gc] Using Parallel
[5.504s][info][gc] GC(0) Pause Young (Allocation Failure) 381M->299M(479M) 203.409ms
[6.233s][info][gc] GC(1) Pause Young (Allocation Failure) 424M->425M(676M) 620.718ms
[7.594s][info][gc] GC(2) Pause Young (Allocation Failure) 676M->676M(928M) 1155.301ms
[8.920s][info][gc] GC(3) Pause Young (Allocation Failure) 927M->928M(1430M) 1119.259ms

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PR Comment: https://git.openjdk.org/jdk/pull/20720#issuecomment-2312131807