RFR: 8378076: Improve inlining around oop_oop_iterate

[Thomas Schatzl]

On Tue, 17 Feb 2026 10:35:40 GMT, Ivan Walulya <iwalulya at openjdk.org> wrote:

> Please review this change to improve inlining around `oop_oop_iterate`. The change improves `Concurrent Mark From Roots` in BigRamTester (BRT) by ~15 - 20%.
> 
> Before:
> 
> [59.292s][info   ][gc,marking] GC(10) Concurrent Mark From Roots 5366.043ms
> [165.244s][info   ][gc,marking] GC(19) Concurrent Mark From Roots 5537.965ms
> [270.502s][info   ][gc,marking] GC(29) Concurrent Mark From Roots 5587.758ms
> [365.912s][info   ][gc,marking] GC(38) Concurrent Mark From Roots 5471.903ms
> [492.253s][info   ][gc,marking] GC(48) Concurrent Mark From Roots 5146.705ms
> 
> After:
> 
> [52.924s][info   ][gc,marking] GC(8) Concurrent Mark From Roots 4419.289ms
> [156.467s][info   ][gc,marking] GC(17) Concurrent Mark From Roots 4540.361ms
> [263.955s][info   ][gc,marking] GC(27) Concurrent Mark From Roots 4630.036ms
> [361.794s][info   ][gc,marking] GC(36) Concurrent Mark From Roots 4780.361ms
> [483.695s][info   ][gc,marking] GC(46) Concurrent Mark From Roots 4480.253ms
> 
> 
> For the BigArrayScanTest attached to [JDK-8057003](https://bugs.openjdk.org/browse/JDK-8057003):
> 
> Before:
> 
> [0.033s][info ][gc,marking] GC(1) Concurrent Mark From Roots 2.759ms
> [6.983s][info ][gc,marking] GC(9) Concurrent Mark From Roots 3474.147ms
> [15.181s][info ][gc,marking] GC(29) Concurrent Mark From Roots 3405.123ms
> [22.045s][info ][gc,marking] GC(35) Concurrent Mark From Roots 3261.046ms
> [28.802s][info ][gc,marking] GC(41) Concurrent Mark From Roots 2714.513ms
> 
> 
> After:
> 
> [0.033s][info ][gc,marking] GC(1) Concurrent Mark From Roots 2.699ms
> [5.738s][info ][gc,marking] GC(9) Concurrent Mark From Roots 2345.396ms
> [12.808s][info ][gc,marking] GC(27) Concurrent Mark From Roots 3288.624ms
> [20.477s][info ][gc,marking] GC(34) Concurrent Mark From Roots 2604.406ms
> [27.397s][info ][gc,marking] GC(40) Concurrent Mark From Roots 2499.408ms
> 
> 
> Mach5 Testing: Tier 1-3

Marked as reviewed by tschatzl (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/29755#pullrequestreview-3818674852