[jdk23u] RFR: 8333716: Shenandoah: Check for disarmed method before taking the nmethod lock

[Neethu Prasad]

On Tue, 25 Jun 2024 18:44:03 GMT, Neethu Prasad <nprasad at openjdk.org> wrote:

> Backport of [JDK-8333716](https://bugs.openjdk.org/browse/JDK-8333716).
> Change has already been backported to 21 and 17.
> 
> **Testing**
> 1. hotspot_gc tests
> 
> 2. Benchmarking on [c6a.12xlarge](https://aws.amazon.com/ec2/instance-types/c6a/)
> Prior to PR:
> 
> dev-dsk-neethp-jdk-2c-ad54955c % jdk23u/build/linux-x86_64-server-release/images/jdk/bin/java -Xmx1g -Xms1g -XX:+UseShenandoahGC -Xlog:gc ManyThreadsStacks.java 2>&1 | grep "marking roots"
> [0.666s][info][gc] GC(0) Concurrent marking roots 70.709ms
> [0.769s][info][gc] GC(1) Concurrent marking roots 77.658ms
> [0.876s][info][gc] GC(2) Concurrent marking roots 86.840ms
> [0.966s][info][gc] GC(3) Concurrent marking roots 72.479ms
> [1.066s][info][gc] GC(4) Concurrent marking roots 82.360ms
> [1.272s][info][gc] GC(5) Concurrent marking roots 76.854ms
> [1.403s][info][gc] GC(6) Concurrent marking roots 81.824ms
> [1.541s][info][gc] GC(7) Concurrent marking roots 83.342ms
> [1.686s][info][gc] GC(8) Concurrent marking roots 89.838ms
> [1.849s][info][gc] GC(9) Concurrent marking roots 88.486ms
> [2.001s][info][gc] GC(10) Concurrent marking roots 78.584ms
> [2.143s][info][gc] GC(11) Concurrent marking roots 85.297ms
> [2.280s][info][gc] GC(12) Concurrent marking roots 78.562ms
> [2.409s][info][gc] GC(13) Concurrent marking roots 78.005ms
> [2.543s][info][gc] GC(14) Concurrent marking roots 77.846ms
> [2.682s][info][gc] GC(15) Concurrent marking roots 88.989ms
> [2.816s][info][gc] GC(16) Concurrent marking roots 81.305ms
> [2.954s][info][gc] GC(17) Concurrent marking roots 73.452ms
> [3.084s][info][gc] GC(18) Concurrent marking roots 71.614ms
> 
> 
> 
> After PR:
> 
> 
> dev-dsk-neethp-jdk-2c-ad54955c % jdk23u/build/linux-x86_64-server-release/images/jdk/bin/java -Xmx1g -Xms1g -XX:+UseShenandoahGC -Xlog:gc ManyThreadsStacks.java 2>&1 | grep "marking roots"
> [0.620s][info][gc] GC(0) Concurrent marking roots 5.057ms
> [0.645s][info][gc] GC(1) Concurrent marking roots 3.123ms
> [0.669s][info][gc] GC(2) Concurrent marking roots 3.256ms
> [0.690s][info][gc] GC(3) Concurrent marking roots 2.654ms
> [0.712s][info][gc] GC(4) Concurrent marking roots 2.518ms
> [0.944s][info][gc] GC(5) Concurrent marking roots 3.363ms
> [1.016s][info][gc] GC(6) Concurrent marking roots 2.768ms
> [1.085s][info][gc] GC(7) Concurrent marking roots 2.461ms
> [1.154s][info][gc] GC(8) Concurrent marking roots 2.800ms
> [1.224s][info][gc] GC(9) Concurrent marking roots 3.097ms
> [1.295s][info][gc] GC(10) Concurrent marking roots 2.878ms
> [1.365s][info][gc] GC(11) Concurrent marking roots 2.745ms
> [1.436s][info][gc] GC(12) Co...

Thanks for review & approval.

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PR Comment: https://git.openjdk.org/jdk23u/pull/9#issuecomment-2194720700