May 2025 - hotspot-jfr-dev

Re: RFR: 8352251: Implement Cooperative JFR Sampling [v17]
by Markus Grönlund 11 May '25

11 May '25

> Greetings, > > This is the implementation of JEP [JDK-8350338 Cooperative JFR Sampling](https://bugs.openjdk.org/browse/JDK-8350338). > > Implementations in this change set are provided and have been tested on the following platforms: > > - windows-x64 > - windows-x64-debug > - linux-x64 > - linux-x64-debug > - macosx-x64 > - macosx-x64-debug > - linux-aarch64 > - linux-aarch64-debug > - macosx-aarch64 > - macosx-aarch64-debug > > Testing: tier1-6, jdk_jfr, stress testing. > > Platform porters note: > Some platform-specific code needs to be provided, mainly in the interpreter. Take a look at the following files for changes: > > - src/hotspot/cpu/x86/frame_x86.cpp > - src/hotspot/cpu/x86/interp_masm_x86.cpp > - src/hotspot/cpu/x86/interp_masm_x86.hpp > - src/hotspot/cpu/x86/javaFrameAnchor_x86.hpp > - src/hotspot/cpu/x86/macroAssembler_x86.cpp > - src/hotspot/cpu/x86/macroAssembler_x86.hpp > - src/hotspot/cpu/x86/templateInterpreterGenerator_x86.cpp > - src/hotspot/cpu/x86/templateTable_x86.cpp > - src/hotspot/os_cpu/linux_x86/javaThread_linux_x86.hpp > > Thanks > Markus Markus Grönlund has updated the pull request incrementally with one additional commit since the last revision: 8350338: the minimal arm32 support ------------- Changes: - all: https://git.openjdk.org/jdk/pull/24296/files - new: https://git.openjdk.org/jdk/pull/24296/files/e448090e..42288d36 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=24296&range=16 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24296&range=15-16 Stats: 101 lines in 3 files changed: 93 ins; 5 del; 3 mod Patch: https://git.openjdk.org/jdk/pull/24296.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/24296/head:pull/24296 PR: https://git.openjdk.org/jdk/pull/24296

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New candidate JEP: 518: JFR Cooperative Sampling
by Mark Reinhold 09 May '25

09 May '25

https://openjdk.org/jeps/518 Summary: Improve the stability of the JDK Flight Recorder (JFR) when it asynchronously samples Java thread stacks. Achieve this by walking call stacks only at safepoints, while minimizing safepoint bias. - Mark

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RFR: 8345500: Timeout in jdk.jfr.api.consumer.streaming.TestJVMCrash
by Gerard Ziemski 09 May '25

09 May '25

In this fix we add 1 second delay after we create a process. On macOS we seem to be creating a process so quickly, that other threads need time to see it. ------------- Commit messages: - allow process to be visible by other threads Changes: https://git.openjdk.org/jdk/pull/23163/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23163&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8345500 Stats: 11 lines in 1 file changed: 11 ins; 0 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/23163.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/23163/head:pull/23163 PR: https://git.openjdk.org/jdk/pull/23163

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Re: RFR: 8352251: Implement Cooperative JFR Sampling [v14]
by Markus Grönlund 05 May '25

05 May '25

> Greetings, > > This is the implementation of JEP [JDK-8350338 Cooperative JFR Sampling](https://bugs.openjdk.org/browse/JDK-8350338). > > Implementations in this change set are provided and have been tested on the following platforms: > > - windows-x64 > - windows-x64-debug > - linux-x64 > - linux-x64-debug > - macosx-x64 > - macosx-x64-debug > - linux-aarch64 > - linux-aarch64-debug > - macosx-aarch64 > - macosx-aarch64-debug > > Testing: tier1-6, jdk_jfr, stress testing. > > Platform porters note: > Some platform-specific code needs to be provided, mainly in the interpreter. Take a look at the following files for changes: > > - src/hotspot/cpu/x86/frame_x86.cpp > - src/hotspot/cpu/x86/interp_masm_x86.cpp > - src/hotspot/cpu/x86/interp_masm_x86.hpp > - src/hotspot/cpu/x86/javaFrameAnchor_x86.hpp > - src/hotspot/cpu/x86/macroAssembler_x86.cpp > - src/hotspot/cpu/x86/macroAssembler_x86.hpp > - src/hotspot/cpu/x86/templateInterpreterGenerator_x86.cpp > - src/hotspot/cpu/x86/templateTable_x86.cpp > - src/hotspot/os_cpu/linux_x86/javaThread_linux_x86.hpp > > Thanks > Markus Markus Grönlund has updated the pull request incrementally with one additional commit since the last revision: include guards ------------- Changes: - all: https://git.openjdk.org/jdk/pull/24296/files - new: https://git.openjdk.org/jdk/pull/24296/files/ed57ed9f..c65bc8b6 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=24296&range=13 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24296&range=12-13 Stats: 57 lines in 4 files changed: 10 ins; 47 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/24296.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/24296/head:pull/24296 PR: https://git.openjdk.org/jdk/pull/24296

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Re: RFR: 8352251: Implement Cooperative JFR Sampling [v15]
by Markus Grönlund 05 May '25

05 May '25

> Greetings, > > This is the implementation of JEP [JDK-8350338 Cooperative JFR Sampling](https://bugs.openjdk.org/browse/JDK-8350338). > > Implementations in this change set are provided and have been tested on the following platforms: > > - windows-x64 > - windows-x64-debug > - linux-x64 > - linux-x64-debug > - macosx-x64 > - macosx-x64-debug > - linux-aarch64 > - linux-aarch64-debug > - macosx-aarch64 > - macosx-aarch64-debug > > Testing: tier1-6, jdk_jfr, stress testing. > > Platform porters note: > Some platform-specific code needs to be provided, mainly in the interpreter. Take a look at the following files for changes: > > - src/hotspot/cpu/x86/frame_x86.cpp > - src/hotspot/cpu/x86/interp_masm_x86.cpp > - src/hotspot/cpu/x86/interp_masm_x86.hpp > - src/hotspot/cpu/x86/javaFrameAnchor_x86.hpp > - src/hotspot/cpu/x86/macroAssembler_x86.cpp > - src/hotspot/cpu/x86/macroAssembler_x86.hpp > - src/hotspot/cpu/x86/templateInterpreterGenerator_x86.cpp > - src/hotspot/cpu/x86/templateTable_x86.cpp > - src/hotspot/os_cpu/linux_x86/javaThread_linux_x86.hpp > > Thanks > Markus Markus Grönlund has updated the pull request incrementally with one additional commit since the last revision: Configuration and test for jdk.SafepointLatency event ------------- Changes: - all: https://git.openjdk.org/jdk/pull/24296/files - new: https://git.openjdk.org/jdk/pull/24296/files/c65bc8b6..b0f9c5e5 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=24296&range=14 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24296&range=13-14 Stats: 82 lines in 4 files changed: 79 ins; 0 del; 3 mod Patch: https://git.openjdk.org/jdk/pull/24296.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/24296/head:pull/24296 PR: https://git.openjdk.org/jdk/pull/24296

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