September 2024 - hotspot-jfr-dev

RFR: 8340969: jdk/jfr/startupargs/TestStartDuration.java should be marked as flagless
by Leonid Mesnik 06 Dec '24

06 Dec '24

Test jdk/jfr/startupargs/TestStartDuration.java checks duration, the time might be too small for stress options like Xcomp. So it makes sense to mark it as flaglesss. ------------- Commit messages: - 8340969: jdk/jfr/startupargs/TestStartDuration.java should be marked as flagless Changes: https://git.openjdk.org/jdk/pull/21237/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21237&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8340969 Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/21237.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21237/head:pull/21237 PR: https://git.openjdk.org/jdk/pull/21237

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RFR: 8279016: JFR Leak Profiler is broken with Shenandoah
by Aleksey Shipilev 06 Nov '24

06 Nov '24

While testing unrelated Shenandoah patch, I caught a GC assert when Leak Profiler was running ([JDK-8337194](https://bugs.openjdk.org/browse/JDK-8337194)) Leak Profiler is notorious in using the mark words for its own needs. We have been trying to mitigate its impact on GCs by moving to separate bitsets for tracking marked objects, or by treating "marked without fwdptr" as "JFR marked" and handling it. But this is not reliable, since things like [putting indexes in mark word](https://github.com/openjdk/jdk/blob/3baff2af6a30cc6cb2e0d4391db1cf7e6… sneak in. This is okay for Leak Profiler alone, since it restores the mark words after the operation completes, but that is still not enough when GC is already running. I say we side-step this whack-a-mole by cleanly bailing from JFR op, when we know it is unsafe to do. I thought to use `VM_Operation::doit_prologue`, but I think GC start may sneak in between checking in prologue and op start. This realistically only affects Shenandoah. All other STW collectors would never see what Leak Profiler did with mark words. ZGC would not see it, since it does not care about mark words for its own operation. Additional testing: - [x] `jdk/jfr/event/oldobject/` pass by default (100x times) - [x] `jdk/jfr/event/oldobject/` pass with `-XX:+UseShenandoah` (100x) ------------- Commit messages: - Fix Changes: https://git.openjdk.org/jdk/pull/20328/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20328&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8279016 Stats: 29 lines in 4 files changed: 29 ins; 0 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/20328.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/20328/head:pull/20328 PR: https://git.openjdk.org/jdk/pull/20328

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RFR: 8341131: Some jdk/jfr/event/compiler tests shouldn't be executed with Xcomp
by Leonid Mesnik 08 Oct '24

08 Oct '24

Few jdk/jfr/event/compiler tests sensitive to compile flags and shouldn't be executed with Xcomp. ------------- Commit messages: - fixed requires. Changes: https://git.openjdk.org/jdk/pull/21239/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21239&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8341131 Stats: 5 lines in 3 files changed: 0 ins; 0 del; 5 mod Patch: https://git.openjdk.org/jdk/pull/21239.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21239/head:pull/21239 PR: https://git.openjdk.org/jdk/pull/21239

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RFR: 8341199: Use ClassFile's new API loadConstant(int)
by Shaojin Wen 30 Sep '24

30 Sep '24

The new API loadConstant(int) can shorten the calling path and can replace ldc when the parameter is of int/Integer type. ------------- Commit messages: - use loadConstant instead of ldc Changes: https://git.openjdk.org/jdk/pull/21259/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21259&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8341199 Stats: 9 lines in 4 files changed: 0 ins; 0 del; 9 mod Patch: https://git.openjdk.org/jdk/pull/21259.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21259/head:pull/21259 PR: https://git.openjdk.org/jdk/pull/21259

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RFR: 8340364: JFR: Fix up Class mirror after event retransformation
by Aleksey Shipilev 30 Sep '24

30 Sep '24

See the bug description for details. I am trying to come up with a small regression test for it, please look at the fix meanwhile. Additional testing: - [x] Original Shenandoah verifier reproducer no longer crashes - [x] Linux x86_64 server fastdebug, `jdk_jfr` - [x] Linux x86_64 server fastdebug, `hotspot_gc_shenandoah` ------------- Commit messages: - Fix Changes: https://git.openjdk.org/jdk/pull/21054/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21054&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8340364 Stats: 4 lines in 1 file changed: 4 ins; 0 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/21054.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21054/head:pull/21054 PR: https://git.openjdk.org/jdk/pull/21054

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RFR: 8338405: JFR: Use FILE type for dcmds
by Sonia Zaldana Calles 24 Sep '24

24 Sep '24

Hi all, This PR addresses [8338405](https://bugs.openjdk.org/browse/JDK-8338405) switching `STRING` to `FILE` for JFR.start, JFR.stop and JFR.dump where appropriate. This is consistent with the new `FILE` type that was introduced in [8334492](https://bugs.openjdk.org/browse/JDK-8334492). Testing: - [x] JFR test suite passes - [x] GHA Thanks, Sonia ------------- Commit messages: - 8338405: JFR: Use FILE type for dcmds Changes: https://git.openjdk.org/jdk/pull/21025/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21025&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8338405 Stats: 96 lines in 5 files changed: 48 ins; 38 del; 10 mod Patch: https://git.openjdk.org/jdk/pull/21025.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21025/head:pull/21025 PR: https://git.openjdk.org/jdk/pull/21025

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RFR: 8340233: Missed ThreadWXEnable in jfrNativeLibraryLoadEvent.cpp
by Leonid Mesnik 18 Sep '24

18 Sep '24

The bug is reproduced and fix verified by running java/lang/ClassLoader/loadLibraryUnload/LoadLibraryUnloadTest.java with JFR enabled. ------------- Commit messages: - fix Changes: https://git.openjdk.org/jdk/pull/21028/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21028&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8340233 Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/21028.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21028/head:pull/21028 PR: https://git.openjdk.org/jdk/pull/21028

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RFR: 8340113: Remove JULONG as a Diagnostic Command argument type (jcmd JFR.view)
by Kevin Walls 18 Sep '24

18 Sep '24

The few uses of the operation parameter type "JULONG" in Diagnostic Commands should be changed to INT. ------------- Commit messages: - Merge remote-tracking branch 'upstream/master' into 8340113_JULONG - 8340113: Remove JULONG as a Diagnostic Command argument type (jcmd JFR.view) Changes: https://git.openjdk.org/jdk/pull/21021/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21021&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8340113 Stats: 13 lines in 4 files changed: 0 ins; 0 del; 13 mod Patch: https://git.openjdk.org/jdk/pull/21021.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21021/head:pull/21021 PR: https://git.openjdk.org/jdk/pull/21021

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RFR: 8339486: JFR: Modernize
by Erik Gahlin 04 Sep '24

04 Sep '24

Could I have a review of a PR that leverages the Duration::until method introduced in JDK 23. Testing: jdk/jdk/jfr Thanks Erik ------------- Commit messages: - Initial Changes: https://git.openjdk.org/jdk/pull/20792/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20792&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8339486 Stats: 17 lines in 9 files changed: 0 ins; 0 del; 17 mod Patch: https://git.openjdk.org/jdk/pull/20792.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/20792/head:pull/20792 PR: https://git.openjdk.org/jdk/pull/20792

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