September 2022 - hotspot-jfr-dev

RFR: 8276125: RunThese24H.java SIGSEGV in JfrThreadGroup::thread_group_id
by Markus Grönlund 04 Jun '24

04 Jun '24

Greetings, please help review this changeset. Details are listed in the the JIRA issue. Testing: jdk_jfr Thanks Markus ------------- Commit messages: - 8276125 Changes: https://git.openjdk.java.net/jdk/pull/6702/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6702&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8276125 Stats: 6 lines in 1 file changed: 4 ins; 0 del; 2 mod Patch: https://git.openjdk.java.net/jdk/pull/6702.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/6702/head:pull/6702 PR: https://git.openjdk.java.net/jdk/pull/6702

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Re: RFR: 8280844: Epoch shift synchronization point for Compiler threads is inadequate [v2]
by Markus Grönlund 28 Feb '23

28 Feb '23

> Greetings, > > [JDK-8233111](https://bugs.openjdk.java.net/browse/JDK-8233111) attempted to address artefact tagging for Compiler threads, letting threads run _thread_in_native to avoid the transition. Unfortunately, that attempt proved inadequate. > > The epoch race is avoided only by performing the transition to _thread_in_vm. > > Testing: jdk_jfr > > Thanks > Markus Markus Grönlund has updated the pull request incrementally with one additional commit since the last revision: delegate assertion ------------- Changes: - all: https://git.openjdk.java.net/jdk/pull/8724/files - new: https://git.openjdk.java.net/jdk/pull/8724/files/9ce10130..b4e59b72 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8724&range=01 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8724&range=00-01 Stats: 3 lines in 1 file changed: 0 ins; 2 del; 1 mod Patch: https://git.openjdk.java.net/jdk/pull/8724.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/8724/head:pull/8724 PR: https://git.openjdk.java.net/jdk/pull/8724

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RFR: 8288783: JFR: Error messages are confusing when options conflict in -XX:StartFlightRecording
by Chihiro Ito 09 Feb '23

09 Feb '23

Could I have a review of PR that fixes incorrect error messages regarding of recording. The current message is very confusing. If a user types jcmd <pid> JFR.start name=abc name=def or java --XX:StartFlightRecording=name=abc,name=def, the error message says "Duplicates in diagnostic command arguments", but doesn't know what options are duplicated. Furthermore, if a user specifies two or three duplicate parameters, the same logs will be output. It should say follows, Option name can only be specified once with starting flight recording Options name and disk can only be specified once with starting flight recording Options name, disk and maxage can only be specified once with starting flight recording This problem affects --XX:StartFlightRecording, jcmd JFR.start, JFR.stop, JFR.dump, JFR.check, and MBean. For other than start, the output is as follows, (example of dump) Option name can only be specified once with dumping flight recording Testing: jdk/jdk/jfr Thanks Chihiro ------------- Commit messages: - modify whitespace from windows to linux - modify copyright - Modify log message and test case - JDK-8288783 Initial Changes: https://git.openjdk.org/jdk/pull/9302/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9302&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8288783 Stats: 442 lines in 10 files changed: 431 ins; 2 del; 9 mod Patch: https://git.openjdk.org/jdk/pull/9302.diff Fetch: git fetch https://git.openjdk.org/jdk pull/9302/head:pull/9302 PR: https://git.openjdk.org/jdk/pull/9302

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RFR: 8292177: InitialSecurityProperty JFR event
by Sean Coffey 18 Oct '22

18 Oct '22

New JFR event to record state of initial security properties. Debug output is also now added for these properties via -Djava.security.debug=properties ------------- Commit messages: - merge with master - Correct test bug ids - fix up imports - Add security debug test logic - Add JFR testcase - remove mirror event - 8292177 initial commit Changes: https://git.openjdk.org/jdk/pull/10394/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10394&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8292177 Stats: 200 lines in 11 files changed: 196 ins; 0 del; 4 mod Patch: https://git.openjdk.org/jdk/pull/10394.diff Fetch: git fetch https://git.openjdk.org/jdk pull/10394/head:pull/10394 PR: https://git.openjdk.org/jdk/pull/10394

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RFR: 8293864: Kitchensink24HStress.java fails with SIGSEGV in JfrCheckpointManager::lease
by Markus Grönlund 10 Oct '22

10 Oct '22

Greetings, With [JDK-8289692](https://bugs.openjdk.org/browse/JDK-8289692), a need arose to introduce a mutex mechanism for the buffers on the global list to prevent the JFR Recorder Thread from resetting buffers currently in use. The introduced mutex mechanism was adequate as far as preventing the race condition. However, its protective characteristic was overemphasized, leading to the mistake of introducing a release, or removal, operation onto a current epoch list, as part of periodic flushing. The problem is that although the callback operations are safe, the underlying list type used with the global mspace does not allow for concurrent excision of nodes. The crash occurs because a thread attempts to dereference the next pointer to traverse a node that is excised and deleted after the thread loaded it. I have reviewed how to handle better the introduction of virtual threads and their checkpoint data. I have concluded that the best way is to preserve the old system (pre-Loom) as much as possible, keeping the global and thread-local mspaces as before. Instead, an additional mspace dedicated solely to virtual threads is introduced. This categorization preserves the matching of operations against the underlying list infrastructure. It also provides flexibility in handling virtual threads distinct from regular, or "carrier", threads. The separate mspace of virtual threads is more dynamic as it does not need to preallocate buffers, a memory win for systems not using virtual threads. Also, the sizes of the different buffer types can be better controlled. With this restructuring, there are no longer any list concurrency issues; hence the mutex mechanism introduced with [JDK-8289692](https://bugs.openjdk.org/browse/JDK-8289692) becomes obsolete. Applying a release operation for the current epoch list, of the global mspace, as part of flushing is a broken invariant and is therefore removed. Testing: jdk_jfr, stress testing Thanks Markus ------------- Commit messages: - 8293864 Changes: https://git.openjdk.org/jdk/pull/10467/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10467&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8293864 Stats: 217 lines in 9 files changed: 100 ins; 33 del; 84 mod Patch: https://git.openjdk.org/jdk/pull/10467.diff Fetch: git fetch https://git.openjdk.org/jdk pull/10467/head:pull/10467 PR: https://git.openjdk.org/jdk/pull/10467

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RFR: 8294151: JFR: Unclear exception message when dumping stopped in memory recording
by Erik Gahlin 05 Oct '22

05 Oct '22

Hi Could I have a review of a change that updates the specification for the Recording::dump(Path) method and the exception message if the method fails. Testing: jdk/jdk/jfr Thanks Erik ------------- Commit messages: - Initial Changes: https://git.openjdk.org/jdk/pull/10488/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10488&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8294151 Stats: 48 lines in 4 files changed: 38 ins; 1 del; 9 mod Patch: https://git.openjdk.org/jdk/pull/10488.diff Fetch: git fetch https://git.openjdk.org/jdk pull/10488/head:pull/10488 PR: https://git.openjdk.org/jdk/pull/10488

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RFR: 8294242: JFR: jfr print doesn't handle infinite duration well
by Erik Gahlin 04 Oct '22

04 Oct '22

Hi, Could I have review of a fix that improves the output of the jfr tool when there are event values that are infinite Testing: jdk/jdk/jfr Thanks Erik ------------- Commit messages: - Initial Changes: https://git.openjdk.org/jdk/pull/10497/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10497&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8294242 Stats: 35 lines in 5 files changed: 30 ins; 0 del; 5 mod Patch: https://git.openjdk.org/jdk/pull/10497.diff Fetch: git fetch https://git.openjdk.org/jdk pull/10497/head:pull/10497 PR: https://git.openjdk.org/jdk/pull/10497

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RFR: 8293099: JFR: Typo in TestRemoteDump.java
by Erik Gahlin 03 Oct '22

03 Oct '22

Could I have a review of this test fix. Testing: jdk/jdk/jfr/jmx/TestRemoteDump.java Thanks Erik ------------- Commit messages: - Initial Changes: https://git.openjdk.org/jdk/pull/10509/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10509&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8293099 Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/10509.diff Fetch: git fetch https://git.openjdk.org/jdk pull/10509/head:pull/10509 PR: https://git.openjdk.org/jdk/pull/10509

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RFR: 8292336: JFR: Warn users if -XX:StartFlightRecording:disk=false is specified with maxage or maxsize
by Erik Gahlin 03 Oct '22

03 Oct '22

Hi, Could I have a review of PR that adds a warning message if maxage or maxsize is set when disk = false. Testing: jdk/jdk/jfr Thanks Erik ------------- Commit messages: - Initial Changes: https://git.openjdk.org/jdk/pull/10508/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10508&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8292336 Stats: 8 lines in 1 file changed: 8 ins; 0 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/10508.diff Fetch: git fetch https://git.openjdk.org/jdk pull/10508/head:pull/10508 PR: https://git.openjdk.org/jdk/pull/10508

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RFR: 8291428: JFR: 'jfr print' displays incorrect timestamps during DST
by Erik Gahlin 30 Sep '22

30 Sep '22

Could I have a review of change that fixes incorrect timestamp during DST. For details see issue. Testing: jdk/jdk/jfr Thanks Erik ------------- Commit messages: - Initial Changes: https://git.openjdk.org/jdk/pull/9666/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9666&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8291428 Stats: 18 lines in 5 files changed: 11 ins; 0 del; 7 mod Patch: https://git.openjdk.org/jdk/pull/9666.diff Fetch: git fetch https://git.openjdk.org/jdk pull/9666/head:pull/9666 PR: https://git.openjdk.org/jdk/pull/9666

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