8340547: Starting many threads can delay safepoints #1365
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This backport pull request has now been updated with issue from the original commit. |
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src/hotspot/share/prims/jvm.cpp
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| @@ -2955,9 +2955,10 @@ JVM_ENTRY(void, JVM_StartThread(JNIEnv* env, jobject jthread)) | |||
| // We must release the Threads_lock before we can post a jvmti event | |||
| // in Thread::start. | |||
| { | |||
| MutexLocker throttle_ml(UseThreadsLockThrottleLock ? ThreadsLockThrottle_lock : NULL); | |||
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Should be nullptr, right?
olivergillespie
approved these changes
Jan 28, 2025
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I'd like to backport this fix to fix the issue with starting a lot of threads in a burst. Some users found this to be a barrier to migrating from JDK8.
The backport is not clean as required to adjust
globals.hppand replaceConditionalMutexLockerwith classicMutexLocker. Original fix and discussion are hereTested with
tier1and reproducers from JDK-8340547, JDK-8307970Progress
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gitCheckout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/1365/head:pull/1365$ git checkout pull/1365Update a local copy of the PR:
$ git checkout pull/1365$ git pull https://git.openjdk.org/jdk21u-dev.git pull/1365/headUsing Skara CLI tools
Checkout this PR locally:
$ git pr checkout 1365View PR using the GUI difftool:
$ git pr show -t 1365Using diff file
Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/1365.diff
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