On Mon, 18 Nov 2024 20:56:27 GMT, Leonid Mesnik <lmes...@openjdk.org> wrote:
>> Hi >> Could you please review the the fix that add locks information into SA jhsdb >> stack --mixed output. >> >> Here is the motivation for this rfe and explanation why I add it into SA now. >> >> The information about current owners of Hotspot Mutex is often very useful >> for dealock investigations. >> >> The jcmd usually doesn't work because VM can't reach or exit safepoints. So >> it doesn't respond to jcmd. >> >> The SA 'jstack --mixed' provides information about stacktraces on Java and >> non-Java Threads. So having information about locks along with stack traces >> might significantly help to identify issues. >> >> The gdb allows to provide stacktraces, but the debug symbols are required to >> get info about locks. These symbols are often absent during execution. >> Also the debugger solution is OS specifc. >> >> The significant part of fix is refacotorrng of mutex_array to be vmStructs >> compatible. >> >> The adding support of non-JavaThreads into SA might be implemented later to >> obtain more info about their names. >> The example of output: >> >> [2024-11-06T21:32:48.897414435Z] Gathering output for process 1620563 >> Attaching to process ID 1620533, please wait... >> Debugger attached successfully. >> Server compiler detected. >> JVM version is 24-internal-adhoc.lmesnik.open >> Deadlock Detection: >> >> No deadlocks found. >> >> Internal VM Mutex Threads_lock is owned by Unknnown thread (Might be >> non-Java Thread) with address: 0x00007f8cf825b190 >> Internal VM Mutex Compile_lock is owned by LockerThread with address: >> 0x00007f8cf8309a00 >> ----------------- 1620559 ----------------- >> "C1 CompilerThread4" https://github.com/openjdk/jdk/pull/28 daemon prio=9 >> tid=0x00007f8c300566a0 nid=1620559 runnable [0x0000000000000000] >> java.lang.Thread.State: RUNNABLE >> JavaThread state: _thread_blocked >> 0x00007f8cff11e88d syscall + 0x1d >> 0x00007f8cfe6c99de LinuxWaitBarrier::wait(int) + 0x8e >> 0x00007f8cfe2be409 SafepointMechanism::process(JavaThread*, bool, bool) + >> 0x79 >> 0x00007f8cfd53ea91 ThreadInVMfromNative::ThreadInVMfromNative(JavaThread*) + >> 0xc1 >> 0x00007f8cfd534a00 ciEnv::cache_jvmti_state() + 0x30 >> 0x00007f8cfd679614 CompileBroker::invoke_compiler_on_method(CompileTask*) + >> 0x204 >> 0x00007f8cfd67adc8 CompileBroker::compiler_thread_loop() + 0x5c8 >> 0x00007f8cfdb4426c JavaThread::thread_main_inner() + 0xcc >> 0x00007f8cfe5a0bbe Thread::call_run() + 0xbe >> 0x00007f8cfe16813b thread_native_entry(Thread*) + 0x12b >> ..... >> ----------------- 1620554 ----------------- >> "LockerThread" https://... > > Leonid Mesnik has updated the pull request incrementally with one additional > commit since the last revision: > > tests using osthread fixed Thanks for updates. svc folk will need to do actual Review though. ------------- PR Review: https://git.openjdk.org/jdk/pull/22171#pullrequestreview-2444494159
