There are some debug info in our gc log.

[2025-02-11T10:23:12.379+0800][31569][info   ][safepoint   ] Safepoint "ZMarkStart", Time since last: 408281252 ns, Reaching safepoint: 164391 ns, Cleanup: 5919 ns, At safepoint: 88609 ns, Total: 258919 ns 
[2025-02-11T10:23:13.768+0800][31935][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed5b00ab, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.772+0800][31741][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed15a359, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.775+0800][31741][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed50490c, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.776+0800][31741][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed502bcd, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.777+0800][31741][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed0f4411, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.779+0800][32217][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed34aae4, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.779+0800][32371][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed2405de, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.781+0800][31741][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed502bcd, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.781+0800][32228][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed69a73b, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.782+0800][31545][info   ][gc,phases   ] GC(28) Concurrent Mark 1402.808ms

JVM parameters:

-Xms30G -Xmx30G -Xmn20g -server -Xss256K -XX:SurvivorRatio=8 -XX:-OmitStackTraceInFastThrow -XX:MaxDirectMemorySize=256G -DPreloadBufferPool.MaxMemory=70% -Dioty.maxDirectMemory=10474836480 -DPreloadBufferPool.WritePageExtraWeightMs=86400000 -XX:+UseZGC  -XX:+PrintGCDetails --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED --add-opens=java.base/java.nio=ALL-UNNAMED --add-opens=java.base/jdk.internal.ref=ALL-UNNAMED --add-opens=java.base/jdk.internal.misc=ALL-UNNAMED -Xlog:safepoint=trace,classhisto*=trace,age*=info,gc*=info:file=/export/Logs/jmq4-server/gc-%t.log:time,level,tid,tags:filesize=500M -XX:ZAllocationSpikeTolerance=3 -XX:ZCollectionInterval=60 -XX:+UnlockDiagnosticVMOptions -XX:+LogVMOutput -XX:-ZProactive -XX:MaxMetaspaceSize=10G -DasmEnable=false

Does this log have any impact?

I tried modify the gc parameters, these logs still exist.

There are some debug info in our gc log.

[2025-02-11T10:23:12.379+0800][31569][info   ][safepoint   ] Safepoint "ZMarkStart", Time since last: 408281252 ns, Reaching safepoint: 164391 ns, Cleanup: 5919 ns, At safepoint: 88609 ns, Total: 258919 ns 
[2025-02-11T10:23:13.768+0800][31935][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed5b00ab, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.772+0800][31741][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed15a359, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.775+0800][31741][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed50490c, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.776+0800][31741][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed502bcd, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.777+0800][31741][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed0f4411, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.779+0800][32217][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed34aae4, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.779+0800][32371][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed2405de, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.781+0800][31741][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed502bcd, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.781+0800][32228][debug  ][safepoint   ] ... found polling page loop exception at pc = 0x00007fdfed69a73b, stub =0x00007fdfec845300 
[2025-02-11T10:23:13.782+0800][31545][info   ][gc,phases   ] GC(28) Concurrent Mark 1402.808ms

JVM parameters:

-Xms30G -Xmx30G -Xmn20g -server -Xss256K -XX:SurvivorRatio=8 -XX:-OmitStackTraceInFastThrow -XX:MaxDirectMemorySize=256G -DPreloadBufferPool.MaxMemory=70% -Dioty.maxDirectMemory=10474836480 -DPreloadBufferPool.WritePageExtraWeightMs=86400000 -XX:+UseZGC  -XX:+PrintGCDetails --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED --add-opens=java.base/java.nio=ALL-UNNAMED --add-opens=java.base/jdk.internal.ref=ALL-UNNAMED --add-opens=java.base/jdk.internal.misc=ALL-UNNAMED -Xlog:safepoint=trace,classhisto*=trace,age*=info,gc*=info:file=/export/Logs/jmq4-server/gc-%t.log:time,level,tid,tags:filesize=500M -XX:ZAllocationSpikeTolerance=3 -XX:ZCollectionInterval=60 -XX:+UnlockDiagnosticVMOptions -XX:+LogVMOutput -XX:-ZProactive -XX:MaxMetaspaceSize=10G -DasmEnable=false

Does this log have any impact?

I tried modify the gc parameters, these logs still exist.

• java
• zgc

Share Improve this question Follow asked Feb 11 at 12:57 zhuduohuizhuduohui 133 bronze badges 0

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1 Answer 1

Sorted by: Reset to default 0

I tried modify the gc parameters, these logs still exist.

You're explicitly telling it to log those things.

-Xlog:safepoint=trace