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ZGC memory size without unit check

See original GitHub issue

I find gctoolkit get the raw memory size in ZGCParser.java without the unit check. I think the line liked markStart[index] = trace.getLongGroup(2); should change to markStart[index] = trace.getMemoryInKBytes(2); . However, the lowest heap size of ZGC is 2MB，is the Mb will more suitable than the Kb？

Issue Analytics

State:
Created 2 years ago
Comments:9 (3 by maintainers)

Top GitHub Comments

1reaction

ZhangShushu123commented, Jan 7, 2022

Sure. The log fragment is shown as below @kirk-microsoft .


[2021-12-28T11:32:31.233+0800][7.846s][info][gc,start    ] GC(5) Garbage Collection (Proactive)
[2021-12-28T11:32:31.234+0800][7.846s][info][gc,phases   ] GC(5) Pause Mark Start 0.082ms
[2021-12-28T11:32:31.239+0800][7.852s][info][gc,phases   ] GC(5) Concurrent Mark 5.045ms
[2021-12-28T11:32:31.239+0800][7.852s][info][gc,phases   ] GC(5) Pause Mark End 0.456ms
[2021-12-28T11:32:31.240+0800][7.852s][info][gc,phases   ] GC(5) Concurrent Process Non-Strong References 0.234ms
[2021-12-28T11:32:31.240+0800][7.852s][info][gc,phases   ] GC(5) Concurrent Reset Relocation Set 0.006ms
[2021-12-28T11:32:31.243+0800][7.856s][info][gc,phases   ] GC(5) Concurrent Select Relocation Set 3.428ms
[2021-12-28T11:32:31.243+0800][7.856s][info][gc,phases   ] GC(5) Pause Relocate Start 0.087ms
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,phases   ] GC(5) Concurrent Relocate 1.660ms
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,load     ] GC(5) Load: 0.46/0.96/1.09
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,mmu      ] GC(5) MMU: 2ms/65.3%, 5ms/86.1%, 10ms/91.9%, 20ms/94.3%, 50ms/97.7%, 100ms/98.9%
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,marking  ] GC(5) Mark: 4 stripe(s), 3 proactive flush(es), 1 terminate flush(es), 1 completion(s), 0 continuation(s) 
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,reloc    ] GC(5) Relocation: Successful, 0M relocated
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,nmethod  ] GC(5) NMethods: 10 registered, 0 unregistered
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,metaspace] GC(5) Metaspace: 4M used, 4M capacity, 4M committed, 8M reserved
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,ref      ] GC(5) Soft: 3 encountered, 0 discovered, 0 enqueued
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,ref      ] GC(5) Weak: 10 encountered, 5 discovered, 0 enqueued
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,ref      ] GC(5) Final: 2780 encountered, 1780 discovered, 1780 enqueued
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,ref      ] GC(5) Phantom: 6 encountered, 4 discovered, 0 enqueued
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5) Min Capacity: 8M(0%)
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5) Max Capacity: 2048M(100%)
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5) Soft Max Capacity: 2048M(100%)
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5)                Mark Start          Mark End        Relocate Start      Relocate End           High               Low         
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5)  Capacity:      772M (38%)         772M (38%)         772M (38%)         772M (38%)         772M (38%)         772M (38%)    
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5)   Reserve:       62M (3%)           62M (3%)           62M (3%)           62M (3%)           62M (3%)           62M (3%)     
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5)      Free:     1334M (65%)        1332M (65%)        1586M (77%)        1592M (78%)        1592M (78%)        1332M (65%)    
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5)      Used:      652M (32%)         654M (32%)         400M (20%)         394M (19%)         654M (32%)         394M (19%)    
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5)      Live:         -               348M (17%)         348M (17%)         348M (17%)            -                  -          
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5) Allocated:         -                 2M (0%)            4M (0%)           22M (1%)             -                  -          
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5)   Garbage:         -               303M (15%)          47M (2%)           41M (2%)             -                  -          
[2021-12-28T11:32:31.245+0800][7.858s][info][gc,heap     ] GC(5) Reclaimed:         -                  -               256M (12%)         262M (13%)            -                  -          
[2021-12-28T11:32:31.245+0800][7.858s][info][gc          ] GC(5) Garbage Collection (Proactive) 652M(32%)->394M(19%)

Fragment 772M (38%) is the reason that I suggest the line liked markStart[index] = trace.getLongGroup(2); should change to markStart[index] = trace.getMemoryInKBytes(2); .

1reaction

kariannacommented, Jan 6, 2022

@kirk-microsoft So it sounds like if KBytes are assumed everywhere that the code doesn’t need to change?

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