java - 使用 jmap 查找当前堆大小

Question

我想知道某个时间 Java 进程使用的总堆大小是多少，我必须使用 jmap .

jmap -heap <pid> 的输出给了我这样的东西:

Attaching to process ID 2899, please wait...Debugger attached successfully.             Server compiler detected.                   JVM version is 14.2-b01                     using thread-local object allocation.Parallel GC with 2 thread(s)         Heap Configuration:   MinHeapFreeRatio = 40   MaxHeapFreeRatio = 70   MaxHeapSize      = 1258291200 (1200.0MB)   NewSize          = 1048576 (1.0MB)         MaxNewSize       = 4294901760 (4095.9375MB)   OldSize          = 4194304 (4.0MB)            NewRatio         = 8                          SurvivorRatio    = 8                          PermSize         = 16777216 (16.0MB)          MaxPermSize      = 67108864 (64.0MB)       Heap Usage:PS Young GenerationEden Space:           capacity = 119013376 (113.5MB)   used     = 117277608 (111.84464263916016MB)   free     = 1735768 (1.6553573608398438MB)   98.54153536489882% usedFrom Space:   capacity = 131072 (0.125MB)   used     = 81920 (0.078125MB)   free     = 49152 (0.046875MB)   62.5% usedTo Space:   capacity = 131072 (0.125MB)   used     = 0 (0.0MB)   free     = 131072 (0.125MB)   0.0% usedPS Old Generation   capacity = 954466304 (910.25MB)   used     = 80791792 (77.04905700683594MB)   free     = 873674512 (833.2009429931641MB)   8.46460390077846% usedPS Perm Generation   capacity = 57671680 (55.0MB)   used     = 41699008 (39.76727294921875MB)   free     = 15972672 (15.23272705078125MB)   72.30413263494319% used

我可以使用这些值的公式来找出使用的总内存吗？

欢迎其他关于如何在 Linux 上找到此问题的建议，但 jmap比他们更受欢迎。

谢谢

Answer 1

如果您尝试与显示“总堆使用量”的主窗口比较像 jconsole 或 jvisualvm 之类的东西，我发现通过添加“已用伊甸园空间”和 'used ps old generation space' 我得到了与前面提到的程序中的图表相同的内容——这就是我现在倾向于继续的内容。