Home/ Questions/Q 9155959
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-17T12:41:14+00:00

Possible Duplicate: How to set the maximum memory usage for JVM? I am running

  • 0

Possible Duplicate:
How to set the maximum memory usage for JVM?

I am running a java program but when the memory usage reaches 26.1%, it does not increase any more and the program gets very slow.

What could be the problem? Does java have a limit of memory usage? or is there a limit of memory per app on linux?

java version “1.7.0_11”
Java(TM) SE Runtime Environment (build 1.7.0_11-b21)
Java HotSpot(TM) 64-Bit Server VM (build 23.6-b04, mixed mode)

Tasks: 126 total,   1 running, 125 sleeping,   0 stopped,   0 zombie
Cpu(s): 97.5%us,  0.4%sy,  0.0%ni,  2.1%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:  33018800k total,  9522548k used, 23496252k free,    12100k buffers
Swap: 32764528k total,        0k used, 32764528k free,   391812k cached
  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 3463 wonn24    20   0 8769m 8.2g 9.8m S 391.3 26.1 257:09.24 java
 3725 hong8e    20   0 14876 1148  872 R  0.3  0.0   0:01.81 top
    1 root      20   0  4088  972  720 S  0.0  0.0   0:00.71 init
    2 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 kthreadd
    3 root      RT  -5     0    0    0 S  0.0  0.0   0:00.17 migration/0
    4 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/0
    5 root      RT  -5     0    0    0 S  0.0  0.0   0:00.00 watchdog/0
    6 root      RT  -5     0    0    0 S  0.0  0.0   0:00.15 migration/1
    7 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/1
Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    By default, the server version of Java has a maximum heap size of 1/4 of the main memory. With a little overhead of libraries and thread stacks this could easily be 26 or 27% of main memory.

    When your JVM starts to fill up, it takes lower to perform a GC, and the lower free memory means it also occurs more often (so really bad) Ideally, you actual usage might as low as 40% of your maximum size. In your case you actual usage could be at least 7 GB.

    I suggest you try increasing your maximum heap size to at least 16 GB, possibly 24 GB if you can spare the memory. i.e. -Xmx16g or -Xmx24g

    • 0