I have long been stuck in this problem without any hint. Would really appreciate if someone could help.
I am running a Java application on a device with an ARM v7 processor. Ubuntu is installed on it. Memory usage when browsing using the "top" or "free -m" commands is about 180 MB, which is much more than the methods Runtime.freeMemory and others tell me.
This is how I start my application:
java -Xcheck: jni -XX: MaxPermSize = 25m -Xmx65m -XX: ReservedCodeCacheSize = 10m -jar MyAPP.jar myconfig.xml
As I understand it, the total memory usage of this process should not cross 25 + 65 + 10 = 100 MB. It could be a little bigger (other heap-free spaces that I don't know about). But even then I do not think that the difference should be like that (80 MB).
This is what the “Runtime” commands seem to tell me in my logs (I use these commands to print usage information as part of my debug logs).
Usage Information: Avaialable processor: 2 Free memory for JVM: 8474344, Current memory: 5943576, Maximum JVM memory allowed to use: 66977792
Exit from the "top":
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3926 linaro 20 0 266m 188m 3636 S 1.0 21.1 0:37.81 java
Exiting "free -m":
When starting the Java process:
total used free shared buffers cached
Mem: 893 842 51 0 40 216
-/+ buffers/cache: 585 308
Swap: 0 0 0
When the process is stopped:
total used free shared buffers cached
Mem: 893 656 237 0 40 216
-/+ buffers/cache: 400 493
Swap: 0 0 0
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-Sandeep