See an excellent article by Dianne Hackborn at:

Supported values for libc.debug.malloc (debug level values) are:

procrank source is included in system/extras/procrank,jjj.com, and the binary is located in /system/xbin on an android device.

If the system property libc.debug.malloc has a value other than 0, then when a process is instantiated,30ok登陆器, the C library uses functions for allocating and freeing memory, for that process.

Dalvik Heap

Debugging Android application memory usage

See

procrank

(Note that there are other ways that the debug shared library malloc code ends up being used as well. That is, if you are running in the emulator, and the value of the system property ro.kernel.memcheck is not '0', then you get a debug level of 20. Note that debug level 20 can only be used in the emulator.)

(Information was obtained by looking at <android-source-root>/bionic/libc/bionic/malloc_debug_common.c)

System Memory

The Dalvik heap is preloaded with classes and data by zygote (loading over 1900 classes as of Android version 2.2). When zygote forks to start an android application, the new application gets a copy-on-write mapping of this heap. As Dan Borstein says below, this helps with memory reduction as well as application startup time.

I'm not sure whether these shared libraries are shipped in production devices.

smem tool

You can examine the system's view of the memory on the machine, by examining /proc/meminfo.

to the overall memory load.

How to debug native process memory allocations

Here's a screenshot:

Here is procrank's usage:

The memory of an Android system is managed by several different allocators, in several different pools.

procrank will show you a quick summary of process memory utilization. By default, it shows Vss, Rss, Pss and Uss, and sorts by Vss. However, you can control the sorting order.

Details about memory usage are in

Process Memory

In general, the two numbers you want to watch are the Pss and Uss (Vss and Rss are generally worthless, because they don't accurately reflect a process's usage of pages shared with other processes.)

By default, the standard malloc/free/calloc/realloc/memalign routines are used. By setting libc.debug.malloc, different routines are used, which check for certain kinds of memory errors (such as leaks and overruns). This is done by loading a separate shared library (.so) with these different routines.

# procrank  PID      Vss      Rss      Pss      Uss  cmdline 1217   36848K   35648K   17983K   13956K  system_server 1276   32200K   32200K   14048K   10116K  android.process.acore 1189   26920K   26920K    9293K    5500K  zygote 1321   20328K   20328K    4743K    2344K  android.process.media 1356   20360K   20360K    4621K    2148K  com.android.email 1303   20184K   20184K    4381K    1724K  com.android.settings 1271   19888K   19888K    4297K    1764K  com.android.inputmethod.latin 1332   19560K   19560K    3993K    1620K  com.android.alarmclock 1187    5068K    5068K    2119K    1476K  /system/bin/mediaserver 1384     436K     436K     248K     236K  procrank    1     212K     212K     200K     200K  /init  753     572K     572K     171K     136K  /system/bin/rild  748     340K     340K     163K     152K  /system/bin/sh  751     388K     388K     156K     140K  /system/bin/vold 1215     148K     148K     136K     136K  /sbin/adbd  757     352K     352K     117K      92K  /system/bin/dbus-daemon  760     404K     404K     104K      80K  /system/bin/keystore  759     312K     312K     102K      88K  /system/bin/installd  749     288K     288K      96K      84K  /system/bin/servicemanager  752     244K     244K      71K      60K  /system/bin/debuggerd

In this example, it shows that the native daemons and programs are an order of magnitude smaller than the Dalvik-based services and programs. Also, even the smallest Dalvik program requires about 1.5 meg (Uss) to run.

The shared libraries are named: /system/lib/libc_malloc_debug_leak.so and /system/lib/libc_malloc_debug_qemu.so

The 'top' command will show VSS and RSS.

If you use 'ddms', you can see a summary of the memory used on the machine, by the system and by the different executing processes. Click on the SysInfo tab, and select "Memory Usage" in the box on the upper left of the pane.

Note that you can get the numbers for each process by hovering your mouse over a particular pie slice. Numbers are shown in K and percentages.

You can see very detailed per-process or systemwide memory information with smem.

[INFO NEEDED: how to show dalvik heap info?]

Dan Borstein said this about heap sharing:

# procrank -hUsage: procrank [ -W ] [ -v  -r  -p  -u  -h ]    -v  Sort by VSS.    -r  Sort by RSS.    -p  Sort by PSS.    -u  Sort by USS.        (Default sort order is PSS.)    -R  Reverse sort order (default is descending).    -w  Display statistics for working set only.    -W  Reset working set of all processes.    -h  Display this help screen.

And here is some sample output: