understanding dumpsys meminfo

Question

I have two questions.

1. In dumpsys meminfo , there is one number called Local Binders . What does it mean? Is it simply a kind of native pointer? And in which cases would this number increase? I have observed that the app or even the emulator would crash when this number increased to about 1000.

2. In the memory usage section, there are three columns: native , dalvik , and total , and total=native+dalvik . So why are the two parts ( native and dalvik ) added together? Isn't dalvik heap referring to the Java heap, which should be part of the data section of the Unix process?

Answer 1

1. I think local binder is a binder service, such as framework will create an ApplicationThread which is a binder service, when process fork from zygote.

Every time process create a binder service, the number increase.

What's more, binder will need binder buffer which allocated in kernel space, while kernel space is very valuable for system, So, too many binder service mayby cause some trouble.

2. native heap is for c/c++ use, when you call malloc, new . dalvik heap is for java use, it is managed by dalvik(GC ?) vm, when you call new to create java object

Answer 2

通过阅读其dumpsys可以最好地理解dumpsys的输出。