Android Memory Analysis tool-LogCat GC

D/DALVIKVM: <GC_Reason> <amount_freed>,
One, Gc_reason triggers the collection of garbage collection reasons:

type	Description
Gc_concurrent	When memory usage is full, concurrent garbage collection occurs.
Gc_for_malloc	Garbage collection is triggered when a memory full application tries to allocate memory, so the system stops the app from being garbage collected
Gc_hprof_dump_heap	Garbage collection is triggered when the Hprof file is created to parse memory.
Gc_explicit	Show garbage collection, for example when you call GC () (should avoid calling, but be referred to the system for processing)
Gc_external_alloc	Will only be triggered in the following versions of API 10. The new version will only be allocated on the Dalvik heap.

Second, Amount freed the size of the recovered memory

Iii. Heap stats free memory ratio and (total number of active objects/memory size)

Iv. External Memory Stats API 10 size

The greater the pause time, the longer the heap pauses, two pauses are displayed: One is the start time of the collection and the other is the end time of the collection


Example: D/DALVIKVM (27235): Gc_for_alloc freed 836K, 27% free 9653k/13116k, paused 101ms, total 104ms

Log Information	Description
Freed 836K	This recycling 836K
27% Free	Free memory Space 27%
9653k/13116k	Active objects and total size specifically refer to
Paused 101ms	Time to suspend garbage collection 101ms
Total 104ms	Total Elapsed Time 104ms

　
Other external 0k/0k, which represents the total amount of available external memory/external memory paused 2ms+2ms, the first time value represents the time of Markrootset, and the second time value represents the time of the second mark. If the trigger reason is not gc_concurrent, this behavior is a single time value that represents the time-consuming period of garbage collection.
Can be filtered by "gc_" keyword + TAG two in Logcat

Reference: Https://developer.android.com/tools/debugging/debugging-memory.html#LogMessages

Android Memory Analysis tool-LogCat GC