Frequent Garbage Collection in AOSP MM

[ptes...@gmail.com]

Hello, Android-Platform Group Users.

I have a question about garbage collection, so please help me.

When I tested AOSP Marshmallow and the test is very simple.

After launch calculator app, finish the app by touching back key.

I repeated that scenario.

At that time, garbage collection log is occured every time as below.

=====================================================================================================================================================

2751	05-12	12:01:21.358	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 12634(862KB) AllocSpace objects, 0(0B) LOS objects, 79% free, 1049KB/5MB, paused 468us total 34.062ms
2768	05-12	12:01:21.378	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 3231(207KB) AllocSpace objects, 0(0B) LOS objects, 82% free, 842KB/4MB, paused 306us total 19.507ms
2792	05-12	12:01:21.396	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 6(208B) AllocSpace objects, 0(0B) LOS objects, 82% free, 841KB/4MB, paused 318us total 16.160ms
4288	05-12	12:01:22.687	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 2505(144KB) AllocSpace objects, 0(0B) LOS objects, 79% free, 1044KB/5MB, paused 143us total 27.607ms
4355	05-12	12:01:22.705	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 3079(202KB) AllocSpace objects, 0(0B) LOS objects, 82% free, 842KB/4MB, paused 366us total 16.321ms
4372	05-12	12:01:22.725	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 6(208B) AllocSpace objects, 0(0B) LOS objects, 82% free, 842KB/4MB, paused 344us total 19.871ms
5890	05-12	12:01:23.856	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 2480(142KB) AllocSpace objects, 0(0B) LOS objects, 79% free, 1042KB/5MB, paused 267us total 23.160ms
5957	05-12	12:01:23.874	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 3057(200KB) AllocSpace objects, 0(0B) LOS objects, 82% free, 842KB/4MB, paused 298us total 16.076ms
5974	05-12	12:01:23.893	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 6(208B) AllocSpace objects, 0(0B) LOS objects, 82% free, 841KB/4MB, paused 284us total 18.807ms
7524	05-12	12:01:25.225	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 2505(144KB) AllocSpace objects, 0(0B) LOS objects, 79% free, 1044KB/5MB, paused 292us total 23.224ms
7587	05-12	12:01:25.242	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 3079(202KB) AllocSpace objects, 0(0B) LOS objects, 82% free, 842KB/4MB, paused 353us total 15.760ms
7617	05-12	12:01:25.260	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 3(96B) AllocSpace objects, 0(0B) LOS objects, 82% free, 842KB/4MB, paused 291us total 17.051ms
9140	05-12	12:01:26.561	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 2480(142KB) AllocSpace objects, 0(0B) LOS objects, 79% free, 1042KB/5MB, paused 310us total 20.125ms
9207	05-12	12:01:26.583	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 3060(200KB) AllocSpace objects, 0(0B) LOS objects, 82% free, 842KB/4MB, paused 1.796ms total 20.473ms
9238	05-12	12:01:26.601	I	6273	6273	art		: Explicit concurrent mark sweep GC freed 3(96B) AllocSpace objects, 0(0B) LOS objects, 82% free, 842KB/4MB, paused 295us total 17.561ms

=====================================================================================================================================================

Changing dalvik heap property ( dalvik.vm.heaputilization / dalvik.vm.heapminfree / dalvik.vm.heapmaxfree ) I tested, but that log is reduced little.

Even if free memory is enough ( 1.8GB ( Cached + Kernel Cached + Free Mem ) ), I think that garbage collection operation is too much.

Do you know the reason and wouldn't it be better to reduce garbage collection?

If you know anything about that, please let me know.

Thanks and Regards.