Flood of GC_CONCURRENT freed messages, not my app

Question

I'm getting a flood of GC_CONCURRENT freed messages in LogCat and they are not coming from my own app (I force closed my app to be sure). The memory freed is very consistent (about 1430K) and it occurs about 6 times per second.

How can I troubleshoot this?

It's interfering with my app development because it floods LogCat and forces valuable log statements out of the buffer and also causes LogCat to "jiggle" because the session filter jumps up and down one line each time a GC_CONCURRENT event occurs.

The phone is a Motorola Atrix 2 running Android 2.3.5. I use the phone for development only so it has almost no additional apps than the stock bloatware from AT&T.

11-14 10:50:14.117: D/dalvikvm(724): GC_CONCURRENT freed 1426K, 52% free 4712K/9671K, external 2357K/2773K, paused 3ms+3ms
11-14 10:50:14.273: D/dalvikvm(724): GC_CONCURRENT freed 1426K, 52% free 4714K/9671K, external 2357K/2773K, paused 2ms+3ms
11-14 10:50:14.429: D/dalvikvm(724): GC_CONCURRENT freed 1431K, 52% free 4712K/9671K, external 2357K/2773K, paused 2ms+3ms
11-14 10:50:14.585: D/dalvikvm(724): GC_CONCURRENT freed 1426K, 52% free 4714K/9671K, external 2357K/2773K, paused 2ms+3ms
11-14 10:50:14.742: D/dalvikvm(724): GC_CONCURRENT freed 1428K, 52% free 4714K/9671K, external 2357K/2773K, paused 2ms+3ms
11-14 10:50:14.898: D/dalvikvm(724): GC_CONCURRENT freed 1430K, 52% free 4713K/9671K, external 2357K/2773K, paused 2ms+3ms
11-14 10:50:15.054: D/dalvikvm(724): GC_CONCURRENT freed 1427K, 52% free 4714K/9671K, external 2357K/2773K, paused 2ms+3ms
11-14 10:50:15.210: D/dalvikvm(724): GC_CONCURRENT freed 1432K, 52% free 4711K/9671K, external 2357K/2773K, paused 2ms+3ms
11-14 10:50:15.367: D/dalvikvm(724): GC_CONCURRENT freed 1426K, 52% free 4712K/9671K, external 2357K/2773K, paused 3ms+2ms
11-14 10:50:15.523: D/dalvikvm(724): GC_CONCURRENT freed 1426K, 52% free 4714K/9671K, external 2357K/2773K, paused 2ms+3ms
11-14 10:50:15.679: D/dalvikvm(724): GC_CONCURRENT freed 1432K, 52% free 4711K/9671K, external 2357K/2773K, paused 3ms+3ms
11-14 10:50:15.835: D/dalvikvm(724): GC_CONCURRENT freed 1426K, 52% free 4712K/9671K, external 2357K/2773K, paused 3ms+2ms
11-14 10:50:15.992: D/dalvikvm(724): GC_CONCURRENT freed 1426K, 52% free 4714K/9671K, external 2357K/2773K, paused 2ms+2ms
11-14 10:50:16.148: D/dalvikvm(724): GC_CONCURRENT freed 1429K, 52% free 4713K/9671K, external 2357K/2773K, paused 3ms+3ms
11-14 10:50:16.304: D/dalvikvm(724): GC_CONCURRENT freed 1429K, 52% free 4712K/9671K, external 2357K/2773K, paused 3ms+3ms
11-14 10:50:16.460: D/dalvikvm(724): GC_CONCURRENT freed 1426K, 52% free 4714K/9671K, external 2357K/2773K, paused 2ms+3ms
11-14 10:50:16.617: D/dalvikvm(724): GC_CONCURRENT freed 1430K, 52% free 4713K/9671K, external 2357K/2773K, paused 3ms+3ms
11-14 10:50:16.773: D/dalvikvm(724): GC_CONCURRENT freed 1429K, 52% free 4712K/9671K, external 2357K/2773K, paused 3ms+3ms
11-14 10:50:16.929: D/dalvikvm(724): GC_CONCURRENT freed 1426K, 52% free 4714K/9671K, external 2357K/2773K, paused 3ms+3ms

Answer 1

The process ID is shown in the message (in the above, it's pid 724). You can use adb shell ps to get the Linux process dump; find the entry for pid 724 to see which app it is.

Alternatively, if you're on a developer device, within Eclipse/ADT/DDMS you can open the "Devices" view and see all processes. Select the app with the matching pid (second column), then open the "Threads" view. This shows all the threads in the app. Look for a thread with high values in the "utime" and "stime" columns. If you double-click on it a few times, you will see snapshots of the stack trace that might suggest what's causing all the GCs.