Output may look like this:

[GC (Allocation Failure) 243779K->175288K(253440K), 0.0232570 secs]
[GC (Allocation Failure) , 0.0831990 secs]
[Full GC (Allocation Failure) 253440K->118630K(253440K), 0.2981190 secs]

The second GC got a promotion failure and did not print the heap change information.

This is due to the DefNew code not printing the size information when a promotion failure occurs.

In DefNewGeneration::collect() we have this code:

  if (!_promotion_failed) {
    ...
    gch->print_heap_change(gch_prev_used);
    ...
  } else {
    ...
  }

Impact=Low, just a logging issue
Likelihood=Medium, will happen for every promotion failure with DefNew if logging is enabled
Workaround=Low, Can get the information from PrintHeapAtGC

ILW=LML -> P5