A did a quick test and, interestingly, my fix for this bug does not seem to be affecting how often marking cycles happen (i.e., two runs, one with and one without the fix, do the same number of marking cycles and those cycles are similarly spaced apart). It actually makes sense, as in both cases, the marking cycle is initiated when the used space in the heap is over a given limit. However, in the run without the fix, some of the space that is free, resides in several half-full regions that we might not be able to allocate from Whereas, in the run with the fix, the space that is free resides in more totally empty regions. So, the latter case has less of a chance of getting a concurrent marking failure (as there's actually more free space available for allocation). So, the fix is still worth incorporating.