RFR: 8062943: REDO - Parallelize clearing the next mark bitmap

[Thomas Schatzl]

Hi,

On Thu, 2014-11-06 at 15:53 +0100, Marcus Larsson wrote:
> Hi,
> 
> Can I have some reviews for the following re-do patch to parallelize 
> clearing of the next mark bitmap [1].
> 
> The previous patch would cause some asserts in 
> HeapRegionManager::par_iterate() to fail because iteration was happening 
> concurrently with humongous heap region reclamation. These asserts are 
> invalid if iteration is performed concurrently.
> 
> With this updated patch I add a concurrent flag to the par_iterate() 
> function that when set causes iteration to ignore the humongous status 
> of heap regions, and simply iterate over regions one-by-one.

The change looks good. Thanks for updating the comment to the
"concurrent" parameter after giving me a first look.

Thanks,
  Thomas