RFR (S): 8049341: Parallelize clearing the next mark bitmap

[Mikael Gerdin]

Hi Marcus,

On 2014-09-01 09:43, Marcus Larsson wrote:
> Hi again,
>
> Updated the changeset to a more recent version, with changes suggested
> by Mikael.
>
> Webrev:
> http://cr.openjdk.java.net/~mgerdin/mlarsson/webrev-8049341v2/

Sorry for being picky, but please align the parameters to 
heap_region_par_iterate_chunked. I don't need to re-review that, let's 
just fix it before pushing.

Otherwise it looks good.
/Mikael

>
> Marcus
>
> On 08/28/2014 01:06 PM, Marcus Larsson wrote:
>> Hi,
>>
>> I would like reviews for the following patch to parallelize the
>> clearing of the next mark bitmap in G1.
>>
>> Short summary:
>> The heap is divided into as many parts as there are workers and each
>> worker will clear its corresponding part of the bitmap. Workers will
>> join the suspendible thread set instead of the concurrent mark thread
>> to properly allow them to yield during clearing work. Added support
>> for applying heap region closures to a specific part of the heap.
>> SPECjbb2013 shows a slight performance gain with this change (4%,
>> using 4 concurrent threads).
>>
>> Webrev:
>> http://cr.openjdk.java.net/~brutisso/webrev-8049341/
>>
>> Bug:
>> https://bugs.openjdk.java.net/browse/JDK-8049341
>>
>> Testing:
>> jprt, SPECjbb2013, SPECjbb2005, SPECjvm2008
>>
>> Thanks,
>> Marcus
>