RFR (L): 8058354: SPECjvm2008-Derby -2.7% performance regression on Solaris-X64 starting with 9-b29

[Jon Masamitsu]

On 03/26/2015 08:11 AM, Thomas Schatzl wrote:
> Hi again,
>
> On Thu, 2015-03-26 at 09:47 +0100, Thomas Schatzl wrote:
>> Hi Jon,
>>
>> On Wed, 2015-03-25 at 20:47 -0700, Jon Masamitsu wrote:
>>> Thomas,
>>>
>>> Haven't gotten very far but let me send you one question.
>>>
>>> http://cr.openjdk.java.net/~tschatzl/8058354/webrev.2_to_3/src/share/vm/gc_implementation/g1/g1PageBasedVirtualSpace.cpp.frames.html
>>>
>>>>    157 void G1PageBasedVirtualSpace::commit_tail() {
>>>>    158   char* const aligned_end_address = (char*)align_ptr_down(_high_boundary, _page_size);
>>>>    159   size_t const tail_size = pointer_delta(_high_boundary, aligned_end_address, sizeof(char));
>>> Should there be a check that tail_size is not 0 before attempting to
>>> commit it?
>>    commit_tail() can only be called if is_last_page_partial() is true,
>> i.e. tail_size > 0. I can add an assert for that.
> Here's a change with that assert added.
>
> Full webrev:
> http://cr.openjdk.java.net/~tschatzl/8058354/webrev.4/
> Diff:
> http://cr.openjdk.java.net/~tschatzl/8058354/webrev.3_to_4/
> top-level changes:
> http://cr.openjdk.java.net/~tschatzl/8058354/webrev.hs-gc.1/ (there were
> no changes in it for months, just for completeness)

Thanks.

Jon

>
> Testing: another jprt round
>
> Thanks a lot,
>    Thomas
>
>