RFR: 8027960: Assertion assert(end >= start) failed during nightly testing on solaris

Jon Masamitsu jon.masamitsu at oracle.com
Mon Nov 11 19:56:30 UTC 2013

On 11/11/13 5:23 AM, Stefan Johansson wrote:
> On 2013-11-11 10:02, Thomas Schatzl wrote:
>> Hi Jon,
>> On Fri, 2013-11-08 at 10:52 -0800, Jon Masamitsu wrote:
>>> Stefan,
>>> Change looks good.
> Thanks for looking at this.
>>> There are _gen_alignments and _space_alignments in CollectorPolicy.
>>> Where those are initialized there is no calculation of a new_alignment
>>> based on page size.  For example,
>>> void MarkSweepPolicy::initialize_alignments() {
>>>     _space_alignment = _gen_alignment = (uintx)Generation::GenGrain;
>>>     _heap_alignment = compute_heap_alignment();
>>> }
>>> Should those places be calculating and using a new_alignment?
>>    I am not completely sure what the question is, and whether Jesper's
>> reply already replied or not, but as far as I can tell the question
>> seems to be why the MarkSweepPolicy (for serial gc) does not take page
>> size into account for space and generation alignment.
>> As far as I know, only Parallel GC ever did that as it is also the only
>> collector that is NUMA aware, so I assume this is the reason why that
>> collector does. All collectors align the heap alignment to large page
>> size though if large pages are used.
>> Not really an answer, I know - but we can make an rfe/bug from it I
>> think.
>> Thomas
> Thanks Jesper and Thomas for your input on this. I agree that we might 
> want to look at having spaces and generations page-aligned for all 
> collectors.
> Jon, if you are satisfied with those answers I'll go ahead and get 
> this patch pushed.

Yes, go ahead and push.  My comments did not have direct bearing on
your changes (which are correct).


> Cheers,
> Stefan

More information about the hotspot-gc-dev mailing list