Request for Review (s) - 7012980: PSOldGen is increased if there is no space in Metaspace

Jon Masamitsu jon.masamitsu at oracle.com
Wed Jul 8 16:05:20 UTC 2015


Tom,

Thanks for the review.

On 07/08/2015 07:17 AM, Tom Benson wrote:
> Hi Jon,
> Looks good to me as well.  One thing I noticed is that this will also 
> prevent growth when GC cause is _gc_locker, which I think would have 
> happened before.   I think that's OK, and possibly even good, since 
> the real reason for the GC is lost, but just noting that it is a 
> difference.

Yes, switching from a negative test to a positive test does
change the result.  I think it is OK because the intervals between
GC's due to _gc_locker is not directly related to the amount
of free space in the young gen.  At least not related in a simple
way and trying to include those intervals would not be consistent
with the way the statistics are used.

Jon

> Tom
>
> On 7/8/2015 6:59 AM, Thomas Schatzl wrote:
>> Hi Jon,
>>
>> On Thu, 2015-06-18 at 09:02 -0700, Jon Masamitsu wrote:
>>> A recent integration collided with my patch so I had to merge
>>> and redo the webrev.  Previously in addition to the fix there was
>>> a clean up that introduce a method is_system_gc().  The need
>>> for is_system_gc() was overridden by the already added
>>> is_user_requested_gc().
>>>
>>> New webrev
>>>
>>> http://cr.openjdk.java.net/~jmasa/7012980/webrev.02/
>>>
>>> Thanks.
>>    looks good.
>>
>> One minor nit I can see is the naming of "should_update_promo_stats" - I
>> am not sure why it is has "promo" in the name.
>>
>> The other, with the "eden" in the name can be immediately associated
>> with young gen, the other not so much imo.
>>
>> Maybe there is a better name of it, but maybe it fits because other
>> variables related to allocation in the old/tenured gen also have "promo"
>> in their name. So it is probably best to keep it for uniformity.
>>
>> Thanks,
>>    Thomas
>>
>>
>



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