RFR(S): JDK-8028093 - Initial young size is smaller than minimum young size
bengt.rutisson at oracle.com
Mon Nov 11 11:56:59 UTC 2013
On 2013-11-11 12:03, Jesper Wilhelmsson wrote:
> The intention of the min_gen1_size argument is to make sure there is
> space left in the heap for the old generation. The minimum size of the
> old generation is _min_gen1_size in both cases. In the current code
> you can see that the argument I want to remove is called min_gen1_size
> and the code expects to be called with _min_gen1_size at all times.
> This was also the case before the fix for JDK-8016309, so this bug was
> actually introduced by the collector policy cleanup.
It does not look like the intent of adjust_gen0_sizes() is to always use
min_gen1_size. It just has badly named parameters.
To me, adjust_gen0_sizes() looks like it takes three values, gen0_size,
gen1_size and heap_size, and then adjusts them if they don't match. It's
odd that it would also adjust for the min_gen1_size in all cases. That
should be done separately.
> Bengt Rutisson skrev 11/11/13 10:32 AM:
>> Hi Jesper,
>> This looks wrong to me.
>> adjust_gen0_sizes() is first called with the min values to adjust
>> them. Then
>> called with the initial values to adjust them. With your suggested
>> change we
>> suddenly mix min and initial values when we adjust. That seems very
>> strange to me.
>> If the issue is that the min and initial values don't match I think
>> we should
>> add a third step where we explicitly adjust them to match. Something
>> adjust_gen0_sizes(&_min_gen0_size, &_min_gen1_size, _min_heap_byte_size,
>> adjust_gen0_sizes(&_initial_gen0_size, &_initial_gen1_size,
>> _initial_heap_byte_size, _initial_gen1_size);
>> On 2013-11-10 00:17, Jesper Wilhelmsson wrote:
>>> Can I have a couple of reviews of this small bugfix.
>>> Bug JDK-8028093: https://bugs.openjdk.java.net/browse/JDK-8028093
>>> The problem is that
>>> TwoGenerationCollectorPolicy::adjust_gen0_sizes() is
>>> called with the wrong argument in one place. The last argument
>>> should always
>>> be the value of _min_gen1_size, but in one call it is the
>>> Since these variables are class local I see no reason to take
>>> as an argument at all. Apparently it is error prone. The proposed
>>> fix is
>>> therefore to remove the argument and use _min_gen1_size directly in
>>> Webrev: http://cr.openjdk.java.net/~jwilhelm/8028093/webrev/
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