RFR (M) JDK-8025305 Cleanup CardTableModRefBS usage in G1

Mikael Gerdin mikael.gerdin at oracle.com
Thu Sep 26 04:50:30 PDT 2013


Bengt,

On 09/26/2013 01:39 PM, Bengt Rutisson wrote:
>
> Hi Mikael,
>
> Nice cleanup! Looks good!

thanks for the review.

/Mikael

>
> Bengt
>
>
> On 9/24/13 3:57 PM, Mikael Gerdin wrote:
>> Hi all!
>>
>> In preparation for fixing 8014555 (the bug discussed in the "G1
>> question: concurrent cleaning of dirty cards" thread) I'd like to
>> clean up the CardTableModRefBS-code slightly.
>>
>> Summary of change:
>> * Move some g1 specific functions from CardTableModRefBS to the G1
>> specific variant. I did not change the numeric CardValues. I'm afraid
>> to change the last_reserved value since other GCs seem to depend on
>> which bits are available below it.
>> * Change the setup code for G1 to make sure that the BarrierSet is of
>> the one G1 actually requires.
>> * Remove the ModRefBarrierSet* from G1CollectedHeap (it's always the
>> same as CollectedHeap::_barrier_set)
>> * Add an accessor which performs a down-cast of
>> CollectedHeap::_barrier_set to G1SATBCardTableModRefBS.
>> * Modify G1 code which uses the *claimed or *deferred card values to
>> use the type G1SATBCardTableModRefBS.
>> * Remove the unused function CardTableModRefBS::claim_card (last usage
>> was removed in "6923991: G1: improve scalability of RSet scanning"
>> (rev 0414c1049f15)
>>
>> Webrev: http://cr.openjdk.java.net/~mgerdin/8025305/webrev.0/
>> Bug link: https://bugs.openjdk.java.net/browse/JDK-8025305
>>
>> /Mikael
>



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