RFR (S): 8153170: Card Live Data does not correctly handle eager reclaim

Kim Barrett kim.barrett at oracle.com
Thu Apr 14 15:09:20 UTC 2016


> On Apr 14, 2016, at 6:08 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> 
> On Thu, 2016-04-14 at 00:31 -0400, Kim Barrett wrote:
>> My one concern is that I'm having trouble figuring out when a heap
>> region might have reset_gc_time_stamp called on it.  Can that happen
>> in such a way that it would interfere with the use of the time_stamp
>> being added by these changes?  I will continue to study, but maybe 
>> you already know and can provide guidance.
> 
> I do not think so.
> 
> Global reset_gc_time_stamp() (reset_gc_time_stamp() called on
> G1CollectedHeap and all regions) is called during full gc (which aborts
> getting live data anyway), and at the end of the cleanup pause, after
> finalizing live data.
> 
> So the reset of the gc time stamps should be safe and not interfere
> with this use.

Thanks, that agrees with / confirms what I was coming up with.

> New webrevs at
> http://cr.openjdk.java.net/~tschatzl/8153170/webrev.0_to_1/ (diff)
> http://cr.openjdk.java.net/~tschatzl/8153170/webrev.1/ (full)

Looks good.



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