RFR: 8144040: UpdateRSetDeferred in G1EvacFailure will never visit survivor regions

[Thomas Schatzl]

Hi,

On Wed, 2015-11-25 at 15:39 +0100, Erik Helin wrote:
> Hi all,
> 
> this patch removes an unneeded check from UpdateRSetDeferred which is used in
> the case of an evacuation failure. When we start a GC with G1, we
> change the type of all survivor regions to eden (see the call to
> hr->set_eden_pre_gc() in G1CollectorPolicy::finalize_young_cset_part).
> Therefore, if we ever get an evac failure in a region, then that region
> must be either young or old. Therefore, we don't need to check for
> survivor regions in UpdateRSetDeferred.
> 
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8144040
> 
> Webrev:
> http://cr.openjdk.java.net/~ehelin/8144040/webrev.00/
> 
> Testing:
> - GC test suite with full verification

  looks good.

Thomas