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Bug ID: JDK-7098085 G1: partially-young GCs not initiated under certain circumstances
JDK-7098085 : G1: partially-young GCs not initiated under certain circumstances

Details
Type:
Bug
Submit Date:
2011-10-05
Status:
Closed
Updated Date:
2013-10-04
Project Name:
JDK
Resolved Date:
2012-01-23
Component:
hotspot
OS:
generic
Sub-Component:
gc
CPU:
generic
Priority:
P3
Resolution:
Fixed
Affected Versions:
hs23
Fixed Versions:
hs23 (b03)

Related Reports
Backport:
Backport:

Sub Tasks

Description
It looks as if G1 does not always initiate partially-young GCs after a concurrent marking cycle. The flag that initiates partially-young GCs is _last_full_young_gc (it means: the next GC will be the last young GC and we'll do partially-young ones after that) and it's set in record_concurrent_mark_cleanup_completed(). This is called at the end of concurrent cleanup:

      // Check if cleanup set the free_regions_coming flag. If it
      // hasn't, we can just skip the next step.
      if (g1h->free_regions_coming()) {
        ...

        _sts.join();
        g1_policy->record_concurrent_mark_cleanup_completed();
        _sts.leave();
      }

Note, however, that unfortunately it's only called if free_regions_coming() is true, which is only true if cleanup found totally empty regions to reclaim.

Many thanks to Thomas Schatzl for bringing this up.

                                    

Comments
EVALUATION

See Description.
                                     
2011-10-05
EVALUATION

http://hg.openjdk.java.net/hsx/hotspot-gc/hotspot/rev/ec4b032a4977
                                     
2011-10-14
EVALUATION

See main CR
                                     
2011-10-28



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