RFR (S): 8011891: The vm/gc/heap/heap_summary_after_gc event for CMS contains old data

Bengt Rutisson bengt.rutisson at oracle.com
Tue May 14 08:27:58 UTC 2013


Hi Erik,

Looks good!

Bengt

On 5/9/13 12:16 PM, Erik Helin wrote:
> Hi all,
>
> this change makes sure that the data in 
> vm/gc/heap/heap_summary_after_gc trace event is up-to-date for CMS. 
> The bug happened when CMS got a concurrent mode failure and had not 
> reached the "Resizing" phase (in collect_in_background). The heap 
> summary data would then be the one collected in 
> CMSCollector::checkpointRootsInitialPre which by the time of 
> concurrent mode failure (or interrupt) could be quite old.
>
> The solution consists of collecting the heap summary in 
> CMSCollector::acquire_control_and_collect when checking if an 
> background collection failed (or was interrupted).
>
> Webrev:
> http://cr.openjdk.java.net/~ehelin/8011891/webrev.00/
>
> Bug:
> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8011891
>
> Thanks,
> Erik




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