RFR: 8033923: Use BufferingOopClosure for G1 code root scanning
mikael.gerdin at oracle.com
Fri Feb 7 07:56:50 PST 2014
On Friday 07 February 2014 16.38.26 Stefan Karlsson wrote:
> On 2014-02-07 16:04, Mikael Gerdin wrote:
> > Stefan,
> > On Friday 07 February 2014 14.23.16 Stefan Karlsson wrote:
> >> Hi all,
> >> Please review this patch to use BufferingOopClosure for the code root
> >> scanning in G1.
> >> Webrev:
> >> http://cr.openjdk.java.net/~stefank/8033923/webrev.00
> > There is some time accounting in G1RemSet::scanRS
> > When you call buf_scan_non_heap_roots.done() in g1_process_strong_roots we
> > may miss accounting some of the time spent handling code roots from
> > regions.
> > I think you need to pass down the buf_scan_non_heap_roots closure all the
> > way down to ScanRSClousre::scan_strong_code_roots and construct the
> > CodeBlobToOopClosure there to be able to call .done() before the update of
> > _strong_code_root_scan_time_sec.
> > Alternatively you may be able to add the closure application time from
> > after the extraction of the "object copying" data to the scan_rs
> > phase_time after the done()-call.
> OK. I see what you mean.
> I should probably only use the BufferingOopClosure for the
> process_strong_roots call, and use a non-buffering
> OopClosure/CodeBlobToOopClosure pair for the oops_into_collection_set_do
I'm fine with that as well.
> > /Mikael
> >> RFE:
> >> https://bugs.openjdk.java.net/browse/JDK-8033923
> >> The patch builds upon the changes in:
> >> RFR: 8033764: Remove the usage of StarTask from BufferingOopClosure
> >> mail.openjdk.java.net/pipermail/hotspot-gc-dev/2014-February/009364.ht
> >> ml
> >> thanks,
> >> StefanK
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