RFR (S): 8051973: Eager reclaim leaves marks of marked but reclaimed objects on the next bitmap

Thomas Schatzl thomas.schatzl at oracle.com
Wed Jul 30 11:29:27 UTC 2014


Hi Jon,

  thanks for the review.

On Tue, 2014-07-29 at 13:50 -0700, Jon Masamitsu wrote:
> On 7/29/2014 3:40 AM, Thomas Schatzl wrote:
> > Hi all,
> >
> >    can I have reviews for the following small change?
> >
> > JDK-8027959 implemented eager reclaim of humongous objects, which
> > potentially left stray set marks on the mark bitmap after reclaiming a
> > region.
> >
> > This change fixes this.
> >
> > CR:
> > https://bugs.openjdk.java.net/browse/JDK-8051973
> > Webrev:
> > http://cr.openjdk.java.net/~tschatzl/8051973/webrev/
> 
> The changes look good.
> 
> You left the uses  r->bottom() so you would not
> have to cast obj to HeapWord*?

Yes. If you have objections to that I can change that back. The code is
easier to read for me if there is not that much casting.

> 
> Do you want to specify a region size in the test?  Current
> policy would have  regions sizes such that
> 
>    48     public static final int M = 1024*1024;
> 
> gives you humongous allocations but policy could change, yes?

Done.

See
http://cr.openjdk.java.net/~tschatzl/8051973/webrev.0_to_1
Full webrev:
http://cr.openjdk.java.net/~tschatzl/8051973/webrev.1

Thomas




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