RFR: 8033426: Scale initial NewSize using NewRatio if not set on command line
stefan.johansson at oracle.com
Tue Feb 4 08:08:17 PST 2014
On 2014-02-03 17:50, Jesper Wilhelmsson wrote:
> Hi Stefan,
> Have you looked at how this change plays with the ergonomics for
> NewSize in Arguments::set_cms_and_parnew_gc_flags()? That code will
> also use NewRatio to scale NewSize, but if running with a large
> CMSYoungGenPerWorker it may end up with a larger NewSize. Looks like
> your change will handle it well, but it would be nice with some test
> to verify it going forward.
I hadn't looked into this in depth but I took a look now and it seems to
be handled well as you say. If the NewSize is set to something the new
code will never shrink it.
Regarding testing, Erik H will soon push his fixes for one of the
HeapSize tests. I will make sure nothing is broken with the improved
test and also see if we can add some test case to it to test the NewSize.
> Anyways, looks good to me.
> Ship it!
Thanks for reviewing this.
> Stefan Johansson skrev 3/2/14 4:40 PM:
>> Can I have a couple of reviews for this enhancement:
>> Currently the initial young generation size is the same as the
>> minimum. If not
>> using large pages this will be 1.5M for the default collector
>> regardless of how
>> large the whole heap is. The proposed change is to scale the initial
>> young size
>> the same way the maximum young size is scaled, using the NewRatio
>> This change has been out on review as part of the fix for
>> JDK-8028498, but after
>> discussions we have decided take another approach for that bug.
>> * JPRT
>> * GC tests in jtreg
More information about the hotspot-gc-dev