RFR(XS): 8015244: G1: Verification after a full GC is incorrectly placed
bengt.rutisson at oracle.com
Fri May 24 13:02:15 UTC 2013
The change looks good.
Thanks for running the simple performance test! That was a good idea!
And I think a 4% the overhead seems reasonable.
On 5/23/13 1:20 AM, John Cuthbertson wrote:
> Hi Everyone,
> Can I have a couple of volunteers look over this small fix? The webrev
> can be found at: http://cr.openjdk.java.net/~johnc/8015244/webrev.0/
> While investigating some additional verification code for "7145569:
> G1: optimize nmethods scanning", I realized that the verification that
> occurs after a full GC is misplaced. I think it should come after the
> rebuilding of the RSets and verify the rebuilt RSets. Verifying the
> RSets before the full GC is less interesting and potentially wasteful
> so I placed the RSet verification during full GCs under control of an
> additional diagnostic flag.
> These aren't true performance numbers but when I ran GCOld with the
> new flag enabled (1G heap), I saw an increase in full GC times of
> around 4% on my workstation (VerifyBefore and VerifyAfter were both
> GCOld; CG test suite
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