RFR: 8252093: formula used to calculate decaying variance in numberSeq

[stefan.johansson at oracle.com]

Sounds good, I think this is enough testing.

Thanks,
Stefan

On 2020-09-01 11:42, Albert Yang wrote:
>  > Did you compare the total runtime of the two ZGC runs,
> Yes.
> 
>  > the extra cycles could be caused warmup taking much longer in the 
> second run.
> Seem so. Before the patch, it takes 40 GC cycles to warmup, but after 
> the patch, 78 GC cycles. If we take that into account, the actual GC 
> cycles during the measurement (349-40=309 vs 380-78=302) are very close.
> 
> ```
> # before
> [2.610s][info][gc] GC(0) Garbage Collection (System.gc()) 
> 2480M(2%)->176M(0%)
> [86.779s][info][gc] GC(1) Garbage Collection (System.gc()) 
> 4796M(4%)->1464M(1%)
> [323.875s][info][gc] GC(12) Garbage Collection (System.gc()) 
> 50576M(39%)->1646M(1%)
> [421.629s][info][gc] GC(17) Garbage Collection (System.gc()) 
> 41726M(32%)->1628M(1%)
> [608.851s][info][gc] GC(33) Garbage Collection (System.gc()) 
> 22748M(17%)->1826M(1%)
> [686.220s][info][gc] GC(39) Garbage Collection (System.gc()) 
> 34834M(27%)->1834M(1%)
> [692.493s][info][gc] GC(40) Garbage Collection (System.gc()) 
> 8180M(6%)->1346M(1%)
> [7867.090s][info][gc] GC(349) Garbage Collection (System.gc()) 
> 21014M(16%)->424M(0%)
> [8045.531s][info][gc] GC(356) Garbage Collection (System.gc()) 
> 60270M(46%)->1796M(1%)
> [8051.900s][info][gc] GC(357) Garbage Collection (System.gc()) 
> 8286M(6%)->1350M(1%)
> ```
> 
> ```
> # after
> [2.632s][info][gc] GC(0) Garbage Collection (System.gc()) 
> 2480M(2%)->176M(0%)
> [86.816s][info][gc] GC(1) Garbage Collection (System.gc()) 
> 4774M(4%)->1468M(1%)
> [313.601s][info][gc] GC(12) Garbage Collection (System.gc()) 
> 55236M(42%)->280M(0%)
> [408.054s][info][gc] GC(18) Garbage Collection (System.gc()) 
> 65486M(50%)->1784M(1%)
> [590.894s][info][gc] GC(35) Garbage Collection (System.gc()) 
> 20584M(16%)->422M(0%)
> [690.631s][info][gc] GC(45) Garbage Collection (System.gc()) 
> 22204M(17%)->1638M(1%)
> [791.317s][info][gc] GC(57) Garbage Collection (System.gc()) 
> 21268M(16%)->436M(0%)
> [908.128s][info][gc] GC(68) Garbage Collection (System.gc()) 
> 40480M(31%)->1838M(1%)
> [989.525s][info][gc] GC(77) Garbage Collection (System.gc()) 
> 6198M(5%)->440M(0%)
> [995.913s][info][gc] GC(78) Garbage Collection (System.gc()) 
> 7064M(5%)->1362M(1%)
> [8024.034s][info][gc] GC(380) Garbage Collection (System.gc()) 
> 20714M(16%)->438M(0%)
> [8196.327s][info][gc] GC(388) Garbage Collection (System.gc()) 
> 12494M(10%)->436M(0%)
> [8202.587s][info][gc] GC(389) Garbage Collection (System.gc()) 
> 6920M(5%)->1354M(1%)
> ```
>