Smalltalk and tiered compile data

[Christian Thalinger]

On Feb 3, 2012, at 1:25 AM, Mark Roos wrote:

> So I ran some tests using a simple benchmark using the jdk8-b23 from the Openjdk google code. 
> 
> Without tiered compile I get:  ( times in nanoseconds ) 
> 52101000 
> 53973000 
> 20932000 
> 
> with tiered on 
> 493788000 
> 521448000 
> 513287000 
> 342930000 
> 15048000 
> 
> But if I invalidate all call sites before the benchmark with tiered I see: 
> 
> 449127000 
> 288584000 
> 80717000 
> 36255000 
> 
> and without tiered 
> 49210000 
> 744625000 
> 27179000 
> 26377000 
> 24514000 
> 
> in all cases more runs after show no changes for 30 runs. 
> 
> So tiered starts very very very  slow but ends better.  Both seem to have a hard time if call sites have their 
> targets reset. 
> 
> any thoughts on how I might get the best always? Especially for callsite resets.

What exactly do you mean by "invalidate call sites before the benchmark"?  Are you using MutableCallSites and call setTarget on them?

> 
>  And why would the startup be 10x slower for tiered? 

Good question.  The run times are long enough (around 0.5s) that a C2 compile should happen in the first runs.  But maybe I'm wrong.

Igor, do you have an idea?

-- Chris

> 
> By the way the data for jdk7u4 is similar but its best times are slower. 
> 
> regards 
> mark_______________________________________________
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