RFR (XS) 8238247: CTW runner should sweep nmethods more aggressively

[Andrew Dinn]

On 06/02/2020 10:50, Aleksey Shipilev wrote:
> RFE:
>   https://bugs.openjdk.java.net/browse/JDK-8238247
> 
> Candidate fix:
>   https://cr.openjdk.java.net/~shade/8238247/webrev.01/
> 
> Current CTW runner leaves the just-compiled nmethods behind. At some point the sweeper comes in and
> make them go away, stabilizing on some number of nmethods. However, that stabilization point is too
> far away for the throwaway compilations CTW runner does.
> 
> In the end, this leads to inflation of nmethod and dependencies population, which slows down the
> subsequent compiles and deopts. If you have a very large JAR file, it would take days to CTW. With
> this patch, it takes a few hours. applications/ctw/modules also improves quite nicely with it. See
> the comments in bug report for additional details.
> 
> Testing: adhoc CTW runs, make run-test applications/ctw/modules
Yes, that also looks good.

regards,


Andrew Dinn
-----------
Senior Principal Software Engineer
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