JTreg spawns java processes and uses all memory with CONCURRENCY=auto

Jonathan Gibbons jonathan.gibbons at oracle.com
Mon May 20 15:02:12 PDT 2013


Tomasz,

The "auto" value for concurrency currently evaluates to the number of 
processors on your system. In practice, I would not recommend using that 
value. I generally run with the concurrency to set to about half the 
number of available processors, but you may want to modify that value up 
or down a bit to find a value that works best for you.

-- Jon


On 05/20/2013 01:59 PM, Tomasz Kowalczewski wrote:
> Hello,
>
> during a recent "Adopt OpenJDK" event held in Krakow I was using jtreg 
> for running OpenJDK test cases. It was set up as per instructions 
> published here: https://java.net/projects/adoptopenjdk/pages/InstallJtreg
>
> OpenJDK repository was cloned from http://hg.openjdk.java.net/jdk8/tl 
> and jtreg version was jtreg-4.1-bin-b05_29_nov_2012.zip
>
> I have set 'CONCURRENCY=auto' environment variable.
>
> When running a test suite (.e.g.: 'cd jdk8_tl/test; make jdk_util') 
> jtreg spawns a lot of java processes and it seems not to stop. Ever. 
> It uses all 8 GB of RAM on my machine at which point Windows starts 
> killing random processes.
>
> With 'CONCURRENCY=1' jtreg will spawn only a few java processes and 
> will happily run all the test.
>
> What is the behavior for 'CONCURRENCY=auto'? Which value is used as 
> default? Maybe it is not a bug its just that OpenJDK tests should be 
> run on a big server machine with lots of RAM?
>
> Any suggestions or pointers to documentation will be very appreciated.
>
> -- 
> Regards,
> Tomasz Kowalczewski



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