Truffle on-stack-replacement sometimes not working well with background compilation?
gerard at gerardkrol.nl
Thu Aug 4 20:13:27 UTC 2016
I'm using graalvm version 0.12, with truffle-api 0.15. I'm perfectly happy
with background compilation disabled at the moment, so take your time.
On Thu, Aug 4, 2016 at 9:56 PM, Christian Humer <christian.humer at gmail.com>
> Hi Gerard,
> Thanks for the report. Unfortunately I am unable to have a look at it
> right now, but I will asap.
> Can you, in the meantime, provide me with some info on which version of
> graalvm/truffle you are using so I can try to reproduce?
> On 04.08.2016 21:46:17, "Gerard Krol" <gerard at gerardkrol.nl> wrote:
>> I've had some performance problems with Cover and a specific benchmark.
>> Yesterday I finally figured out what was going on. The problem seems to be
>> that on-stack-replacement doesn't always work well with background
>> The benchmark (fannkuch, ) did take 311 seconds to run, while the GCC
>> version would finish in 25 seconds. Warming up (running the benchmark
>> and timing the second run) would reduce the runtime to 47 seconds. I like
>> to run my benchmarks without warmup though, as that is a good worst-case
>> I then figured out that just adding
>> -Dgraal.TruffleBackgroundCompilation=false made a huge difference. The
>> needed was reduced to 52 seconds.
>> Is this a bug? Expected behavior in some cases? Am I doing something
>> 1. Get Cover from  (don't forget the 5th installation step)
>> 2. Run time ./cover tests/fannkuch-redux_gcc5.cover
>> 3. Run time ./cover -benchmark tests/fannkuch-redux_gcc5.cover (this will
>> disable the background compilation)
>>  https://github.com/gerard-/cover
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