Java Performance Degradation in JDK7 and JDK8

[Jacob Wieland]

Following up on my own post:

maybe this has something to do with the bug as we are using inner classes a
lot JDK-8000316 as we are using inner classes a lot.

2015-04-24 10:49 GMT+02:00 Jacob Wieland <wieland at testingtech.com>:

> Hello Folks,
>
>
> I still have the open problem
> https://bugs.openjdk.java.net/browse/JDK-8039262 that the javac
> performance has degraded significantly from 1.6 to 1.7 (and even worse to
> 1.8) in the 64bit versions. Since in our context, we are dealing with a lot
> of generated source1.4 Java input (either split into very large files with
> inner classes or big packages with lots of smaller classes), compiler
> performance is critical for our tool and this degradation forces us to
> continue recommending to our customers to use Java 1.6 for large projects
> (as is the norm) as 1.7 and 1.8 are pretty much unusable in this respect.
>
> Is anyone still working on this issue or is such significant performance
> degradation not a serious issue?
>
> My observations so far are:
> - it gets worse the more class files are being compiled/the more files
> reside in the source path
> - cpu usage goes through the roof over all available kernels
> - memory usage is much higher
> - garbage collection seems to be much more active
>
> Using -proc:none alleviates the problem slightly for the 1.7 version, but
> not for 1.8 (last we tested with jdk1.8.0_31) where the performance
> difference is a factor 5 or more!
>
> I can understand that a more advanced compiler has capabilities that a
> previous version does not have and thus sometimes has
> to do more work. But, it should still be possible (especially if given the
> -source 1.4 or -source 1.5 option as we do) to optimize it in such a way
> that unnecessary checks for generics, overriding methods, closures,
> annotations and other newer features can be turned off (if they are to
> blame, which I actually doubt from my observations).
>
> I would really appreciate your help in this regard and I think everyone
> would benefit from any bugfix you can offer for this.
>
> BR, Jacob Wieland
>
> --
> --
> ------------------------------
> -------------------------------------------
> Dr. Jacob Wieland
> Senior Software Engineer
>
> Testing Technologies IST GmbH
> Michaelkirchstraße 17/18
> 10179 Berlin, Germany
>
> Phone     +49 30 726 19 19 34        Email     wieland at testingtech.com
> <stanca at testingtech.com>
> Fax         +49 30 726 19 19 20        Internet  www.testingtech.com
>
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-- 
-- 
------------------------------
-------------------------------------------
Dr. Jacob Wieland
Senior Software Engineer

Testing Technologies IST GmbH
Michaelkirchstraße 17/18
10179 Berlin, Germany

Phone     +49 30 726 19 19 34        Email     wieland at testingtech.com
<stanca at testingtech.com>
Fax         +49 30 726 19 19 20        Internet  www.testingtech.com
---------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------

UPCOMING EVENTS

SUBMIT YOUR TOPIC for the UCAAT 2015
Deadline: May 30, 2015ucaat.etsi.org/2015/CallForPresentations.html

Apr 21-23, 2015 | SAE Conference & Exhibition
Detroit, Michigan, USAwww.sae.org/congress/

Apr 28-30, 2015 | iqnite
Dusseldorf, Germanywww.iqnite-conferences.com/de/index.aspx


-----------------------------------------------------------------------------------------------------------------
Geschäftsführung: Theofanis Vassiliou-Gioles, Stephan Pietsch, Pete
Nicholson Handelsregister HRB 77805 B, Amtsgericht Charlottenburg Ust ID
Nr.: DE 813 143 070 This email may contain confidential and privileged
material for the sole use of the intended recipient. Any review, use,
distribution or disclosure by others is strictly prohibited. If you are not
the intended recipient (or authorized to receive for the recipient), please
contact the sender by reply email and delete all copies of this message.
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