[OpenJDK 2D-Dev] <AWT Dev> [9] Review Request: JDK-8041900 [macosx] Java forces the use of discrete GPU

Phil Race philip.race at oracle.com
Wed May 27 18:09:50 UTC 2015

I suppose that NSOpenGLPFAAllowOfflineRenderers must prevent whatever 'tickling'
of the discrete GPU we do from automatically making it the active GPU ?

This seems to merit a source code comment as at face value it seems like an API that allows
you to use that (other) discrete GPU alongside the active GPU, but so we don't
need that part, just the side-effect behaviour.

But do we want this fix in this form ? The integrated GPU is going to perform far less well
than the discrete GPU. If the issue is battery life, then perhaps it should be tied
to whether we are running on battery or mains power. And then perhaps you need to figure out
how to switch GPU on the fly when you go from mains to battery.


On 05/27/2015 08:08 AM, Denis Fokin wrote:
> Hi, Sergey,
> Basically, you should close all apps that can switch the vc  including the utility for switching video cards. Make sure in About This Mac -> Displays that the integrated card is enabled. Start an application with the patched version of Java. Check About This Mac -> Displays. Integrated video card should be still active.
>> 27 мая 2015 г., в 17:30, Sergey Bylokhov <Sergey.Bylokhov at oracle.com> написал(а):
>> Hi, Denis.
>> Can you describe the steps on how to test it. On my mac it still change the vc.
>>> On 27.05.15 17:16, Denis Fokin wrote:
>>> Please review the fix for jdk9
>>> The fix allows do not force discrete video card usage on MacBook Pro models with two video cards. I have tested the fix on several MPBs.
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8041900
>>> Webrev: http://cr.openjdk.java.net/~denis/8041900/webrev.00 <http://cr.openjdk.java.net/%7Edenis/8041900/webrev.00>
>> -- 
>> Best regards, Sergey.

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