RFR: 8148987: [Linux] Allow building on older systems without CPU_ALLOC support

[Daniel D. Daugherty]

On 2/5/16 12:50 AM, David Holmes wrote:
> bug: https://bugs.openjdk.java.net/browse/JDK-8148987
>
> webrev: http://cr.openjdk.java.net/~dholmes/8148987/webrev/

src/os/linux/vm/os_linux.cpp
     No comments on the code.


I like the fact that you minimized the #ifdef's as much as possible.
I also like the fact that you handle CPU_ALLOC and CPU_COUNT separately;
in the world of variant Linux distros, I think handling more possible
variants (with in reason) is good.


> This is a tentative RFR as I'm not yet convinced we should support 
> building on these older platforms in JDK 9. Opinions welcome on that 
> point.

I got the impression that Thomas Stufe's sighting with their
Linux PowerPC build was on JDK9 code base. Now that I reread
that part of the thread, there's nothing stating that clearly,
but I think you should make this chnage in JDK9.

Thumbs up!

Dan


>
> The older systems do not have dynamic cpu set support (CPU_ALLOC) nor 
> do they have the CPU_COUNT utility macro.
>
> Thanks,
> David
>