RFR: JDK-8134161 JVM is creating too many GC helper threads on T7/M7 linux/sparc platform

[Vladimir Kozlov]

Looks good.

Thanks,
Vladimir

On 8/31/15 12:27 PM, Gerald Thornbrugh wrote:
> Hi,
>
> There is a Linux/SPARC related issue in JDK8 and JDK9 where hotspot does
> not identify a SPARC T7/M7
> platform correctly.  Because hotspot does not identify the T7/M7
> platform correctly it uses the default
> number of GC helper threads which is twice the number that is should
> use.  The fix adds code to
> detect a M series platform from the /proc/cpuinfo file and sets the
> correct CPU features.  Setting the
> correct features allow the correct number of GC helper threads to be
> allocated.
>
> The fix only impacts the Linux/SPARC code and does not impact any other
> platform/OS combination.
>
> I have completed successful JPRT test runs for each set of changes and
> have also verified that the change
> addresses the issue on Linux/SPARC M series hardware.
>
> Here is the bug:
>
> https://bugs.openjdk.java.net/browse/JDK-8134161
>
> Here is the JDK9 webrev:
>
> http://cr.openjdk.java.net/~gthornbr/8134161/webrev/
> <http://cr.openjdk.java.net/%7Egthornbr/8134161/webrev/>
>
> Here is the JDK8 webrev:
>
> http://cr.openjdk.java.net/~gthornbr/8134674/webrev/
> <http://cr.openjdk.java.net/%7Egthornbr/8134674/webrev/>
>
> Please let me know if you have any questions or concerns.
>
> Thanks,
>
> Gerald Thornbrugh