RFR(S): 8198794: Hotspot crash on Cassandra 3.11.1 startup with libnuma 2.0.3

[Gustavo Romero]

Hi,

On 03/13/2018 11:50 AM, Hohensee, Paul wrote:
> Looks good to me.

Thanks for reviewing it.


@David, do you mind to review that small change (maybe it
should be marked as XS actually...) regarding libnuma
since you reviewed the previous ones?

bug   : https://bugs.openjdk.java.net/browse/JDK-8198794
webrev: http://cr.openjdk.java.net/~gromero/8198794/v1/


Regards,
Gustavo

> Paul
> 
> On 3/12/18, 6:13 PM, "Gustavo Romero" <gromero at linux.vnet.ibm.com> wrote:
> 
>      Hi.
>      
>      Paul, I just saw today your bug on JBS...
>      https://bugs.openjdk.java.net/browse/JDK-8198794
>      
>      Thanks for reporting and debugging it.
>      
>      It looks like the issue boils down to the fact that although
>      'numa_all_nodes_ptr' was introduced with libnuma API v2, 'numa_nodes_ptr'
>      was only introduced later on libnuma v2.0.9, so it's not present in libnuma
>      2.0.3 which dates back to Jun 2009 [1]. I agree with your initial patch
>      that a reasonable way to address it for archs like x86_64 is to use
>      'numa_all_nodes_ptr' as a surrogate for 'numa_nodes_ptr' (PowerPC needs
>      'numa_nodes_ptr' anyway and will have to stick with libnuma 2.0.9 and above
>      because it's not unusual to have non-configured nodes on PPC64 and nodes
>      can be non-contiguous as well).
>      
>      I just think it's better to handle it inside isnode_in_existing_nodes()
>      interface, which is where such a information is needed in the end. In that
>      sense, if you agree could you please check if the following webrev fixes
>      the issue for you? It must also apply ok for jdk8u:
>      
>      bug   : https://bugs.openjdk.java.net/browse/JDK-8198794
>      webrev: http://cr.openjdk.java.net/~gromero/8198794/v1/
>      
>      If it does solve your issue, I will kindly ask for another Reviewer.
>      
>      Thank you.
>      
>      
>      Best regards,
>      Gustavo
>      
>      [1] http://cr.openjdk.java.net/~gromero/misc/numa_all_nodes_ptr_VS_numa_nodes_ptr.txt
>      
>      
>