Review Request: UseNUMAInterleaving

Paul Hohensee paul.hohensee at
Tue May 17 10:51:27 PDT 2011

Another project for the performance analysis roadmap.  Analyze the
utility of UseNUMA with an eye to turning it on by default.  Basically,
just make sure it doesn't cause regressions.


On 5/17/11 1:35 PM, Igor Veresov wrote:
> Yes, I think doing a broad performance analysis would be very useful.
> Thanks,
> igor
> On 5/17/11 10:16 AM, Paul Hohensee wrote:
>> Do we have a list of such applications? If not, we could add an analysis
>> to the performance
>> team's roadmap.
>> Paul
>> On 5/17/11 12:58 PM, Igor Veresov wrote:
>>> UseNUMA already has this mechanism. If you turn it on it will
>>> deactivate itself if the machine is not NUMA. The problem with turning
>>> it on by default is that it can be not necessarily beneficial for all
>>> applications (however for most of them it is).
>>> igor
>>> On 5/17/11 5:04 AM, Paul Hohensee wrote:
>>>> I believe you can get memory geometry info from Solaris on both 
>>>> sparc or
>>>> intel.
>>>> Don't know about Windows or Linux. Anyone??
>>>> Paul
>>>> On 5/17/11 5:12 AM, Andrew Haley wrote:
>>>>> On 17/05/11 00:18, Paul Hohensee wrote:
>>>>>> I suggest you just use -XX:+UseNUMA rather than adding a new
>>>>>> flag. UseNUMA seems generic enough to cover whatever implementation
>>>>>> is best on a particular platform.
>>>>> Indeed. I am worried by the proliferation of command-line
>>>>> optimization flags that have obscure meanings that are difficult to
>>>>> understand by anyone unfamiliar with a particular computer
>>>>> architecture. This sort of tweakage might be mostly used by people
>>>>> doing benchmarking.
>>>>> When should this flag *not* be used? To make it more useful, is it
>>>>> possible to make any of this the default? Can a system where it is
>>>>> advantageous be autodetected?
>>>>> Andrew.

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