review(S): 7037939: NUMA: Disable adaptive resizing if SHM large pages are used

[Igor Veresov]

Thanks, Ramki!

igor

On 4/25/11 3:47 PM, Y. Srinivas Ramakrishna wrote:
> Looks good to me.
>
> -- ramki
>
> On 4/21/2011 2:22 PM, Igor Veresov wrote:
>> The fix has two parts:
>> 1. On Solaris, when ISM shared memory is used it is always allocated
>> round-robin across the nodes,
>> so the NUMA allocator cannot work. The fix is to disable UseNUMA if
>> ISM method is selected. I let
>> UseNUMA win however if UseLargePages and UseSHM are not explicitly
>> specified.
>>
>> 2. On Linux, it's impossible to use adaptive resizing with UseNUMA if
>> SHM shared memory is used.
>> That is because we cannot uncommit a page in such a mmaping. The
>> solution is to disable adaptive
>> resizing if the userr really wants it, that is when UseNUMA and
>> (UseLargePages or UseSHM) are
>> specified on the command line. Like on Solaris, I let UseNUMA win if
>> it's explicitly specified and
>> UseLargePages and UseSHM are not.
>>
>>
>> Webrev: http://cr.openjdk.java.net/~iveresov/7037939/webrev.00/
>>
>>
>> Thanks,
>> igor
>