review (XXS): 7151089: PS NUMA: NUMA allocator should not attempt to free pages when using SHM large pages

[Igor Veresov]

Sure: http://cr.openjdk.java.net/~iveresov/7151089/webrev.01/ 

I also decided to use the check of UseSHM explicitly to make the idea clearer.  

Thanks!
igor


On Monday, March 5, 2012 at 7:12 PM, Vladimir Kozlov wrote:

> Add comment explaining the condition.
> 
> Vladimir
> 
> Igor Veresov wrote:
> > We already turn adaptive resizing off (UseAdaptiveNUMAChunkSizing and 
> > UseAdaptiveSizePolicy) when using SHM-based large pages because these 
> > don't support uncommiting. However that is not enough - during the 
> > initialization we still do it once, which on linux leads to mmaping over 
> > the eden portion of the SHM segment. By doing this we loose large pages 
> > support and also increase memory requirements. 
> > 
> > The solution is to avoid attempting to free memory for SHM-based setups.
> > 
> > Webrev: http://cr.openjdk.java.net/~iveresov/7151089/webrev.00/
> > 
> > igor 

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