Re: [rfc 6/6] dma-remap: double the default DMA coherent pool size

[Christoph Hellwig]

On Sun, Mar 01, 2020 at 04:05:27PM -0800, David Rientjes wrote:
> When AMD memory encryption is enabled, some devices may used more than
> 256KB/sec from the atomic pools.  Double the default size to make the
> original size and expansion more appropriate.
> 
> This provides a slight optimization on initial expansion and is deemed
> appropriate for all configs with CONFIG_DMA_REMAP enabled because of the
> increased reliance on the atomic pools.
> 
> Alternatively, this could be done only when CONFIG_AMD_MEM_ENCRYPT is
> enabled.

Can we just scale the initial size based on the system memory size?