Re: [dpdk-dev] [PATCH v4 1/4] igb_uio: add wc option

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 6/29/2018 1:17 PM, Rafal Kozik wrote:
> From: Kozik <rk@semihalf.com>
> 
> Write combining (WC) increases NIC performance by making better
> utilization of PCI bus, but cannot be use by all PMD.
> 
> To get internal_addr memory need to be mapped. But as memory could not be
> mapped twice: with and without WC it should be skipped for WC. [1]
> 
> To do not spoil other drivers that potentially could use internal_addr,
> parameter wc_activate adds possibility to skip it for those PMDs,
> that do not use it.
> 
> [1] https://www.kernel.org/doc/ols/2008/ols2008v2-pages-135-144.pdf
> 	section 5.3 and 5.4
> 
> Signed-off-by: Rafal Kozik <rk@semihalf.com>
> Acked-by: Bruce Richardson <bruce.richardson@intel.com>

Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>

(I am still not able to confirm this is needed, but since the behavior change is
controlled by module param and internal_addr is not used at all, no need to
block the patch)