Re: [PATCH 36/41] IB/hfi1: add low level page locking

Haggai Eran
2015-07-09T07:33:16Z

On 09/07/2015 01:08, Marciniszyn, Mike wrote:
>> anything wrong with the umem services provided by the IB core that
>> requires this implementation? what?
>>
>
> The current level of the API is mismatched with the PSM SDMA.
>
> The ib_umem api:
> - maps an SG list which isn't required by PSM since DMA mapping is done by the low level SDMA
Can I ask why do you prefer mapping page by page over using a single sg
list?

> - the mapping is bi-directional vs. from device
> - The pd's context is not there
>
> Certainly we would consider a core change that provides just the page locking and we could fake a context.
>
> Mike