Re: linux rdma 3.14 merge plans

Or Gerlitz
2014-01-30T08:19:06Z

On 29/01/2014 19:56, Bart Van Assche wrote:
> On 01/29/14 16:06, Sagi Grimberg wrote:
>>
>> Didn't understand why should it matter where the copy is done (iser/block)?
> In the Linux kernel community it is considered important to avoid code duplication. Hence the proposal to keep code that copies data buffers in the block layer core and to avoid that such functionality has to be reimplemented in every block driver or SCSI LLD.

Hi Bart,

Thanks for narrowing this down, I see your point, however the solution I
propose if to remove this copy altogether... for those rare cases where
fast-registration can't be done -- in SRP I think the code goes to
indirect mode under which there no copy (right?). As for iSER, we will
add to our TODO enhancing the code to avoid using bounce-buffer, few
designs might be possible, one way would be to create set of
FMRS/Fast-reg element which are capable to map chunks which are <
PAGE_SIZE, e.g in the order of single block, and hence can map what ever
arbitrary set of blocks provided by the upper layer.

Or.