[PATCH RFC 2/2] nvmet-rdma: Support 8K inline

[Max Gurtovoy]

Thanks Steve for running this.
Me and Parav kinda put this task aside...

On 5/9/2018 5:34 PM, Steve Wise wrote:
> Allow up to 2 pages of inline for NVMF WRITE operations.  This reduces
> latency for 8K WRITEs by removing the need to issue a READ WR for IB,
> or a REG_MR+READ WR chain for iWarp.
> 
> Signed-off-by: Steve Wise <swise at opengridcomputing.com>
> ---
>   drivers/nvme/target/rdma.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
> index 52e0c5d..9e3f08a 100644
> --- a/drivers/nvme/target/rdma.c
> +++ b/drivers/nvme/target/rdma.c
> @@ -33,9 +33,9 @@
>   #include "nvmet.h"
>   
>   /*
> - * We allow up to a page of inline data to go with the SQE
> + * We allow up to 2 pages of inline data to go with the SQE
>    */
> -#define NVMET_RDMA_INLINE_DATA_SIZE	PAGE_SIZE
> +#define NVMET_RDMA_INLINE_DATA_SIZE    (PAGE_SIZE << 1)

Sometimes 8K != (PAGE_SIZE << 1).
do we realy want to have this in PPC systems, for example, that 
PAGE_SIZE == 64K ?
We might want to re-think on changing this to SZ_4K.

>   
>   struct nvmet_rdma_cmd {
>   	struct ib_sge		sge[2];
>