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

[Steve Wise]

On 5/14/2018 5:16 AM, Max Gurtovoy wrote:
> Thanks Steve for running this.
> Me and Parav kinda put this task aside...
>

Hey Max,

> 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.
>

Yes, I agree.

Thanks,

Steve.