Re: RFC: Immediate data support for SRP

Sagi Grimberg
2015-07-20T09:44:26Z

On 7/20/2015 12:43 AM, Or Gerlitz wrote:
> On Sun, Jul 19, 2015 at 7:07 PM, Sagi Grimberg <sagig-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org> wrote:
>> On 7/16/2015 6:25 PM, Bart Van Assche wrote:
>
>> I agree it would definitely help as the lack of immediate data
>> emphasizes the additional latency of doing rdma reads.
>
> Sagi, do we have black box evidence from iSER showing notable
> (results? setup?) IO latency improvement from using immediate data vs.
> RDMA read?

I've seen it. The LIO target has a better write performance due to
ImmediateData. I also have a patch in the pipe that optimize the
this flow at the target side which improves up to 40% for 512B-8K IOs.

Sagi.