Re: RFC: Immediate data support for SRP

Or Gerlitz
2015-07-20T15:26:53Z

On 7/20/2015 12:44 PM, Sagi Grimberg wrote:
> 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.

Numberz, please...

Also, do you see any gain with TGT too? if not, what's you thinking re
the LIO vs TGT difference?

> 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.
>

So you have 140% better IOPS with immediate-data vs. non immediate
data?! numberz?

Or.