[ofa-general] SRP/mlx4 interrupts throttling performance

[Cameron Harr]

Vladislav Bolkhovitin wrote:
> Cameron Harr wrote:
>> Vladislav Bolkhovitin wrote:
>>> Cameron Harr wrote:
>>>> Vladislav Bolkhovitin wrote:
>>>>> I guess, you use a regular caching IO? The lowest packet size it 
>>>>> can produce is a PAGE_SIZE (4K). Target can't change it. You can 
>>>>> have lower packets only with O_DIRECT or sg interface. But I'm not 
>>>>> sure it will be performance effective.
>>>> I do everything with Direct IO, which is automatic when using the 
>>>> BLOCKIO method in SCST.
>>> I meant on initiator(s), not on the target.
>>>
>> Sorry - but yes, I always run the benchmark apps with direct IO
>
> Then, there's one more reason why we should find out the cause of such 
> a big variation between runs. Can you repeat all the tests with the 
> latest SCST SVN trunk/ including SRPT driver with each run for at 
> least few minutes?

 From a little testing, the updated SCST tree doesn't work with the 
OFED-1.3.1 SRP stack, though I have gotten it working with the 
infiniband drivers in the normal distribution kernel. Shall I use those 
modules?

Also, as I mentioned before, my time is going to be fairly limited for a 
while, but I'll try to squeeze this in and will make sure I run for 
longer periods of time. I'll also try to calculate an exact end number 
based on iop/runtime.
>
> Which backstorage do you use for BLOCKIO?
Fusion IO ioDrive. I generally use 1 or 2, but somtimes up to 4 at a time.