[ofa-general] Re: [Scst-devel] SRP aggregate bandwidth decreasing as threads increase

[Chris Worley]

On Mon, May 18, 2009 at 12:23 PM, Vladislav Bolkhovitin <vst at vlnb.net> wrote:
> Chris Worley, on 05/18/2009 08:21 PM wrote:
>>
>> I'm seeing peak performance at ~4 threads (1.6GB/s), w/ threads >10
>> I'm seeing aggregate performance drop significantly.  This is not a
>> drive issue: locally, the drives get best performance >~32 threads,
>> and maintain their aggregate way beyond that.
>>
>> Is there any tunable parameter or source code change in the initiator
>> or target code that would effect performance with a high thread count?
>
> Check README of ib_srpt from the SCST SVN trunk.

There are 42 README's in scst.  Do you mean the one in scst/trunk/srpt
which talks of three performance issues:

1) Minimizing QUEUEFULL conditions.
2) Setting IRQ affinity on the drives.
3) Setting "thread=1".

?

Chris