[ofa-general] Is response time of GMP is more than SMP

[Sumit Gaur - Sun Microsystem]

Hi Hal,

Hal Rosenstock wrote:
> Hi Sumit,
> 
> On Wed, 2008-06-25 at 12:11 +0530, Sumit Gaur - Sun Microsystem wrote:
> 
>>Hi Hal/Sashak,
>>
>>Hal Rosenstock wrote:
>>
>>>Hi Sumit,
>>>
>>>On Tue, 2008-06-24 at 14:21 +0530, Sumit Gaur - Sun Microsystem wrote:
>>>
>>>
>>>>Hi,
>>>>I am using OFED 2.5.*
>>>
>>>                  ^^^^^
>>>                  1.2.5.* ?
>>>
>>
>>Sorry for typo .. it is 1.2.5.*
>>
>>>>and observing that my SMI requests are serving very fast 
>>>>and response time is very less on the contrary my GSI requests were served in 
>>>>more time and response time sometime goes more than 2 sec. Any light on this 
>>>>different behavior.
>>>
>>>
>>>What are the specific GS requests which are slow in response ? Are they
>>>compute intensive ?
>>
>>I am sending only request for
>>
>>	rpc.mgtclass = IB_PERFORMANCE_CLASS;
>>	rpc.method = IB_MAD_METHOD_GET;
>>
>>at every one second.
>>
>>
>>>In general, there are a few possibilities (which can cause this). SM
>>>traffic is VL15 whereas GS traffic is on a data VL (usually VL0 in most
>>>subnets).
>>>
>>>Some possibilities are:
>>>1. Timeout/retry being hit for some GS traffic (GS request or response
>>>lost/corrupted)
>>
>>Yes, this is also happening, Sometimes I am getting corrupt data back,
> 
> 
> Is there an error indicated ?
For such packets I am getting umad_status as 110.
> 
> 
>>and if I retry to send same request again it fails or send corrupted data back again.
> 
> 
>>>2. Data VL busy (is there anything else utilizing VL0 ?)
>>
>>Not sure about it. Is there anything to verify it?
> 
> 
> There's an optional counter not commonly implemented so maybe starting
> by verifying all the PortCounters along the path from requester to
> responder to see whether there are any low level issues with your
> subnet.
>