[ofa-general] IPOB CM (NOSRQ) [PATCH V9] patch

[Pradeep Satyanarayana]

Pradeep Satyanarayana wrote:
> Sean Hefty wrote:
>>> Yes, the admin could run into the problem that you describe. That is
>>> exactly
>>> why we have these as module parameters. It gives him/her the flexibility.
>> But it doesn't give additional flexibility, and makes it more difficult.
>>
>> Increasing this value by itself may not do anything unless the admin
>> also increase max QPs / RQ size / mtu.  Similarly, increasing max QP /
>> RQ size / mtu may not work without also increasing this value.  Multiple
>> values need to be manipulated.
>>
>> Decreasing this value can have the side effect of limiting max QP.  This
>> side effect is arbitrary.
>>
>> And even if this value is left unchanged, the results of changing other
>> parameters is unknown.
>>
>> The only sure way that the admin can know what will happen is to
>> understand the relationship that max QP / RQ size / mtu have on memory
>> use.  This parameter doesn't remove that need and makes the relationship
>> between them show up in confusing ways.
>>
>> If admins want some way of limiting how much memory is consumed by
>> ipoib, then how about creating a simple userspace app to convert their
>> request into the proper kernel settings?  This way, the policy is kept
>> in userspace, rather than hard-coded in the kernel driver.
>>
> 
> Sean,
> 
> As we debate this issue I do not want no srq patch to miss the 2.6.24 merge.
> This has been waiting to be merged for a very long time.
> 
> We all have a slightly different view point. This was the reason I did not 
> touch the module parameters in my previous patches. Can we agree to continue
> discussing this, but merge the patch (I will provide the fix that you pointed out)?
> 

In the interest of reaching a quick resolution, would it be acceptable if I put
in a warning message (printing current memory usage) when memory usage say exceeds 1GB 
for no srq and also eliminate the max_receive_buffer module parameter. Is that 
satisfactory?

Pradeep