[openib-general] RFC: e2e credits

[James Lentini]

On Thu, 2 Mar 2006, Michael S. Tsirkin wrote:

mst> I am, therefore, considering one of the following options:
mst> - Add a flag rq_e2e_flow_control to create qp, make e2e flow control
mst>   disabled by default
mst> - Add a flag disable_rq_e2e_flow_control to create qp, make e2e flwo control
mst>   enabled by default
mst> - Add a module option to mthca to enable e2e flow control for all QPs,
mst>   disabled by default
mst> - Add a module option to mthca to disable e2e flow control for all QPs,
mst>   enabled by default
mst> - Do nothing, assume an application always keeps an extra receive qork request
mst>   available at all times.

If some consumers require this support and others do not, it would be 
best to make it a per-QP parameter. That would allow both types of 
consumers to be supported simultaneously.

Is e2e flow control enabled or disabled in the mthca driver currently? 

The principle of least astonishment dictates that the future default 
setting should be the same a the current default setting.