[openib-general] Re: RDMA Generic Connection Management

[Yaron Haviv]

> -----Original Message-----
> From: openib-general-bounces at openib.org [mailto:openib-general-
> bounces at openib.org] On Behalf Of Roland Dreier
> Sent: Tuesday, August 30, 2005 2:36 PM
> To: Talpey, Thomas
> Cc: openib-general at openib.org
> Subject: Re: [openib-general] Re: RDMA Generic Connection Management
> 
>     Thomas> Well, you're saying somebody has to do it, right? Is it
>     Thomas> easier to fob this off to upper layers that (frankly)
>     Thomas> don't care what hardware they're talking to!? This means
>     Thomas> we have N copies of this, and N ways to do it. Talk about
>     Thomas> cacheline pingpong.
> 
> Upper layers have the luxury of being able to do this at a
> per-connection level, can sleep, etc.  If we push it down into the
> verbs, then we have to do it in every verbs call, including the fast
> path verbs call.  And that means we get into all sorts of crazy code
> to deal with a device disappearing between a consumer calling
> ib_post_send() and the core code being entered, etc.
> 
> Right now we have a very simple set of rules:
> 

If all the ULPs need to do exactly the same, or the implementation is
different for IB/iWarp, than we should probably do it under the API like
its defined in kDAPL.

Also note that with Virtual machines this type of event may be more
frequent and we may want to decouple the ULPs from the actual hardware
device as much as we can 

Yaron