[openib-general] Re: RDMA Generic Connection Management

[Talpey, Thomas]

kDAPL does this!

:-)


At 02:35 PM 8/30/2005, Roland Dreier wrote:
>    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:
>
>  An upper level protocol consumer may begin using an IB device as
>  soon as the add method of its struct ib_client is called for that
>  device.  A consumer must finish all cleanup and free all resources
>  relating to a device before returning from the remove method.
>
>  A consumer is permitted to sleep in its add and remove methods.
>
> - R.