On Aug 2, 2011, at 5:25 PM, Hefty, Sean wrote: >> If the target QP is opened in low level driver, then it's owned by group of >> processes that share the same XRC domain. > > Can you define what you mean by 'owned'? > > With the latest patches, the target qp is created in the kernel. Data > received on the target qp can go to any process sharing the associated xrc > domain. However, only the creating process is permitted to modify the qp.
Owned - the group of process may use the tgt qp to receive data. So it seems that we are on the same page here. BTW, did we have the same limitation/feature (only creating process is allowed to modify) in original XRC driver ? > >> And , as I mentioned in the reply to Jack, I totally agree that maximum life >> time of target QP is bound to XRC domain life time, > > This is the main point I was trying to get agreement on from the MPI > developers, and it appears that everyone agrees now. Indeed. > >> even so it should be a way to destroy the QP before XRC domain distraction. > > This is also doable with the latest patches. The process which creates the > tgt qp has the ability to explicitly destroy it. Hmm, is it way to destroy the QP, when the original process does not exist anymore ? Some MPI implements network fall tolerance mechanisms over IB. It means that if QP (or device) enters to error state it should be a way to destroy the specific QP and open new one. > >> main point is that the target qp should be maintained by low level driver and >> not specific MPI process (like send qp) > > As with 'owned', can you clarify what you mean by 'maintained'? > > The target qp can continue to exist even after the creating process exits. This is what I was talking about. Regards, P-- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
