RE: [openib-general] agent_mad_send
Title: RE: [openib-general] agent_mad_send The reason for this is that for special QPs the driver insert the AV to the packet and not the HW. In regular QP the HW reads the AV only when is actually doing the send and thus you have to wait and not destroy the AV till the send completes. Tziporet -Original Message- From: Roland Dreier [mailto:[EMAIL PROTECTED]] Sent: Wednesday, October 27, 2004 6:18 AM To: Sean Hefty Cc: [EMAIL PROTECTED] Subject: Re: [openib-general] agent_mad_send Sean> In agent_mad_send, a call is made to create an address Sean> handle. Immediately after calling ib_post_send_mad, the Sean> address handle is destroyed. I think that we want to wait Sean> until the send is completed before destroying the address Sean> handle, and require this of all callers of ib_post_send_mad. Yes, that's correct. Because of a quirk in the way Mellanox HCA's implement special QPs, it's actually OK to destroy the AH immediately after posting the send, but for an ordinary QP this will lead to some bizarre problems. - R. ___ openib-general mailing list [EMAIL PROTECTED] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general ___ openib-general mailing list [EMAIL PROTECTED] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
Re: [openib-general] agent_mad_send
On Wed, 2004-10-27 at 12:47, Sean Hefty wrote: > > I can post a patch for this but this depends on whether the agent or MAD > > layer should destroy the AH. > > I think that the MAD agent should, since it allocated the AH. That's what I thought but didn't want to post a patch and find out otherwise. -- Hal ___ openib-general mailing list [EMAIL PROTECTED] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
Re: [openib-general] agent_mad_send
On Wed, 27 Oct 2004 09:47:25 -0400 Hal Rosenstock <[EMAIL PROTECTED]> wrote: > On Tue, 2004-10-26 at 18:29, Sean Hefty wrote: > > In agent_mad_send, a call is made to create an address handle. > > Immediately after calling ib_post_send_mad, the address handle is destroyed. > > I think that we want to wait until the send is completed before destroying > > the address handle, and require this of all callers of ib_post_send_mad. > > I can post a patch for this but this depends on whether the agent or MAD > layer should destroy the AH. I think that the MAD agent should, since it allocated the AH. > > Also, I don't think that we want to have this code access the port_priv > > structure, such as the send_list_lock (which ends up being acquired twice). > > The agent is using a different port_priv structure and send_list_lock > than the one the MAD layer uses. Where is it acquired twice ? My bad. I was working off of the variable names, and didn't check that they had different types. - Sean -- ___ openib-general mailing list [EMAIL PROTECTED] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
Re: [openib-general] agent_mad_send
On Tue, 26 Oct 2004 21:17:34 -0700 Roland Dreier <[EMAIL PROTECTED]> wrote: > Sean> In agent_mad_send, a call is made to create an address > Sean> handle. Immediately after calling ib_post_send_mad, the > Sean> address handle is destroyed. I think that we want to wait > Sean> until the send is completed before destroying the address > Sean> handle, and require this of all callers of ib_post_send_mad. > > Yes, that's correct. Because of a quirk in the way Mellanox HCA's > implement special QPs, it's actually OK to destroy the AH immediately > after posting the send, but for an ordinary QP this will lead to some > bizarre problems. I'm concerned about handling QP overrun cases, where the call to ib_post_send_mad doesn't immediately post to the QP. - Sean ___ openib-general mailing list [EMAIL PROTECTED] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
Re: [openib-general] agent_mad_send
On Tue, 2004-10-26 at 18:29, Sean Hefty wrote: > In agent_mad_send, a call is made to create an address handle. > Immediately after calling ib_post_send_mad, the address handle is destroyed. > I think that we want to wait until the send is completed before destroying > the address handle, and require this of all callers of ib_post_send_mad. I can post a patch for this but this depends on whether the agent or MAD layer should destroy the AH. > Also, I don't think that we want to have this code access the port_priv > structure, such as the send_list_lock (which ends up being acquired twice). The agent is using a different port_priv structure and send_list_lock than the one the MAD layer uses. Where is it acquired twice ? > Queuing of MADs should be done by the ib_post_send_mad call, > and not by its caller. This will be needed to handle QP overflow anyway. > Agent_send_handler has a similar issue. The agent layer is queuing the send to release resources (PCI unmap and free MAD memory) on send completion, not for retransmission on QP overflow. -- Hal ___ openib-general mailing list [EMAIL PROTECTED] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
Re: [openib-general] agent_mad_send
Sean> In agent_mad_send, a call is made to create an address Sean> handle. Immediately after calling ib_post_send_mad, the Sean> address handle is destroyed. I think that we want to wait Sean> until the send is completed before destroying the address Sean> handle, and require this of all callers of ib_post_send_mad. Yes, that's correct. Because of a quirk in the way Mellanox HCA's implement special QPs, it's actually OK to destroy the AH immediately after posting the send, but for an ordinary QP this will lead to some bizarre problems. - R. ___ openib-general mailing list [EMAIL PROTECTED] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
