> -----Original Message----- > From: Steve Wise [mailto:[email protected]] > Sent: Thursday, July 03, 2014 1:27 AM > To: Devesh Sharma; 'Chuck Lever'; [email protected]; linux- > [email protected] > Subject: RE: [PATCH v1 05/13] xprtrdma: Don't drain CQs on transport > disconnect > > > > > -----Original Message----- > > From: Devesh Sharma [mailto:[email protected]] > > Sent: Wednesday, July 02, 2014 2:54 PM > > To: Steve Wise; 'Chuck Lever'; [email protected]; > > [email protected] > > Subject: RE: [PATCH v1 05/13] xprtrdma: Don't drain CQs on transport > > disconnect > > > > > > > > > -----Original Message----- > > > From: Steve Wise [mailto:[email protected]] > > > Sent: Thursday, July 03, 2014 1:21 AM > > > To: Devesh Sharma; 'Chuck Lever'; [email protected]; linux- > > > [email protected] > > > Subject: RE: [PATCH v1 05/13] xprtrdma: Don't drain CQs on transport > > > disconnect > > > > > > > > > > > > > -----Original Message----- > > > > From: Devesh Sharma [mailto:[email protected]] > > > > Sent: Wednesday, July 02, 2014 2:43 PM > > > > To: Steve Wise; Chuck Lever; [email protected]; > > > > [email protected] > > > > Subject: RE: [PATCH v1 05/13] xprtrdma: Don't drain CQs on > > > > transport disconnect > > > > > > > > > -----Original Message----- > > > > > From: Steve Wise [mailto:[email protected]] > > > > > Sent: Thursday, July 03, 2014 12:59 AM > > > > > To: Devesh Sharma; Chuck Lever; [email protected]; > > > > > linux- [email protected] > > > > > Subject: Re: [PATCH v1 05/13] xprtrdma: Don't drain CQs on > > > > > transport disconnect > > > > > > > > > > On 7/2/2014 2:06 PM, Devesh Sharma wrote: > > > > > > This change is very much prone to generate poll_cq errors > > > > > > because of un-cleaned completions which still point to the > > > > > > non-existent QPs. On the new connection when these completions > > > > > > are polled, the poll_cq will fail > > > > > because old QP pointer is already NULL. > > > > > > Did anyone hit this situation during their testing? > > > > > > > > > > Hey Devesh, > > > > > > > > > > iw_cxgb4 will silently toss CQEs if the QP is not active. > > > > > > > > Ya, just now checked that in mlx and cxgb4 driver code. On the > > > > other hand ocrdma is asserting a BUG-ON for such CQEs causing system > panic. > > > > Out of curiosity I am asking, how this change is useful here, is > > > > it reducing the re-connection time...Anyhow rpcrdma_clean_cq was > > > > discarding the completions (flush/successful both) > > > > > > > > > > Well, I don't think there is anything restricting an application from > destroying > > > the QP with pending CQEs on its CQs. So it definitely shouldn't cause a > > > BUG_ON() I think. I'll have to read up in the Verbs specs if destroying > > > a > QP > > > kills all the pending CQEs... > > > > Oh confusion...let me clarify: in ocrdma BUG ON is hit in poll_cq() > > after re-connection happens and cq is polled again. > > Now the first completion in CQ still points to old QP-ID for which > > ocrdma does not have valid QP pointer. > > > > Right. Which means it’s a stale CQE. I don't think that should cause a > BUG_ON.
Yes this surely needs a fix in ocrdma. > > > > > > > > > > > > > > > > > > > > > > > >> -----Original Message----- > > > > > >> From: [email protected] [mailto:linux-rdma- > > > > > >> [email protected]] On Behalf Of Chuck Lever > > > > > >> Sent: Tuesday, June 24, 2014 4:10 AM > > > > > >> To: [email protected]; [email protected] > > > > > >> Subject: [PATCH v1 05/13] xprtrdma: Don't drain CQs on > > > > > >> transport disconnect > > > > > >> > > > > > >> CQs are not destroyed until unmount. By draining CQs on > > > > > >> transport disconnect, successful completions that can change > > > > > >> the r.frmr.state field can be missed. > > > > > > > > Still those are missed isn’t it....Since those successful > > > > completions will still be dropped after re- connection. Am I > > > > missing something to understanding the motivation... > > > > > > > > > >> > > > > > >> Signed-off-by: Chuck Lever <[email protected]> > > > > > >> --- > > > > > >> net/sunrpc/xprtrdma/verbs.c | 5 ----- > > > > > >> 1 file changed, 5 deletions(-) > > > > > >> > > > > > >> diff --git a/net/sunrpc/xprtrdma/verbs.c > > > > > >> b/net/sunrpc/xprtrdma/verbs.c index 3c7f904..451e100 100644 > > > > > >> --- a/net/sunrpc/xprtrdma/verbs.c > > > > > >> +++ b/net/sunrpc/xprtrdma/verbs.c > > > > > >> @@ -873,9 +873,6 @@ retry: > > > > > >> dprintk("RPC: %s: > > > rpcrdma_ep_disconnect" > > > > > >> " status %i\n", __func__, rc); > > > > > >> > > > > > >> - rpcrdma_clean_cq(ep->rep_attr.recv_cq); > > > > > >> - rpcrdma_clean_cq(ep->rep_attr.send_cq); > > > > > >> - > > > > > >> xprt = container_of(ia, struct rpcrdma_xprt, rx_ia); > > > > > >> id = rpcrdma_create_id(xprt, ia, > > > > > >> (struct sockaddr *)&xprt- > > > >rx_data.addr); > > > > > @@ -985,8 +982,6 @@ > > > > > >> rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct > > > > > >> rpcrdma_ia > > > > > >> *ia) { > > > > > >> int rc; > > > > > >> > > > > > >> - rpcrdma_clean_cq(ep->rep_attr.recv_cq); > > > > > >> - rpcrdma_clean_cq(ep->rep_attr.send_cq); > > > > > >> rc = rdma_disconnect(ia->ri_id); > > > > > >> if (!rc) { > > > > > >> /* returns without wait if not connected */ > > > > > >> > > > > > >> -- > > > > > >> To unsubscribe from this list: send the line "unsubscribe linux- > rdma" > > > > > >> in the body of a message to [email protected] More > > > > > majordomo > > > > > >> info at http://vger.kernel.org/majordomo-info.html > > > > > > N r y b X ǧv ^ ){.n + { " ^n r z h & G > > > > > > h > > > > > > ( 階 ݢj" m z ޖ f h ~ mml== > > > >
