> -----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... > > > > > > >> -----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== -- 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
