On Jul 2, 2014, at 3:48 PM, Devesh Sharma <[email protected]> wrote:
> > >> -----Original Message----- >> From: Steve Wise [mailto:[email protected]] >> Sent: Thursday, July 03, 2014 1:16 AM >> To: 'Chuck Lever'; Devesh Sharma >> Cc: [email protected]; 'Linux NFS Mailing List' >> Subject: RE: [PATCH v1 05/13] xprtrdma: Don't drain CQs on transport >> disconnect >> >> >> >>> -----Original Message----- >>> From: Chuck Lever [mailto:[email protected]] >>> Sent: Wednesday, July 02, 2014 2:40 PM >>> To: Steve Wise; Devesh Sharma >>> Cc: [email protected]; Linux NFS Mailing List >>> Subject: Re: [PATCH v1 05/13] xprtrdma: Don't drain CQs on transport >>> disconnect >>> >>> >>> On Jul 2, 2014, at 3:28 PM, Steve Wise <[email protected]> >> wrote: >>> >>>> 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? >>> >>> I tested this aggressively with a fault injector that triggers regular >>> connection disruption. >>> >>>> Hey Devesh, >>>> >>>> iw_cxgb4 will silently toss CQEs if the QP is not active. >>> >>> xprtrdma relies on getting a completion (either successful or in >>> error) for every WR it has posted. The goal of this patch is to avoid >>> throwing away queued completions after a transport disconnect so we >>> don't lose track of FRMR rkey updates (FAST_REG_MR and LOCAL_INV >>> completions) and we can capture all RPC replies posted before the >> connection was lost. >>> >>> Sounds like we also need to keep the QP around, even in error state, >>> until all known WRs on that QP have completed? >>> > > Why not poll and process every completion during rpcrdma_cq_cleanup()…. Yes, I have a patch in the next version of this series that does that. It just calls rpcrdma_sendcq_upcall() from the connect worker. I will squash that change into this patch. Maybe it needs to invoke rpcrdma_recvcq_upcall() there as well. > >> >> Perhaps. >> >>> >>>> >>>> >>>>>> -----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. >>>>>> >>>>>> 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-nfs" >>>> in the body of a message to [email protected] More >> majordomo >>>> info at http://vger.kernel.org/majordomo-info.html >>> >>> -- >>> Chuck Lever >>> chuck[dot]lever[at]oracle[dot]com >>> >>> >> > -- > 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 > -- Chuck Lever chuck[dot]lever[at]oracle[dot]com -- 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
