From: Chuck Lever <chuck.lever@xxxxxxxxxx> Performance regression reported with NFS/RDMA using Omnipath. Tracing on the server reports: nfsd-7771 [060] 1758.891809: svcrdma_sq_post_err: cq.id=205 cid=226 sc_sq_avail=13643/851 status=-12 sq_post_err reports ENOMEM, and the rdma->sc_sq_avail (13643) is larger than rdma->sc_sq_depth (851). The number of available Send Queue entries is always supposed to be smaller than the Send Queue depth. That seems like a Send Queue accounting bug in svcrdma. As it's getting to be late in the 6.9-rc cycle, revert this commit. It can be revisited in a subsequent kernel release. Link: https://bugzilla.kernel.org/show_bug.cgi?id=218743 Fixes: e084ee673c77 ("svcrdma: Add Write chunk WRs to the RPC's Send WR chain") Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> --- include/linux/sunrpc/svc_rdma.h | 13 +---- net/sunrpc/xprtrdma/svc_rdma_rw.c | 86 ++++++++------------------------- net/sunrpc/xprtrdma/svc_rdma_sendto.c | 5 -- 3 files changed, 26 insertions(+), 78 deletions(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index 24cd199dd6f3..d33bab33099a 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -210,7 +210,6 @@ struct svc_rdma_recv_ctxt { */ struct svc_rdma_write_info { struct svcxprt_rdma *wi_rdma; - struct list_head wi_list; const struct svc_rdma_chunk *wi_chunk; @@ -239,10 +238,7 @@ struct svc_rdma_send_ctxt { struct ib_cqe sc_cqe; struct xdr_buf sc_hdrbuf; struct xdr_stream sc_stream; - - struct list_head sc_write_info_list; struct svc_rdma_write_info sc_reply_info; - void *sc_xprt_buf; int sc_page_count; int sc_cur_sge_no; @@ -274,14 +270,11 @@ extern void svc_rdma_cc_init(struct svcxprt_rdma *rdma, extern void svc_rdma_cc_release(struct svcxprt_rdma *rdma, struct svc_rdma_chunk_ctxt *cc, enum dma_data_direction dir); -extern void svc_rdma_write_chunk_release(struct svcxprt_rdma *rdma, - struct svc_rdma_send_ctxt *ctxt); extern void svc_rdma_reply_chunk_release(struct svcxprt_rdma *rdma, struct svc_rdma_send_ctxt *ctxt); -extern int svc_rdma_prepare_write_list(struct svcxprt_rdma *rdma, - const struct svc_rdma_pcl *write_pcl, - struct svc_rdma_send_ctxt *sctxt, - const struct xdr_buf *xdr); +extern int svc_rdma_send_write_list(struct svcxprt_rdma *rdma, + const struct svc_rdma_recv_ctxt *rctxt, + const struct xdr_buf *xdr); extern int svc_rdma_prepare_reply_chunk(struct svcxprt_rdma *rdma, const struct svc_rdma_pcl *write_pcl, const struct svc_rdma_pcl *reply_pcl, diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c index f2a100c4c81f..40797114d50a 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_rw.c +++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c @@ -230,28 +230,6 @@ static void svc_rdma_write_info_free(struct svc_rdma_write_info *info) queue_work(svcrdma_wq, &info->wi_work); } -/** - * svc_rdma_write_chunk_release - Release Write chunk I/O resources - * @rdma: controlling transport - * @ctxt: Send context that is being released - */ -void svc_rdma_write_chunk_release(struct svcxprt_rdma *rdma, - struct svc_rdma_send_ctxt *ctxt) -{ - struct svc_rdma_write_info *info; - struct svc_rdma_chunk_ctxt *cc; - - while (!list_empty(&ctxt->sc_write_info_list)) { - info = list_first_entry(&ctxt->sc_write_info_list, - struct svc_rdma_write_info, wi_list); - list_del(&info->wi_list); - - cc = &info->wi_cc; - svc_rdma_wake_send_waiters(rdma, cc->cc_sqecount); - svc_rdma_write_info_free(info); - } -} - /** * svc_rdma_reply_chunk_release - Release Reply chunk I/O resources * @rdma: controlling transport @@ -308,11 +286,13 @@ static void svc_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc) struct ib_cqe *cqe = wc->wr_cqe; struct svc_rdma_chunk_ctxt *cc = container_of(cqe, struct svc_rdma_chunk_ctxt, cc_cqe); + struct svc_rdma_write_info *info = + container_of(cc, struct svc_rdma_write_info, wi_cc); switch (wc->status) { case IB_WC_SUCCESS: trace_svcrdma_wc_write(&cc->cc_cid); - return; + break; case IB_WC_WR_FLUSH_ERR: trace_svcrdma_wc_write_flush(wc, &cc->cc_cid); break; @@ -320,11 +300,12 @@ static void svc_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc) trace_svcrdma_wc_write_err(wc, &cc->cc_cid); } - /* The RDMA Write has flushed, so the client won't get - * some of the outgoing RPC message. Signal the loss - * to the client by closing the connection. - */ - svc_xprt_deferred_close(&rdma->sc_xprt); + svc_rdma_wake_send_waiters(rdma, cc->cc_sqecount); + + if (unlikely(wc->status != IB_WC_SUCCESS)) + svc_xprt_deferred_close(&rdma->sc_xprt); + + svc_rdma_write_info_free(info); } /** @@ -620,19 +601,13 @@ static int svc_rdma_xb_write(const struct xdr_buf *xdr, void *data) return xdr->len; } -/* Link Write WRs for @chunk onto @sctxt's WR chain. - */ -static int svc_rdma_prepare_write_chunk(struct svcxprt_rdma *rdma, - struct svc_rdma_send_ctxt *sctxt, - const struct svc_rdma_chunk *chunk, - const struct xdr_buf *xdr) +static int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma, + const struct svc_rdma_chunk *chunk, + const struct xdr_buf *xdr) { struct svc_rdma_write_info *info; struct svc_rdma_chunk_ctxt *cc; - struct ib_send_wr *first_wr; struct xdr_buf payload; - struct list_head *pos; - struct ib_cqe *cqe; int ret; if (xdr_buf_subsegment(xdr, &payload, chunk->ch_position, @@ -648,25 +623,10 @@ static int svc_rdma_prepare_write_chunk(struct svcxprt_rdma *rdma, if (ret != payload.len) goto out_err; - ret = -EINVAL; - if (unlikely(cc->cc_sqecount > rdma->sc_sq_depth)) - goto out_err; - - first_wr = sctxt->sc_wr_chain; - cqe = &cc->cc_cqe; - list_for_each(pos, &cc->cc_rwctxts) { - struct svc_rdma_rw_ctxt *rwc; - - rwc = list_entry(pos, struct svc_rdma_rw_ctxt, rw_list); - first_wr = rdma_rw_ctx_wrs(&rwc->rw_ctx, rdma->sc_qp, - rdma->sc_port_num, cqe, first_wr); - cqe = NULL; - } - sctxt->sc_wr_chain = first_wr; - sctxt->sc_sqecount += cc->cc_sqecount; - list_add(&info->wi_list, &sctxt->sc_write_info_list); - trace_svcrdma_post_write_chunk(&cc->cc_cid, cc->cc_sqecount); + ret = svc_rdma_post_chunk_ctxt(rdma, cc); + if (ret < 0) + goto out_err; return 0; out_err: @@ -675,27 +635,25 @@ static int svc_rdma_prepare_write_chunk(struct svcxprt_rdma *rdma, } /** - * svc_rdma_prepare_write_list - Construct WR chain for sending Write list + * svc_rdma_send_write_list - Send all chunks on the Write list * @rdma: controlling RDMA transport - * @write_pcl: Write list provisioned by the client - * @sctxt: Send WR resources + * @rctxt: Write list provisioned by the client * @xdr: xdr_buf containing an RPC Reply message * * Returns zero on success, or a negative errno if one or more * Write chunks could not be sent. */ -int svc_rdma_prepare_write_list(struct svcxprt_rdma *rdma, - const struct svc_rdma_pcl *write_pcl, - struct svc_rdma_send_ctxt *sctxt, - const struct xdr_buf *xdr) +int svc_rdma_send_write_list(struct svcxprt_rdma *rdma, + const struct svc_rdma_recv_ctxt *rctxt, + const struct xdr_buf *xdr) { struct svc_rdma_chunk *chunk; int ret; - pcl_for_each_chunk(chunk, write_pcl) { + pcl_for_each_chunk(chunk, &rctxt->rc_write_pcl) { if (!chunk->ch_payload_length) break; - ret = svc_rdma_prepare_write_chunk(rdma, sctxt, chunk, xdr); + ret = svc_rdma_send_write_chunk(rdma, chunk, xdr); if (ret < 0) return ret; } diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index dfca39abd16c..bb5436b719e0 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -142,7 +142,6 @@ svc_rdma_send_ctxt_alloc(struct svcxprt_rdma *rdma) ctxt->sc_send_wr.sg_list = ctxt->sc_sges; ctxt->sc_send_wr.send_flags = IB_SEND_SIGNALED; ctxt->sc_cqe.done = svc_rdma_wc_send; - INIT_LIST_HEAD(&ctxt->sc_write_info_list); ctxt->sc_xprt_buf = buffer; xdr_buf_init(&ctxt->sc_hdrbuf, ctxt->sc_xprt_buf, rdma->sc_max_req_size); @@ -228,7 +227,6 @@ static void svc_rdma_send_ctxt_release(struct svcxprt_rdma *rdma, struct ib_device *device = rdma->sc_cm_id->device; unsigned int i; - svc_rdma_write_chunk_release(rdma, ctxt); svc_rdma_reply_chunk_release(rdma, ctxt); if (ctxt->sc_page_count) @@ -1015,8 +1013,7 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) if (!p) goto put_ctxt; - ret = svc_rdma_prepare_write_list(rdma, &rctxt->rc_write_pcl, sctxt, - &rqstp->rq_res); + ret = svc_rdma_send_write_list(rdma, rctxt, &rqstp->rq_res); if (ret < 0) goto put_ctxt;
