diff options
Diffstat (limited to 'net/sunrpc/xprtrdma')
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 2 | ||||
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_rw.c | 181 | ||||
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_sendto.c | 148 | ||||
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_transport.c | 15 |
4 files changed, 213 insertions, 133 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c index c9be677864..e5a78b7610 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -90,7 +90,7 @@ static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma, */ get_page(virt_to_page(rqst->rq_buffer)); sctxt->sc_send_wr.opcode = IB_WR_SEND; - return svc_rdma_send(rdma, sctxt); + return svc_rdma_post_send(rdma, sctxt); } /* Server-side transport endpoint wants a whole page for its send diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c index c00fcce61d..40797114d5 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_rw.c +++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c @@ -197,28 +197,6 @@ void svc_rdma_cc_release(struct svcxprt_rdma *rdma, llist_add_batch(first, last, &rdma->sc_rw_ctxts); } -/* State for sending a Write or Reply chunk. - * - Tracks progress of writing one chunk over all its segments - * - Stores arguments for the SGL constructor functions - */ -struct svc_rdma_write_info { - struct svcxprt_rdma *wi_rdma; - - const struct svc_rdma_chunk *wi_chunk; - - /* write state of this chunk */ - unsigned int wi_seg_off; - unsigned int wi_seg_no; - - /* SGL constructor arguments */ - const struct xdr_buf *wi_xdr; - unsigned char *wi_base; - unsigned int wi_next_off; - - struct svc_rdma_chunk_ctxt wi_cc; - struct work_struct wi_work; -}; - static struct svc_rdma_write_info * svc_rdma_write_info_alloc(struct svcxprt_rdma *rdma, const struct svc_rdma_chunk *chunk) @@ -253,6 +231,49 @@ static void svc_rdma_write_info_free(struct svc_rdma_write_info *info) } /** + * svc_rdma_reply_chunk_release - Release Reply chunk I/O resources + * @rdma: controlling transport + * @ctxt: Send context that is being released + */ +void svc_rdma_reply_chunk_release(struct svcxprt_rdma *rdma, + struct svc_rdma_send_ctxt *ctxt) +{ + struct svc_rdma_chunk_ctxt *cc = &ctxt->sc_reply_info.wi_cc; + + if (!cc->cc_sqecount) + return; + svc_rdma_cc_release(rdma, cc, DMA_TO_DEVICE); +} + +/** + * svc_rdma_reply_done - Reply chunk Write completion handler + * @cq: controlling Completion Queue + * @wc: Work Completion report + * + * Pages under I/O are released by a subsequent Send completion. + */ +static void svc_rdma_reply_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 svcxprt_rdma *rdma = cq->cq_context; + + switch (wc->status) { + case IB_WC_SUCCESS: + trace_svcrdma_wc_reply(&cc->cc_cid); + return; + case IB_WC_WR_FLUSH_ERR: + trace_svcrdma_wc_reply_flush(wc, &cc->cc_cid); + break; + default: + trace_svcrdma_wc_reply_err(wc, &cc->cc_cid); + } + + svc_xprt_deferred_close(&rdma->sc_xprt); +} + +/** * svc_rdma_write_done - Write chunk completion * @cq: controlling Completion Queue * @wc: Work Completion @@ -580,41 +601,33 @@ static int svc_rdma_xb_write(const struct xdr_buf *xdr, void *data) return xdr->len; } -/** - * svc_rdma_send_write_chunk - Write all segments in a Write chunk - * @rdma: controlling RDMA transport - * @chunk: Write chunk provided by the client - * @xdr: xdr_buf containing the data payload - * - * Returns a non-negative number of bytes the chunk consumed, or - * %-E2BIG if the payload was larger than the Write chunk, - * %-EINVAL if client provided too many segments, - * %-ENOMEM if rdma_rw context pool was exhausted, - * %-ENOTCONN if posting failed (connection is lost), - * %-EIO if rdma_rw initialization failed (DMA mapping, etc). - */ -int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma, - 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 xdr_buf payload; int ret; + if (xdr_buf_subsegment(xdr, &payload, chunk->ch_position, + chunk->ch_payload_length)) + return -EMSGSIZE; + info = svc_rdma_write_info_alloc(rdma, chunk); if (!info) return -ENOMEM; cc = &info->wi_cc; - ret = svc_rdma_xb_write(xdr, info); - if (ret != xdr->len) + ret = svc_rdma_xb_write(&payload, info); + if (ret != payload.len) goto out_err; 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 xdr->len; + return 0; out_err: svc_rdma_write_info_free(info); @@ -622,9 +635,37 @@ out_err: } /** - * svc_rdma_send_reply_chunk - Write all segments in the Reply chunk + * svc_rdma_send_write_list - Send all chunks on the Write list * @rdma: controlling RDMA transport - * @rctxt: Write and Reply chunks from client + * @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_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, &rctxt->rc_write_pcl) { + if (!chunk->ch_payload_length) + break; + ret = svc_rdma_send_write_chunk(rdma, chunk, xdr); + if (ret < 0) + return ret; + } + return 0; +} + +/** + * svc_rdma_prepare_reply_chunk - Construct WR chain for writing the Reply chunk + * @rdma: controlling RDMA transport + * @write_pcl: Write chunk list provided by client + * @reply_pcl: Reply chunk provided by client + * @sctxt: Send WR resources * @xdr: xdr_buf containing an RPC Reply * * Returns a non-negative number of bytes the chunk consumed, or @@ -634,39 +675,45 @@ out_err: * %-ENOTCONN if posting failed (connection is lost), * %-EIO if rdma_rw initialization failed (DMA mapping, etc). */ -int svc_rdma_send_reply_chunk(struct svcxprt_rdma *rdma, - const struct svc_rdma_recv_ctxt *rctxt, - const struct xdr_buf *xdr) +int svc_rdma_prepare_reply_chunk(struct svcxprt_rdma *rdma, + const struct svc_rdma_pcl *write_pcl, + const struct svc_rdma_pcl *reply_pcl, + struct svc_rdma_send_ctxt *sctxt, + const struct xdr_buf *xdr) { - struct svc_rdma_write_info *info; - struct svc_rdma_chunk_ctxt *cc; - struct svc_rdma_chunk *chunk; + struct svc_rdma_write_info *info = &sctxt->sc_reply_info; + struct svc_rdma_chunk_ctxt *cc = &info->wi_cc; + struct ib_send_wr *first_wr; + struct list_head *pos; + struct ib_cqe *cqe; int ret; - if (pcl_is_empty(&rctxt->rc_reply_pcl)) - return 0; - - chunk = pcl_first_chunk(&rctxt->rc_reply_pcl); - info = svc_rdma_write_info_alloc(rdma, chunk); - if (!info) - return -ENOMEM; - cc = &info->wi_cc; + info->wi_rdma = rdma; + info->wi_chunk = pcl_first_chunk(reply_pcl); + info->wi_seg_off = 0; + info->wi_seg_no = 0; + info->wi_cc.cc_cqe.done = svc_rdma_reply_done; - ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, + ret = pcl_process_nonpayloads(write_pcl, xdr, svc_rdma_xb_write, info); if (ret < 0) - goto out_err; + return ret; - trace_svcrdma_post_reply_chunk(&cc->cc_cid, cc->cc_sqecount); - ret = svc_rdma_post_chunk_ctxt(rdma, cc); - if (ret < 0) - 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; - return xdr->len; + 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; -out_err: - svc_rdma_write_info_free(info); - return ret; + trace_svcrdma_post_reply_chunk(&cc->cc_cid, cc->cc_sqecount); + return xdr->len; } /** diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index 1a49b7f020..bb5436b719 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -205,9 +205,13 @@ out: xdr_init_encode(&ctxt->sc_stream, &ctxt->sc_hdrbuf, ctxt->sc_xprt_buf, NULL); + svc_rdma_cc_init(rdma, &ctxt->sc_reply_info.wi_cc); ctxt->sc_send_wr.num_sge = 0; ctxt->sc_cur_sge_no = 0; ctxt->sc_page_count = 0; + ctxt->sc_wr_chain = &ctxt->sc_send_wr; + ctxt->sc_sqecount = 1; + return ctxt; out_empty: @@ -223,6 +227,8 @@ 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_reply_chunk_release(rdma, ctxt); + if (ctxt->sc_page_count) release_pages(ctxt->sc_pages, ctxt->sc_page_count); @@ -293,7 +299,7 @@ static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc) struct svc_rdma_send_ctxt *ctxt = container_of(cqe, struct svc_rdma_send_ctxt, sc_cqe); - svc_rdma_wake_send_waiters(rdma, 1); + svc_rdma_wake_send_waiters(rdma, ctxt->sc_sqecount); if (unlikely(wc->status != IB_WC_SUCCESS)) goto flushed; @@ -312,51 +318,76 @@ flushed: } /** - * svc_rdma_send - Post a single Send WR - * @rdma: transport on which to post the WR - * @ctxt: send ctxt with a Send WR ready to post + * svc_rdma_post_send - Post a WR chain to the Send Queue + * @rdma: transport context + * @ctxt: WR chain to post + * + * Copy fields in @ctxt to stack variables in order to guarantee + * that these values remain available after the ib_post_send() call. + * In some error flow cases, svc_rdma_wc_send() releases @ctxt. + * + * Note there is potential for starvation when the Send Queue is + * full because there is no order to when waiting threads are + * awoken. The transport is typically provisioned with a deep + * enough Send Queue that SQ exhaustion should be a rare event. * - * Returns zero if the Send WR was posted successfully. Otherwise, a - * negative errno is returned. + * Return values: + * %0: @ctxt's WR chain was posted successfully + * %-ENOTCONN: The connection was lost */ -int svc_rdma_send(struct svcxprt_rdma *rdma, struct svc_rdma_send_ctxt *ctxt) +int svc_rdma_post_send(struct svcxprt_rdma *rdma, + struct svc_rdma_send_ctxt *ctxt) { - struct ib_send_wr *wr = &ctxt->sc_send_wr; - int ret; + struct ib_send_wr *first_wr = ctxt->sc_wr_chain; + struct ib_send_wr *send_wr = &ctxt->sc_send_wr; + const struct ib_send_wr *bad_wr = first_wr; + struct rpc_rdma_cid cid = ctxt->sc_cid; + int ret, sqecount = ctxt->sc_sqecount; might_sleep(); /* Sync the transport header buffer */ ib_dma_sync_single_for_device(rdma->sc_pd->device, - wr->sg_list[0].addr, - wr->sg_list[0].length, + send_wr->sg_list[0].addr, + send_wr->sg_list[0].length, DMA_TO_DEVICE); /* If the SQ is full, wait until an SQ entry is available */ - while (1) { - if ((atomic_dec_return(&rdma->sc_sq_avail) < 0)) { + while (!test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) { + if (atomic_sub_return(sqecount, &rdma->sc_sq_avail) < 0) { + svc_rdma_wake_send_waiters(rdma, sqecount); + + /* When the transport is torn down, assume + * ib_drain_sq() will trigger enough Send + * completions to wake us. The XPT_CLOSE test + * above should then cause the while loop to + * exit. + */ percpu_counter_inc(&svcrdma_stat_sq_starve); - trace_svcrdma_sq_full(rdma, &ctxt->sc_cid); - atomic_inc(&rdma->sc_sq_avail); + trace_svcrdma_sq_full(rdma, &cid); wait_event(rdma->sc_send_wait, - atomic_read(&rdma->sc_sq_avail) > 1); - if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) - return -ENOTCONN; - trace_svcrdma_sq_retry(rdma, &ctxt->sc_cid); + atomic_read(&rdma->sc_sq_avail) > 0); + trace_svcrdma_sq_retry(rdma, &cid); continue; } trace_svcrdma_post_send(ctxt); - ret = ib_post_send(rdma->sc_qp, wr, NULL); - if (ret) - break; + ret = ib_post_send(rdma->sc_qp, first_wr, &bad_wr); + if (ret) { + trace_svcrdma_sq_post_err(rdma, &cid, ret); + svc_xprt_deferred_close(&rdma->sc_xprt); + + /* If even one WR was posted, there will be a + * Send completion that bumps sc_sq_avail. + */ + if (bad_wr == first_wr) { + svc_rdma_wake_send_waiters(rdma, sqecount); + break; + } + } return 0; } - - trace_svcrdma_sq_post_err(rdma, &ctxt->sc_cid, ret); - svc_xprt_deferred_close(&rdma->sc_xprt); - wake_up(&rdma->sc_send_wait); - return ret; + return -ENOTCONN; } /** @@ -839,16 +870,10 @@ static void svc_rdma_save_io_pages(struct svc_rqst *rqstp, * in sc_sges[0], and the RPC xdr_buf is prepared in following sges. * * Depending on whether a Write list or Reply chunk is present, - * the server may send all, a portion of, or none of the xdr_buf. + * the server may Send all, a portion of, or none of the xdr_buf. * In the latter case, only the transport header (sc_sges[0]) is * transmitted. * - * RDMA Send is the last step of transmitting an RPC reply. Pages - * involved in the earlier RDMA Writes are here transferred out - * of the rqstp and into the sctxt's page array. These pages are - * DMA unmapped by each Write completion, but the subsequent Send - * completion finally releases these pages. - * * Assumptions: * - The Reply's transport header will never be larger than a page. */ @@ -857,6 +882,7 @@ static int svc_rdma_send_reply_msg(struct svcxprt_rdma *rdma, const struct svc_rdma_recv_ctxt *rctxt, struct svc_rqst *rqstp) { + struct ib_send_wr *send_wr = &sctxt->sc_send_wr; int ret; ret = svc_rdma_map_reply_msg(rdma, sctxt, &rctxt->rc_write_pcl, @@ -864,16 +890,19 @@ static int svc_rdma_send_reply_msg(struct svcxprt_rdma *rdma, if (ret < 0) return ret; + /* Transfer pages involved in RDMA Writes to the sctxt's + * page array. Completion handling releases these pages. + */ svc_rdma_save_io_pages(rqstp, sctxt); if (rctxt->rc_inv_rkey) { - sctxt->sc_send_wr.opcode = IB_WR_SEND_WITH_INV; - sctxt->sc_send_wr.ex.invalidate_rkey = rctxt->rc_inv_rkey; + send_wr->opcode = IB_WR_SEND_WITH_INV; + send_wr->ex.invalidate_rkey = rctxt->rc_inv_rkey; } else { - sctxt->sc_send_wr.opcode = IB_WR_SEND; + send_wr->opcode = IB_WR_SEND; } - return svc_rdma_send(rdma, sctxt); + return svc_rdma_post_send(rdma, sctxt); } /** @@ -937,7 +966,7 @@ void svc_rdma_send_error_msg(struct svcxprt_rdma *rdma, sctxt->sc_send_wr.num_sge = 1; sctxt->sc_send_wr.opcode = IB_WR_SEND; sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; - if (svc_rdma_send(rdma, sctxt)) + if (svc_rdma_post_send(rdma, sctxt)) goto put_ctxt; return; @@ -984,10 +1013,19 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) if (!p) goto put_ctxt; - ret = svc_rdma_send_reply_chunk(rdma, rctxt, &rqstp->rq_res); + ret = svc_rdma_send_write_list(rdma, rctxt, &rqstp->rq_res); if (ret < 0) - goto reply_chunk; - rc_size = ret; + goto put_ctxt; + + rc_size = 0; + if (!pcl_is_empty(&rctxt->rc_reply_pcl)) { + ret = svc_rdma_prepare_reply_chunk(rdma, &rctxt->rc_write_pcl, + &rctxt->rc_reply_pcl, sctxt, + &rqstp->rq_res); + if (ret < 0) + goto reply_chunk; + rc_size = ret; + } *p++ = *rdma_argp; *p++ = *(rdma_argp + 1); @@ -1030,45 +1068,33 @@ drop_connection: /** * svc_rdma_result_payload - special processing for a result payload - * @rqstp: svc_rqst to operate on - * @offset: payload's byte offset in @xdr + * @rqstp: RPC transaction context + * @offset: payload's byte offset in @rqstp->rq_res * @length: size of payload, in bytes * + * Assign the passed-in result payload to the current Write chunk, + * and advance to cur_result_payload to the next Write chunk, if + * there is one. + * * Return values: * %0 if successful or nothing needed to be done - * %-EMSGSIZE on XDR buffer overflow * %-E2BIG if the payload was larger than the Write chunk - * %-EINVAL if client provided too many segments - * %-ENOMEM if rdma_rw context pool was exhausted - * %-ENOTCONN if posting failed (connection is lost) - * %-EIO if rdma_rw initialization failed (DMA mapping, etc) */ int svc_rdma_result_payload(struct svc_rqst *rqstp, unsigned int offset, unsigned int length) { struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; struct svc_rdma_chunk *chunk; - struct svcxprt_rdma *rdma; - struct xdr_buf subbuf; - int ret; chunk = rctxt->rc_cur_result_payload; if (!length || !chunk) return 0; rctxt->rc_cur_result_payload = pcl_next_chunk(&rctxt->rc_write_pcl, chunk); + if (length > chunk->ch_length) return -E2BIG; - chunk->ch_position = offset; chunk->ch_payload_length = length; - - if (xdr_buf_subsegment(&rqstp->rq_res, &subbuf, offset, length)) - return -EMSGSIZE; - - rdma = container_of(rqstp->rq_xprt, struct svcxprt_rdma, sc_xprt); - ret = svc_rdma_send_write_chunk(rdma, chunk, &subbuf); - if (ret < 0) - return ret; return 0; } diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 4f27325ace..2b1c16b954 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -415,15 +415,20 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) if (newxprt->sc_max_send_sges > dev->attrs.max_send_sge) newxprt->sc_max_send_sges = dev->attrs.max_send_sge; rq_depth = newxprt->sc_max_requests + newxprt->sc_max_bc_requests + - newxprt->sc_recv_batch; + newxprt->sc_recv_batch + 1 /* drain */; if (rq_depth > dev->attrs.max_qp_wr) { rq_depth = dev->attrs.max_qp_wr; newxprt->sc_recv_batch = 1; newxprt->sc_max_requests = rq_depth - 2; newxprt->sc_max_bc_requests = 2; } - ctxts = rdma_rw_mr_factor(dev, newxprt->sc_port_num, RPCSVC_MAXPAGES); - ctxts *= newxprt->sc_max_requests; + + /* Arbitrarily estimate the number of rw_ctxs needed for + * this transport. This is enough rw_ctxs to make forward + * progress even if the client is using one rkey per page + * in each Read chunk. + */ + ctxts = 3 * RPCSVC_MAXPAGES; newxprt->sc_sq_depth = rq_depth + ctxts; if (newxprt->sc_sq_depth > dev->attrs.max_qp_wr) newxprt->sc_sq_depth = dev->attrs.max_qp_wr; @@ -460,12 +465,14 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) qp_attr.cap.max_send_wr, qp_attr.cap.max_recv_wr); dprintk(" cap.max_send_sge = %d, cap.max_recv_sge = %d\n", qp_attr.cap.max_send_sge, qp_attr.cap.max_recv_sge); - + dprintk(" send CQ depth = %u, recv CQ depth = %u\n", + newxprt->sc_sq_depth, rq_depth); ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, &qp_attr); if (ret) { trace_svcrdma_qp_err(newxprt, ret); goto errout; } + newxprt->sc_max_send_sges = qp_attr.cap.max_send_sge; newxprt->sc_qp = newxprt->sc_cm_id->qp; if (!(dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS)) |