diff options
author | Chuck Lever <chuck.lever@oracle.com> | 2020-12-08 13:14:15 -0500 |
---|---|---|
committer | Chuck Lever <chuck.lever@oracle.com> | 2021-01-25 09:36:28 -0500 |
commit | 43042b90cae11cc2d9827c91df6d6b5fe498d5ce (patch) | |
tree | 4d75270b9c14d57db51832ac9d5ff0a8f2959185 /net/sunrpc | |
parent | c6226ff9a62a17182b8092883ca201df5cd47f59 (diff) | |
download | linux-43042b90cae11cc2d9827c91df6d6b5fe498d5ce.tar.bz2 |
svcrdma: Reduce Receive doorbell rate
This is similar to commit e340c2d6ef2a ("xprtrdma: Reduce the
doorbell rate (Receive)") which added Receive batching to the
client.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'net/sunrpc')
-rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 82 |
1 files changed, 43 insertions, 39 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index 7d14a74df716..ab0b7e9777bc 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -266,33 +266,46 @@ void svc_rdma_release_rqst(struct svc_rqst *rqstp) svc_rdma_recv_ctxt_put(rdma, ctxt); } -static int __svc_rdma_post_recv(struct svcxprt_rdma *rdma, - struct svc_rdma_recv_ctxt *ctxt) +static bool svc_rdma_refresh_recvs(struct svcxprt_rdma *rdma, + unsigned int wanted, bool temp) { + const struct ib_recv_wr *bad_wr = NULL; + struct svc_rdma_recv_ctxt *ctxt; + struct ib_recv_wr *recv_chain; int ret; - trace_svcrdma_post_recv(ctxt); - ret = ib_post_recv(rdma->sc_qp, &ctxt->rc_recv_wr, NULL); + recv_chain = NULL; + while (wanted--) { + ctxt = svc_rdma_recv_ctxt_get(rdma); + if (!ctxt) + break; + + trace_svcrdma_post_recv(ctxt); + ctxt->rc_temp = temp; + ctxt->rc_recv_wr.next = recv_chain; + recv_chain = &ctxt->rc_recv_wr; + rdma->sc_pending_recvs++; + } + if (!recv_chain) + return false; + + ret = ib_post_recv(rdma->sc_qp, recv_chain, &bad_wr); if (ret) goto err_post; - return 0; + return true; err_post: - trace_svcrdma_rq_post_err(rdma, ret); - svc_rdma_recv_ctxt_put(rdma, ctxt); - return ret; -} - -static int svc_rdma_post_recv(struct svcxprt_rdma *rdma) -{ - struct svc_rdma_recv_ctxt *ctxt; + while (bad_wr) { + ctxt = container_of(bad_wr, struct svc_rdma_recv_ctxt, + rc_recv_wr); + bad_wr = bad_wr->next; + svc_rdma_recv_ctxt_put(rdma, ctxt); + } - if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) - return 0; - ctxt = svc_rdma_recv_ctxt_get(rdma); - if (!ctxt) - return -ENOMEM; - return __svc_rdma_post_recv(rdma, ctxt); + trace_svcrdma_rq_post_err(rdma, ret); + /* Since we're destroying the xprt, no need to reset + * sc_pending_recvs. */ + return false; } /** @@ -303,20 +316,7 @@ static int svc_rdma_post_recv(struct svcxprt_rdma *rdma) */ bool svc_rdma_post_recvs(struct svcxprt_rdma *rdma) { - struct svc_rdma_recv_ctxt *ctxt; - unsigned int i; - int ret; - - for (i = 0; i < rdma->sc_max_requests; i++) { - ctxt = svc_rdma_recv_ctxt_get(rdma); - if (!ctxt) - return false; - ctxt->rc_temp = true; - ret = __svc_rdma_post_recv(rdma, ctxt); - if (ret) - return false; - } - return true; + return svc_rdma_refresh_recvs(rdma, rdma->sc_max_requests, true); } /** @@ -324,8 +324,6 @@ bool svc_rdma_post_recvs(struct svcxprt_rdma *rdma) * @cq: Completion Queue context * @wc: Work Completion object * - * NB: The svc_xprt/svcxprt_rdma is pinned whenever it's possible that - * the Receive completion handler could be running. */ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) { @@ -333,6 +331,8 @@ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) struct ib_cqe *cqe = wc->wr_cqe; struct svc_rdma_recv_ctxt *ctxt; + rdma->sc_pending_recvs--; + /* WARNING: Only wc->wr_cqe and wc->status are reliable */ ctxt = container_of(cqe, struct svc_rdma_recv_ctxt, rc_cqe); @@ -340,9 +340,6 @@ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) if (wc->status != IB_WC_SUCCESS) goto flushed; - if (svc_rdma_post_recv(rdma)) - goto post_err; - /* All wc fields are now known to be valid */ ctxt->rc_byte_len = wc->byte_len; ib_dma_sync_single_for_cpu(rdma->sc_pd->device, @@ -356,11 +353,18 @@ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) spin_unlock(&rdma->sc_rq_dto_lock); if (!test_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags)) svc_xprt_enqueue(&rdma->sc_xprt); + + if (!test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags) && + rdma->sc_pending_recvs < rdma->sc_max_requests) + if (!svc_rdma_refresh_recvs(rdma, RPCRDMA_MAX_RECV_BATCH, + false)) + goto post_err; + return; flushed: -post_err: svc_rdma_recv_ctxt_put(rdma, ctxt); +post_err: set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); svc_xprt_enqueue(&rdma->sc_xprt); } |