From dd2d055b278b20920ab454b233ec76038966788a Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 30 Dec 2020 14:08:53 -0500 Subject: svcrdma: DMA-sync the receive buffer in svc_rdma_recvfrom() The Receive completion handler doesn't look at the contents of the Receive buffer. The DMA sync isn't terribly expensive but it's one less thing that needs to be done by the Receive completion handler, which is single-threaded (per svc_xprt). This helps scalability. Signed-off-by: Chuck Lever Reviewed-by: Christoph Hellwig --- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/sunrpc') diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index ab0b7e9777bc..6d28f23ceb35 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -342,9 +342,6 @@ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) /* 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, - ctxt->rc_recv_sge.addr, - wc->byte_len, DMA_FROM_DEVICE); spin_lock(&rdma->sc_rq_dto_lock); list_add_tail(&ctxt->rc_list, &rdma->sc_rq_dto_q); @@ -851,6 +848,9 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) spin_unlock(&rdma_xprt->sc_rq_dto_lock); percpu_counter_inc(&svcrdma_stat_recv); + ib_dma_sync_single_for_cpu(rdma_xprt->sc_pd->device, + ctxt->rc_recv_sge.addr, ctxt->rc_byte_len, + DMA_FROM_DEVICE); svc_rdma_build_arg_xdr(rqstp, ctxt); /* Prevent svc_xprt_release from releasing pages in rq_pages -- cgit v1.2.3