diff options
Diffstat (limited to 'net/sunrpc/xprtrdma/svc_rdma_sendto.c')
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_sendto.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index 7b9853214769..90cba3058f04 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -541,6 +541,7 @@ static int svc_rdma_dma_map_buf(struct svcxprt_rdma *rdma, /** * svc_rdma_pull_up_needed - Determine whether to use pull-up * @rdma: controlling transport + * @sctxt: send_ctxt for the Send WR * @rctxt: Write and Reply chunks provided by client * @xdr: xdr_buf containing RPC message to transmit * @@ -549,11 +550,20 @@ static int svc_rdma_dma_map_buf(struct svcxprt_rdma *rdma, * %false otherwise */ static bool svc_rdma_pull_up_needed(struct svcxprt_rdma *rdma, + struct svc_rdma_send_ctxt *sctxt, const struct svc_rdma_recv_ctxt *rctxt, struct xdr_buf *xdr) { int elements; + /* For small messages, copying bytes is cheaper than DMA mapping. + */ + if (sctxt->sc_hdrbuf.len + xdr->len < RPCRDMA_PULLUP_THRESH) + return true; + + /* Check whether the xdr_buf has more elements than can + * fit in a single RDMA Send. + */ /* xdr->head */ elements = 1; @@ -636,6 +646,7 @@ static int svc_rdma_pull_up_reply_msg(struct svcxprt_rdma *rdma, memcpy(dst, tailbase, taillen); sctxt->sc_sges[0].length += xdr->len; + trace_svcrdma_send_pullup(sctxt->sc_sges[0].length); return 0; } @@ -675,7 +686,7 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, /* For pull-up, svc_rdma_send() will sync the transport header. * No additional DMA mapping is necessary. */ - if (svc_rdma_pull_up_needed(rdma, rctxt, xdr)) + if (svc_rdma_pull_up_needed(rdma, sctxt, rctxt, xdr)) return svc_rdma_pull_up_reply_msg(rdma, sctxt, rctxt, xdr); ++sctxt->sc_cur_sge_no; |