Looks good Reveiwed-By: Devesh Sharma <devesh.sharma@xxxxxxxxxxxxx> On Fri, Jul 10, 2015 at 2:12 AM, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > The client has been setting up a reply chunk for NFS READs that are > smaller than the inline threshold. This is not efficient: both the > server and client CPUs have to copy the reply's data payload into > and out of the memory region that is then transferred via RDMA. > > Using the write list, the data payload is moved by the device and no > extra data copying is necessary. > > Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> > --- > net/sunrpc/xprtrdma/rpc_rdma.c | 21 ++++----------------- > 1 file changed, 4 insertions(+), 17 deletions(-) > > diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c > index 8cf9402..e569da4 100644 > --- a/net/sunrpc/xprtrdma/rpc_rdma.c > +++ b/net/sunrpc/xprtrdma/rpc_rdma.c > @@ -427,28 +427,15 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) > /* > * Chunks needed for results? > * > + * o Read ops return data as write chunk(s), header as inline. > * o If the expected result is under the inline threshold, all ops > * return as inline (but see later). > * o Large non-read ops return as a single reply chunk. > - * o Large read ops return data as write chunk(s), header as inline. > - * > - * Note: the NFS code sending down multiple result segments implies > - * the op is one of read, readdir[plus], readlink or NFSv4 getacl. > - */ > - > - /* > - * This code can handle read chunks, write chunks OR reply > - * chunks -- only one type. If the request is too big to fit > - * inline, then we will choose read chunks. If the request is > - * a READ, then use write chunks to separate the file data > - * into pages; otherwise use reply chunks. > */ > - if (rpcrdma_results_inline(rqst)) > - wtype = rpcrdma_noch; > - else if (rqst->rq_rcv_buf.page_len == 0) > - wtype = rpcrdma_replych; > - else if (rqst->rq_rcv_buf.flags & XDRBUF_READ) > + if (rqst->rq_rcv_buf.flags & XDRBUF_READ) > wtype = rpcrdma_writech; > + else if (rpcrdma_results_inline(rqst)) > + wtype = rpcrdma_noch; > else > wtype = rpcrdma_replych; > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
