diff options
| -rw-r--r-- | net/sunrpc/xprtrdma/rpc_rdma.c | 21 | ||||
| -rw-r--r-- | net/sunrpc/xprtrdma/transport.c | 9 | ||||
| -rw-r--r-- | net/sunrpc/xprtrdma/xprt_rdma.h | 5 |
3 files changed, 33 insertions, 2 deletions
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 721dae7..d245c0b 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -118,6 +118,10 @@ rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos, } if (xdrbuf->tail[0].iov_len) { + /* the rpcrdma protocol allows us to omit any trailing + * xdr pad bytes, saving the server an RDMA operation. */ + if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize) + return n; if (n == nsegs) return 0; seg[n].mr_page = NULL; @@ -594,7 +598,7 @@ rpcrdma_count_chunks(struct rpcrdma_rep *rep, unsigned int max, int wrchunk, __b * Scatter inline received data back into provided iov's. */ static void -rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len) +rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad) { int i, npages, curlen, olen; char *destp; @@ -660,6 +664,13 @@ rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len) } else rqst->rq_rcv_buf.tail[0].iov_len = 0; + if (pad) { + /* implicit padding on terminal chunk */ + unsigned char *p = rqst->rq_rcv_buf.tail[0].iov_base; + while (pad--) + p[rqst->rq_rcv_buf.tail[0].iov_len++] = 0; + } + if (copy_len) dprintk("RPC: %s: %d bytes in" " %d extra segments (%d lost)\n", @@ -794,14 +805,20 @@ repost: ((unsigned char *)iptr - (unsigned char *)headerp); status = rep->rr_len + rdmalen; r_xprt->rx_stats.total_rdma_reply += rdmalen; + /* special case - last chunk may omit padding */ + if (rdmalen &= 3) { + rdmalen = 4 - rdmalen; + status += rdmalen; + } } else { /* else ordinary inline */ + rdmalen = 0; iptr = (__be32 *)((unsigned char *)headerp + 28); rep->rr_len -= 28; /*sizeof *headerp;*/ status = rep->rr_len; } /* Fix up the rpc results for upper layer */ - rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len); + rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len, rdmalen); break; case __constant_htonl(RDMA_NOMSG): diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index ec6d1e7..c7d2380 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -71,6 +71,7 @@ static unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE; static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE; static unsigned int xprt_rdma_inline_write_padding; static unsigned int xprt_rdma_memreg_strategy = RPCRDMA_FRMR; + int xprt_rdma_pad_optimize = 0; #ifdef RPC_DEBUG @@ -136,6 +137,14 @@ static ctl_table xr_tunables_table[] = { .extra2 = &max_memreg, }, { + .ctl_name = CTL_UNNUMBERED, + .procname = "rdma_pad_optimize", + .data = &xprt_rdma_pad_optimize, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, + { .ctl_name = 0, }, }; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 2db2344..fde6499 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -280,6 +280,11 @@ struct rpcrdma_xprt { #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, xprt) #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data) +/* Setting this to 0 ensures interoperability with early servers. + * Setting this to 1 enhances certain unaligned read/write performance. + * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */ +extern int xprt_rdma_pad_optimize; + /* * Interface Adapter calls - xprtrdma/verbs.c */ |