From: Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> To: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Subject: [PATCH v1 06/22] svcrdma: Clean up RPC-over-RDMA Reply header encoder Date: Sat, 07 Jan 2017 12:16:06 -0500 [thread overview] Message-ID: <20170107171606.14126.90832.stgit@klimt.1015granger.net> (raw) In-Reply-To: <20170107170258.14126.8503.stgit-Hs+gFlyCn65vLzlybtyyYzGyq/o6K9yX@public.gmane.org> Replace C structure-based XDR decoding with pointer arithmetic. Pointer arithmetic is considered more portable, and is used throughout the kernel's existing XDR encoders. The gcc optimizer generates similar assembler code either way. Byte-swapping before a memory store on x86 typically results in an instruction pipeline stall. Avoid byte-swapping when encoding a new header. svcrdma currently doesn't alter a connection's credit grant value after the connection has been accepted, so it is effectively a constant. Cache the byte-swapped value in a separate field. Signed-off-by: Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> --- include/linux/sunrpc/svc_rdma.h | 11 +++++--- net/sunrpc/xprtrdma/svc_rdma_marshal.c | 39 +++++++++++++++++++----------- net/sunrpc/xprtrdma/svc_rdma_sendto.c | 10 ++------ net/sunrpc/xprtrdma/svc_rdma_transport.c | 1 + 4 files changed, 35 insertions(+), 26 deletions(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index 997bc78..61cfee8 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -140,7 +140,8 @@ struct svcxprt_rdma { atomic_t sc_sq_avail; /* SQEs ready to be consumed */ unsigned int sc_sq_depth; /* Depth of SQ */ unsigned int sc_rq_depth; /* Depth of RQ */ - u32 sc_max_requests; /* Forward credits */ + __be32 sc_fc_credits; /* Forward credits */ + u32 sc_max_requests; /* Max requests */ u32 sc_max_bc_requests;/* Backward credits */ int sc_max_req_size; /* Size of each RQ WR buf */ @@ -211,10 +212,10 @@ extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *, extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int); extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int, __be32, __be64, u32); -extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *, - struct rpcrdma_msg *, - struct rpcrdma_msg *, - enum rpcrdma_proc); +extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *rdma, + __be32 *rdma_argp, + __be32 *rdma_resp, + __be32 rdma_type); extern unsigned int svc_rdma_xdr_get_reply_hdr_len(__be32 *rdma_resp); /* svc_rdma_recvfrom.c */ diff --git a/net/sunrpc/xprtrdma/svc_rdma_marshal.c b/net/sunrpc/xprtrdma/svc_rdma_marshal.c index 4e72034..5efa019 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_marshal.c +++ b/net/sunrpc/xprtrdma/svc_rdma_marshal.c @@ -249,7 +249,7 @@ int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt, *va++ = rmsgp->rm_xid; *va++ = rmsgp->rm_vers; - *va++ = cpu_to_be32(xprt->sc_max_requests); + *va++ = xprt->sc_fc_credits; *va++ = rdma_error; *va++ = cpu_to_be32(err); if (err == ERR_VERS) { @@ -330,18 +330,29 @@ void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary, seg->rs_length = cpu_to_be32(write_len); } -void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt, - struct rpcrdma_msg *rdma_argp, - struct rpcrdma_msg *rdma_resp, - enum rpcrdma_proc rdma_type) +/** + * svc_rdma_xdr_encode_reply_header - Encode Reply's fixed header fields + * @rdma: controlling transport + * @rdma_argp: Call's transport header + * @rdma_resp: Reply's transport header + * @rdma_type: procedure number + * + */ +void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *rdma, + __be32 *rdma_argp, __be32 *rdma_resp, + __be32 rdma_type) { - rdma_resp->rm_xid = rdma_argp->rm_xid; - rdma_resp->rm_vers = rdma_argp->rm_vers; - rdma_resp->rm_credit = cpu_to_be32(xprt->sc_max_requests); - rdma_resp->rm_type = cpu_to_be32(rdma_type); - - /* Encode <nul> chunks lists */ - rdma_resp->rm_body.rm_chunks[0] = xdr_zero; - rdma_resp->rm_body.rm_chunks[1] = xdr_zero; - rdma_resp->rm_body.rm_chunks[2] = xdr_zero; + __be32 *p; + + p = rdma_resp; + + *p++ = *rdma_argp; /* XID */ + *p++ = *(rdma_argp + 1); /* vers */ + *p++ = rdma->sc_fc_credits; + *p++ = rdma_type; + + /* Start with empty chunks */ + *p++ = xdr_zero; + *p++ = xdr_zero; + *p = xdr_zero; } diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index ba76f1617..7150201 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -560,7 +560,6 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) struct rpcrdma_msg *rdma_argp; struct rpcrdma_msg *rdma_resp; struct rpcrdma_write_array *wr_ary, *rp_ary; - enum rpcrdma_proc reply_type; int ret; int inline_bytes; struct page *res_page; @@ -597,12 +596,9 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) if (!res_page) goto err0; rdma_resp = page_address(res_page); - if (rp_ary) - reply_type = RDMA_NOMSG; - else - reply_type = RDMA_MSG; - svc_rdma_xdr_encode_reply_header(rdma, rdma_argp, - rdma_resp, reply_type); + svc_rdma_xdr_encode_reply_header(rdma, (__be32 *)rdma_argp, + (__be32 *)rdma_resp, + rp_ary ? rdma_nomsg : rdma_msg); /* Send any write-chunk data and build resp write-list */ if (wr_ary) { diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 4d34afb..3258af7 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -1042,6 +1042,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) newxprt->sc_max_req_size = svcrdma_max_req_size; newxprt->sc_max_requests = min_t(u32, dev->attrs.max_qp_wr, svcrdma_max_requests); + newxprt->sc_fc_credits = cpu_to_be32(newxprt->sc_max_requests); newxprt->sc_max_bc_requests = min_t(u32, dev->attrs.max_qp_wr, svcrdma_max_bc_requests); newxprt->sc_rq_depth = newxprt->sc_max_requests + -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html
WARNING: multiple messages have this Message-ID (diff)
From: Chuck Lever <chuck.lever@oracle.com> To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Subject: [PATCH v1 06/22] svcrdma: Clean up RPC-over-RDMA Reply header encoder Date: Sat, 07 Jan 2017 12:16:06 -0500 [thread overview] Message-ID: <20170107171606.14126.90832.stgit@klimt.1015granger.net> (raw) In-Reply-To: <20170107170258.14126.8503.stgit@klimt.1015granger.net> Replace C structure-based XDR decoding with pointer arithmetic. Pointer arithmetic is considered more portable, and is used throughout the kernel's existing XDR encoders. The gcc optimizer generates similar assembler code either way. Byte-swapping before a memory store on x86 typically results in an instruction pipeline stall. Avoid byte-swapping when encoding a new header. svcrdma currently doesn't alter a connection's credit grant value after the connection has been accepted, so it is effectively a constant. Cache the byte-swapped value in a separate field. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> --- include/linux/sunrpc/svc_rdma.h | 11 +++++--- net/sunrpc/xprtrdma/svc_rdma_marshal.c | 39 +++++++++++++++++++----------- net/sunrpc/xprtrdma/svc_rdma_sendto.c | 10 ++------ net/sunrpc/xprtrdma/svc_rdma_transport.c | 1 + 4 files changed, 35 insertions(+), 26 deletions(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index 997bc78..61cfee8 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -140,7 +140,8 @@ struct svcxprt_rdma { atomic_t sc_sq_avail; /* SQEs ready to be consumed */ unsigned int sc_sq_depth; /* Depth of SQ */ unsigned int sc_rq_depth; /* Depth of RQ */ - u32 sc_max_requests; /* Forward credits */ + __be32 sc_fc_credits; /* Forward credits */ + u32 sc_max_requests; /* Max requests */ u32 sc_max_bc_requests;/* Backward credits */ int sc_max_req_size; /* Size of each RQ WR buf */ @@ -211,10 +212,10 @@ extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *, extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int); extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int, __be32, __be64, u32); -extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *, - struct rpcrdma_msg *, - struct rpcrdma_msg *, - enum rpcrdma_proc); +extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *rdma, + __be32 *rdma_argp, + __be32 *rdma_resp, + __be32 rdma_type); extern unsigned int svc_rdma_xdr_get_reply_hdr_len(__be32 *rdma_resp); /* svc_rdma_recvfrom.c */ diff --git a/net/sunrpc/xprtrdma/svc_rdma_marshal.c b/net/sunrpc/xprtrdma/svc_rdma_marshal.c index 4e72034..5efa019 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_marshal.c +++ b/net/sunrpc/xprtrdma/svc_rdma_marshal.c @@ -249,7 +249,7 @@ int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt, *va++ = rmsgp->rm_xid; *va++ = rmsgp->rm_vers; - *va++ = cpu_to_be32(xprt->sc_max_requests); + *va++ = xprt->sc_fc_credits; *va++ = rdma_error; *va++ = cpu_to_be32(err); if (err == ERR_VERS) { @@ -330,18 +330,29 @@ void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary, seg->rs_length = cpu_to_be32(write_len); } -void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt, - struct rpcrdma_msg *rdma_argp, - struct rpcrdma_msg *rdma_resp, - enum rpcrdma_proc rdma_type) +/** + * svc_rdma_xdr_encode_reply_header - Encode Reply's fixed header fields + * @rdma: controlling transport + * @rdma_argp: Call's transport header + * @rdma_resp: Reply's transport header + * @rdma_type: procedure number + * + */ +void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *rdma, + __be32 *rdma_argp, __be32 *rdma_resp, + __be32 rdma_type) { - rdma_resp->rm_xid = rdma_argp->rm_xid; - rdma_resp->rm_vers = rdma_argp->rm_vers; - rdma_resp->rm_credit = cpu_to_be32(xprt->sc_max_requests); - rdma_resp->rm_type = cpu_to_be32(rdma_type); - - /* Encode <nul> chunks lists */ - rdma_resp->rm_body.rm_chunks[0] = xdr_zero; - rdma_resp->rm_body.rm_chunks[1] = xdr_zero; - rdma_resp->rm_body.rm_chunks[2] = xdr_zero; + __be32 *p; + + p = rdma_resp; + + *p++ = *rdma_argp; /* XID */ + *p++ = *(rdma_argp + 1); /* vers */ + *p++ = rdma->sc_fc_credits; + *p++ = rdma_type; + + /* Start with empty chunks */ + *p++ = xdr_zero; + *p++ = xdr_zero; + *p = xdr_zero; } diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index ba76f1617..7150201 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -560,7 +560,6 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) struct rpcrdma_msg *rdma_argp; struct rpcrdma_msg *rdma_resp; struct rpcrdma_write_array *wr_ary, *rp_ary; - enum rpcrdma_proc reply_type; int ret; int inline_bytes; struct page *res_page; @@ -597,12 +596,9 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) if (!res_page) goto err0; rdma_resp = page_address(res_page); - if (rp_ary) - reply_type = RDMA_NOMSG; - else - reply_type = RDMA_MSG; - svc_rdma_xdr_encode_reply_header(rdma, rdma_argp, - rdma_resp, reply_type); + svc_rdma_xdr_encode_reply_header(rdma, (__be32 *)rdma_argp, + (__be32 *)rdma_resp, + rp_ary ? rdma_nomsg : rdma_msg); /* Send any write-chunk data and build resp write-list */ if (wr_ary) { diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 4d34afb..3258af7 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -1042,6 +1042,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) newxprt->sc_max_req_size = svcrdma_max_req_size; newxprt->sc_max_requests = min_t(u32, dev->attrs.max_qp_wr, svcrdma_max_requests); + newxprt->sc_fc_credits = cpu_to_be32(newxprt->sc_max_requests); newxprt->sc_max_bc_requests = min_t(u32, dev->attrs.max_qp_wr, svcrdma_max_bc_requests); newxprt->sc_rq_depth = newxprt->sc_max_requests +
next prev parent reply other threads:[~2017-01-07 17:16 UTC|newest] Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-01-07 17:15 [PATCH v1 00/22] convert NFS server to new rdma_rw API Chuck Lever 2017-01-07 17:15 ` Chuck Lever [not found] ` <20170107170258.14126.8503.stgit-Hs+gFlyCn65vLzlybtyyYzGyq/o6K9yX@public.gmane.org> 2017-01-07 17:15 ` [PATCH v1 01/22] svcrdma: Another sendto chunk list parsing update Chuck Lever 2017-01-07 17:15 ` Chuck Lever 2017-01-07 17:15 ` [PATCH v1 02/22] svcrdma: Replace RPCRDMA_SQ_DEPTH_MULT Chuck Lever 2017-01-07 17:15 ` Chuck Lever 2017-01-07 17:15 ` [PATCH v1 03/22] svcrdma: Remove unused sc_dto_q field Chuck Lever 2017-01-07 17:15 ` Chuck Lever 2017-01-07 17:15 ` [PATCH v1 04/22] svcrdma: Combine list fields in struct svc_rdma_op_ctxt Chuck Lever 2017-01-07 17:15 ` Chuck Lever 2017-01-07 17:15 ` [PATCH v1 05/22] svcrdma: Poll CQs in "workqueue" mode Chuck Lever 2017-01-07 17:15 ` Chuck Lever 2017-01-07 17:16 ` Chuck Lever [this message] 2017-01-07 17:16 ` [PATCH v1 06/22] svcrdma: Clean up RPC-over-RDMA Reply header encoder Chuck Lever 2017-01-07 17:16 ` [PATCH v1 07/22] svcrdma: Clean up RPC-over-RDMA Call header decoder Chuck Lever 2017-01-07 17:16 ` Chuck Lever 2017-01-07 17:16 ` [PATCH v1 08/22] svcrdma: Introduce local rdma_rw API helpers Chuck Lever 2017-01-07 17:16 ` Chuck Lever 2017-01-07 17:16 ` [PATCH v1 09/22] svcrdma: Use rdma_rw API in RPC reply path Chuck Lever 2017-01-07 17:16 ` Chuck Lever 2017-01-07 17:16 ` [PATCH v1 10/22] svcrdma: Backchannel sendto clean up Chuck Lever 2017-01-07 17:16 ` Chuck Lever 2017-01-07 17:16 ` [PATCH v1 11/22] svcrdma: Clean up RDMA_ERROR path Chuck Lever 2017-01-07 17:16 ` Chuck Lever 2017-01-07 17:16 ` [PATCH v1 12/22] svcrdma: Reduce size of sge array in struct svc_rdma_op_ctxt Chuck Lever 2017-01-07 17:16 ` Chuck Lever 2017-01-07 17:17 ` [PATCH v1 13/22] svcrdma: Remove old RDMA Write completion handlers Chuck Lever 2017-01-07 17:17 ` Chuck Lever 2017-01-07 17:17 ` [PATCH v1 14/22] svcrdma: Remove the req_map cache Chuck Lever 2017-01-07 17:17 ` Chuck Lever 2017-01-07 17:17 ` [PATCH v1 15/22] svcrdma: Clean up RPC-over-RDMA backchannel reply processing Chuck Lever 2017-01-07 17:17 ` Chuck Lever [not found] ` <20170107171719.14126.10512.stgit-Hs+gFlyCn65vLzlybtyyYzGyq/o6K9yX@public.gmane.org> 2017-01-07 17:36 ` Trond Myklebust 2017-01-07 17:36 ` Trond Myklebust 2017-01-07 17:17 ` [PATCH v1 16/22] svcrdma: Use generic RDMA R/W API in RPC Call path Chuck Lever 2017-01-07 17:17 ` Chuck Lever 2017-01-07 17:17 ` [PATCH v1 17/22] svcrdma: Remove unused Read completion handlers Chuck Lever 2017-01-07 17:17 ` Chuck Lever 2017-01-07 17:17 ` [PATCH v1 18/22] svcrdma: Remove frmr cache Chuck Lever 2017-01-07 17:17 ` Chuck Lever 2017-01-07 17:17 ` [PATCH v1 19/22] svcrdma: Clean up after converting svc_rdma_recvfrom to rdma_rw API Chuck Lever 2017-01-07 17:17 ` Chuck Lever 2017-01-07 17:17 ` [PATCH v1 20/22] svcrdma: Clean-up in svc_rdma_post_recv Chuck Lever 2017-01-07 17:17 ` Chuck Lever 2017-01-07 17:18 ` [PATCH v1 21/22] svcrdma: Clean-up svc_rdma_unmap_dma Chuck Lever 2017-01-07 17:18 ` Chuck Lever 2017-01-07 17:18 ` [PATCH v1 22/22] svcrdma: Re-order fields in svc_rdma_op_ctxt Chuck Lever 2017-01-07 17:18 ` Chuck Lever 2017-01-08 14:34 ` [PATCH v1 00/22] convert NFS server to new rdma_rw API Christoph Hellwig 2017-01-08 14:34 ` Christoph Hellwig [not found] ` <20170108143402.GA2243-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org> 2017-01-08 17:19 ` Chuck Lever 2017-01-08 17:19 ` Chuck Lever 2017-01-13 16:42 ` J. Bruce Fields 2017-01-13 16:42 ` J. Bruce Fields [not found] ` <20170113164208.GD24709-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org> 2017-01-13 16:54 ` Chuck Lever 2017-01-13 16:54 ` Chuck Lever [not found] ` <33FF9D08-075A-4153-ADDA-C460C1A4D93B-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> 2017-01-13 17:08 ` J. Bruce Fields 2017-01-13 17:08 ` J. Bruce Fields 2017-01-13 22:04 ` Sagi Grimberg 2017-01-13 22:04 ` Sagi Grimberg
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