diff options
author | Chuck Lever | 2020-03-13 10:42:11 -0400 |
---|---|---|
committer | Chuck Lever | 2020-11-30 13:00:22 -0500 |
commit | 9d0b09d5ef0c842592a5df3a5b8b59124485ff1b (patch) | |
tree | 411c71caffd1c556ee4f7f4516a308cc03c63e02 /net/sunrpc/xprtrdma | |
parent | 6911f3e10cd9792ccfd6980da91a171f54984692 (diff) |
svcrdma: Support multiple write chunks when pulling up
When counting the number of SGEs needed to construct a Send request,
do not count result payloads. And, when copying the Reply message
into the pull-up buffer, result payloads are not to be copied to the
Send buffer.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'net/sunrpc/xprtrdma')
-rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 14 | ||||
-rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 9 | ||||
-rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_sendto.c | 188 |
3 files changed, 129 insertions, 82 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c index 5e7c4ba9e147..63f8be974df2 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -74,11 +74,17 @@ out_unlock: */ static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma, struct rpc_rqst *rqst, - struct svc_rdma_send_ctxt *ctxt) + struct svc_rdma_send_ctxt *sctxt) { + struct svc_rdma_recv_ctxt *rctxt; int ret; - ret = svc_rdma_map_reply_msg(rdma, ctxt, NULL, &rqst->rq_snd_buf); + rctxt = svc_rdma_recv_ctxt_get(rdma); + if (!rctxt) + return -EIO; + + ret = svc_rdma_map_reply_msg(rdma, sctxt, rctxt, &rqst->rq_snd_buf); + svc_rdma_recv_ctxt_put(rdma, rctxt); if (ret < 0) return -EIO; @@ -86,8 +92,8 @@ static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma, * the rq_buffer before all retransmits are complete. */ get_page(virt_to_page(rqst->rq_buffer)); - ctxt->sc_send_wr.opcode = IB_WR_SEND; - return svc_rdma_send(rdma, ctxt); + sctxt->sc_send_wr.opcode = IB_WR_SEND; + return svc_rdma_send(rdma, sctxt); } /* Server-side transport endpoint wants a whole page for its send diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index 7d44e9d2e7a3..af32c3ad45a6 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -194,8 +194,13 @@ void svc_rdma_recv_ctxts_destroy(struct svcxprt_rdma *rdma) } } -static struct svc_rdma_recv_ctxt * -svc_rdma_recv_ctxt_get(struct svcxprt_rdma *rdma) +/** + * svc_rdma_recv_ctxt_get - Allocate a recv_ctxt + * @rdma: controlling svcxprt_rdma + * + * Returns a recv_ctxt or (rarely) NULL if none are available. + */ +struct svc_rdma_recv_ctxt *svc_rdma_recv_ctxt_get(struct svcxprt_rdma *rdma) { struct svc_rdma_recv_ctxt *ctxt; struct llist_node *node; diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index 1fdbbad3f7dc..50f0216fb08c 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -531,6 +531,45 @@ static int svc_rdma_dma_map_buf(struct svcxprt_rdma *rdma, offset_in_page(base), len); } +struct svc_rdma_pullup_data { + u8 *pd_dest; + unsigned int pd_length; + unsigned int pd_num_sges; +}; + +/** + * svc_rdma_xb_count_sges - Count how many SGEs will be needed + * @xdr: xdr_buf containing portion of an RPC message to transmit + * @data: pointer to arguments + * + * Returns: + * Number of SGEs needed to Send the contents of @xdr inline + */ +static int svc_rdma_xb_count_sges(const struct xdr_buf *xdr, + void *data) +{ + struct svc_rdma_pullup_data *args = data; + unsigned int remaining; + unsigned long offset; + + if (xdr->head[0].iov_len) + ++args->pd_num_sges; + + offset = offset_in_page(xdr->page_base); + remaining = xdr->page_len; + while (remaining) { + ++args->pd_num_sges; + remaining -= min_t(u32, PAGE_SIZE - offset, remaining); + offset = 0; + } + + if (xdr->tail[0].iov_len) + ++args->pd_num_sges; + + args->pd_length += xdr->len; + return 0; +} + /** * svc_rdma_pull_up_needed - Determine whether to use pull-up * @rdma: controlling transport @@ -539,50 +578,71 @@ static int svc_rdma_dma_map_buf(struct svcxprt_rdma *rdma, * @xdr: xdr_buf containing RPC message to transmit * * Returns: - * %true if pull-up must be used - * %false otherwise + * %true if pull-up must be used + * %false otherwise */ -static bool svc_rdma_pull_up_needed(struct svcxprt_rdma *rdma, - struct svc_rdma_send_ctxt *sctxt, +static bool svc_rdma_pull_up_needed(const struct svcxprt_rdma *rdma, + const struct svc_rdma_send_ctxt *sctxt, const struct svc_rdma_recv_ctxt *rctxt, - struct xdr_buf *xdr) + const struct xdr_buf *xdr) { - bool write_chunk_present = rctxt && rctxt->rc_write_list; - int elements; + /* Resources needed for the transport header */ + struct svc_rdma_pullup_data args = { + .pd_length = sctxt->sc_hdrbuf.len, + .pd_num_sges = 1, + }; + int ret; - /* For small messages, copying bytes is cheaper than DMA mapping. - */ - if (!write_chunk_present && - sctxt->sc_hdrbuf.len + xdr->len < RPCRDMA_PULLUP_THRESH) + ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, + svc_rdma_xb_count_sges, &args); + if (ret < 0) + return false; + + if (args.pd_length < RPCRDMA_PULLUP_THRESH) return true; + return args.pd_num_sges >= rdma->sc_max_send_sges; +} - /* Check whether the xdr_buf has more elements than can - * fit in a single RDMA Send. - */ - /* xdr->head */ - elements = 1; - - /* xdr->pages */ - if (!rctxt || !rctxt->rc_write_list) { - unsigned int remaining; - unsigned long pageoff; - - pageoff = xdr->page_base & ~PAGE_MASK; - remaining = xdr->page_len; - while (remaining) { - ++elements; - remaining -= min_t(u32, PAGE_SIZE - pageoff, - remaining); - pageoff = 0; - } +/** + * svc_rdma_xb_linearize - Copy region of xdr_buf to flat buffer + * @xdr: xdr_buf containing portion of an RPC message to copy + * @data: pointer to arguments + * + * Returns: + * Always zero. + */ +static int svc_rdma_xb_linearize(const struct xdr_buf *xdr, + void *data) +{ + struct svc_rdma_pullup_data *args = data; + unsigned int len, remaining; + unsigned long pageoff; + struct page **ppages; + + if (xdr->head[0].iov_len) { + memcpy(args->pd_dest, xdr->head[0].iov_base, xdr->head[0].iov_len); + args->pd_dest += xdr->head[0].iov_len; } - /* xdr->tail */ - if (xdr->tail[0].iov_len) - ++elements; + ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT); + pageoff = offset_in_page(xdr->page_base); + remaining = xdr->page_len; + while (remaining) { + len = min_t(u32, PAGE_SIZE - pageoff, remaining); + memcpy(args->pd_dest, page_address(*ppages) + pageoff, len); + remaining -= len; + args->pd_dest += len; + pageoff = 0; + ppages++; + } - /* assume 1 SGE is needed for the transport header */ - return elements >= rdma->sc_max_send_sges; + if (xdr->tail[0].iov_len) { + memcpy(args->pd_dest, xdr->tail[0].iov_base, xdr->tail[0].iov_len); + args->pd_dest += xdr->tail[0].iov_len; + } + + args->pd_length += xdr->len; + return 0; } /** @@ -595,54 +655,30 @@ static bool svc_rdma_pull_up_needed(struct svcxprt_rdma *rdma, * The device is not capable of sending the reply directly. * Assemble the elements of @xdr into the transport header buffer. * - * Returns zero on success, or a negative errno on failure. + * Assumptions: + * pull_up_needed has determined that @xdr will fit in the buffer. + * + * Returns: + * %0 if pull-up was successful + * %-EMSGSIZE if a buffer manipulation problem occurred */ -static int svc_rdma_pull_up_reply_msg(struct svcxprt_rdma *rdma, +static int svc_rdma_pull_up_reply_msg(const struct svcxprt_rdma *rdma, struct svc_rdma_send_ctxt *sctxt, const struct svc_rdma_recv_ctxt *rctxt, const struct xdr_buf *xdr) { - unsigned char *dst, *tailbase; - unsigned int taillen; - - dst = sctxt->sc_xprt_buf + sctxt->sc_hdrbuf.len; - memcpy(dst, xdr->head[0].iov_base, xdr->head[0].iov_len); - dst += xdr->head[0].iov_len; - - tailbase = xdr->tail[0].iov_base; - taillen = xdr->tail[0].iov_len; - if (rctxt && rctxt->rc_write_list) { - u32 xdrpad; - - xdrpad = xdr_pad_size(xdr->page_len); - if (taillen && xdrpad) { - tailbase += xdrpad; - taillen -= xdrpad; - } - } else { - unsigned int len, remaining; - unsigned long pageoff; - struct page **ppages; - - ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT); - pageoff = xdr->page_base & ~PAGE_MASK; - remaining = xdr->page_len; - while (remaining) { - len = min_t(u32, PAGE_SIZE - pageoff, remaining); - - memcpy(dst, page_address(*ppages) + pageoff, len); - remaining -= len; - dst += len; - pageoff = 0; - ppages++; - } - } + struct svc_rdma_pullup_data args = { + .pd_dest = sctxt->sc_xprt_buf + sctxt->sc_hdrbuf.len, + }; + int ret; - if (taillen) - memcpy(dst, tailbase, taillen); + ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, + svc_rdma_xb_linearize, &args); + if (ret < 0) + return ret; - sctxt->sc_sges[0].length += xdr->len; - trace_svcrdma_send_pullup(sctxt->sc_sges[0].length); + sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len + args.pd_length; + trace_svcrdma_send_pullup(sctxt, args.pd_length); return 0; } |