From: Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> To: anna.schumaker-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Subject: [PATCH v4 4/9] xprtrdma: Reduce required number of send SGEs Date: Mon, 13 Feb 2017 11:56:53 -0500 [thread overview] Message-ID: <20170213165653.15801.98139.stgit@manet.1015granger.net> (raw) In-Reply-To: <20170213163936.15801.31225.stgit-FYjufvaPoItvLzlybtyyYzGyq/o6K9yX@public.gmane.org> The MAX_SEND_SGES check introduced in commit 655fec6987be ("xprtrdma: Use gathered Send for large inline messages") fails for devices that have a small max_sge. Instead of checking for a large fixed maximum number of SGEs, check for a minimum small number. RPC-over-RDMA will switch to using a Read chunk if an xdr_buf has more pages than can fit in the device's max_sge limit. This is considerably better than failing all together to mount the server. This fix supports devices that have as few as three send SGEs available. Reported-by: Selvin Xavier <selvin.xavier-dY08KVG/lbpWk0Htik3J/w@public.gmane.org> Reported-by: Devesh Sharma <devesh.sharma-dY08KVG/lbpWk0Htik3J/w@public.gmane.org> Reported-by: Honggang Li <honli-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Reported-by: Ram Amrani <Ram.Amrani-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org> Fixes: 655fec6987be ("xprtrdma: Use gathered Send for large ...") Tested-by: Honggang Li <honli-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Tested-by: Ram Amrani <Ram.Amrani-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org> Tested-by: Steve Wise <swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org> Reviewed-by: Parav Pandit <parav-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org> Signed-off-by: Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> --- net/sunrpc/xprtrdma/rpc_rdma.c | 26 +++++++++++++++++++++++--- net/sunrpc/xprtrdma/verbs.c | 13 +++++++------ net/sunrpc/xprtrdma/xprt_rdma.h | 2 ++ 3 files changed, 32 insertions(+), 9 deletions(-) diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index c634f0f..d889883 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -125,14 +125,34 @@ void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *r_xprt) /* The client can send a request inline as long as the RPCRDMA header * plus the RPC call fit under the transport's inline limit. If the * combined call message size exceeds that limit, the client must use - * the read chunk list for this operation. + * a Read chunk for this operation. + * + * A Read chunk is also required if sending the RPC call inline would + * exceed this device's max_sge limit. */ static bool rpcrdma_args_inline(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst) { - struct rpcrdma_ia *ia = &r_xprt->rx_ia; + struct xdr_buf *xdr = &rqst->rq_snd_buf; + unsigned int count, remaining, offset; + + if (xdr->len > r_xprt->rx_ia.ri_max_inline_write) + return false; - return rqst->rq_snd_buf.len <= ia->ri_max_inline_write; + if (xdr->page_len) { + remaining = xdr->page_len; + offset = xdr->page_base & ~PAGE_MASK; + count = 0; + while (remaining) { + remaining -= min_t(unsigned int, + PAGE_SIZE - offset, remaining); + offset = 0; + if (++count > r_xprt->rx_ia.ri_max_send_sges) + return false; + } + } + + return true; } /* The client can't know how large the actual reply will be. Thus it diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 23f4da4..61d16c3 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -488,18 +488,19 @@ static void rpcrdma_destroy_id(struct rdma_cm_id *id) */ int rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia, - struct rpcrdma_create_data_internal *cdata) + struct rpcrdma_create_data_internal *cdata) { struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private; + unsigned int max_qp_wr, max_sge; struct ib_cq *sendcq, *recvcq; - unsigned int max_qp_wr; int rc; - if (ia->ri_device->attrs.max_sge < RPCRDMA_MAX_SEND_SGES) { - dprintk("RPC: %s: insufficient sge's available\n", - __func__); + max_sge = min(ia->ri_device->attrs.max_sge, RPCRDMA_MAX_SEND_SGES); + if (max_sge < RPCRDMA_MIN_SEND_SGES) { + pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge); return -ENOMEM; } + ia->ri_max_send_sges = max_sge - RPCRDMA_MIN_SEND_SGES; if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) { dprintk("RPC: %s: insufficient wqe's available\n", @@ -524,7 +525,7 @@ static void rpcrdma_destroy_id(struct rdma_cm_id *id) ep->rep_attr.cap.max_recv_wr = cdata->max_requests; ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS; ep->rep_attr.cap.max_recv_wr += 1; /* drain cqe */ - ep->rep_attr.cap.max_send_sge = RPCRDMA_MAX_SEND_SGES; + ep->rep_attr.cap.max_send_sge = max_sge; ep->rep_attr.cap.max_recv_sge = 1; ep->rep_attr.cap.max_inline_data = 0; ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index c137154..3d7e9c9 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -74,6 +74,7 @@ struct rpcrdma_ia { unsigned int ri_max_frmr_depth; unsigned int ri_max_inline_write; unsigned int ri_max_inline_read; + unsigned int ri_max_send_sges; bool ri_reminv_expected; bool ri_implicit_roundup; enum ib_mr_type ri_mrtype; @@ -311,6 +312,7 @@ struct rpcrdma_mr_seg { /* chunk descriptors */ * - xdr_buf tail iovec */ enum { + RPCRDMA_MIN_SEND_SGES = 3, RPCRDMA_MAX_SEND_PAGES = PAGE_SIZE + RPCRDMA_MAX_INLINE - 1, RPCRDMA_MAX_PAGE_SGES = (RPCRDMA_MAX_SEND_PAGES >> PAGE_SHIFT) + 1, RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1, -- 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: anna.schumaker@netapp.com Cc: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Subject: [PATCH v4 4/9] xprtrdma: Reduce required number of send SGEs Date: Mon, 13 Feb 2017 11:56:53 -0500 [thread overview] Message-ID: <20170213165653.15801.98139.stgit@manet.1015granger.net> (raw) In-Reply-To: <20170213163936.15801.31225.stgit@manet.1015granger.net> The MAX_SEND_SGES check introduced in commit 655fec6987be ("xprtrdma: Use gathered Send for large inline messages") fails for devices that have a small max_sge. Instead of checking for a large fixed maximum number of SGEs, check for a minimum small number. RPC-over-RDMA will switch to using a Read chunk if an xdr_buf has more pages than can fit in the device's max_sge limit. This is considerably better than failing all together to mount the server. This fix supports devices that have as few as three send SGEs available. Reported-by: Selvin Xavier <selvin.xavier@broadcom.com> Reported-by: Devesh Sharma <devesh.sharma@broadcom.com> Reported-by: Honggang Li <honli@redhat.com> Reported-by: Ram Amrani <Ram.Amrani@cavium.com> Fixes: 655fec6987be ("xprtrdma: Use gathered Send for large ...") Tested-by: Honggang Li <honli@redhat.com> Tested-by: Ram Amrani <Ram.Amrani@cavium.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> --- net/sunrpc/xprtrdma/rpc_rdma.c | 26 +++++++++++++++++++++++--- net/sunrpc/xprtrdma/verbs.c | 13 +++++++------ net/sunrpc/xprtrdma/xprt_rdma.h | 2 ++ 3 files changed, 32 insertions(+), 9 deletions(-) diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index c634f0f..d889883 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -125,14 +125,34 @@ void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *r_xprt) /* The client can send a request inline as long as the RPCRDMA header * plus the RPC call fit under the transport's inline limit. If the * combined call message size exceeds that limit, the client must use - * the read chunk list for this operation. + * a Read chunk for this operation. + * + * A Read chunk is also required if sending the RPC call inline would + * exceed this device's max_sge limit. */ static bool rpcrdma_args_inline(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst) { - struct rpcrdma_ia *ia = &r_xprt->rx_ia; + struct xdr_buf *xdr = &rqst->rq_snd_buf; + unsigned int count, remaining, offset; + + if (xdr->len > r_xprt->rx_ia.ri_max_inline_write) + return false; - return rqst->rq_snd_buf.len <= ia->ri_max_inline_write; + if (xdr->page_len) { + remaining = xdr->page_len; + offset = xdr->page_base & ~PAGE_MASK; + count = 0; + while (remaining) { + remaining -= min_t(unsigned int, + PAGE_SIZE - offset, remaining); + offset = 0; + if (++count > r_xprt->rx_ia.ri_max_send_sges) + return false; + } + } + + return true; } /* The client can't know how large the actual reply will be. Thus it diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 23f4da4..61d16c3 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -488,18 +488,19 @@ static void rpcrdma_destroy_id(struct rdma_cm_id *id) */ int rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia, - struct rpcrdma_create_data_internal *cdata) + struct rpcrdma_create_data_internal *cdata) { struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private; + unsigned int max_qp_wr, max_sge; struct ib_cq *sendcq, *recvcq; - unsigned int max_qp_wr; int rc; - if (ia->ri_device->attrs.max_sge < RPCRDMA_MAX_SEND_SGES) { - dprintk("RPC: %s: insufficient sge's available\n", - __func__); + max_sge = min(ia->ri_device->attrs.max_sge, RPCRDMA_MAX_SEND_SGES); + if (max_sge < RPCRDMA_MIN_SEND_SGES) { + pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge); return -ENOMEM; } + ia->ri_max_send_sges = max_sge - RPCRDMA_MIN_SEND_SGES; if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) { dprintk("RPC: %s: insufficient wqe's available\n", @@ -524,7 +525,7 @@ static void rpcrdma_destroy_id(struct rdma_cm_id *id) ep->rep_attr.cap.max_recv_wr = cdata->max_requests; ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS; ep->rep_attr.cap.max_recv_wr += 1; /* drain cqe */ - ep->rep_attr.cap.max_send_sge = RPCRDMA_MAX_SEND_SGES; + ep->rep_attr.cap.max_send_sge = max_sge; ep->rep_attr.cap.max_recv_sge = 1; ep->rep_attr.cap.max_inline_data = 0; ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index c137154..3d7e9c9 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -74,6 +74,7 @@ struct rpcrdma_ia { unsigned int ri_max_frmr_depth; unsigned int ri_max_inline_write; unsigned int ri_max_inline_read; + unsigned int ri_max_send_sges; bool ri_reminv_expected; bool ri_implicit_roundup; enum ib_mr_type ri_mrtype; @@ -311,6 +312,7 @@ struct rpcrdma_mr_seg { /* chunk descriptors */ * - xdr_buf tail iovec */ enum { + RPCRDMA_MIN_SEND_SGES = 3, RPCRDMA_MAX_SEND_PAGES = PAGE_SIZE + RPCRDMA_MAX_INLINE - 1, RPCRDMA_MAX_PAGE_SGES = (RPCRDMA_MAX_SEND_PAGES >> PAGE_SHIFT) + 1, RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,
next prev parent reply other threads:[~2017-02-13 16:56 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-02-13 16:56 [PATCH v4 0/9] Series short description Chuck Lever 2017-02-13 16:56 ` Chuck Lever [not found] ` <20170213163936.15801.31225.stgit-FYjufvaPoItvLzlybtyyYzGyq/o6K9yX@public.gmane.org> 2017-02-13 16:56 ` [PATCH v4 1/9] xprtrdma: Fix Read chunk padding Chuck Lever 2017-02-13 16:56 ` Chuck Lever 2017-02-13 16:56 ` [PATCH v4 2/9] xprtrdma: Per-connection pad optimization Chuck Lever 2017-02-13 16:56 ` Chuck Lever 2017-02-13 16:56 ` [PATCH v4 3/9] xprtrdma: Disable pad optimization by default Chuck Lever 2017-02-13 16:56 ` Chuck Lever 2017-02-13 16:56 ` Chuck Lever [this message] 2017-02-13 16:56 ` [PATCH v4 4/9] xprtrdma: Reduce required number of send SGEs Chuck Lever 2017-02-13 16:57 ` [PATCH v4 5/9] xprtrdma: Shrink send SGEs array Chuck Lever 2017-02-13 16:57 ` Chuck Lever 2017-02-13 16:57 ` [PATCH v4 6/9] xprtrdma: Properly recover FRWRs with in-flight FASTREG WRs Chuck Lever 2017-02-13 16:57 ` Chuck Lever 2017-02-13 16:57 ` [PATCH v4 7/9] xprtrdma: Handle stale connection rejection Chuck Lever 2017-02-13 16:57 ` Chuck Lever 2017-02-13 16:57 ` [PATCH v4 8/9] xprtrdma: Refactor management of mw_list field Chuck Lever 2017-02-13 16:57 ` Chuck Lever 2017-02-13 16:57 ` [PATCH v4 9/9] sunrpc: Allow xprt->ops->timer method to sleep Chuck Lever 2017-02-13 16:57 ` Chuck Lever
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