From 5e9fc6a06bba9e6821ce964067fcf4401496bc29 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 29 Nov 2016 10:52:24 -0500 Subject: xprtrdma: Support for SG_GAP devices Some devices (such as the Mellanox CX-4) can register, under a single R_key, a set of memory regions that are not contiguous. When this is done, all the segments in a Reply list, say, can then be invalidated in a single LocalInv Work Request (or via Remote Invalidation, which can invalidate exactly one R_key when completing a Receive). This means a single FastReg WR is used to register, and one or zero LocalInv WRs can invalidate, the memory involved with RDMA transfers on behalf of an RPC. In addition, xprtrdma constructs some Reply chunks from three or more segments. By registering them with SG_GAP, only one segment is needed for the Reply chunk, allowing the whole chunk to be invalidated remotely. Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/frwr_ops.c | 20 +++++++++++++------- net/sunrpc/xprtrdma/xprt_rdma.h | 1 + 2 files changed, 14 insertions(+), 7 deletions(-) (limited to 'net/sunrpc') diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c index adbf52c..e99bf61 100644 --- a/net/sunrpc/xprtrdma/frwr_ops.c +++ b/net/sunrpc/xprtrdma/frwr_ops.c @@ -101,7 +101,7 @@ frwr_op_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mw *r) struct rpcrdma_frmr *f = &r->frmr; int rc; - f->fr_mr = ib_alloc_mr(ia->ri_pd, IB_MR_TYPE_MEM_REG, depth); + f->fr_mr = ib_alloc_mr(ia->ri_pd, ia->ri_mrtype, depth); if (IS_ERR(f->fr_mr)) goto out_mr_err; @@ -157,7 +157,7 @@ __frwr_reset_mr(struct rpcrdma_ia *ia, struct rpcrdma_mw *r) return rc; } - f->fr_mr = ib_alloc_mr(ia->ri_pd, IB_MR_TYPE_MEM_REG, + f->fr_mr = ib_alloc_mr(ia->ri_pd, ia->ri_mrtype, ia->ri_max_frmr_depth); if (IS_ERR(f->fr_mr)) { pr_warn("rpcrdma: ib_alloc_mr status %ld, frwr %p orphaned\n", @@ -210,11 +210,16 @@ static int frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep, struct rpcrdma_create_data_internal *cdata) { + struct ib_device_attr *attrs = &ia->ri_device->attrs; int depth, delta; + ia->ri_mrtype = IB_MR_TYPE_MEM_REG; + if (attrs->device_cap_flags & IB_DEVICE_SG_GAPS_REG) + ia->ri_mrtype = IB_MR_TYPE_SG_GAPS; + ia->ri_max_frmr_depth = min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS, - ia->ri_device->attrs.max_fast_reg_page_list_len); + attrs->max_fast_reg_page_list_len); dprintk("RPC: %s: device's max FR page list len = %u\n", __func__, ia->ri_max_frmr_depth); @@ -241,8 +246,8 @@ frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep, } ep->rep_attr.cap.max_send_wr *= depth; - if (ep->rep_attr.cap.max_send_wr > ia->ri_device->attrs.max_qp_wr) { - cdata->max_requests = ia->ri_device->attrs.max_qp_wr / depth; + if (ep->rep_attr.cap.max_send_wr > attrs->max_qp_wr) { + cdata->max_requests = attrs->max_qp_wr / depth; if (!cdata->max_requests) return -EINVAL; ep->rep_attr.cap.max_send_wr = cdata->max_requests * @@ -348,6 +353,7 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg, int nsegs, bool writing, struct rpcrdma_mw **out) { struct rpcrdma_ia *ia = &r_xprt->rx_ia; + bool holes_ok = ia->ri_mrtype == IB_MR_TYPE_SG_GAPS; struct rpcrdma_mw *mw; struct rpcrdma_frmr *frmr; struct ib_mr *mr; @@ -383,8 +389,8 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg, ++seg; ++i; - - /* Check for holes */ + if (holes_ok) + continue; if ((i < nsegs && offset_in_page(seg->mr_offset)) || offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len)) break; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index f6ae1b2..b8424fa 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -75,6 +75,7 @@ struct rpcrdma_ia { unsigned int ri_max_inline_write; unsigned int ri_max_inline_read; bool ri_reminv_expected; + enum ib_mr_type ri_mrtype; struct ib_qp_attr ri_qp_attr; struct ib_qp_init_attr ri_qp_init_attr; }; -- cgit v1.1