xprtrdma: mind the device's max fast register page list depth

Some rdma devices don't support a fast register page list depth of
at least RPCRDMA_MAX_DATA_SEGS.  So xprtrdma needs to chunk its fast
register regions according to the minimum of the device max supported
depth or RPCRDMA_MAX_DATA_SEGS.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 96ead526b1255d278c47cb8591065f4ad393814f..400aa1b77d728cb56a6fc46afd61879380d94b6e 100644 (file)
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -248,10 +248,6 @@ rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target,
        /* success. all failures return above */
        req->rl_nchunks = nchunks;
 
-       BUG_ON(nchunks == 0);
-       BUG_ON((r_xprt->rx_ia.ri_memreg_strategy == RPCRDMA_FRMR)
-              && (nchunks > 3));
-
        /*
         * finish off header. If write, marshal discrim and nchunks.
         */

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 93726560eaa8864465b72a03e11d3dfa6d97703e..55fb09a004383aa8f1b6c597b529ed18009bafb9 100644 (file)
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -539,6 +539,11 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
                                __func__);
                        memreg = RPCRDMA_REGISTER;
 #endif
+               } else {
+                       /* Mind the ia limit on FRMR page list depth */
+                       ia->ri_max_frmr_depth = min_t(unsigned int,
+                               RPCRDMA_MAX_DATA_SEGS,
+                               devattr.max_fast_reg_page_list_len);
                }
                break;
        }
@@ -659,24 +664,42 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
        ep->rep_attr.srq = NULL;
        ep->rep_attr.cap.max_send_wr = cdata->max_requests;
        switch (ia->ri_memreg_strategy) {
-       case RPCRDMA_FRMR:
+       case RPCRDMA_FRMR: {
+               int depth = 7;
+
                /* Add room for frmr register and invalidate WRs.
                 * 1. FRMR reg WR for head
                 * 2. FRMR invalidate WR for head
-                * 3. FRMR reg WR for pagelist
-                * 4. FRMR invalidate WR for pagelist
+                * 3. N FRMR reg WRs for pagelist
+                * 4. N FRMR invalidate WRs for pagelist
                 * 5. FRMR reg WR for tail
                 * 6. FRMR invalidate WR for tail
                 * 7. The RDMA_SEND WR
                 */
-               ep->rep_attr.cap.max_send_wr *= 7;
+
+               /* Calculate N if the device max FRMR depth is smaller than
+                * RPCRDMA_MAX_DATA_SEGS.
+                */
+               if (ia->ri_max_frmr_depth < RPCRDMA_MAX_DATA_SEGS) {
+                       int delta = RPCRDMA_MAX_DATA_SEGS -
+                                   ia->ri_max_frmr_depth;
+
+                       do {
+                               depth += 2; /* FRMR reg + invalidate */
+                               delta -= ia->ri_max_frmr_depth;
+                       } while (delta > 0);
+
+               }
+               ep->rep_attr.cap.max_send_wr *= depth;
                if (ep->rep_attr.cap.max_send_wr > devattr.max_qp_wr) {
-                       cdata->max_requests = devattr.max_qp_wr / 7;
+                       cdata->max_requests = devattr.max_qp_wr / depth;
                        if (!cdata->max_requests)
                                return -EINVAL;
-                       ep->rep_attr.cap.max_send_wr = cdata->max_requests * 7;
+                       ep->rep_attr.cap.max_send_wr = cdata->max_requests *
+                                                      depth;
                }
                break;
+       }
        case RPCRDMA_MEMWINDOWS_ASYNC:
        case RPCRDMA_MEMWINDOWS:
                /* Add room for mw_binds+unbinds - overkill! */
@@ -1043,16 +1066,16 @@ rpcrdma_buffer_create(struct rpcrdma_buffer *buf, struct rpcrdma_ep *ep,
        case RPCRDMA_FRMR:
                for (i = buf->rb_max_requests * RPCRDMA_MAX_SEGS; i; i--) {
                        r->r.frmr.fr_mr = ib_alloc_fast_reg_mr(ia->ri_pd,
-                                                        RPCRDMA_MAX_SEGS);
+                                               ia->ri_max_frmr_depth);
                        if (IS_ERR(r->r.frmr.fr_mr)) {
                                rc = PTR_ERR(r->r.frmr.fr_mr);
                                dprintk("RPC:       %s: ib_alloc_fast_reg_mr"
                                        " failed %i\n", __func__, rc);
                                goto out;
                        }
-                       r->r.frmr.fr_pgl =
-                               ib_alloc_fast_reg_page_list(ia->ri_id->device,
-                                                           RPCRDMA_MAX_SEGS);
+                       r->r.frmr.fr_pgl = ib_alloc_fast_reg_page_list(
+                                               ia->ri_id->device,
+                                               ia->ri_max_frmr_depth);
                        if (IS_ERR(r->r.frmr.fr_pgl)) {
                                rc = PTR_ERR(r->r.frmr.fr_pgl);
                                dprintk("RPC:       %s: "
@@ -1498,8 +1521,8 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
        seg1->mr_offset -= pageoff;     /* start of page */
        seg1->mr_len += pageoff;
        len = -pageoff;
-       if (*nsegs > RPCRDMA_MAX_DATA_SEGS)
-               *nsegs = RPCRDMA_MAX_DATA_SEGS;
+       if (*nsegs > ia->ri_max_frmr_depth)
+               *nsegs = ia->ri_max_frmr_depth;
        for (page_no = i = 0; i < *nsegs;) {
                rpcrdma_map_one(ia, seg, writing);
                pa = seg->mr_dma;

diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index cc1445dc1d1a865d141afa43c519f8dc9c5e7048..98340a31f2bcb0e399a771026d6735db744d3995 100644 (file)
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -66,6 +66,7 @@ struct rpcrdma_ia {
        struct completion       ri_done;
        int                     ri_async_rc;
        enum rpcrdma_memreg     ri_memreg_strategy;
+       unsigned int            ri_max_frmr_depth;
 };
 
 /*