Hi Steve-
I reviewed and successfully tested this patch with mlx4 using FRMR and MTHCAFMR.
A couple of cosmetic notes are below:
On Apr 10, 2014, at 11:13 AM, Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx> wrote:
> 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@xxxxxxxxxxxxxxxxxxxxx>
> ---
>
> net/sunrpc/xprtrdma/rpc_rdma.c | 2 -
> net/sunrpc/xprtrdma/verbs.c | 64 ++++++++++++++++++++++++++++-----------
> net/sunrpc/xprtrdma/xprt_rdma.h | 1 +
> 3 files changed, 47 insertions(+), 20 deletions(-)
>
> diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
> index 96ead52..14d7634 100644
> --- a/net/sunrpc/xprtrdma/rpc_rdma.c
> +++ b/net/sunrpc/xprtrdma/rpc_rdma.c
> @@ -249,8 +249,6 @@ rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target,
> req->rl_nchunks = nchunks;
>
> BUG_ON(nchunks == 0);
I don’t see a path through rpcrdma_create_chunks() where nchunks can be 0 here. If you
agree, can you remove the above BUG_ON as well, if you re-submit a new version of this
patch?
> - 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 93726560..c08f193 100644
> --- 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;
> @@ -1796,6 +1819,7 @@ rpcrdma_register_external(struct rpcrdma_mr_seg *seg,
> {
> struct rpcrdma_ia *ia = &r_xprt->rx_ia;
> int rc = 0;
> + int tmp_nsegs = nsegs;
I don’t understand what the changes to rpcrdma_register_external() do. As a test, I reverted
these, and the patch behaves the same. Am I missing something?
>
> switch (ia->ri_memreg_strategy) {
>
> @@ -1805,35 +1829,39 @@ rpcrdma_register_external(struct rpcrdma_mr_seg *seg,
> seg->mr_rkey = ia->ri_bind_mem->rkey;
> seg->mr_base = seg->mr_dma;
> seg->mr_nsegs = 1;
> - nsegs = 1;
> + tmp_nsegs = 1;
> break;
> #endif
>
> /* Registration using frmr registration */
> case RPCRDMA_FRMR:
> - rc = rpcrdma_register_frmr_external(seg, &nsegs, writing, ia, r_xprt);
> + rc = rpcrdma_register_frmr_external(seg, &tmp_nsegs, writing,
> + ia, r_xprt);
> break;
>
> /* Registration using fmr memory registration */
> case RPCRDMA_MTHCAFMR:
> - rc = rpcrdma_register_fmr_external(seg, &nsegs, writing, ia);
> + rc = rpcrdma_register_fmr_external(seg, &tmp_nsegs, writing,
> + ia);
> break;
>
> /* Registration using memory windows */
> case RPCRDMA_MEMWINDOWS_ASYNC:
> case RPCRDMA_MEMWINDOWS:
> - rc = rpcrdma_register_memwin_external(seg, &nsegs, writing, ia, r_xprt);
> + rc = rpcrdma_register_memwin_external(seg, &tmp_nsegs, writing,
> + ia, r_xprt);
> break;
>
> /* Default registration each time */
> default:
> - rc = rpcrdma_register_default_external(seg, &nsegs, writing, ia);
> + rc = rpcrdma_register_default_external(seg, &tmp_nsegs, writing,
> + ia);
> break;
> }
> if (rc)
> return -1;
>
> - return nsegs;
> + return tmp_nsegs;
> }
>
> int
> diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
> index cc1445d..98340a3 100644
> --- 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;
> };
>
> /*
>
> --
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--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com
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