By the way, Devesh: Is the device advertising FRMR support, yet setting
the max page list len to zero? That's a driver bug...
On 5/16/2014 9:10 AM, Steve Wise wrote:
I guess the client code doesn't verify that the device supports the
chosen memreg mode. That's not good. Lemme fix this and respin this
patch.
On 5/16/2014 2:08 AM, Devesh Sharma wrote:
Chuck
This patch is causing a CPU soft-lockup if underlying vendor reports
devattr.max_fast_reg_pagr_list_len = 0 and ia->ri_memreg_strategy =
FRMR (Default option).
I think there is need to refer to device capability flags. If
strategy = FRMR is forced and devattr.max_fast_reg_pagr_list_len=0
then flash an error and fail RPC with -EIO.
See inline:
-----Original Message-----
From: linux-rdma-owner@xxxxxxxxxxxxxxx [mailto:linux-rdma-
owner@xxxxxxxxxxxxxxx] On Behalf Of Chuck Lever
Sent: Thursday, May 01, 2014 1:00 AM
To: linux-nfs@xxxxxxxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx
Cc: Anna.Schumaker@xxxxxxxxxx
Subject: [PATCH V3 01/17] xprtrdma: mind the device's max fast register
page list depth
From: Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx>
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>
Reviewed-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/rpc_rdma.c | 4 ---
net/sunrpc/xprtrdma/verbs.c | 47 +++++++++++++++++++++++++++++-
---------
net/sunrpc/xprtrdma/xprt_rdma.h | 1 +
3 files changed, 36 insertions(+), 16 deletions(-)
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c
b/net/sunrpc/xprtrdma/rpc_rdma.c index 96ead52..400aa1b 100644
--- 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 9372656..55fb09a 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;
If ia->ri_max_frmr_depth is = 0. This loop becomes infinite loop.
+ } 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 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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