Calling ib_poll_cq() to sort through WCs during a completion is a
common pattern amongst RDMA consumers. Since commit 14d3a3b2498e
("IB: add a proper completion queue abstraction"), WC sorting can
be handled by the IB core.
By converting to this new API, xprtrdma is made a better neighbor to
other RDMA consumers, as it allows the core to schedule the delivery
of completions more fairly amongst all active consumers.
Because each ib_cqe carries a pointer to a completion method, the
core can now post its own operations on a consumer's QP, and handle
the completions itself, without changes to the consumer.
Send completions were previously handled entirely in the completion
upcall handler. Thus IB_POLL_SOFTIRQ is a direct replacement for the
current xprtrdma send code path.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/frwr_ops.c | 99 +++++++++++++++++++++++++----------
net/sunrpc/xprtrdma/verbs.c | 109 ++++++++-------------------------------
net/sunrpc/xprtrdma/xprt_rdma.h | 10 +---
3 files changed, 94 insertions(+), 124 deletions(-)
diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index 23382fa..3040fda 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -244,39 +244,80 @@ frwr_op_maxpages(struct rpcrdma_xprt *r_xprt)
rpcrdma_max_segments(r_xprt) * ia->ri_max_frmr_depth);
}
-/* If FAST_REG or LOCAL_INV failed, indicate the frmr needs
- * to be reset.
+static void
+__frwr_sendcompletion_flush(struct ib_wc *wc, struct rpcrdma_frmr *frmr,
+ const char *wr)
+{
+ frmr->fr_state = FRMR_IS_STALE;
+ if (wc->status != IB_WC_WR_FLUSH_ERR)
+ pr_err("RPC: %s: %s %s (%u, vendor %u)\n",
+ __func__, ib_wc_status_msg(wc->status),
+ wr, wc->status, wc->vendor_err);
+}
+
+/**
+ * frwr_wc_fastreg - Invoked by RDMA provider for each polled FastReg WC
+ * @cq: completion queue (ignored)
+ * @wc: completed WR
*
- * WARNING: Only wr_id and status are reliable at this point
+ * FastReg WRs are typically unsignaled, but flushed WRs still need to
+ * be handled.
*/
static void
-__frwr_sendcompletion_flush(struct ib_wc *wc, struct rpcrdma_mw *r)
+frwr_wc_fastreg(struct ib_cq *cq, struct ib_wc *wc)
{
- if (likely(wc->status == IB_WC_SUCCESS))
- return;
-
- /* WARNING: Only wr_id and status are reliable at this point */
- r = (struct rpcrdma_mw *)(unsigned long)wc->wr_id;
- if (wc->status == IB_WC_WR_FLUSH_ERR)
- dprintk("RPC: %s: frmr %p flushed\n", __func__, r);
- else
- pr_warn("RPC: %s: frmr %p error, status %s (%d)\n",
- __func__, r, ib_wc_status_msg(wc->status), wc->status);
+ struct rpcrdma_frmr *frmr;
+ struct ib_cqe *cqe;
- r->frmr.fr_state = FRMR_IS_STALE;
+ /* WARNING: Only wr_cqe and status are reliable at this point */
+ if (wc->status != IB_WC_SUCCESS) {
+ cqe = wc->wr_cqe;
+ frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe);
+ __frwr_sendcompletion_flush(wc, frmr, "fastreg");
+ }
}
+/**
+ * frwr_wc_localinv - Invoked by RDMA provider for each polled LocalInv WC
+ * @cq: completion queue (ignored)
+ * @wc: completed WR
+ *
+ * LocalInv WRs are typically unsignaled, but flushed WRs still need to
+ * be handled.
+ */
static void
-frwr_sendcompletion(struct ib_wc *wc)
+frwr_wc_localinv(struct ib_cq *cq, struct ib_wc *wc)
{
- struct rpcrdma_mw *r = (struct rpcrdma_mw *)(unsigned long)wc->wr_id;
- struct rpcrdma_frmr *f = &r->frmr;
+ struct rpcrdma_frmr *frmr;
+ struct ib_cqe *cqe;
- if (unlikely(wc->status != IB_WC_SUCCESS))
- __frwr_sendcompletion_flush(wc, r);
+ /* WARNING: Only wr_cqe and status are reliable at this point */
+ if (wc->status != IB_WC_SUCCESS) {
+ cqe = wc->wr_cqe;
+ frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe);
+ __frwr_sendcompletion_flush(wc, frmr, "localinv");
+ }
+}
- if (f->fr_waiter)
- complete(&f->fr_linv_done);
+/**
+ * frwr_wc_localinv - Invoked by RDMA provider for each polled LocalInv WC
+ * @cq: completion queue (ignored)
+ * @wc: completed WR
+ *
+ * Awaken anyone waiting for an MR to finish being fenced.
+ */
+static void
+frwr_wc_localinv_wake(struct ib_cq *cq, struct ib_wc *wc)
+{
+ struct rpcrdma_frmr *frmr;
+ struct ib_cqe *cqe;
+
+ /* WARNING: Only wr_cqe and status are reliable at this point */
+ cqe = wc->wr_cqe;
+ frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe);
+ if (wc->status != IB_WC_SUCCESS)
+ __frwr_sendcompletion_flush(wc, frmr, "localinv");
+ complete(&frmr->fr_linv_done);
}
static int
@@ -313,7 +354,6 @@ frwr_op_init(struct rpcrdma_xprt *r_xprt)
list_add(&r->mw_list, &buf->rb_mws);
list_add(&r->mw_all, &buf->rb_all);
- r->mw_sendcompletion = frwr_sendcompletion;
r->frmr.fr_xprt = r_xprt;
}
@@ -350,7 +390,6 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
} while (mw->frmr.fr_state != FRMR_IS_INVALID);
frmr = &mw->frmr;
frmr->fr_state = FRMR_IS_VALID;
- frmr->fr_waiter = false;
mr = frmr->fr_mr;
reg_wr = &frmr->fr_regwr;
@@ -400,7 +439,8 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
reg_wr->wr.next = NULL;
reg_wr->wr.opcode = IB_WR_REG_MR;
- reg_wr->wr.wr_id = (uintptr_t)mw;
+ frmr->fr_cqe.done = frwr_wc_fastreg;
+ reg_wr->wr.wr_cqe = &frmr->fr_cqe;
reg_wr->wr.num_sge = 0;
reg_wr->wr.send_flags = 0;
reg_wr->mr = mr;
@@ -437,12 +477,12 @@ __frwr_prepare_linv_wr(struct rpcrdma_mr_seg *seg)
struct rpcrdma_frmr *f = &mw->frmr;
struct ib_send_wr *invalidate_wr;
- f->fr_waiter = false;
f->fr_state = FRMR_IS_INVALID;
invalidate_wr = &f->fr_invwr;
memset(invalidate_wr, 0, sizeof(*invalidate_wr));
- invalidate_wr->wr_id = (unsigned long)(void *)mw;
+ f->fr_cqe.done = frwr_wc_localinv;
+ invalidate_wr->wr_cqe = &f->fr_cqe;
invalidate_wr->opcode = IB_WR_LOCAL_INV;
invalidate_wr->ex.invalidate_rkey = f->fr_mr->rkey;
@@ -511,7 +551,7 @@ frwr_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
* are complete.
*/
f->fr_invwr.send_flags = IB_SEND_SIGNALED;
- f->fr_waiter = true;
+ f->fr_cqe.done = frwr_wc_localinv_wake;
init_completion(&f->fr_linv_done);
INIT_CQCOUNT(&r_xprt->rx_ep);
@@ -560,7 +600,8 @@ frwr_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
invalidate_wr = &mw->frmr.fr_invwr;
memset(invalidate_wr, 0, sizeof(*invalidate_wr));
- invalidate_wr->wr_id = (uintptr_t)mw;
+ frmr->fr_cqe.done = frwr_wc_localinv;
+ invalidate_wr->wr_cqe = &frmr->fr_cqe;
invalidate_wr->opcode = IB_WR_LOCAL_INV;
invalidate_wr->ex.invalidate_rkey = frmr->fr_mr->rkey;
DECR_CQCOUNT(&r_xprt->rx_ep);
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 53c30e2..2f38388 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -112,73 +112,22 @@ rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
}
}
-static void
-rpcrdma_cq_async_error_upcall(struct ib_event *event, void *context)
-{
- struct rpcrdma_ep *ep = context;
-
- pr_err("RPC: %s: %s on device %s ep %p\n",
- __func__, ib_event_msg(event->event),
- event->device->name, context);
- if (ep->rep_connected == 1) {
- ep->rep_connected = -EIO;
- rpcrdma_conn_func(ep);
- wake_up_all(&ep->rep_connect_wait);
- }
-}
-
-static void
-rpcrdma_sendcq_process_wc(struct ib_wc *wc)
-{
- /* WARNING: Only wr_id and status are reliable at this point */
- if (wc->wr_id == RPCRDMA_IGNORE_COMPLETION) {
- if (wc->status != IB_WC_SUCCESS &&
- wc->status != IB_WC_WR_FLUSH_ERR)
- pr_err("RPC: %s: SEND: %s\n",
- __func__, ib_wc_status_msg(wc->status));
- } else {
- struct rpcrdma_mw *r;
-
- r = (struct rpcrdma_mw *)(unsigned long)wc->wr_id;
- r->mw_sendcompletion(wc);
- }
-}
-
-/* The common case is a single send completion is waiting. By
- * passing two WC entries to ib_poll_cq, a return code of 1
- * means there is exactly one WC waiting and no more. We don't
- * have to invoke ib_poll_cq again to know that the CQ has been
- * properly drained.
- */
-static void
-rpcrdma_sendcq_poll(struct ib_cq *cq)
-{
- struct ib_wc *pos, wcs[2];
- int count, rc;
-
- do {
- pos = wcs;
-
- rc = ib_poll_cq(cq, ARRAY_SIZE(wcs), pos);
- if (rc < 0)
- break;
-
- count = rc;
- while (count-- > 0)
- rpcrdma_sendcq_process_wc(pos++);
- } while (rc == ARRAY_SIZE(wcs));
- return;
-}
-
-/* Handle provider send completion upcalls.
+/**
+ * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
+ * @cq: completion queue (ignored)
+ * @wc: completed WR
+ *
+ * Send WRs are typically unsignaled, but flushed WRs still need to
+ * be handled.
*/
static void
-rpcrdma_sendcq_upcall(struct ib_cq *cq, void *cq_context)
+rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
{
- do {
- rpcrdma_sendcq_poll(cq);
- } while (ib_req_notify_cq(cq, IB_CQ_NEXT_COMP |
- IB_CQ_REPORT_MISSED_EVENTS) > 0);
+ /* WARNING: Only wr_cqe and status are reliable at this point */
+ if (wc->status != IB_WC_SUCCESS && wc->status != IB_WC_WR_FLUSH_ERR)
+ pr_err("RPC: %s: Send: %s (%u, vendor %u)\n",
+ __func__, ib_wc_status_msg(wc->status),
+ wc->status, wc->vendor_err);
}
static void
@@ -269,8 +218,6 @@ rpcrdma_flush_cqs(struct rpcrdma_ep *ep)
while (ib_poll_cq(ep->rep_attr.recv_cq, 1, &wc) > 0)
rpcrdma_recvcq_process_wc(&wc);
- while (ib_poll_cq(ep->rep_attr.send_cq, 1, &wc) > 0)
- rpcrdma_sendcq_process_wc(&wc);
}
static int
@@ -562,9 +509,8 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
struct rpcrdma_create_data_internal *cdata)
{
struct ib_cq *sendcq, *recvcq;
- struct ib_cq_init_attr cq_attr = {};
unsigned int max_qp_wr;
- int rc, err;
+ int rc;
if (ia->ri_device->attrs.max_sge < RPCRDMA_MAX_IOVS) {
dprintk("RPC: %s: insufficient sge's available\n",
@@ -616,9 +562,9 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
init_waitqueue_head(&ep->rep_connect_wait);
INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
- cq_attr.cqe = ep->rep_attr.cap.max_send_wr + 1;
- sendcq = ib_create_cq(ia->ri_device, rpcrdma_sendcq_upcall,
- rpcrdma_cq_async_error_upcall, NULL, &cq_attr);
+ sendcq = ib_alloc_cq(ia->ri_device, NULL,
+ ep->rep_attr.cap.max_send_wr + 1,
+ 0, IB_POLL_SOFTIRQ);
if (IS_ERR(sendcq)) {
rc = PTR_ERR(sendcq);
dprintk("RPC: %s: failed to create send CQ: %i\n",
@@ -626,13 +572,6 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
goto out1;
}
- rc = ib_req_notify_cq(sendcq, IB_CQ_NEXT_COMP);
- if (rc) {
- dprintk("RPC: %s: ib_req_notify_cq failed: %i\n",
- __func__, rc);
- goto out2;
- }
-
recvcq = ib_alloc_cq(ia->ri_device, NULL,
ep->rep_attr.cap.max_recv_wr + 1,
0, IB_POLL_SOFTIRQ);
@@ -667,10 +606,7 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
return 0;
out2:
- err = ib_destroy_cq(sendcq);
- if (err)
- dprintk("RPC: %s: ib_destroy_cq returned %i\n",
- __func__, err);
+ ib_free_cq(sendcq);
out1:
if (ia->ri_dma_mr)
ib_dereg_mr(ia->ri_dma_mr);
@@ -706,11 +642,7 @@ rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
}
ib_free_cq(ep->rep_attr.recv_cq);
-
- rc = ib_destroy_cq(ep->rep_attr.send_cq);
- if (rc)
- dprintk("RPC: %s: ib_destroy_cq returned %i\n",
- __func__, rc);
+ ib_free_cq(ep->rep_attr.send_cq);
if (ia->ri_dma_mr) {
rc = ib_dereg_mr(ia->ri_dma_mr);
@@ -889,6 +821,7 @@ rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
spin_lock(&buffer->rb_reqslock);
list_add(&req->rl_all, &buffer->rb_allreqs);
spin_unlock(&buffer->rb_reqslock);
+ req->rl_cqe.done = rpcrdma_wc_send;
req->rl_buffer = &r_xprt->rx_buf;
return req;
}
@@ -1252,7 +1185,7 @@ rpcrdma_ep_post(struct rpcrdma_ia *ia,
}
send_wr.next = NULL;
- send_wr.wr_id = RPCRDMA_IGNORE_COMPLETION;
+ send_wr.wr_cqe = &req->rl_cqe;
send_wr.sg_list = iov;
send_wr.num_sge = req->rl_niovs;
send_wr.opcode = IB_WR_SEND;
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 4be4c9b..fcfd4c0 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -95,10 +95,6 @@ struct rpcrdma_ep {
#define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
#define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
-/* Force completion handler to ignore the signal
- */
-#define RPCRDMA_IGNORE_COMPLETION (0ULL)
-
/* Pre-allocate extra Work Requests for handling backward receives
* and sends. This is a fixed value because the Work Queues are
* allocated when the forward channel is set up.
@@ -205,11 +201,11 @@ struct rpcrdma_frmr {
struct scatterlist *sg;
int sg_nents;
struct ib_mr *fr_mr;
+ struct ib_cqe fr_cqe;
enum rpcrdma_frmr_state fr_state;
+ struct completion fr_linv_done;
struct work_struct fr_work;
struct rpcrdma_xprt *fr_xprt;
- bool fr_waiter;
- struct completion fr_linv_done;;
union {
struct ib_reg_wr fr_regwr;
struct ib_send_wr fr_invwr;
@@ -226,7 +222,6 @@ struct rpcrdma_mw {
struct rpcrdma_fmr fmr;
struct rpcrdma_frmr frmr;
};
- void (*mw_sendcompletion)(struct ib_wc *);
struct list_head mw_list;
struct list_head mw_all;
};
@@ -283,6 +278,7 @@ struct rpcrdma_req {
struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
struct rpc_task *rl_task;
+ struct ib_cqe rl_cqe;
struct list_head rl_all;
bool rl_backchannel;
};
--
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