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xprtrdma: Use new CQ API for RPC-over-RDMA client send CQs

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Calling ib_poll_cq() to sort through WCs during a completion is a
common pattern amongst RDMA consumers. Since commit 14d3a3b249
("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 (ie, deferring to a process context is unneeded).
Thus IB_POLL_SOFTIRQ is a direct replacement for the current
xprtrdma send code path.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Chuck Lever 2016-03-04 11:28:53 -05:00 committed by Anna Schumaker
parent c882a655b7
commit 2fa8f88d88
3 changed files with 94 additions and 128 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

105
net/sunrpc/xprtrdma/frwr_ops.c
View File

@ -158,6 +158,8 @@ __frwr_init(struct rpcrdma_mw *r, struct ib_pd *pd, struct ib_device *device,
sg_init_table(f->sg, depth);
init_completion(&f->fr_linv_done);
return 0;
out_mr_err:
@ -244,39 +246,76 @@ 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.
*
* WARNING: Only wr_id and status are reliable at this point
*/
static void
__frwr_sendcompletion_flush(struct ib_wc *wc, struct rpcrdma_mw *r)
__frwr_sendcompletion_flush(struct ib_wc *wc, struct rpcrdma_frmr *frmr,
const char *wr)
{
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);
r->frmr.fr_state = FRMR_IS_STALE;
frmr->fr_state = FRMR_IS_STALE;
if (wc->status != IB_WC_WR_FLUSH_ERR)
pr_err("rpcrdma: %s: %s (%u/0x%x)\n",
wr, ib_wc_status_msg(wc->status),
wc->status, wc->vendor_err);
}
/**
* frwr_wc_fastreg - Invoked by RDMA provider for each polled FastReg WC
* @cq: completion queue (ignored)
* @wc: completed WR
*
*/
static void
frwr_sendcompletion(struct ib_wc *wc)
frwr_wc_fastreg(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, "fastreg");
}
}
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
*
*/
static void
frwr_wc_localinv(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 */
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");
}
}
/**
* 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_all(&frmr->fr_linv_done);
}
static int
@ -313,7 +352,6 @@ 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 +388,6 @@ 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 +437,8 @@ 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 +475,12 @@ __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;
@ -511,8 +549,8 @@ 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;
init_completion(&f->fr_linv_done);
f->fr_cqe.done = frwr_wc_localinv_wake;
reinit_completion(&f->fr_linv_done);
INIT_CQCOUNT(&r_xprt->rx_ep);
/* Transport disconnect drains the receive CQ before it
@ -564,7 +602,8 @@ 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);

107
net/sunrpc/xprtrdma/verbs.c
View File

@ -112,73 +112,20 @@ 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.
/**
* rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
* @cq: completion queue (ignored)
* @wc: completed WR
*
*/
static void
rpcrdma_sendcq_poll(struct ib_cq *cq)
rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
{
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.
*/
static void
rpcrdma_sendcq_upcall(struct ib_cq *cq, void *cq_context)
{
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("rpcrdma: Send: %s (%u/0x%x)\n",
ib_wc_status_msg(wc->status),
wc->status, wc->vendor_err);
}
static void
@ -263,8 +210,6 @@ rpcrdma_flush_cqs(struct rpcrdma_ep *ep)
while (ib_poll_cq(ep->rep_attr.recv_cq, 1, &wc) > 0)
rpcrdma_receive_wc(NULL, &wc);
while (ib_poll_cq(ep->rep_attr.send_cq, 1, &wc) > 0)
rpcrdma_sendcq_process_wc(&wc);
}
static int
@ -556,9 +501,8 @@ 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",
@ -610,9 +554,9 @@ 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",
@ -620,13 +564,6 @@ 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);
@ -661,10 +598,7 @@ 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);
@ -700,11 +634,7 @@ 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);
@ -883,6 +813,7 @@ 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;
}
@ -1246,7 +1177,7 @@ 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;

10
net/sunrpc/xprtrdma/xprt_rdma.h
View File

@ -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;
};
@ -282,6 +277,7 @@ struct rpcrdma_req {
struct rpcrdma_regbuf *rl_sendbuf;
struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
struct ib_cqe rl_cqe;
struct list_head rl_all;
bool rl_backchannel;
};